HomeMy WebLinkAboutAgenda - 11-17-1998 - 5aORANGE COUNTY
BOARD OF COMMISSIONERS
ACTION AGENDA ITEM ABSTRACT
Meeting Date: November 17, 1998
Action Agenda
Item # ~~
SUBJECT: Storage of High-Level Radioactive Waste at the Shearon Harris Nuclear Power Plant
DEPARTMENT: County Manager PUBLIC HEARING: Yes _x_ No
ATTACHMENT(S):
OC Commission for the Environment
resolution
Rosemary Waldorf letter
Margaret Pollard letter
Mary MacDowell material
Dr. Vanderhook fax
County Engineer's report
Draft BOCC resolution
BUDGET AMENDMENT: Yes x No
INFORMATION CONTACT:
County Engineer Extension 2303
TELEPHONE NUMBERS:
Hillsborough - 732-8181
Durham - 688-7331
Mebane - 227-2031
Chapel Hill - 967-9251/968-4501
PURPOSE: To present for the BOCC's review, discussion, revision and adoption aresolution -
and related background material -requesting the appropriate state agencies and the
Nuclear Regulatory Commission hold public hearings, receive public input and
undertake rigorous environmental and risk projection analysis of the CP&L
proposal to continue storing local and imported high level radioactive waste and to
expand storage capacity for that high level radioactive waste at the Shearon Harris
nuclear power facilities.
BACKGROUND: As a direct result of the federal government's failure to provide permanent
storage facilities for the high level radioactive waste generated by this
county's nuclear power generating plants, CP&L's Shearon Harris plant
has been storing its waste on site for a number of years. This material has
been stored in facilities intended for temporary storage of high level
radioactive waste. Furthermore, the temporary storage facilities at Shearon
Harris have also been used to store high level radioactive wastes imported
into this area from CP&L's nuclear plants at Brunswick, NC, and Robinson,
SC. As the capacity of the existing storage facilities at Shearon Harris has
been nearly exhausted, CP&L has proposed to ~;xpand the capacity of
Shearon Harris facilities to accommodate additional waste storage.
2
The current and proposed high level radioactive waste storage activity and
planning have proceeded with minimal public knowledge and input.
Various local environmentally activist individuals and groups, the Chapel
Hill Town Board, the Chatham County BOCC and the Orange County
Commission for the Environment have expressed concern about these
practices and plans and the lack of public input into the regulatory approval
process. Some of these individuals and groups have requested that the
BOCC intervene in the approval process by formally advocating the creation
of a forum for public comment on plans to expand waste storage capacity.
A draft resolution has been prepared for BOCC review, discussion, revision
and adoption if the Board so chooses.
RECOMMENDATION: As the Board decides.
3
RESOLUTION
WHEREAS, on September 15 the Board of County Commissioners were advised
about potential expansion of the high-level radioactive waste pool planned
for Carolina Power and Light's Shearon Harris nuclear plant in Wake County;
and
WHEREAS, on November 9 the Commission for the Environment was apprised of
the possible risks inherent with the potential doubling of the high-level
radioactive waste pools and long-term storage to accept radioactive waste
from two other nuclear plants, and
WHEREAS, a major waste pool accident would have an adverse impact on Orange
County:
NOW, THEREFORE, BE IT RESOLVED
that the Commission for the Environment asks the Orange County Board of
Commissioners to request additional information from Carolina Power and
Light (CP&L) on this potential expansion and long-term storage before any
action is taken. The Commission further asks the Board of Commissioners to
request that CP&L provide this information at a public hearing to be held
by the appropriate entity, and that the Board consider action on this
matter at their November 17 meeting, and forward cumments or concerns to
the appropriate agencies.
This, the 9th day of November, 1998
Loraine Kohorn
Chair, Commission for the Environment
Attest
R. Eugene Bell
~~ ~ Cr ~~ 4
~' '~~
?e
Rr y~.
h CAKO
TOWN OF CHAPEL HILL
306 NORTH COLUMBIA STREET
CHAPEL HILL, NORTH CAROLINA 27516
OFFICE OF TH8 1NAYOR
October 7, 1998
Wayne McDevitt
Secretary
NC Department of Environment and Natural Resources
512 N. Salisbury Street
Raleigh, NC 27604
Dear Secretary McDevitt:
(9(9)968-2714
FAX (919) 967-8406
The Members of the Town Council and I are concerned about the application by Carolina
Power and L:~ Company to ~~ rTL_?.L; R~~;~to,- C~,..,,,,issiaa~:~:rii+wru,g al,l,luvai co open
two additional fuel pools at the Shazon Harris Nucleaz Power Plant in Wake County.
My understanding is that these pools are planned primarily for storage of activated fuel
rods from CP&L's Robinson Plant in South Carolina and Brunswick Plant in Wilmington, and
that already fuel has been shipped in for storage in the two existing pools at the Harris plant.
I request that the Department of Environment and Natural Resources try to prevent
CP&L's application from being granted. We have a lazge population concentrated within fifty
miles of the Han is Plant, and the possibility of an accident exists as these rods aze being
transported there, and again when they are sent elsewhere. In addition, I think that the Hams
Plant should store only its own spent fuel because of the increased risk whenever fuel is
transported.
If the application to add additional pools is granted, I request the fullest possible
involvement by the state government of North Cazolina both in the transportation and unloading
of the fuel, and during the period it is stored, to protect citizens from the possibility of a disaster.
It is my understanding that if the application is approved by the NRC, the Harris site
would hold one of the two largest concentrations of high-level waste from nuclear power plants in
the U.S. for an i.~definite period until a penriar_ent aisposal site i; ppc:jaa. Don't w~ ~~ant t~
avoid being in that position? Isn't there some place to which these rods can be shipped where the
5
human population is very low? Why doesn't the NRC decide to store it in one or more of the
large, unpopulated areas out west?
In my view, it is frightening enough to drive across Jordan Lake and see the steam from
the Hams plant drifting across the horizon. I am shocked at the idea of transporting in and out of
there additional fuel rods from other plants for the purpose of storage for a period of time as yet
undetermined. This lack of planning or change in direction about how to handle these problems in
the nuclear power industry is very unsettling. Life in such arapidly-growing area as the middle of
North Carolina is anxiety producing enough now, without the increased risk of a nucleaz disaster.
I wge you to take very seriously concerns expressed to you about this issue. Please do all
you can to regulate and control these rods and pools, and keep them as far away as you can, as
appazently South Carolina is doing.
Sincerely,
~S~ ~ ..
I
Rosemary I. Waldorf
Mayor
~:. rh~e~ x~li ~-_ -- ~.
.v..li ~.JUi~~.Yl
Bill Holman
Sen. Howard Lee
Sen. Ellie Kinnaird
Sen. Wib Gulley
Sen. Jeanne Lucas
Rep. George Miller
Rep. Joe Hackney
Rep. Verla Insko
Rep. David Miner
Congressman David Price
Wake County Chair John Converse
Lee County Chair Bertha L. Matthews
Harnett County Chair Dan Andrews
Orange County Chair Margaret Brown
Gerald Holleman, Mayor of Holly Springs
Koka Booth, Mayor of Cary
Robert Bazker, Mayor of Fuqua Varina
Winston C. Hester, Mayor of Sanford
Kieith H. Weatherly, Mayor of Apex
Charles Devinney, llFaynr of PittgFjnrn
Mace Nelson, Mayor of Carrboro
~1~i a „~
COUNTY OF CHATHAM
COMMISSIONERS
MARGARET BRYANT POLLARD, Chair
BETTY WILSON, Vlee Chair
HENRY DUNLAP
JOHN GRIMES
UVA HOLLAND
PITTS80R0, N. C. 27312
ORGANIZED 1770 707 SQUARE MILES
September 18, 1998
Wayne McDevitt
Secrets ry
NC Department of Environment and Natural Resources
512 N. Salisbury Street
Raleigh, NC 27604
Dear Secretary McDevitt:
6
CHARLIE MORNE
County Mansger
ROBERT L. GUNN
County Attorney
Phone (919) 542-8200
Increased storage of high-level radioactive waste in North Carolina at the Shearon
Harris Nuclear Power Plant is being proposed by Carolina Power and Light
(CP&L). From documents sent me by the Nuclear Regulatory Commission (NRC),
I became aware of CP8tL's intent to submit an application in October, requesting
NRC approval by the end of 1999 to open two additional fue! pools at the Harris
Plant in Wake County.
These pools are planned primarily for storage of activated fuel rods from CP~tI_'s
Robinson Plant in South Carolina and Brunswick Plant in Wilmington. Already fuel
from these two plants has been shipped in for storage at the Harris plant in the two
operating pools. The irony of this fact, as you know, is that South Carolina, by
legislative action, is prohibiting low-level radioactive waste from any North Carolina
generator at the Barnwell, SC site, yet South Carolina high-level waste is being
and more would be shipped into North Carolina.
We understand that the U.S. NRC has sole jurisdiction in licensing the plant and
any fuel pools or dry casks for storage or transport. Also the U.S. Department of
Transportation has jurisdiction over some other aspects of transport. However, we
hope the state government of North Carolina would help to assure safety for North
Carolinians while the fuel is being transported, while it is unloaded at the Harris
site and for the period of time it must remain in storage there.
P. O. BOX 87
Secretary McDevitt
September 18, 1998
Page 2 of 3
The problem that most concerns us with the planned expansion is that fuel pools,
according to nuclear safety engineer, David Lochbaum, were designed for short
term storage of a small quantity of fuel. However, they are having to be modified
to take a much larger, more closely packed set of rods for an indefinite period of
time. This is because the federal Department of Energy, which is responsible for a
permanent disposal site has been unable to provide one and future prospects for a
site are very uncertain. The nuclear industry planned on sending their activated
fue! for reprocessing when the plants were designed, but that option was ruled out
by federal action to prevent the spread of nuclear weapons, after commercial
failures of early reprocessing plants.
In his book examining spent fuel storage safety, Lochbaum reports that
unfortunately, the three-layer defense-in-depth strategy of minimizing the chances
of an accident, mitigating the severity of an accident and containing the
consequences of an accident employed for reactor safety is not in place
consistently for fuel pool storage in this country. In addition he cites numerous
incidents where near-misses have occurred in fuel pools because of inoperable
equipment, personnel errors, seal failures, etc. that suggest that safety standards
are inadequate or not maintained. The consequences for the public within a 50-
mile radius of a loss of cooling water accident could be severe according to
Lochbaum. The NRC has stated a concern that deregulation or preparation for
deregulation will put financial pressures on the nuclear utility industry that could
compromise safety at nuclear plants.
If the application is approved by the NRC, the Hams site would apparently hold
one of the two largest concentrations of high-level waste in the United States from
nuclear power plants for an indefinite period until a permanent disposal site is
opened.
Because of the indeterminate length of storage, the questions on defense-in-depth
safety, and the large quantity of high-level waste that would be shipped into and
through North Carolina, we request the assistance of the state of North Carolina in
three matters:
1. Please assist us, with the expertise in radiation protection and engineering
at your disposal, in reviewing the fuel pool application and in then submitting
comments as warranted to the NRC in order to assure the safety of NC citizens.
We hope that review would be conducted as an open public process like DENR's
review of the low-level radioactive waste site license application.
2. Please ask the NRC to require an Environmental Impact Statement to fully
consider alternatives from the safety point of view, before it allows shipment of the
Secretary McDevitt
September 18, 1998 $
Page 3 of 3
fuel rods through North Carolina and more pool storage in an area of rapidly
growing population.
3. Please give serious consideration to changing any North Carolina policies
or laws that allow (or contribute to allowing) high-level waste from South Carolina
to be shipped for storage into North Carolina, in light of the fact that South
Carolina is illegally excluding North Carolina low-level waste from the Barnwell, SC
disposal site. If there is nothing North Carolina can do, please advocate for the
state's citizens with the NRC.
Thank you for your serious attention to these matters.
Sincerely,
a
Margaret Bryant Pollard, Chair
cc. Bill Holman
Senator Howard Lee
Senator Ellie Kinnaird
Senator Wib Gulley
Senator Jeanne Lucas
Representative George Miller
Representative Joe Hackney
Representative Verla Insko
Representative David Miner
Congressman David Price
Wake County Chair John Converse
Lee County Chair Bertha L. Matthews
Harnett County Chair Dan Andrews
Orange County Chair Margaret Brown
Gerald Holleman, Mayor of Holly Springs
Koka Booth, Mayor of Cary
Robert Barker, Mayor of Fuqua Varina
Winston C. Hester, Mayor of Sanford
Keith H. Weatherly, Mayor of Apex
Charles Devinney, Mayor of Pittsboro
Rosemary Waldorf, Mayor of Chapel Hill
Mike Nelson, Mayor of Carrboro
9
Memo to Interested Persons
From Mary MacDowell, Reseazch Coordinator
Chatham County
10/6/98
pc~c~adr~
oa z s ~~ea D
RE: Harris Plant Fuel Pool Expansion Request
Attached is information to help local citizens and government representatives evaluate
safety concerns regarding high-level radioactive waste pool expansion in the Triangle.
Two of the last chapters of a book on high level waste management safety, titled Nucleaz
Waste Disposal Crisis by David Lochbaum aze enclosed. Lochbaum is a nucleaz safety
engineer who worked for nuclear power companies for a number of yeazs before joining a
consulting firm. He published this book in 1996. Then about a yeaz ago, he joined the
staff of the Union of Concerned Scientists to concentrate on advancing nucleaz safety at
all power plants in the US.
The fuel pool expansion license amendment request is expected to be submitted in
November and then after publication in the Federal Register will be allowed comments
from the public or local and state governments for 30 days only in a formal proceeding
under NRC rules. Therefore, if you aze interested in learning more or commenting, there
is not a lot of time before such decisions must be made. Pages from the federal register
outlining their process are attached.
Also attached is a summary of a 1996 report we have requested that evaluated Spent Fuel
Cooling (AEOD/596-02) by the NRC Office for Analysis and Evaluation of Operational
Data which was formed after the Three Mile Island accident to learn from and prevent
accidents and the precursors of possible accidents. It concludes that the loss of pool
coolant greater than 1 foot has occurred at a rate of about 1 per 100 reactor years. This is
disquieting when one considers that the Harris plant will operate for about 30 more yeazs,
and then a 20 year extension is desired by CPBtL and the NRC has decided that pools can
safely operate for 30 yeazs after their operations cease. This leaves us with 80 yeazs and
8 chances out of 10 that the fuel pool level will drop at some time. It also states that the
primary cause of these events has been human error, which unfortunately cannot be
engineered out. So far these events have not resulted in a radiation release as far as we
know, but they illustrate the vulnerability of the storage system.
