ML20205A753
| ML20205A753 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities, 05000000 |
| Issue date: | 09/02/1988 |
| From: | Morgan W COMMONWEALTH EDISON CO. |
| To: | Erickson P Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20205A758 | List: |
| References | |
| 5115K, NUDOCS 8810260087 | |
| Download: ML20205A753 (3) | |
Text
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. Commonwealth Edison
/
) One Fest Nabonal Paza. Chogo, larce
) Address Reply to. PosTOFde bot 7C
/ Ch cago, lanois 60690 0767 1
September 2, 1988 Mr. Peter B.
Erickson Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Dresden Station Unit 1 Response to Request for Additional Information Pertaining to the Emergency Plan Requirements for Dresden Unit 2 Fuel Storage NRC_DocknLMon dQ-10 References (a) P.B. Erickson letter to W.E. Morgan dated July 7, 1988 (b) D.L. Ziemann letter to C. Reed dated August 1, 1979
Dear Mr. Erickson:
In response to the above reference letter (a) Commonwealth Edison has reviewed the request for additional informutjon as ;utlined in the letter and provides the following esponses Question _11 What are the worst case skin doses projected onsite, in areas that would be occupieJ, and at the site boundary for a fuel rod rupture accident at Dresden 17 Responsei Dienden Unit 1 is officially retired from service and currently has a Possess-But-Not-Operate License, which prohibits retetor operation.
Additionally, the proposed Technical Specificitions prohibit ever loading the fuel into the reactor core.
The spent fuel is stored in the Dresden Unit 1 spent fuel pool, where it will remain until such time that a Federal Repository becomes available to receive the fuel. Therefore, fuel handling in the future is espected to consist of maneuvers in the spent fuel pool during rack inspections, or while loading a cask for fuel shipment.
In January of 1977, the NRC requested Commonwealth Edison to evaluate the previously unevaluated potential ecnsequences of a postulated fuel handling accident inside containment at Dresden Unit 1.
Commenwealth Edfson performed an evaluation, assuming that all the f uel pins in the equivalent of a single fuel assembly failed following the dropping of a fuel assembly onto the top of the core. Corresponding doses where within 10 CTR Part 100 Guidelines at the Exclusion Area Doundery. The NRC reviewed this evaluation and concluded that an evin more severe accident than that analysed by Commonwealth Edison was possible (Reference (b), attached). This could occur during refueling operations when a fuel transfer basket loaded with 16 fuel assemblies is transported down the fuel transfer tube using an overhead crane. Failure of the overhead during this operation could result in a failure of all the pins in the 16 fuel assemblies.
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. Corresponding doses, however, were still within the guidelines of 10 CFR part 100 guidelines at the Exclusion Area Boundary. This type of refueling accident was assumed to be most limiting. To complete their Safety Evaluation, the NRC also considered the case in which a spent fuel assembly could be dropped during maneuvers in the spent fuel pool. Their analysis resulted in the following statement:
"Analysis of dropping a spent fuel assembly during maneuvers in the spent fuel pool resulted in no calculated fuel pin damage to the dropped or target fuel assemblies."
Thus, it can be concluded from this Safety Evaluation by the NRC, that a fuel rod rupture would only occur during refueling operations, and not during maneuvers in the spent fuel pool.
Since refueling operations are prohibited at Dresden Unit 1, and a fuel rod rupture will not occur during maneuvers in the spent fuel pool, worst case skin doses (i.e. Beta dose due to Krypton-85 release during a rod rupture), do not apply.
Ques tlan_21 What protective actions would be implemen',ed onsite and offsite in the event of a worst case fuel rod rupture at Dresden 1.
l Responatt Th!2 question follows Question 1, and is based on a fuel rod rupture accident at Dresden Unit 1, which, as emplained above, will not occur i
as a result of dropping a spent fuel assembly during maneuvers in the spent fuel pool?
I Question _3t In the event of an emergency at Dresden 1, what licensee staff augmentation would be implemented?
i The license staf f agumentation w!!! be that which is required by the Dresden Station Emergency Program Implementation plan call out list, which varies with each emergency classification.
l l
Question _4t What are the Emergency Action Levels for a fuel handling accident at Dresden 17 i
I
Response
The fuel handling incident will be