Pools were designed for short term storage of about 1/3 of a reactor core load of fuel and
are now being pressed into service for 8 or more times that amount for an indefinite
period, because of the uncertainty of access to a permanent disposal site. CP&L's
purpose in opening these two new fuel pools is primarily for shipments of activated fuel
rods from their 3 plants in Wilmington, NC and Hartsville, SC.
I will be out of town until October 20, but my part-time office assistant may be able to
field questions or get you in touch with someone who can. Please leave a message at
542-4878.
i "~~
C:\Documents\Cover letter for Lochbaum chapters.doc
Check our web-site at: http:l/chathampslac.home.mindspring.com
10
Chapter 8
Spel~~ Ft.~e! Risks
The NRC first evaluated the spent fuel risk in the Reactor Safety Stud~• (RS~1
released in October 19i ~. The NRC had assumed that a spent fuel accident
~.•uuld only involve one-third of a reactor cure's in~•entorv, because the fuel
assemblies discharged each refueling outage would be shipped uffsite fur repru-
ce~sing shortly thereafter. The NRC considered the spent fuel risk to be smell
compared to the risk from accidents involving the reactor cure.
The National Em•irunmental Policy Act of 1969 compelled the \RC to
release an environmental impact statement for spent fuel storage in August 199.
The ~iRC reaffirmed its conviction that the "storage of spent foe! in water puul~
is a well established technology, and under the static conditions of storage repre-
sents aloes em~ironmental impact and low potential risk to the health and safety
of the public."=
The NRC recognized that certain actions had erodeu'-the bads fur its origi-
nal spent fuel risk analysis: after reprocessing vas eliminated, utilities had
expanded spent fuel storage capacities at nuclear power plants and disposal had
been indefinitely deferred. The RSS had not considered su many spent fuel
assemblies being stored fur so many years. In addition, studies demonstrated that
fire could propagate bet•veen irradiated fuel assemblies in the storage racks, a
mechanism nut contemplated in the RSS analysis. The NRC undertook a stud~~ u~
the early 198Us to determine if the interim spent fuel storage rule presented unan-
alyzed accident scenarios or more severe consequences than pre~•iuusly analyzed.
The study involved a probabilistic risk analysis of pustulated spent fuel pool acci-
dents initiated by random system failures, seismic events and dropping hea~-~•
loads. The analysis considered initiating event frequencies, s~•stem respunse~,
and accident consequences such as cladding fires to evaluate the health effects
from the pustulated accidents.'
The NRC's study reported that a spent fuel pool accident im•ul~•in~ toe!
damage could result in an 8x10" person-rem total radiation exposure to the
btii,~88 people living within a SU mile radius of the plant. This radiological dc»z
averages 11.98 Rem per person, equivalent to ~ki9? times the maximum dose that
federal revelations permit any member of the public to recei~•e in an entire ~•ear.
The study estimated that such an accident could result in off-site propert~• ~iim-
age totalling 53.E billion in 1983 dollars. As in the RSS, tLe stud~• assumed that the
accident involved only the fuel discharged during the must recent refueling out-
age (i.e, one-third of a reactor con:).'
Huwe~•er the vRC~ study also reported that the chance. ut a spent fuel pool
accident resulting m fuel damage ~~•ere l.~~ll) per reaitur year. ~~r ley thin ~~ne
t09
1.1
Nuclear Wasre Disposal Cns~s
accident e+•erv 60,UO1) years given the lUy plants Lvrrently operating. Due to the
accident's perceived low probability, the I~RC concluded that it represented an
acceptable nsk to public health and safety despite the severe consequences.
The 1leart of probabilistic risk assessment IPRA) is statistical analysis. Such
ciphering has valuable applications, but PRA proponents quantifying nuclear
safety risks should consider the fief that a SRC statistician published this c~n-
clusion un Vlarch 9, 1979:
The probability is less than 0.~ that the next (i.e.. the first) major accident
occurs within the next-100 reactor vein. The probability is less than .0. that
the next major accident occurs in the next 21 reactor years. The probability
is larger than 0.~ that the next major accident will occur after the next SOU
reactor years."
The major accidcr~t•at Three IV[ile Island Unit 2 occurred on March 3b, 1979-
fe++•er than 500 hours later.
The primary faults of PRAs include nut addressing all credible initiating
e+•ents and using invalid assumptions. (t is exceedingly difficl-lt to co+•er every
conceivable failure mule and effect in a PRA for something as complex as a
nuclear power plant. According to a consultant to the ~iRC who reviewed
Individual Plant Examinations featuring PRA, "attention to detail makes sate
plants-lack of attention to details kills people."~
The nuclear power industn• has nut evaluated the integrated risk from
nuclear pu~ver plant operation with the on-site storage of significantly more
spent fuel assemblies than had been considered +vhen the plants +~•ere designed.
Spent fuel risk assessments assume that only one-third of a reactor core's inven-
turv ++•ill be damaged, vet spent fuel pools now contain up++ards of seven reactor
cures of irradiated fuel assemblies as shown in Table i-l. These details demand
proper attention.
The spent fuel rises sessments dismiss the se+•ere consequences from a
spent fuel accident primarily due to the perceived lung time that the operating
staff his to perform mitigating actions. However, these risk assessments fail to
account fur the single must important element in any mitigation effort-name!v,
the problem's detection. The instrumentation used to monitor spent fuel pool
temperature and level is almost al+vavs nonemergencv equipment. This means
that it is nut designed, procured, installed. maintained. or tested with the same
high standards applied to emergency system components to guarantee their per-
furmance. As repeatedly illustrated by the fulluwin~; incidents, the initiating
e+~ent frequently Sues undetected fur hours ur even days due to inoperable spent
fuel pout instrumentation. It seems prudent, if nut mandaturc, to pnn•ide reason-
,ible a~sur,~nce that spent fuel pu~~l hr~~blrm~ ~~ III be readily detected before their
~r.~~•e cun.e~luence~ are disrmr. ed h,i~+•~1 .,n remedi<il actuuu.
r;p
12
Chapter Eight • Spent Fuel Rtsks
Loss of Water Inventory
The principal spent fuel accident concern is losing spent fuel pool ~.•ater end
the capability to caul the irradiated fuel assemblies. [f the spent fuel pool drams,
the spent fuel assemblies discharged within the past three to four veirti ,till pr~-
duce sufficient decay heat to cause meltdown. in addihun, the htel'~ cla~idin
could initiate and sustain rapid oxidation (often referred to as "fire' uut~id~~ the
nuclear power industry) during heatup prior to melting. The resultiti, .la~idin~
fire in a spent fuel pool equipped with high-density storage rark~ ruul~i :pre~d
to every spent fuel assembly.
The probability that the cladding would catch urrfire after the spent fuel
pool completely drains has been estimated at 100~'~ for PWRs and 2~=.'. fur B~~'Ps.'
The BWR probability is significantly lower because it was assumed that tl~e BtVR
spent fuel assemblies are stored with their fuel channels in place, thus acting as
barriers preventing the fire from spreading. Storing BWR spent fuel assemblies
kith the fuel channels in place significantly reduces spent fuel risk, vet the SRC
dues nut require or even recommend that BWR plants implement thu ine~pen-
sive safety precaution.
The loss of spent fuel pool water inventory e~•ent has the potential fur c~nt-
aminating the environment tivorse than would occur from a reactor core accident
due to the significantly la der quantity of radioactive material a. ~ilable fur
release.' Additionally, the loss of spent foe! pool ~.•ater im•entun• r~•~•nt i~ inher-
ently worse than the reactor cure accident because the fuel d.ima~__• ,utd radiuar-
tivity release urcvr outside the major barrier protecting the pubic,. the prtman~
containment. Therefore, it is mute likely that radioactive material r~•lriwd in a
spent fuel pool accident would reach the environment.
Several failure mules causing spent fuel puuTweter in~•enturv to be lust
were considered during the design process. The predominant fai!t;r,: [nude is
structural integrity damage that drains the spent fuel pool ~.•ater at ,t r,~te e~ceed-
ing makeup capability. The events producing this failure mo~i~ , r!•
quakes, heavy loads dropping into the pouf ur onto its wall, and ti: .
ed missiles. The secondary failure mule im•olves fuel pool cuolin warm mil-
htnrhuns enabling accelerated water loss from the pool. Thy e.•ent> prudurin
this failure mule include a fuel pool cooling system pipe break and a failure of
the system's heat removal function. Another failure mud e, typically nut run~id-
ered dunng the design process but pru~•ing to be rather troublesome nonetheless.
in~•ul~•es sell failure that allu..-s water to leak from the pool into ,t~ii,t:eni .tr~a,
Sorb as the containment, the shipping cask pit, and the fuel tran.t~ r tuh~~
The spent Fuel pools at nuclear power plants to the t_ rit~•~1 ~t.lte•. are
de~t~ned to withstand earthquakes without loss ut inte~rtt~' Thy \l:C ~~. ,~lu.tted
the spent fuel pooh at the ~'ermunt Yankee an~i the H. B R~~i•r•~~m hl,tnt~ t.,
~irt~•rnunr thetr.ulnerabilit~' to earthquakes more ~r.•ert~ thin ~~•~•.;,I~~r~•.i .lurut
~i~~~i~n Th~•~~ runrludrd that the spenc fuel pool, ~.~ouid prol~,ti~l~ •ur. n u .ut
13
Nuclear 'Haste Disposal Cnsis
earthquake three tunes la der than they were de>>gned to handle. Then also con-
cluded that it •••uuld take an earthquake nearly ten times greaten than the design
basis earthquake to cause the spent fuel pools to fail catastrophically.'° ..
Spent Fuel pools are nut designed to withstand a shipping cask weighing T
to 110 turn dropping onto their flours ur .valls. A dropped cask will probably
cause the spent fuel pool to fail catastrophically. Although the consequences from
a cask dropping into the spent fuel pool are significant, the probability that such ;
an e.•ent .will occur has been considered to be sufficiently low as to effectively ;:
manage this risk factor. "~
While the nuclear pu•ver industry has nut experienced the prototypical cask `'
drug event, there have been precursors. On December 28, 1994, a core shroud w
head bolt dropped into the Unit 1 spent Euel pool at Georgia Power Company's.: ~:
Edwin I. Hatch Nuclear Plant from one foot above the water surface when the `
sling holding the butt broke. The bolt, 17 feet lung by three inches in diameter and
weighing 36~ pounds, glanced off the side wall and fell to the bottom of the spent • .
fuel pool v`•ithuut hitting the storage racks or irradiated fuel assemblies. The bolt
tore a three inch gash in the 3/16 inch thick stainless steel liner. Approximately
2,000 gallons leaked through the hole and through a drain line to the radwaste
system before valves in es eind31minlutes, causing the fuel p~l coolulgFsystem
dropped nearly t<vo Inch
pumps to trip un low suction pressure. Operators restored level after the leakage
path was isolated, then returned the fuel pool cooling system to service. Georgia
Po.••er removed the bolt and placed a larje rubber mat (i.e., a nuclear-sized sink
stopper) over the hole to limit leakage until underwater welding repairs were
completed.
The Hatch incident occurred less than a vear after a screwdriver dropped
into the spent fuel pool at a foreign nuclear pu•ver plant with similar results. On
January 31, 1994, workers at Tricastin Unit 1 in France were removing the control
rod duster ;aide tube from a spent fuel assembly. A 15 foot long screwdriver
..•eighing -4-4 pounds fell into the spent fuel pool and punctured the stainless steel
liner. The le.•el in the spent fuel pool dropped nearly four inches. A stainless steel
plate .vas ••'elded over the lwle.
Spent fuel pools are nut designed to .yithstand the impact from a turbine
venerated missile. A turbine generated missile can result from the main turbine's
gross failure. The detached blading ur shroud from a large turbine spinning at
1,50(1 rpm can be extremely detrimental to .vhatever it impac~• The probability
that a turbine generated missile will cause spent fuel pool integrity failure has
been estimated to be •i.ix10~ per reactor vear. This prubability is predicated on a
l~lU' per reactor year prubability that a turbine failure event generates a missile
cuinbined ~.'itlt a -4.1x10 `prubability that such a missile strikes the spent fuel pool
~.•tth suffi~tel~t enemy to be ~iestruchye. ' 1993,
Full~~~• ul~ the marl turbine failure at Fermi l; nit ? un Christm~N Dr~[ed by
Drtnnt Edi>~m Company determu~e~i th,it .~ hi:;h trajectory missile ~_
Ill
i Chapter Eioht • Spent Fuel Risks
~-.
P
the turbine could damage the spent fuel pcwl. The conditional probability ~~f this
occurrence, given the turbine failure, was estimated to be 1.Ox1U, per year. = ~'+~
~+~+zth the cask drop event, ++•hile the consequences from a turbine generated mis-
sale striking the spent fuel pool are significant, the probability that such an e+~ent
would occur vas considered to be sufficiently low as to effectively control this
risk factor.
• Spent fuel pools are designed to handle a loss of fuel pool cooling. This ini-
-~ bating event culminates in appreciable loss of spent fuel pool ~+•ater in+•entun~
' only when the spent fuel pool boils ~~ithout makeup. This failure mode 11as been
discounted in safety studies due to the extended period (relative to traditional
reactor acddent analysis time fumes) available to restore cooling or pro+•ide
makeup.
On January 25, 1994, Commonwealth Edison Company disco+•ered cun~id-
erable water in the basement of the containment structure at its Dresden L'nit 1
•plant. Dresden Unit 1 shutdown in October 1978 and remains +•irtuallv aban-
Boned next to the operating Dresden Unit 2 and 3 plants. A service ti•ater system
pipe in the unheated Unit 1 containment had frozen and ruptured, draining
: about 5,000 gallons from the system into the basement. Commomvealth Edison
determined that piping in the spent fuel pool transfer system vas also suscepti-
ble to freezing. If this piping had broken, the spent fuel pool would ha+•e drained
to two feet below the top of the 660 irradiated fuel assemblies in the storage racks.
''At that level, the dose rate at the spent fuel pool railing vas estimated at X33
;.Rem/hr, radiation levels that could have impaired operations on Dresden Units
2 and 3." Dresden Unit 1 vas not equipped ++•ith spent fuel pool le+•el instru-
mentation to detect in+•entorv loss." This event had significant potential radio-
_. logical consequences even though only 660 irradiated spent fuel assemblies
=_ resided in the spent fuel pool and these assemblies had undergone over 1~ years
•' of radioactive decay.
Failure of inflatable and mechanical seals is the must frequent reason that
~ spent fuel pool water inventory is lost. Figure S-1 illustrates various seal applica-
". lions used in BWRs. Mechanical seals are used between t}~e reactor pressure ves-
~sel and the containment structure (labeled "RPV to Drvv,-eIl Bellows Seal" in
~~ Figure 8-1) and between the drywell and the refueling cavity (labelled "Drv~vell
`i to Reactor Building Bello++'s" in Figure 8-1). Inflatable seals are used around
'~ removable gates (labeled "Gates" and "Double Gates" in Figure 3-1 ). Inflatable
-seals are like bicycle fire intertubes-when filled ~•ith air, they form a nearly leak
1 tight bamer. The problem occurs when the inflatable seal loses air pressure and
;`the barrier becomes rather porous.
;fix ' The refueling cavity water mechanical seal (comparable to the "Dn~+•ell to
Reactor Building Bello++•s" shown in Figure S-1) at tl~e Haddam tieck plant suf-
fered a gross failure in August 19b4 when mechanical interference significantl~~
=;.displaced the seal. At the time cif the failure. the refueling ca~•ity was tluc~ded in
preparation for refueling. The refueling ca+•it+• ~+•ater le~•el decreased ~ ~ feet tc~ the
is
~~ 113
"c: y
~;Y-
4 .~ - W Yi'T
• ~~i' ..
14
Nuclear Waste Disposal Cnsrs
Veat Dueta
Dr er Drywall to RPV to Dr well
Y Reactor Building Bellows
Separator ~ Eellowa
Pool _ .., ~
Drywall
~\ Draia Reactor Vessel
' \ .,.;.:. ;,; '.` Double
,:..:: . Gated RP
Reactor Well ~~ Fuel Pool
~J.
' ~'~% ~~``-~"`Removable
/ ' .Shield Plugs
-'i
Low Point Drain
15
'Y
' i~
Retura Diffuser ~'~
:-~,
~ ~~~~ r:
~~
'"" Gated .
- Fuel Poal
•Drywellt
RPV to Dry7wel~
Bellowa Seal
To Leak Detection
Figure 8-i Reactor Well Seals
reactor vessel flange level within 2U minutes, flooding the containment with :-~
approximately 2UU,000 gallons. [f a spent fuel assembly had been in transit at the ;
time, it could have been partially or completely uncovered with potentially high '`
radiatiun levels, fuel cladding failure and radioactivity release. In addition, if the ,a
fuel transfer tube had been open, the spent fuel pout could have drained to a level =.=
that would have uncovered the top of the irradiated fuel assemblies in the stor- '~
a;e racks.'`
The inflatable seal on the gate to the transfer canal between the Unit 1 and i;
the [trait 2 spent fuel pools at the Edwin I. Hatch C`fuclear Pl<int deflated in :j
December 1u56 after the air supply to the seals was mistakenly isolated. Nearly y
111,000 gallons leaked from the spent fuel pools into the transfer canal, lowering ;~
the SFP level five feet. The leak was nut identified fur several hours because a leak
detection instrument vas inoperable at the time. Georgia Power determined that ~~
the leakage path ~uuld ha~•e drained the spent heel pool to the bottom of the
transfer canal, lea~•in~ only hvu feet of ~~•ater over the top of irradiated fuel
a~semblie~ to the ~tura~e rack>. The radiatiun field at the spent fuel pool railing
~~ uuld hay ~ been 11111 Rem - hr in that ~undihun, primarily from the control blades
r l.t
fin... i.s ~ ~ .
s .~- ~ ..
-.-~ ..y.. --..~. ,.... ..
~'~~
~;- ~ Chapter Eighr • Spent fuel R~sxs
storrd an the side of the spent fuel pool.` Several other incidents in,•ulyin' peal
failure are described in Appendix A.
After the Haddam \eck event, the I~RC required the pustulated grcns fail-
ure of the refueling ca,•it~• „•ater seals to be evaluated for e,•erv nuclear po+,'er
plant. The evaluation results varied due to different seal designs and refueling
ca,•ir<• geometries. Some plants required modifications to reduce the gross failure
risk ur provide seal leakage indication.
The results from the \ortheast Utilities' e,•aluatiun of the Millstone Unity 1,
2. and 3 plants for the Haddam Neck event represent h~pical findings. Northeast
Utilities determined that in the unlikely event that the seal experienced cata-
strophic failure, the Millstone Unit 1 SFP level „•ould dn.~p to 20 inches above the
irradiated fuel assemblies in 11 minutes „'ith the resulting radiation field esti-
mated to be 2.-1x10- Rem/hr at the spent fuel pool Wiling and 65 Rem/hr on the
refueling fluor. For the same postulated e,•ent on Ivlillstune Unit 2, the SFP le,•el
+,•uuld dmp to 12 inches above the irradiated fuel assemblies in SO minutes „•ith
the resulting radiation field estimated to be 4.0x10" P.em/hr at the pool railing
and S-1 Pem /hr on the refueling floor. For the same postulated event on Millstone
Unit 3, the SFP level ,vould drop to 21 inches abu,•e the irradiated fuel assemblies
in 130 minutes „•ith the resulting radiation field estimated to be 1.9x10" Rem/IZr
at the pool railing and 3i Rem/hr on the refueling floor." ' -
Tu put these radiation fields in perspective, a worker exposed to 3i Rem/hr
receives the maximum annual radiation dose permitted by federal la„• in about
4q seconds, +,•hile a +,•orker exposed to 1.9x10" Rem/hr receives a fatal radiation
dose in about one second. Because the probability that the refueling cayih• „•ate-
seal suffers catastrophic failure is considered to be neg igibly small (despite
already happenin, once), these otential y devastahng consequences have een
accepte y the l~R at Millstone an other nuc ear power plants.
'h a spent fuel pool +,•atez in,•enton• loss involves adverse consequences.
too much +,~ater can also provide problems. On June 3, 1981, demineralized eater
leaked into the Sorry Unit 1 spent fuel pool causing it to overflu„•. The spent fuel
pool high level alarm +,•as de-enerv,,ized at the time and did nut alert operators to
the problem. 1~Nater o,•ertlo„•ed into the ne,v fuel storage area, then to the foe!
receipt area and out the roll-up dour to the stationstorm drains. In addition to the
unmonitored radioacti,•ih• release. the demineralized v`•ater diluted the baron
concentration in the spent fuel pool water and threatened subcriticality margin.
These spent fuel pool near-misses share many causal factors. [n the majori-
t~• of cases, the failure of a nonemergencv s~•stem or component ~•ithout the ayail-
abilih• of a backup resulted in +,~ater in,•entorv loss from the spent foe] pool. [n
mam• cases, the inyentun• fuss +,~as nut promptly detected due to inoperable level
instrumentation. The potential consequences from these events include high radi-
ation fields and uncoyenn' irradiated fuel assemblies outside pnman• rontam-
ment. Gi+•en that federal regulations require the a5wrtiptiun that nonemer~~enc~'
~+•stems and compunent~ tall l~r are una,•ailahle tally+,•m~ de~l~ll ba~« r, ents•
>>5
17
.. ~-~•.
Nuclear Waste Orsposal Crrsrs
the frequency of these spent fuel pool peal failures should warrant heightened
attention, especially as mute and mute irradiated foe! assemblies are placed into
the spent fuel pools.
_ ~~Loss of Cooling ~'
' The inability uE the fuel pouf cooling system ur its backups to remove the
decay heat from the spent fuel pool poses an indirect challenge to public health.
' and safety. The water in the spent fuel pout serves as a heat sink that provides
time to restore fuel pool cooling prior to the spent fuel pool boiling. The boiling.
. spent fuel pool produces a slow, sustained water inventory loss from the pooLAs~
long as the boiling spent fuel pool's water level is maintained above the top of the
_ irradiated fuel assemblies, these assemblies will be adequately cooled. Howev
- the consequences From spent fuel pool boiling un the remainder of the plant tan
~ be extremely adverse as discussed in Chapter 9. '
'~ Fuel pool cooling can be lost for a large number of causes. Several inddents
are described in Appendix A. As with the water inventurv fuss events, the pri~~-
~~ mary cause fur loss of spent fuel pool cooling events has been the failure of a non_,
`~ --. ~ j emerency System ur component. The loss of spent fuel pool cooling frequently;
;,x' <~~' I~ remained undetected for several hours. The time that the spent fuel pool cooling
;; failure goes undetected is important because federal regulations do not mandate'
- ' '- a minimum time for the spent Euel pout water to reach boiling following loss of
'_.•~ . ~ cooling, and it can require considerable time to restore fuel pool cooling. Thus,
. ~ the spent fuel pool water can potentially heat up while a loss of cooling event
remains undetected such that the pool boils before cooling can be restored. The
severe consequences from spent fuel pool boiling are described in Chapter 9.
Radiation Overexposure :~-
The water in spent fuel pools serves as a cooling medium to remove decay
heat and as a shielding mechanism against the highh• radioactive spent fuel.,.;
assemblies. The spent fuel pool water inventurv loss e~•ents previously desaibed;~
involved the potential for ndiatiun u~•erexposure as the shielding pro~d~ bY.;;
the water was eliminated, but the follu~~•ing events and similar events summa-
rised in Appendix A involve potential and actual radiation overexposure that-'~
-occurred even though the required tipent fuel pool avater level was maintained- ~ 't.
The health physics (HPl technicians at the Bro~~•ns Ferrv i`ludear Plant were ;
instructed during the summer of 1950 nut to use portable teletectors to obtain.;t
~untact ~{use rates fur spent toe! assemblies. l'urtable teletectors are hand-held
ray{lotion muniton with a probe muunte~i at one en~i of a lung aluminum tube
and the readout at the other end. Appar~ntl~~, HP technicians at other plants had ;l
dipped the probe into the spent fuel purl to determine the ray{iuauti~•ity le~'el of
;pint foe! assemblies. The hullu~~~ alununLrm tubes un the teletectors displaced
the ~.•ater, significantly re~iucur~ the >hiel~iin~ fa~tur an~1 pru~•iding a stream1nS
4'.
-~.
`t:':,.
~`Y~
.~f;_..
»;`"~._
. ~~,.
i~6
r' ~ .L~
'1t ..~; .-G' . ~•.. a r~~ w'
~ t• ~,q~ '~ _
+ r L..•~ -"..
'L'am.
- ~y .v : , i
-_ - ~74L
~ Chapter E;oht • Spent Fuei Rlsks
+; pathway. The HP technicians standing at the spent fuel pool railing holding the
Y teietectors at waist height pointed at spent fuel assemblies essentially had "guns"
aimed at vital organs.
In June 1952, a diver installing storage nck support plates in the Indian
Point Unit 2 spent fuel pool received an exposure of about 3.7 Rem to his head. A
w second diver received a ~•hole body dose of about 1.6 Rem. An irradiated fuel
' assembly had been inadvertently transferred to a storage location tt+•o to four feet
from the divers' r+•ork area. Limited visibilit<~ in the pool caused by cloudy ~•ater
and insufficient unden+•ater lighting prevented the misplaced fuel assembly fruin
being detected. Alarming dosimeters mounted inside the divers' helmets failed
to alarm at the 200 mr setpoint.'"
While these events involved tangible hazards to individuals' ++•ell-being, the
general public's health and safety +vas ne+•er at risk. Therefore, the risk of radia-
tion overexposure +n•hen the spent fuel pool level is maintained is confined to
nuclear po~~er plant workers.
Handling Mishaps
The operation of o+•er 100 nuclear pu+ver plants in this country since
Shippingport's startup in December 1957 has requh2d several hundred thousand
irradiated fuel assembly movements. Spent fuel assemblies are discharged from
the reactor core and irradiated fuel assemblies are repositioned ++•ithin the reactor
core every refueling outage. The entire reactor core is periodically off-loaded one
assembly at a time to the spent fuel pool to allow in-vessel work, ++•ith fuel assem-
blies later reloaded for the next operating cycle. Spent fuel assemblies are mu+•ed
within the spent fuel pool for inspections and to allo+v storage rack replacements.
Eq~ailures and personnel errors durine these activities have resulted in
a few hundre minor incidents such as the following events and similar events
summarized in Appendix A.
During a refueling outage at Pilgrim in December 1979, an irradiated fuel
assembly was inadvertently lifted from the storage racks high enough to acti+•ate
the area radiation alarms on the refueling floor. The reactor building overhead
crane +vas transferring ne+v fuel assemblies from the inspection stand to the stor-
age racks in the spent fuel pout. After a ne+v fuel assembly +,•as placed into a st~r-
age rack, the lifting hook caught between the lifting bail and the fuel channel un
an adjacent irradiated fuel assembly. The operating staff failed to realize that the
irradiated fuel assembly +vas being lifted from the spent fuel pool until the radi-
ation alarms sounded. The operators quickly returned the irradiated fuel assem-
bly to its storage location.
A top nozzle separated from a spent fuel assembly during transfer to tl~e
new• high-density fuel storage racks at Prairie Island in December lySl. Tl~i~ foul
assembly had operated in the reactor for three cycles prior to being discharged in
August 19:8. It failed at a mechanical ball joint behveen stemless steel and
zircalov. The failure im•ol+•ed lh joints in the area of maximum ~uryature an~i ~+•~~
18
19 .
Nuclear Waste Dispas:,1 Cnsrs
caused by stress corrosion cracking of the stainless steel. The stress corrosion
cracking vas nut belie~•ed to ha~•e occurred during reactor uperatiun because the
hydrogen overpressure should result in low Free oxygen levels. However, the
spent fuel pool has highly oxygenated ~~•ater at low temperature that could cause
cracking in the presence of high stresses and sensitized stainless steel. A total of
2? spent foe! assemblies at Prairie [slam were examined with 12 showing signs
of corrosion.'"
At Brunstivick in October 19y-1, while being seated on a loaded ~v03 spe L
fuel shipping cask, a closure head became cocked and required realignment
Durin; the lifting uperatiun, the closure head became stuck on one side of the'
cask causing trvo of tour lifting cables to become overstressed and break The
reactor building overhead crane was nut equipped with a load cell to indicat-''e
excessive loading. .,
The nuclear power industry encountered a number of fuel handling itt~;
dents in the early days that compelled hardware changes and training upgrades.
Once the break-in period passed, the frequency of the fuel handling inddenta
decreased to approach that level defined by random equipment failures and pei~
sonnel errors. ~ _;.
The risk from a fuel handling incident is limited to a single irradiated fuel
assembly and whatever it strikes during transport or after being dropped
Nuclear power plants analyze pustulated refueling accidents to ensure thatthe
radiological consequences are within 10 CFR, Part 20 guidelines for nuclear
pu~ver plant workers and 10 CFR, Part IUO guidelines Eor the public and the envi-
ronment. The typical analysis assumes an irradiated fuel assembly is dropped
from the maximum allowable height onto irradiated fue! assemblies in the rear
fur core ur in the spent Euel pool's storage racks. The dropped assembly impacts
one ur more fuel assemblies before coming to rest. The number of fuel rods dam=p
aged in the event is conservatively determined from an energy balance and theme'
fuel assemblies' material properties. The Eissiun products released from the dam-.;
aged fuel rods are estimated and applied to ventilation and filter conf~guratio s
to develop the site and off-site radiological doses. The calculated dose to the pub;
lic and to the workers is generally a small Fraction of the allowable limits. ~_^
Cri~icali~y ~:
Spent fuel storage racks are designed to maintain the spent Euel assemblies`-^
in a subcritical confiwratiun. This assi~•e function undertook increased si f
o P ~=.
once when high-density storage racks featuring irradiated fuel assemblies in.
tightl~• packed arrays were introduced. ~ small number of incidents challenging
this subcriticality requirement have been reported:
Gaps were measured in the Buratlex material used in the high-density fuel
stura,~e rack at Quad Cities l,'nits l and '_ ui Slav 1y5~ .The gap formation meeh-
anum ~~•as considered to be related to large local stresses in the Buraflex from fab-,
ncahun-induced restraint «•ithm the nck and to tearing and shrinkage of the
r ~=•
v~•'
`""~=+.
1~8
- ~..:
- c=~ w-
_i~ -
-``y- ~ ~: .. 20
!~:
~~.
Chapter Eight • Spent Fu°! Risks
~;
•"d~materiaL'I11e average gap size was 1-1 /2 inches, ~+•ith the lamest measuring near-
Iy four inches. The gaps were discovered in the upper t+vo-thirds of the cell
l~g~ ~
z .- During testing of selected South Texas Project Electric Generating Station
Y~ ~ Unit 1 storage racks in August 1994, 20 of the 37 storage cells tested sho++~ed some
evidence of gaps or significant neutron absorption panel dew adation. The neu-
:~. tron absorption panels contain a polymer matrix of boron carbide and silicon rub-
. ~ ber The large area degradations (up to 3 or 4-1 /2 feet in length) represented
~, accelerated dissolution of the BorafIex material caused by spent fuel pool ~+•ater
flowing through the poison enclosures. Samples of spent fuel pool ++•ater re+•ealed
increased silica amounts. Research determined that once the silicia concentration
;r~ reaches equilibrium, the neutron absorption panel dissolution rate effectively
stops. Removal of the silicia by the fuel pool cleanup system therefore sustains
W the degradation phenomenon. However, failure to remove the silica can adverse-
; Iy affect reactor coolant chemistry during refueling outages when the refueling
:;cavity is directly connected to the spent fuel pool. Silica depositing on the fuel
'~• assemblies in the reactor core can adversely affect the heat transfer rate across the
h^.-
• fuel rod cladding, causing fuel centerline temperatures to ineaease.
k ~ During the licensing process to obtain NRC's approval to install high-den-
8 -, sity storage racks, utilities frequently committed to test the adequacy of the neu-
r:. tron-absorbing material contained within the rack structure. This testing has led
~rto the discovery of the deficiencies described above. Depending on the extent of
~,_ the problem, the affected locations within a storage rack may be administrati+•e-
.-~ Iy barred from being used or the entire storage rack may be unloaded and
~• •-
~. replaced. As spent fuel pools are filled with irradiated fuel assemblies, these
<~.'".options may be restricted. For example, at some point a nuclear po++•er plant may
s.'~-' :•
fir:.; Iose the capability to completely unload a storage rack due to the unavailability
~~~'of sufficient em locations in other racks.
,.. PtY
~~~ Spent fuel pool criticality is managed exclusively through passive design
' features and administrative controls. Critiglity in the spent fuel pool ++~ould yield
,~„~sigivficant consequences if it ever were to occur. First, nuclear power plants are
. `~ ~ not equipped with instrumentation to directly monitor subaiticality in the spent
-fuel pool Second, nuclear power plants are not equipped with features to miti-
gate spent fuel pool criticality if it occurs, with the possible exception of PVVRs
. •~~that can borate the spent fuel .pool water. And finally, nuclear po+ver plants are
':~ not designed to shield against spent.fuel pool criticality. The risk management is
-solely dependent on criticality preventipn.
=Passive Storage_
'~ The previous sections discussed the spent Fuel risk from an initiating e+•ent
~snch as the inadvertent drop of a fuel assembly or the failure of the fuel pool cool-
sng systeat. The risk from spent fuel Y,as5eatblies under normal storage conditions
'-aLso has been evaluated. Understanding this passive risk is important because ~t
°.~ x~Jt~
~' i 19 ..
.::: \„ ~'
i,pi- ,:•
Nuclear Wasre Oisposai Crrsrs
applies to all nuclear pu~ver plants virtually all of the time; in fact, at all tiaiea
except fur those rare occasiun~ when a tuel assembly i5 dropped or the tooling
system Eails. ;
Atomic Energy of Canada, Limited (AECL) and Ontario Hydro eonduc
the first major spent fuel pool storage study during l9Ti-1975. Several spent fud
assemblies From nuclear pu~ver plants and experimental reactors were d''i5ass`~Oem.
bled and examined. The assemblies included in this study had been sto
spent fuel pools between l3 and 27 years. Destructive examinations were
formed on specific fuel rods From each spent fuel assembly, while the
fuel rods were returned to the spent fuel pools for continued storage. ~.
Ten years later, AECL and Ontario Hydro repeated the study to evalua
effects after another decade of storage. AECL and Ontario Hydro visually exam
fined the spent Euel assemblies. Nu indications of fuel rod cladding d
(i.e., pitting, galvanic corrosion, etc.) were observed on any fuel ~~ ~
Neutron radiography techniques were used to took for the presence of~•
inside fuel rods. If water vas present inside a fuel rod, then that fuel:
cladding was known to be defective. The neutron radiography e.~caminatioas
1955-1959 indicated that no fuel rods had failed since the examinations
1975. '~'
During the 1955-1989 study, AECL performed gamma scanning of~
spent fuel rods that had been in pool storage for 21 years. The gamma ~~
results indicated no evidence of leaching or redistribution of fission pn~u
Euel rods. Room temperature ring-tensile tests were performed on 30 fuel
from 1.4 spent fuel assemblies that had been stored underc.•ater for 13 to 27
The tests were conducted to determine if there had been amp change in ~dd~'i
mechanical properties due to storage under water. No significant difference
cladding's mechanical properties were identified. AECL and Ontario Hy~.,,~
eluded from the studies that spent fuel assemblies can be safely stored underv
ter for at least ~0 vears.=' -`
EPRI and Battelle Pacific Northwest Laboratory researched empiri ~
analytical information available through 198 on underwater scent Ebel
in this country. This team discovered nu evidence that spent toe! asse~b
degrade to any appreciable degree during long periods of underwater sto-~.,nr.
The team concluded that substantial technical basis exists to justify all
spent fuel to remain in vet storage fur several decades=
. =+a
Managing the Risks y~
vuclear power plants hive stored spent fuel assemblies fur nearly ~0 etv -~
without am• significant incidents. The primary threat to public health and saf e ,-
from spent fuel storage results from loss of spent foe! pool water inventory ~ .
consequences from a spent heel pool accident include butte radiation exposure
(5x1(7' person-rem) and expense 153.E billion in 1y53 dollars). Lzsser threats ro'
X20
22
-s
,y,~
a.,
~;
~~.
~::;
•~'
E'.
Chapter Eight • Spent Fuel Risks
fir, public H•elfare are posed by loss of spent fuel pool cooling, radiation overexpu-
?== sure to spent fuel, and spent foe! handling.
Near misses have been logged over the years, including numerous repeti-
lions of the some events. Spent fuel risk assessments conclude that the probabil-
-' ities of the ~•orst case accidents occurring are reasonably lo~v as to provide ade-
_. quate assurance of public safety However, these risk assessments are nonconser-
. ~ -- vative because several of their key assumptions are invalid. For example, the risk
~.; assessments assume that a relatively long period is available following the initi-
ating event to implement actions to prevent or mitigate resulting fuel damage. Yet
"' the spent fuel pool temperature and level instrumentation at most nuclear po~+~er
(' plants is nonemergency equipment with a history of frequently being inoperable
or unavailable follo++ring initiating events. The initiating event may go undetect-
__ _• ed for several hours, thus redudng or eliminating the available response time.
The risk assessments nonconservatively assume that the operating staff has
' unlimited access to the systems that can be used to mitigate a spent fuel pool acci-
' ' ; dent. The spent fuel pool, along ~~ith most of the equipment that cools and pro-
i -•'w vides makeup water to the pool, are located inside the secondary containment
`: structure at most BWR plants. Following a reactor accident involving fuel dam-
~~ age, secondary containment can be rendered inaccessible due to extremely high
radiation levels. The consequences of such a reactor accident can mechanistically
cause a loss of spent fuel pool cooling event. Hence, the risk assessments are
wrong to assume unlimited access for restoration and mitigation efforts.
- The risk assessments also nonconservatively assume that the probabilit~• of
~` a fuel cladding fire propagating to adjacent fuel assemblies is significantly lower
'~ .for BWRs than for PW1Zs because BWR fuel channels act as fire barriers. Many
BWR spent fuel assemblies are stored with the fuel channels in place; not for risk
t`~=: reduction, but for convenience. There are no requirements or even recommends-
,; lions that BWR spent fuel assemblies be stored with their fuel channels. Hence, it
~: ~;:
^;~: a is wrong for the risk assessments to assume that the fuel channels are ahvavs pre-
~~F;; sent to prevent a fuel cladding fire in a BWR spent fuel pool from propagating.
The predominant invalid assumption in the spent fuel storage risk assess-
~,::::.
,•~ ~' menu involves the extent of fuel damage resulting from a spent fuel pool acci-
~~.':.~ dent. From the initial NRC risk assessment in 1975 through the NRC's updated
'f~~;~ risk assessments in the 1980s, it has been assumed that only one-third of a reac-
~{ ~~ for core's inventory ~•ould suffer damage following a spent fuel pool accident.
:~E;--
~~?'; Nuclear power plants currently store the equivalent of several reactor cores in
'_sY~ closely packed arrays within the spent fuel pools (see Table r-1-}- Stvdies have
demonstrated that a spent fuel assembly discharged within the past three to four
_~; years still produces sufficient decay heat to cause its foe! cladding to burn.
~'. Studies have also demonstrated that the resulting cladding fire can spread tc~
involve every irradiated fuel assembly in the spent fuel pool, e~•en those that
,,,~= were discharged many years ago. Therefore, limiting the postulated rele~~e~ from
,...
.1Z1
,.~x ..
clear Waste Disposal Cns~s
a spent fuel pool accident to that r~diuactivity contained in only one-third of a
reactor cure's inventory nun-cunsen•atively biases the consequences, _
Risk is defined as the product of the probability that an event occurs and its
consequences. Both the spent fuel pool accident's probability and its eonse-_•;~,:
yuences have been underestimated. Therefore, the spent fuel risk is higher than ~;
perceived by the existing assessments. _ ~; =~,~°~•
The spent fuel risk is far from unmanageable. tt only require; providing tta-
sonable assurance that spent fuel assemblies remain covertari with water.at all
times. The nuclear power industry has successfully ke t s ent fuel_`~"~`~r
P P asseatLli~.
covered with water since Shippingport began commercial operation in 11957.
task grows increasingly more difficult as more and more spent fuel assemblies
stored at the nuclear power plants. To prevent the safety margin f:oair
ing, the nuclear power industry should place greater emphasis on .the'
mentatiun monitoring spent fuel pool conditions. Spent foe! storage:nsk
ments should reflect actual plant configurations and operating conditions.,.
measures should provide reasonable assurance that spent fuel storage at nu
power plants presents negligible risk to public health and safety. ip
I
i~
~~
a
\uclear Rr;ularorv Communion. °Reactor Safett• Study: An Assessment of
C.S. Commercial Nuclear Po~.•er Plants." WASH-I-WO (NliREG-T~/t)l~t), O
Nuclear Regulatory Communion. "Final--Generic Environmental [mpa
Handling and Storage and Spenc Light Water Power Reactor Fuei " \L'REC
'_. and 3..-~ugunt 19~ 9
P. G. Prasntnus. C. 1'. Kimura. D. B. ~kCallen. R. C. ~lurrav, Lawrence Live
Laboratory. and ~1. K. Ra~•indra. R. D. Campbell. P. S. Hashimoto. A.:~l. Yaf
ELE Engineering, [nc.. Nuclear Regulatory Cumminsiun, "Seismic Failut$
.~nal~•ses of the Spent Fuel Pads at Two Representative Nuclear Power Planf:
1-6, January 19ti9
E. D. Thn~m. Nuclear Regulatory Commission. "Rrwlatorv Analysis for
Generic lnsue 83. "Br~•und Destgn Banu Accidents in Spent•Fuel Poots;' I
,~prtl lygy. p. ~-~'.
Throm, p ;.;.
;:;rf
d. Da~•ni Rubenntein..~pplied Statuncs Branch. Nuclear Regulatory Commission, bo Rt
~luure. Chief. Applied Stahnttcs Branch. Nuclear Regulatory Cummissiun, "PtOb:
That the ~r~ct ~lalur ~rcident Uccur~ within Prescribed [nten•als," March 9, 1979.
-. John Darb~• to Cnue~i Stare \udrar Re;ularur~• Communion. "Concerns with NRC
Re•:~rw5.' March ly. Ivy;, p 11). •
~. Thrum. p ES-2.
`' Prin,mu. rt al. p ~w
Ilt Pras~inu~ rt al. p Dui
Y L~'•
~~St'..'('ii~..
:~'.r,
~r.s~~-~~:.:r ..
.• ~,.,; .
r .`~
u~.-,
,. ~ •...
I I Thrum. ~ ~• I
12
Chapter Erghr • Spent Fuel Rrsks
24
1'_ E.i,vard L Gn•rnman. Director, Dtyts+on vt Reactor Pn,lrits. \uclear Re_ulatory
i`.nnnussam n+ 1luuglas R. Cipaon. Srmur Vicr President. \uclrar Uprrehuns. Detruu
Ldi~on C,,n,I+•u,~. '"\RC Rr~ion III Augmented Inspection Team 1,\IT Rryte„ ut the
Decrmhrr =~. lU"', Frrmt ? Turbtnr-Generator Failure." Frbruar~-. luu•1, F, 1_.
1 : \u.-Icar R~~~ulatun Commission Operating Reactors Eyent~ Beefing 44-tlh, "Dresden Lmt 1
Cold 1Veathc•r Impact un Decommissioned Rrach,r Facilih•." Frbrvan~ `+, 1U44
1; \u.'Irar Rr~sulaton C.+mmission Bulletin \0 4ga11. '"Potential Furl PiK,I Uraindo~. n Caused
i~~ InadcKluatr V,unn•nancr Practices at Dresden L'mt l." Apnl 1•I, 1444. and
\u.lwr R~~~ulatun Cummissum lnh,rmatiun \oticr \u 44-35, 'Trsults ut a S}+cwtal \RC
' ^-,•.,!,•n \uclrar Puwrr Station Lnit 1 Fullrn.'utg a Rupture of Se•ryue \\'atrr
_...•~r Vtay ~". 1444. and
L~mrs 1. \lilhiain. Deputy E><rwhyr Director fur \uclrar Reactor Regulation. \uclrar
R, •,•.il ~ . ~• L,nn:^~~~iun, to 'Nicharl J l\'allair. Vice President. Chief \uclrar Officer.
Commonwealth Ediwn Cumpam'. "Dresden Stamm-l,mt 1, \utice of \'iulatn+n and
Proposed Impusuwn of Civil Penalty- SZOO.IxRI and Notice of Deciatiun ilnsprctiun Rrport
\u SO-01(1/441101 i," lone 13. 1~4, and
~\' L. Axrlson. Director. Divisum of Radiation Safrh' and Standards. \uclear Re;ulah,n
Lummis~unt. to \iicharl J. Nrallace. \•ice President. Chief \uclear Otficer. Commonwealth
Ed;>,•,, ~ ouipanc. ~C:ntiirmawn• .4ctiun letter 1CALl Rlil-y4-1A11 fur Dresden I and Response
tt, Ins}+riuun Fullu~+up Items m Inspection Rrport \u. 50-010:44001." Junr'_4. 1v4~1, and
Vlichac•1 D. Duster. Sue Vice President. Commonwealth Edison Cumpam•, to lames
Lieberman. \uclear Re~ulaton• Cummissum. ''James L. Vlilhuan letter to \tkharl I ~\'allacr.
dated luny l4. 1444. transmittinK Nuhce ut \'iulatiun and Pn,poxd Im}xsition of Civil
I'enalh•: Ins}>rctiun ReFwrt No. ?0-0}0/4.1001." Jule 1 ~, 1y44.
15 \uclrar Regulaton Cummuswn Bulletin \u b4-03. °RetueGng Cavity l\'atrr Seal. .august
'_-1. 14ti4
lb \uclear Rrgulatort• Ca,mmissutn Infc,rmanun \once \u R~ -1 ~. "Potential for High R.idiation
Fields Fullu~.'utg Luss of ~\'ater tmm Furl Pcwl." February ?-I. 14ti'
1; 1y G Cuunsil, Srna,r \'icr President. Northea>t Ltilitirs, to Dr Thomas E Turley. Rektental
Administrator, Rrgtun I, \uclear Rrgulatun• Commission, "Haddam Neck Plant / \ttllstunr
\uclrar Po,ver Station Units No 1.:. and ~ / IE Bulletin \u 54-03 ; Refueling Cavity P~~,I
Seal." Nu~•rmber 24. 14F4
Ih. \uclear Rrgulaturv Commission Inturmatiun \utice tio ~_-~1. "Ovrre~}x+sure ut Uicrr
Dunng tVurk in Furl Sturagr Piwl.•' lulu 2ti. 145=.
l4 Earl K. Bn,,. n. Lead Engineer. Engtnrenng S)•strms, Reactor Oprrehons Analvsr. Branch.
\uclrar It~,~uian+rv Cummissum, to Karl \' Srvfnt. Chirt. Reactor Operations .~nal~~is
Bran. h t iui.r of Anah•sis and Evaluation ut Operational Data. \uclear R~~_ulatun
Gannti.~i,•n. "Furl ~sx•mbly Degndanun l\'hile in the Spent Furl Storage fool." Ctiti+i~rr
'_l. l4ti_. and
L l1 \'laver, Manager ut \uclrar Sup}x,rt ~rn•ices. \orthern States I'or.rr Comp,ui, n~
Rrgu+nal •\dmim.trah+r. Rrgum I11.'~uclear Rcgulatun~ Comnussum. °tipcnt Furl ~~~rmrl,
D-:4 Tol• \,vtlc E~ant." Dc•crmbrr +tt. lV1l
_ \u.lr.,r R.C:+Idtun C.,mnu..+,m Intormatt~m \onir \o ~-..; C..t},•+n \rutrun-~h~.~rt~,i•,•,
\latcnai m I li_!t•I'1rn~rtt ~rh•n; Fuel rtnr.t_r R.,.ks " ~•p[cmbrr ~. l4ti
t2~
,~.rr Rr~r,,rth Institute 'k~amtnattun of Spent
,
h hrsearch. Elrit-,. I ~ 1•R.,,nu,-~. \la. 1""t
'- Year. ~.t f ,n,l >;'
CA\DL'" Furl h+llo,•u,g -' -
~~ J Ba,ir~..-\ B I,~hnson Ir. D E Blaimik, IL I l~runthrr .u,d <) D I .,nn~ny,.'BuRrl ilancefoE
\urth,~'rst Laburan+nrs. Elc~tni 1'o~.rr Research Institute I:rp~+rt \I ~~
LW 1: 5prnt Furl m ~\rt 5tur,iie." Uctobrr 14D4
~7
25
Chapter 10
Solving the ~Vucleer
Waste Dispos211 Crisis
Defense-in-Depth
The nuclear pug+•er industry in the United States applies a defense-in-depth
approach to safety. Defense-in-depth relies on design features to pro~•ide assur-
ance that (a) the frequency of major accidents is as logy as reasonably achie~•able.
(b) the consequences from a major accident are mitigated to the greatest extent
reasonably achievable, and (c) the public and the environment are protected even
if a major accident ~~ith substantial radiological release occurs. The primary fac-
tors in real estate may be "location, location, and location," but in nuclear safety
they are "prevention, mitigation, and containment." Collectively, these defense-
in-depth principles maintain the inherent risks acceptable lo~v, thereby pru~•iding
the solid foundation for safe nuclear energy in this country.
For an example of how defense-in-depth ~~•orks, nuclear po~~•er plants are
designed to withstand a loss-of-coolant accident. The design basis LOCH
involves the pustulated instantaneous break in the largest diameter pipe con-
nected to the reactor pressure vessel. To satisfy the Eirst defense-in-depth pnnci-
ple, the piping connected to the reactor pressure vessel is designed, constructed,
and inspected to exacting standards that ensure its integrih•. The chances of a
pipe failing are therefore extremely unlikely. Yet, defense-in-depth assumes that
the pipe fails an«.•av and requires design provisions to mitigate its conse-
quences.
To satisfy the second defense-in-depth principle. the eme ~ency systems fur
nuclear pu~•er plants are designed. constructed, and tested against rigorous cri-
teria that ensure adequate makeup water is supplied to the reactor pressure ~•es-
se! to compensate for the reactor coolant loss in a LOCH, thus preventing fuel
damage from inadequate core cooling. The conditional probability of fuel dam-
age given an initiating pipe break is therefore extremely lo~~•. Yet, defense-in-
depth assumes that fuel damage occurs anvw•av and requires design provisions
to contain the radioactivity released from the cure.
Tu satisfy the third defense-in-depth principle, the containment sv~tems f~~r
nuclear power plants ire des:~ned. constructed, <ind tested to ensure that
radioactive material resulhn~ from a pustulated reactor care damage e~ ent is nut
released to the em•trunment. The cund:nunal probability of sa~n:ficant radiuac-
tn•ity release :yen In .ucuient :nyulytn~ reactor care damage :s therefore
extremely lu~.•.
i5~
26
Nuc~e.7r Waste Orsposal Crrs+s
Defense-m-depth protects public health and safet~• +n the unlikely event the
reactor cure is damaged fulluwin;; an unlikely lus~-uf-coolant accident. The
defense-in-depth cun~ept diswssed fur the pustulated pipe break event is svs-
tematLCally applied to all design basis transients, accidents, and events-water
line break. steam line break, generator load rejection, inadvertent valve closure,
spurious relief .•alve opening, pump seizure. control system failure, earthquake,
and many other. 1Vuclear pu~~~er plants are nut inherently safe, but they are safe-
ly operated through risk management based un defense-in-depth.
Defense-in-.iepth also applies when handling spent fuel assemblies. The
design basis fuel handling accident pustulates the drop of an irradiated Euel
assembly from the maximum possible height. Tu satisfy the first defense-in-depth
principle, the fuel grapple is equipped ~•'ith interluclcs that present a fuel assem-
bly from being inadsertently released. Tu satisfy the second defense-in-depth
prindple, the storage racks are designed to restrict the damage from a dropped
fuel assembly to that assembly and the small number of fuel assemblies it
impacts. Tu satisfy the third defense-in-depth principle, the ventilation system for
the fuel handling area processes air through filters before discharging it to the
atmosphere. thug limiting the radioactivity released into the en~'ironment. Again,
defense-in-depth protects public health and safety in the unlikely went that irra-
diated fuel assemblies are damaged fullu~sing an unlikely fuel handling accident.
Public health and safety is prutt~cted ~.•hen at least one of the three defense-
in-depth elements remains unbroken. [f an accident Weyer occurs, then mitigation
and containment features remain unchallenged. if a major accident occurs,-then
the public is protected if either mitigating features prevent fuel damage or con-
tainment features prevent uncontrolled release ui radiuactt~•ity. Therefore, all
three defense-in-depth principles must br breached fur the public to be jeopar-
dized by nuclear power plant operation. Defense-in-depth's salue u clearly evi-
dent in the t..•o wont nuclear pu~.•er plant accidents-Three ~•tile Island and
Chernobyl.
the T'nree Mni~er~is~ande TAcc edent it ~ plant
[n tl~e predawn hours
near Harrisburg, [ ennsslvania, expenenced the ~.•orst accident in Lnited Stites
commercial nuclear pu~~'er history. The Tivl[-'_ accident bran as an innocuous
transient that interrupted feedwater tlu~s to the steam generator at this P~~
plant. Then a backup system failed to supply auxiliary feed~sater to the steam
~;eneratur. Heat transfer from the reactor coolant system to the secundarv loop
;tapped after the steam generators bulled dry un the secundarv side. ~n equiF"
ment hilure allowed the uncontrolled release ut coolant from the primary sys-
tem. The operating staff. relv,n ~m tilsr level indicatwns and una"are of the
rea~tur coolant rm'enturv fuss, turned utf the emer~enry pump. that had auto-
mahcally ;carted providing mak~uF~ eater to the traitor coolant system.
Dehn~ ed of cu~~lins~ eater, the T~II-'_ reactor ~orc ~,yerit~•atvd.
r5S
27
Chapter Ten • Solwng the Nuclear Waste D~sposat Cns~s
i
i
i
The overheated TMI-'_ reactor core suffered partial meltdu~~'n ~~'ith rel~ca-
tion of approximately ~~`"but statisrically unlikelvaDespitetsubst nt ~l role se`of
ously considered possible
highh~ radioactive fission gt~sthe e ca to of all butsmininuileradiu~cti~ih to the
TNII-'_ containment prey en p
a~osphere. The tint hvo del ~ ma eeBut Plne third defense-ens epth prin~ ple
oo~-red that resulted in ~ ~ ~~ the
worked because vl nted from rea h ng the en~i onment it substanti~ ~ rnounts.
accident was pre e
The Chernobyl Accident
In the preda~~'n h erienced~tpe ~ ont a~cident inllconlmerc it nuclear pu~eer
Kiev in the Ukraine exp
history. The Chem lo. rea dor pb~ er. Wh en lne oper tin~sbi f dec dedit rqu cl:-
do~Nn capabiliri a
ly shutdown the reactor in r~ p he core actu ly ?n Teased pug ers r ther thlin
test, control rod insertion to
reducing pu~~'er, due trusiun generated considerable o ergyt that producted a steam
resulting pu••'er exCU o
explosion and the disassembh• of the reactor core and internals.
The Chernobyl core suffered ca`as~ Plmnent ~ size blle qualntihe oft lughl~•
the structure enclosin~ the reactor p
radioactive fission gases anatmosoheprern~ th serious public healtldand en 'irun-
proceeded directly into the p
mental consequences. resulted in fu 1 damage ~vitl~irtl,elulncontroldled releaee u
accident occurred that
large amounts of radiuactiyih' to the em'ironment.
Following the Chernobyl ace d 'el'and lire Unatede States' Congresstfhat
try reassured the American p P uired in American nuclear pa~~'er
Chernobyl lacked several desi?n features req
plants that made the t`' ften cited the containment sb terns loran lotted lbv feder-
try. These reassuran~e_ u
al lam' for American nuc`ear e"tuel dlmisaellThe vRCts final lon lusion t~d reel
if an accident results to _e e
f ommendations from its e~cl'~am;n ofet~en hplrno~tioFl~v 1<,Senaptured intllU CFP..
for the defense-in-dept' „mented b~' continuous. a~~gresst`'e ~'en-
Part ~0 and its attendant reulatiuns, au,
fication that all three pnn~tple` tre intact.
4 pe th?
` Reiinquishing Defense-in- P
In No~•emhcr 1""~. the \l:C ~~'a` notified of the ~u~.luehanna ~un~er
~ These concerns pnmani~ im ~,~~ e the third deten`e-'n-~i~'Pth F rinciPle. ~p~'~iEi~ ~i-
t~?
28
Nuclear Wasie Orsposal Cnsrs
Iv, the usability of the SSES containment .vstrms to limit the release of radiuachve
material following an accident invoh•ing fuel damage. These systems fail due to
design deficiendes associated with the coolinn of the spent fuel pools as
described in Chapter 9.
The NRC reyie«~ed the Susquehanna concerns and concluded that although
the SSES design did nut conform to numerous federal regulations in effect at the
time the plant vas designed and constructed, these safety regulations no longer
applied to this facility since both the o~~'ner of the plant and the NRC had failed
to detect the nun-conformance at that time. Apparently, in the \RC's eves, igno-
ranee of the la~.• is an excuse---e'en though the ~iRC cited noncompliance with
safety regulatiuru as a contributor to the wont accident in nuclear power histo-
rv: "The evidence from the accident suggests that Chernobyl [;nit 4 vas nut in
compliance with ... specific requirements in the 1982 regulations."'
The NRC further concluded that nonconfurmances at SSES represented re!-
atiyely minor safety significance. The NRC based its safety conclusion on a risk
assessment indicating a very low probability of SSES encountering a boiling
spent fuel pool. Hu~•~ever, this risk assessment ~.•as predominately biased
tu~vards the SSES configuration after numerous plant modifications, analyses,
procedure changes, and retraining had been implemented addressing the defi-
ciencies. The NRC's evaluation significantly underestimated the risk at the time
of discovery. The NRC's bias is important because it misrepresents the risk from
the design deficiencies-problems that may remain uncorrected at numerous
other operating nuclear power plants similar to SSES.
The NRC essentially determined that satisri~ing only the first two defense-
in-depth principles is adequate; apparently the public and the environment no
longer warrant protection from the release of radioactive material following an
accident with fuel damage. However, this determination conflicts v`~ith the stan-
dard American defense-in-depth risk management philusophv and more closely
resembles the Chernobyl design philosophy:
Suyiet safety analysis tends to place greater emphasis un prevention and
early mitigation of selected design-basis accidents than it dues on the con-
sequernes and mitigation of se~•ere accidents beyond the design basis of the
plant=
The Chernobyl design philusophv was roundly criticized in the west
lincluding critical ~vurds by the \P.C). vet it nu~~• seems that ~~•e are embracing it.
The Chernobyl design philosophy isn"t cup~'righted, so at least we won't pay
extra fur less protection.
(ndicidual Plant Examinations ([PEs) provide further evidence that the
~RL is neglecting the third defense-in-depth principle. [PEs are plant-=peck
probabilistic nsk assessments ~~t the cure damage frequencies from design bast
r~. ents. IPEs evaluate the plant's response to postulated initiatins; e~'ents, factor-
in~ in r~lwpment failure r;~tes and uperah~r rrn~n
' (i~7
29
Chapter Ten • Solvrng the Nuclear Waste Disposal Crisis
I
I The (\RC re~1tlired utilities to perform IPEs for their nuclear pu~:er p ants.
~' but did nut re~luire the scopadtu~ht1~Ph,relea edttdo the pubinc trumtan .~ ~~ n
prindple---minimiatn, the r
~ involvtng fuel dan~ge. It could bin hu~~ acing the ffectivenless of thel firs
~ ern nuclear p~,~: er plant up ~ the integrity of the
_' and second defense-in-depth principles ~~ithout affechn~
third principle. That ~;r:~een lu_ed bUrd~e NRC to justify relaaen bcontainment
' results from lPE_~ have b
' leakage rate limitst ` h`lfueltdamage occurs. more rad tnon will be retleasedtto
Thus, if an acctden
' the em•ironment.
The independence of the three defense-in-depth lavers provides strengt ~.
'~ Nuclear po~~'er plant desigi~~' 1`~ min maize tlhe 11an~es that a pustu ated accident
nuclear pu~•'er plant design_
I causes fuel damage. Fur added protetrion, nuclear pu~~'er plant designs minimize
the radioacti~•ity released` °; lthat ustifiesene keningPhe~lird a~ ertbased on the
ing fuel damage. ~.ny ach 1
perceived effe;tii n k manlieement tom ~rds~the C ernubyl philosophy of exclu-
defense-in-de} tl o
sively focusing on accident pre~-entiun and miti~atiun.
The i op, Middle, ~-~/
and Bottom Lines Are l SAFI,1G , , electrical
;~iudear power has played an impurta
energy needs of the United tr n ~enucleartpu~ne plants lessened our dependence
1970s and l9SOs, electricity
on foreign ~~il imports. The led r un•er indust'n' s assertions that nuclear energy
and 19y05 supported the nuc p
was better fur the environment than other available sources. Nuclear pu~~•er
plants toda~'supply over ~0` ~ ~~f this nation's electricity needs.
The success of the nuclei cpltreer~tnd~ p e r(a) m nimizekl e than e th t~`~n
icy based un defense-in-depth . E
accident uccvrs. (b) mi l~ancestthatlthe radiuatctivit,•creleasedufTU ~n accident
and (c~ miniirrize the c
~:ith Fuel damae reaches thtllF'icl ie~te~it>~~~te i go 1 of prun a a+3 ~fet clean elt'~r
pu~.•er industt~• t~, continue ~uten-
tnc~t~~. ~t rs impt'rati~•e tha Sul lip ued` hel e ~ ~irunment frc n~tan aaide ~t are tuu
hal ~un~e~lutnres t~' the E
^,a~.~, to ~u.nf~• c~limu'ati`i~nt , ~~urr 1That`ris~k manl~ement philus~ pih~~`~1i~rnut
ahilit~ that much an .~~~
work at Lh~•rnuha, it ~:uuhi n~~t ha:~• ~~'url.e~i at Three vlile lsla~~~{. ~~n~i it ~~ ill nut
~: url. in the ttiture
iti1
30
Sowing ~~e Nuclear V1/as~e
Disposal Crisis
I~tle tlrSt ~t2^ 111 5u1y111~ tlll IlUclt',V \c,1~t2 d:_ithai ~.':~;~ h hl Identify the
~rttblem: '
L~i'i !" t,Nt' %lltlltiR'ti ~/!t 4!"liltl >I't'!It .'l lt•' .1~<t'rr!L'i lt'~ Jr~ -. ,'re'....: !I:II a'!lr ~'UCCC'r yl7rit
~itt'~ 11 Ntlt'r iU)ItIItlUli~ tllQt iltl i't' llt':'C'r i't't'll fll illl ,11!:1;:/a':1
5luppln~ ;pent fuel assemblies from nuclear ptl\\-er pi,lr,cs to r. ~eoluJical
repository fur permanent disposal \.vuld sulye thl~ probie:a. Tire De~anment of
Enemy is drilling a tunnel into the Lucca ~luuntain in \e'.•ada to Determine its
sultabllity Eur a repusiturv. The DOE's site analysis anti de\•eiupmenc efforts cur-
rently deiav the repository's opening until the year ?'.)ll). ~e•.•eral yarables out-
s;de the DOE's control, notably tl~e State of ~e~•ada's per•;:;a::t opposition to the
repusitor: anti the potential that the studies disco~•er an anurlaiy t,:.-tt renders
Lucca ~luuntain technically unsuitable. cloud the hurzon ara: threaten to slip file
repusiton•'s opening date e\-en hlrther into the nexi c_nn:-,: [n the melntime,
:pent toe! assemblies continue to be discharged from t;uci2ar r-u\.•er r:ancs. E~-en
It a federal repositun• opened tuda.•, it \\•ould tike se~.-eral years to transfer the
spent fuel assemblies from the nuclear pu~.•er plants :,nd bun• them. Therefore, a
repusitun• alone cannot sulye the nuclear ~\•aste disposal cr:_is.
The optimum solution to the problem extends defen_2-:n-decih rtsk man-
aement philu~uphy to coyer the stor;l~e of irradia~c•~ ruel ,is~ealbiies in scent
r.:el pools and In dry stun;e at nuclear pu\\•er plants. This sulutwn protects the
pubiic and the em•ironment if the repository opens tut'.ay, tornurro~~. in the year
~~JIU, ur e\•en in late afternoon of the year ?~?~. - •
The first ti2fense•in-depth laver minimizes the chances of an accuent. Spent
tL:el pUUl5 ,1Ce already deigned to minimi2e the chanaa ta: t „^e \\~ater Is lest.
Hu\\ e\•er. a \•ltal factor in assuring adequate cuulin,• inti rat'.;at:un shie!di^~ is
prompt detecttun of am- cunditwn reducing spent t.:e: rt`' '. ~••~:-.-'-•.
~.:IllerOU~ Int::tlents hll'e ~htri\'n Nl.lt exl5tl11" fuel Cl':tl i2.^..- '....-_ ..i:~: ..
u;.trumentatiun tines nut reliabl\• ,uanntee~prolnp: d2tec::un. Ti~erefure, the
>peat tile! pool level and temperature insttvmentac:un ac e'.•2ry nuc':ear pu\~er
pLlnt. u~cludin;~ those facilities permanently closed !^ut retauurn_ ir-..-tdiated foe!
assemblies in thr:r spent foe! pools, ~htluld br evaluated to t:uniir^^.~ that adequate
_ muniturin;~ capability exists under ail drsi'n cunditil\ns.
The second defense-in-depth la\•er minimves Nor c^ar.t:~~ Naar ,:r, accaieai
results 111 tllel d,lm.l,~e. Irradlatcd toe! a~~2:nbiies in _~rnt ':a'' ^t)l):~ ,ire ^rt':2~~'
z•.i from Itlel t{,ltll,l~~~ ,1~ lttll~ ,1~ the', .l re :uyert'd t\'ltt; t ;:~~'. ~'. ~!1 1. :!'.a `.\'.lt~•' L`
:'t'l:ln~ ~UCle,lr ptt\\'2.' pl,lnb ,let' dc'~1_ i \\!th b ^ ,. ! t ~!
let .iii :2^t t:l ~:t :11•` -
:r:a~ Ur 2lllt'rL'-.li'. ~\'~Ct::11~ :11,11 cn'\ ItiC mal.2uc ,a''•`. ., .. ,`ttlll: 'e:.. ...~:
,''tti ~.Iltt'ftll!l,ltc'!\ tilt' It\i.lt:ttil .tt silt' ~F''"1! tllt'l r't`t.`L` ,. ::1 :2'..`:11:.1C'.~ ~,'tl-
7:
31
NuC'°7, Wes,' ~•_~CS~ Cn5i5
Cha~t:r ~- • J~'IVtl1Q r(72 . y
ent at m t ~~\ (~ F~I,l tl t5 ~h 1llCll ~l'~ thl` s~CCtnd lad er. Full~~\~ tn_ an ,li~l~~~at
tainm `,; 6 ~ \. , -tar, tram ~nt-
in\'ol\•~g fuel d~ma~,e, rodt.~qun lr:el~ ma\ F re ent tht ~ prrattn\\•\t`[;~ It the
rile backup ax~lin~ :\•stem and tlla rnlcr,.:e[l~7• mal.eup .
tin tin ~
spent fuel poo\ erect and\dann~~eduThe1ep~ ~d~e~~phullcc~nfi`~ ur.~ urn' at e\ ~•'\.
tualh• be un~
nuclear po\:er plant` Pind~maktuth~6`i[,11` }?an be Ftrfurnled\un~i~r[allr~irtll~
the necessan• coulttl_ . F
conditions. -
The major dtEference brt\: een ~p~nt fuel >tura,e ~t 1'~~ ~ atld 6~~~(. punt. t~
the pre`ence of a Euel it r111lent he l`a ~embite> beuau,~e`tld\,lare acre . te~1 t:.~tn'
nels often remain un p
e,~cposure in the rea;t`ldicate that[st rnt[fue!lc sh [`' reduced t\\ henllirr ~iiated furl
assemblies. Stvdte_ u F
assemblies are stored `col a c dents shoal tlbe ~\ ~luat a andtllFpreF~ isle ~ien~:l
mitigaring spent the p
lion pro~•ided to B~~`R ~`V rnn is and sttllhZ t'tntatntthej o~ ~,d d et tree-yncdepth
stored without their tt. e
protection la~•er.
The drv storage ui sF~rnt ntel 1ss~mVllC` m\'Ul:es less ri~i. than \:et ~ \~n_~
of spent fuel assemblies ul spent fuel pvul` br, ll` tl>< t tee ~,`~`Mall: al dr~e nura'e
leading to fuel dama~,N. E~penence has _h.
cask or module is detected ~:[ih some pii\•-t~a1 imp~riecti~,n t.lat
repair Or re^laGdnlen[. It apF'ear~ ~redibir t111t d dill` It La?h l'r 111~~d111C ~~~l:la
require replacement after bean, luaued \\ tth trra.:iatrd rut! .>>~ra~hhr> Tneren're
serious considerahun :huuld be ~t\ cn to re~lt::nn II~~1C~ t'n~i~':;t reel ;.erne t,l~ll ;
ities featunn, dr: ~t~,ra_e tt' ha\ e the c, pay titt\ to t:amter the tr:a~ iate~i fuC:
asSembhe~ In the Iaruest, ~InLIe ~a~h Jr 111~,~:ul~ tV Utlltr >tUra~<` Illc'~ll,l The >c`~-
ond defense-in-depth ia\ er applied tee dr\• ~t;~ra=e re~~utrer tht~ nuh~_an\n~ ca}'<<-
bilit~~.
The thud defen~a-m-drF'th la\'er mt[umtzt= the ~han~r> the t tine '.~~iti`a~tt\
itv caused b\' an a~adent re~ulttn~ In loci dama,e l? rules?t'~i IIl .lnlt'lI.1C~ h.lrtll-
ful to the pubic. 1'iu\~ u\ ur, tt thu ~prnc foul r ~,~~1 '~ \~il> at a E1~ R
tainmunt nla\• Earl due tr I\1':h tenlF~tratUCr. hlillll~..ll\. .ln~i 1~~I1~lUn'`,n[lC`ll th.lt`~
The design of e\•ur\ nuclear p\,\~ rr F'iant >iu~uid hu e\ aluatud t~
, ~ n~~t ~Jlll' R nll>c alt thlr: ~{~•t~~~~~~-II\-~i~, tl\ ..l\t'r
r' '
boiling spent ruel ~i,l~l ~~ t'. ~ ~ r rLlt•l .1~~c". ll"•\• >t~ r.l•_~
I '
The post to e\t~:ui .tll ~ie:cttx-ui-du~a,l la\:;` tip .F u•~t _ ,v`tt[~ : ~ .~I~t•~t:,~~••
at nt:Cllar F~~l\\'l'T F'+Ia11t ~IIC> ~ :nn~d hl' LTCilil.lllC~; Un, it Ihu `\ 111 11 ,I Ill't".i ;. ~{~' .11,'.
are ~anlpiuted to ~iur:n~, thu ~~~,F'~• ut ~",rl.. ~,.:tt\ F Ling .
tllin~, tv a~~ure Chu :n[~••_rl•\ ,~[ thu th:r~ la\:r. ~.~ntu F'Ltnr . ~\
• ~ .,.• ,, •t .l.inu:
ruceduru> am teat: ~ ~~ •~~t~• ~~ :'[
istrat;\•e ~cnurt,i> t, ~ .t\ • n~i "~tunt;al rt.
iuul r\x,l tn~iri[111C:1[.ln,~a -\tl~l ~~~tn~ f ia::t- r;.t\ n~•~• " ,. t;~.,l •_
mu~iu[ratu~n> '~~ a~-ur: .;~~ a~atlai'ti:[\ ~~t a .'a.~~~:' "^~i:n•,
~\•~tctn.
32
Nuclear Wane Disposal Crisis
The cost of nut extending defense-in-depth to tipent fuel assembly storage at
nuclear pu..'er plant sites will range between Three Mile Island and Chernobyl
magnitude if a major accident happens at a facility where the second and third
laver of defense-in-depth are compromised. The Susquehanna concerns repre-
sented credible sequences that penetrated the second and third lavers fur a design
basis loss-uf-coolant accident with pustulated cure damage.
A major reactor accident like Three Vlile Island may never happen again
because the tint and second lavers of defense-in-depth combine to significantly
reduce this probability. But nuclear pu..•er plant operation in this country is pred-
icated on the knowledge that even if such an accident occurs, and e~•en if emer-
~encv systems fail to mitigate the accident and prevent fuel damage, containment
pro.'isions are in place to protect the public.
It is imperative that the nuclear pu..•er industry apply defense-in-depth
principles to spent fuel risk as rigorously as they are applied to reactor operation.
If the cost to achieve spent fuel risk defense-in-depth protection is prohibitive,
Congress must implement legislation that enables the Nuclear Waste Fund to
finance implementation of necessary safety measures. After all, the Nuclear
Waste Fund ~.•as established by the rate pa~•en of utilities with nuclear power
plants. These rate payers have the spent fuel assemblies stored at these plants in
their back yards. Defense-in-depth protection, strung in theory and dem~nstrat-
ed effective at Three Mile Island, will resol~•e the crisis in nuclear waste disposal
and make these back yards sate.
1 \udear Fagulatun~ Cummueiun. "Fepurt un the .~cddent at the Chernobyl Nuclear Po..•er
Station." \'tr'REG-131 Rev 1. December 1QH~. p. 3-%.
it a important to dishnl;vish brn~•ren dn• uurae...•here irradiated fuel assemblies that hate
undergone se.•eral .•ean of rediuacn.•e deca.• are placed tntu hea.•tiv shielded casks, and an
accident drarning the ~.ater from a ~prnt fuel p.wl...~here irradiated fuel assemblies pose
~anuu: rodianun r.powre hazard. and :Quid .utter damage.
~ u,u
33
r•
Appendix A
k '
`~ -~ Spent i=ue! Incidents
4.
3-_ ..
~' The following incident summaries supplement the discussion of spent fuel
risks presented in Chapter 8. These summaries provide a representative sampling
~~of the types and potential consequences of incidents that have occurred in the
~, nuclear power industry.
Sea! Failures
~. '. September 1972: An inflated seal at the transfer gate on the Point Beach Unit
~1 spent fuel pool deflated when its air supply failed. Nearly 1?00 gallons leaked
:s~ from the spent fuel pool, although no irradiated fuel assemblies were in the pool
at the time.
.r:.:
~; ~.;,- October 1976: An inflated seal at the inner pool gate on the Brunswick Unit
a;: 2 spent fuel pool deflated due to an air leak and a power failure for the air com-
~. ~ressor. The leakage caused the SFI' level to drop five inches.
~~ ' ~~ June 1980: The inflatable seal at the transfer gate on the Trojan spent fuel
pool was not properly inflated prior to draining the refueling cavity. The leakage
atcaused the SFP level to drop ten inches below the minimum level permitted by
,' .,..
thN plant's operating license.'
:~-~~ May 1981: After draining the fuel transfer canal with the transfer canal door
`:~~'closed and the door seal inflated on the Arkansas Nuclear One Unit 2 spent fuel
;usu.
' pool, maintenance on the air system interrupted air supply to the seal. The leak-
age caused the SFI' level to drop seven feet until the water levels between the
.; ....
=spent fuel pool and the fuel transfer canal equalized. If the seal had leaked with
the-fuel transfer tube gate valve open and the Euel transfer tube blind flange
• removed, the spent fuel pool could have drained down to just above the top of
~` ~ 171 .
e irradiated fuel assemblies:
~. October 1984: The inflatable seal on the gate between the San Onofre Unit 2
.spent fuel pool and the spent fuel shipping cask pit deflated following an air com-
~assor failure. The backup air compressor failed to start. Nearly 20,000 gallons
leaked from the spent fuel pool and dropped the SFP level 19-1/2 inches
although no irradiated fuel assemblies were in the pool at the time.'
~+.: •-
a~ December 1987: A valve in the return line to the refueling water storage tank
~wa~t Wolf Creek was inadvertently left open, allowing the SFi' level to drop to a
!~mirumum of ~? feet over the irradiated fuel assemblies during the next two days.
~.~he problem was not detected by the operators because the SFP level alarm was
~~ operable at the time.'
~~'.; ..
t65
34
Nuclear Wasie Disposal Crisis
(V[av 1988: The refueling cavity water seal at Sorry Unit 1 failed with the
reactor core fully offloaded into the spent fuel pool. The leakage dropped the SFP
level about three feet.`
October 1988: The air supply line to the inflatable seal on the transfer canal
dour at Sorry Unit 1 experienced a pinhole leak that was quickly detected and
repaired. At the time, the fuel transfer canal was drained, the fuel transfer tube
was open with the blind flange removed on the containment side and the gate
valve open on the spent fuel pool side for testing in preparation for an upcoming
refueling outage. Virginia Power determined that the spent fuel pool could have
been drained to within 13 inches of the top of irradiated fuel assemblies in the
storage racks. The radiation field on the refueling floor was estimated at 50
Rem/hr in that condition. If this postulated event occurred shortly after refueling
instead of just prior to refueling, the radiation field would have been significant-
ly higher.°
Loss of Fue! Pool Cooling
January 19Ti: A power interruption lasting two hours shut down the cool-
ing pump for the spent fuel pool at General Electric's Midwest Fuel Recovery
Plant. The outside temperature ~.•as -19°F at the time. When the power was
restored, it was quickly discovered that a pipe in the cooling system had Frozen
and ruptured. The cooling system remained shut down for several weeks ~~•hile
the piping vas repaired. Decay heat from the irradiated fuel assemblies heated
the pool to an equilibrium temperature of 115'F. The humidity in the building
rose to an uncomfortable level, but otherwise this incident had nu adverse impact
on either plant personnel or the general public.
tV[av 199?: A spent fuel pool cooling system failure at Comanche Peak Unit
1 went undetected for 17 hour until the VRC Resident Inspector noted discrep-
ancies behn~een log entries and control room indicators. Both Unit 1 spent fuel
pool cooling trains were discovered to be inoperable. Texas l-'tilitn~~ ~~iectnc
Company had to use touting water from the unfinished and untested l_ nit . to
cowl the Unit 1 spent fuel pool.'
June 1993: Cooling water to the spent fuel pool heat exchanger at South
Texas Unit 2 vas inadvertently lost. This event remained undetected fur 13 hours
during a refueling outage with the reactor core fully off-loaded into the spent fuel
pool. During the transfer of electrical power buses for maintenance activities, the
component cooling water (CCW) system momentarily experienced a spurious
surge tank low level signal. The signal closed the CCW supply an~i return ~~alves
to the spent fuel pool heat zxchangers. The fuel pool cooling s~•~tem pu~;~p, c~n-
tinued to dreulate ~~'ater through the heat exchangers altliuugh nu heat removal
~.a: rccurrin~ The SFP heated up from 99°F to 115'F during the 1? h~~ur~
October lyu ~. Cooling ~.ater to the spent fuel pool heat r~~h.u~:;er~ at Farley
1. nit ? was mistakenly' uulated fur three hours during a refueling vuta~;e ~~ nth the
160
35
Appendix A
~.'.
~•:
r.
reactor core fully off-loaded into the spent foe! pool. During motor-operated
-valve testing, the outlet valve on the in-service CCW heat exchanger was closed
°jinstead of the outlet valve on the standby heat exchanger. The SFP heated up
ifrom 90°F to 130°F in three hours. The annunciation of high SFP temperature at
'i'K130°F alerted operators to the problem. Spent fuel pool temperature peaked at
nearly 140°F before cooling flow could be reestablished.
"~t`~~ February 1995: The fuel pool cooling system at Indian Point Unit 3 was out
;~of service for 2 hours and 15 minutes after a crane outside the Indian Point 2 pro-
:~tected area caused the 138 kV off-site feeder line for Unit 3 to arc. The emergency
.,;.
,diesel generators started and supplied power to the safety related equipment at
~~the plant Following off-site power restoration, the nonsafety related fuel pool
~ cooling system was returned to service.
Radiation Overexposure
~~~;•• Before 1972: An irradiated fuel assembly being withdrawn from the reactor
mre was inadvertently raised to ~•ithin four feet of the water's surface. As the
Euel assembly reached the normal upper limit position, the operator released the
hoist's 11P button. The hoist continued to raise the fuel assembly until the opera-
tor pressed the STOP button to de-energize the hoist motor. The radiation level at
the operator's location was estimated to be 125 mr/hr with the irradiated foe!
assembly at its maximum height. Investigation disclosed that repetitive jogging
of the hoist had welded the UP relay contacts closed."
~~'~• April 1978: Two radiation protection technicians at the Trojan Nuclear
+^'
Power Plant received whole body radiation doses of 27.3 and 17.1 Rem while per- ._
forming a survey adjacent to an exposed section of the spent fuel assembly trans-
'fer htbe.10
...
;~ f ; March 1984: A diver repairing the fuel transfer upender at the Palisades
Nuclear Generating Plant received an exposure of about 4.5 Rem to the right
'thigh during a three dive series. The diver kneeled in a radioactive sludge layer
. ~;;
on the tilt pit floor."
Fuel Handling
~~ 1971: An irradiated fuel assembly became disengaged from the fuel han-
h• .'_
Yelling tool and dropped approximately 10 feet into an empty fuel storage position
A~. »..
during fuel transfer operations at a PWR. Visual examination did not disclose any
" ~ ' .
y discernible damage to the fuel assembly. The fuel handling tool's top edge
showed some slight galling that prevented the tool from properly latching the
~'ftiel assemblv.'=
i; ..-
~<`'~- January 1974: While an irradiated fuel assembly was being transferred from
~~the reactor core to the spent fuel pool at the Pilgrim Nuclear Plant, the main refu-
~~eling grapple loti~ered ti•ithout the operator's kno~~ledge. The fuel assembly
,'struck the reactor pressure yesse!'~ side but ~.•as nc~t damaged. Investigation dis-
r•
,:
4~
~F'
~;. ~ 6
36
Nuclear Waste Disposal Crisis
closed that the rctc~rn-to-norrrarf spring in the grapple's control circuit had broke
After the operator raised the grapple to the fully retracted position and released3'
the up-down switch, the switch fell through the neutral position to the down pps1='~
lion due to the broken spring, causing the grapple to lower.
January 1974: While transferring an irradiated fuel assembly from the s ~-~
fuel pool to the channel inspection facility at the Pilgrim Nuclear Plant, thee``
assembly became detached from the main grapple and fell approximately 20 ~"~
to the bottom of the spent fuel pool. Examination of the fuel assembly revealed;
that its channel slipped down over the nose piece and that the impact rnyShed t~`'~
nose piece and lower end of the channel There were no indications of broken fuel'
rods, and the fuel pool liner did not suffer damage. The grapple hook ma "~
have been completely latched under the fuel assembly's handle allowing tlie~
operator to lift the fuel assembly with only a friction grip on its handle." ;~~
January 1977: A fuel assembly was inadvertently released from the
at Peach Bottom Unit 3 and fell across the core. The assembly's release was~attrP'1~.+
uted to inadvertent operation of the grapple open switch when the refueling m
controls had to be rotated away from the operator in conjunction with a slack
cable signal when the fuel assembly nose cone contacted the core as it was being
lowered, thereby satisfying all the interlocks for the ~.,~
May 1977: A fuel assembly and mast were inadgveztenltly dropped at DYS ~"~,.
Creek while lowering the assembly into a storage rack The fuel and mast move
ment were arrested by the able brake drum, without further damage, when the
operator released the grapple lower lever. The drop resulted from shearing siz`~
bolts that coupled the refueling mast speed reducer to the cable druai.''c~
Examination indicated that all but two bolts had previously failed." F,
t..
December 1979: A new fuel assembly was dropped at Pilgrim while it was;
being transferred to its storage location in the spent fuel pool. The assembly wash
being transported with the reactor building overhead crane when it struck the top
edge of the high-density fuel racks and the latching device on the auxiliary hook
failed to retain the fuel assembly lifting bail. The assembly fell, striking the lifting' ~.~"~
bails on four spent fuel assemblies, then coming to rest on the top of the storage .:
racks. The four spent fuel assemblies were not damaged. Spent fuel pool water .q
samples were analyzed with no discernible change in activity levels detected." ~=>
March 1981: During refueling at Millstone Unit 1, a new fuel assembly was
dropped onto the upper core grid. It had just been placed in a core location. In the
process of removing the fuel grapple and telescoping mast from this fuel assem-~'"
blv the latching mechanism did not fullv retract. Upon retraction of the mast, the
fuel assembly was removed from the core in an unsecured condition to a point '
just above the upper core grid where it became loose and fell onto the upper core's
grid, coming to rest in a diagonal position about 3~~ above the horizontal. The
operator failed to detect the fuel assembly on the grappie.because he did not per-
form an adequate rotational check of the telescoping mast before raising it.
Y
~-~= 16d
~~: `..
-m~L:
~'.,'s, .
¢_~~: ,
~:<..:
!q~.:,, :~ ~:
.`~"~ ~
-~
ti
`::-7P
~:L
'~ _
a.,,
ai
37
Appendix A
~' June 1981: A spent fuel assembly at Donald C. Cook Unit 1 was damaged
o when its lo~•er end struck a ledge outside of the reactor pressure vessel. During
lifting of the fuel assembly from the core, the two air lines and the electric cable
serving the gripper tangled and caught the gripper-tube-up position switch, clos-
~' ing it before the gripper tube and attached fuel assembly were in the full-up posi-
lion inside the canister. Closing the switch cleared the interlock allowing lateral
n;, movement of the manipulator crane. The lower end of the fuel assembly pro-
-
~, traded below the canister and it struck a ledge on the refueling cavity floor just
outside the reactor pressure vessel area. Several fuel rods in the assembly were
~° damaged ~•ith one fuel rod dislodging from the assembly and falling onto the
n reactor cavity floor.'"
i February 1986: An irradiated fuel assembly was inadvertently lifted from
E the Haddam Neck core when the upper core support structure was removed
f from the reactor vessel. The irradiated fuel assembly stuck to the structure
c because of a bent fuel assembly locating pin. AS the structure was moved lateral-
ly, the assembly struck the core barrel and dropped two to four feet onto the core.
The dropped assembly and the two irradiated fuel assemblies it impacted were
4 damaged."
June 1994: While lowering a fuel assembly into the Quad Cities Unit 1 reac-
e for core, the lower end-fitting caught on either the edge of the control rod blade
guide or the upper core grid plate. The operator did not notice that the lower end-
= fitting was caught and continued to lower the fuel assembly. A fuel handling ver-
ifier noticed the problem when the fuel assembly was leaning 45° to 65' from ver- /
tical and notified the operator. The fuel assembly was raised, repositioned, aril
~. inserted into the core. After inserting the fuel assembly into the core, the refuel-
', ing grapple would not release from the fuel assembly's bail handle. The fuel
;assembly was returned to the spent fuel pool. Inspection determined that the
refueling mast grapple would not release because the bail handle had been bent.
No other damage to the fuel assembly or adjacent core components was identi-
fied.
:;~ May 1995: As a storage cask loaded with 40 spent fuel assemblies was lifted
out of the Prairie Island spent fuel pool, an overload device actuated to stop the
~r. .
w'ane's movement. The storage cask's bottom remained three inches below the
f top of the spent fuel pool's walls. The loaded cask remained suspended over the
spent fuel pool for nearly 16 hours until station personnel manually bypassed the
overload interlock to permit the crane to resume lifting.
~.,
`~~' June 1995: The lower tie plate and 41 fuel rods separated from the upper rie
plate and the remaining eight fuel rods while an irradiated fuel assembly ~•as
`.being relocated ti•ithin the Oyster Creek spent fuel pool. The fuel assembly had
~: operated in the Oyster Creek reactor during the 19i0s before being discharged in
~, April 1980. A similar event occurred at Ouster Creek in 1986. Following the earli-
:~ er event, the fuel rods ~-ere remo~•ed from the broken fuel assembly and placed
~• into a defecti~•e fuel canister.'
169
38
:lean Waste Disposal Crisis
1. E. D. Thrum, Nuclear Regulatory Cummrssron, "Regulatory Analysts for the Resolunun of
Generic Issue 82. 'Beyond Deign Basis Accidents in Spent Furl Puuls'," NUREG/CR-U53,
April 1989, Table 4.6-1.
2• Nuclear Regulatory Commission Information Nuttce No. 88-92. "Potennal fur Spent Fue! Poul
Drainduwn," November 2_'. 1988.
3 J. G. Haynes, Station Manager, San Onofre Nuclear Generating Station. Southern California
Edison Company, to Nuclear Regulatory Commission. "Licensee Event Report No. 84-060 /
San Onufre Nuclear Generating Stattun, Unit 2," November 3. 1984.
r 4. Nuclear Regulatory Commission Information Notice No. 88-65, "Inadvertent Drainages of
Spent Fuel Pools,"August 19, 1988.
~ W. J. Fulev, R. S. Dean, A. Hrnnick, Parameter Inc., Nuclear Regulatory Commission Report
NUREG/CR-i525. "Closeout of IE Bulletin 84-03: Refueling Cavity Water Sral," June 1990.
6. Information Notice No. 88-92.
7 Nuclear Regulatory Commission, "Final-Generic Environmental Impact Statement on
Handling and Storage and Spent Light Water Power Reactor Fuel," NUREG-0575 Volume I,
E:cecvtive Summary and Tert, August 1979, pp. 4-21 and 4-~?.
8. "Staff Has Proposed Fining Teras Utilities Electric Cu.," Irrstdr NRC, August 10, 199?
9 Atomic Energy Commission Reactor Operating E:cprrience 72-1, "Fuel Handling Incidents,"
January 14, 1972.
10. Nuclear Regulatory Commission !E Buliettn Nu. i8-08, "Radiation Levels from Fuel Element
Transfer Tubes." June 12. 1978.
Il. Nuclear Regulaturv_ Commission Infortrtation Notice No. S~i-bl, "O.•ere~cpusure of Diver in
Pressurized Water Reactor (PWR) Refueling Cavity," August 8, 1984.
12. Operating E:cperience iZ-l.
13. Atomic Energy Commission Reactor Operating E:cperience 74-18, "Fuel Handling Problems."
June 17. 1974.
la. 'Nuclear Regulatory Cummissiun IE Circular Nu. 7i-12, "Dropped Fuel Assemblies at BbVR
Facilities," September 2U, 19T'.
15. Nuclear Regulatory Cummissiun Information Nuticr Nu. 80-01, "Fuel Handling Events."
January 4, 1980.
16. Nuclear Regulatory Cummissiun Information Vutice Nu. 81-?3, "Fuel Assembly Damaged
Dur to Improper Positioning of Handling Equipmrnt," August 4. 1981.
li. Nuclear Regulatory Cummissiun Information Vutice Nu. 86-58, "Dropped Fuel assembly,"
July I1, 1986.
lY Deborah Cuumbr. "Ouster Cnrrk mishap is termed nu threat." Tlrr jtnr-(-a•d~r•r. June I;, 199=.
p. 2l. and
Neil A. Sheehan. "tiuclrar pl.tnt t.urkin;4 un rrtuvrrv ut u.cti! furl nn1s." .4•(~uni !'drk Pn~s.
l70
>.~- -_ -
Reactors 39
4.2.E Isolation Condenser System
Reliability, 1987 - 1993
AEOD/S96-O1
See Section 3.2.2 of this volume.
4.2.6 Assessment of Spent Fuel Cooling
AEOD/596-02
As a result of questions that had been raised
about the adequacy of spent fuel pools (SFPs),
the Executive Director for Operations requested
that AEOD perform an independent study of the
likelihood and consequences of an extended loss
of SFP cooling. AEOD staff conducted an
extensive review of more than 12 years of
domestic and foreign operating experience data;
visited six nuclear sites (with nine nuclear
power plants) and the headquarters of
Pennsylvania Power and Light, the operator of
the Susquehanna Steam Electric Station (SSES);
and met with contract engineers who had
submitted a 10 CFR Part 21 report about
potential defects and noncompliances at SSES.
The staff reviewed previous SFP risk
assessments and contracted with the Idaho
National Engineering and Environmental
Laboratory to perform a limited PRA of the
SSES SFP. AEOD also performed independent
assessments of the electrical systems,
instrumentation, heat loads and radiation levels
associated with the SFPs.
On the basis of the study findings, the staff
concluded that loss of SFP coolant inventory
greater than 1 foot has occurred at a rate of
about 1 per 100 reactor years, and loss of SFP
cooling with a temperature rise greater than
20°F has occurred at a rate of approximately 3
per 1000 reactor years. The consequences of
these actual events have not been severe.
However, events have occurred that have
resulted in the loss of several feet of SFP
coolant level and have lasted more than 24
hours. The primary cause of these events has
been human error. Both the likelihood and the
consequences of loss of SFP cooling events are
highly dependent on human performance as well
as individual plant design features. From their
review of existing SFP risk assessments, the
staff found that the relative risk from the loss of
spent fuel cooling is low compared to the risk
from events involving active fuel in the reactor
vessel.
As a result of this study, the staff has
determined that the typical U.S. plant may need
improvements in SFP instrumentation, operator
procedures and training, and/or configuration
control. The need for specific corrective actions
should be evaluated for those plants where
failures of reactor cavity or gate seals or
ineffective antisiphon devices could potentially
cause sufficient loss flf SFP coolant inventory to
uncover the fuel or endanger makeup capability.
The need for improving configuration controls
related to the SFP to prevent and/or mitigate
SFP loss of inventory events and loss of cooling
events should be evaluated on aplant-specific
basis. The need for plant modifications at some
multi-unit sites to account for the potential
effects of SFP boiling conditions on safe
shutdown equipment for the operating unit,
particularly during full core off-loads, should be
evaluated on aplant-specific basis. The need for
improved procedures and training for control
room operators to respond to SFP loss of
cooling events consistent with the time frames
over which events can proceed, recognizing the
heat load and the possibility of loss of
inventory, should be evaluated on a plant-
specific basis. The need for improvements to
instrumentation and power supplies to the SFP
equipment to aid operator response to SFP
events should be evaluated on aplant-specific
basis.
4.2.7 Emergency Diesel Generator Power
System Reliabiiity,1987 - 1993
AEOD/S96-03
See Section 3.2.1 of this volume.
4.3 Engineering Evaluations
4.3.1 Motor-Operated Valve Key
Failures
33 Reports
42
North Carolina to be stored at the Barnwell site. That waste is generally generated by the medical
community.
The high level nucleaz waste in question at Shearon Harris consists of the spent fuel rods from a nucleaz
reactor itself. Waste or spent fuel rods are the result of the process of nucleaz or radioactive decay
during use. Through the decay process, the fuel rods lose a great deal of their initial capacity to produce
a sustained high level (but controlled) nucleaz fission reaction (which produces the enormous quantities
of heat that aze used to make steam that turns or powers steam turbines which produce electricity).
Though still quite hazardous, in terms of radioactive emissions, the spent fuel rods are typically stored
on site in a "temporary" storage pool. These pools aze large in-ground concrete containment structures
which were originally designed to temporarily hold the spent fuel rods (that aze held in concrete and
metal casks) submerged under water. The water serves to reduce or absorb the heat generated by the
rods and prevent the escape of radioactivity. In the original strategy for dealing with the spent storage
rods, the federal government was to provide along-term high level radioactive waste storage site at
Yucca Mountain, Nevada. The on-site temporary storage pools were intended to hold the spent fuel rods
until arrangements could be made to ship them to Yucca Mountain. The federal government has not
constructed the Yucca Mountain storage site and it does not appear that it will be able to provide high-
level radioactive waste storage at any time in the near future. Nuclear power plants have been forced to
provide long term storage for their spent fuel rods in their temporary storage pools.
There are numerous elements of concern, not necessarily specific to the Sheazon Harris site, related to
long .term storage of spent fuel rods at temporary storage sites. Those concerns relate to: 1) loss of
water from the storage pool which could lead to superheating of remaining water and an atmospheric
release of radioactivity; 2) loss of water allowing the formation of a critical or neaz-critical mass and
melt-down of the still highly radioactive fuel rods that have been stored in a facility containing more
nuclear material arranged in a more densely packed configuration than was originally anticipated in the
design for the temporary storage facilities; 3) increased likelihood of radioactivity releases due to human
error caused by greatly increased levels of nuclear materials handling. activity and tighter quarters in
storage areas; 4) increased likelihood of radioactivity release due to the increased levels of handling and
shipping of nucleaz materials between nucleaz power facilities, etc. These concerns are exacerbated by
the public perception that there is no such thing as a minor nuclear accident. There aze also serious and
widespread public concerns about the efficacy of the Nucleaz Regulatory Commission's (NRC) use of its
rules and its enforcement activities as it is both the primary nuclear regulatory agency and one of chief
proponents of the use of nucleaz power. The adequacy of NRC rules and standazds related to storage
pools has also been called into question, because the pools were, after all, intended and designed to
provide only temporary storage.
CP&L has been storing spent fuel rods on-site in its temporary storage pool at Shearon Harris since the
facility's first refueling operation. According to CP&L, the Sheazon Harris plant it is the newest nuclear
facility and contains the most modern and up-to-date technology. Accordingly, CP&L has designated
(and apparently used) the Shearon Harris plant as its storage site for spent fuel rods from its Brunswick,
NC, and Robinson, SC, nucleaz plants as well. The original design for Sheazon Harris called for four
reactors. This was later scaled back to one reactor, but at least some of the construction was completed
for four temporary fuel storage pools. Two were completed and put into operation while two others
were left incomplete. CP&L contents that the safest and most economically feasible strategy for storage
43
of spent nucleaz fuel rods from all of its plants is to complete the two pools at Shearon Harris and
continue using Shearon Hams facilities to store all of its spent fuel rods. CP&L has petitioned the NRC
for permission to complete construction of the storage pools at Shearon Harris. The fuel storage
capacity at Sheazon Harris is, according to CP&L, intended solely for its own use and CP&L will not
accept spent fuel rods from other utilities.
In summary, the primary elements of the controversy surrounding the Sheazon Harris plant stem from:
1) the past, present and future use of Shearon Harris as a long term storage site for high level radioactive
waste, an existing practice and future plan that were essentially unknown to the citizens of this azea until
recently; 2) the proposal to increase both the capacity and utilization of on-site storage; 3) the use of
Shearon Harris to store radioactive waste from other areas; and 4) the number of people living in the
nucleaz accident impact azea (that azea within a fifty mile radius of Sheazon Hams). CP&L is
appazently very sensitive to public reaction from both the general public and local governmental entities
to its waste storage proposals and plans. A spokesperson from CP&L's public affairs division met with
BOCC Chair Brown and myself to discuss the situation at Sheazon Harris and CP&L's proposal. An
offer was extended to provide the elected officials and policy makers of Orange County with a guided
tour of Shearon Harris facilities. As the Sheazon Harris plant is currently shut down for refueling, the
tour was proposed for some time in eazly January 1999. The purpose of the tour would be to:
a) demonstrate CP&L's high level of concern for and expertise in safety and security matters at the
plant; and b) reassure elected officials that CP&L is not proposing a storage strategy that would pose a
danger or a threat to the citizens of this azea. It also appears that CP&L may hope to persuade the
BOCC to let CP&L make its case to the Boazd before the Boazd adopts a posture similaz to that
evidenced by the Rosemary Waldorf/Chapel Hill Town Boazd and the Margaret Pollazd/Chatham
County BOCC letters to Wayne McDevitt.
If I may provide additional information or clarification, please advise.
44
ORANGE COUNTY BOARD OF COMMISSIONERS
A RESOLUTION REGARDING PROPOSED EXPANSION OF HIGH LEVEL
RADIOACTIVE WASTE STORAGE FACILITIES
AT CP&L'S SHEARON HARRIS NUCLEAR POWER PLANT
WHEREAS, on September 15, 1998, the Orange County Boazd of Corrunissioners were advised as to
plans for the expansion of the high level radioactive waste storage facilities at Cazolina Power &
Light's Shearon Harris nucleaz power plant in Chatham County; and
WHEREAS, the Boazd of County Commissioners have been apprised of the potential risks inherent
with the doubling of the storage capacity of the temporary storage pools for high level radioactive
waste for the purpose of long term storage of high level radioactive waste, not only from the Shearon
Harris plant, but also from two other nuclear power plants from elsewhere in North and South
Carolina; and
WHEREAS, citizens of Orange County who aze alarmed about the plans to expand the waste storage
capacity at the Shearon Hams facility and the lack of public input into the approval process for those
plans have requested that the Boazd of County Commissioners intervene in the plan approval process
on behalf of the citizens of Orange County to ensure that no such expansion occurs without the
public's knowledge and consent; and
WHEREAS, on November 9, 1998, the Orange County Commission for the Environment passed a
resolution asking that Board of County Commissioners request that an appropriate entity hold public
hearings in which Cazolina Power and Light will provide additional information about its plans to
expand its storage capacity at Sheazon Harris and respond to questions about long term storage of high
level radioactive wastes:
NOW, THEREFORE BE IT RESOLVED THAT the Orange County Boazd of Commissioners
requests that the North Carolina Department of Environment and Natural Resources and the Nuclear
Regulatory Commission conduct public hearings in which Cazolina Power & Light and appropriate
regulatory staff: 1) explain the plans to expand the storage facilities for high level radioactive waste at
the Sheazon Harris nucleaz power plant; 2) outline the risks or lack thereof and explain the risk
assessment methodology employed to develop risk projections related to the use of facilities designed
for short term storage of high level radioactive wastes for long term storage; 3) outline the risks or lack
thereof and explain the risk assessment methodology employed to develop risk projections associated
with the transportation and handling of materials from other distant nucleaz power generating facilities;
and 4) accept and consider public comments relative to support for or opposition to operating or
expanding such a facility in this azea.
This, the 17`h day of November, 1998
Margaret W. Brown, Chair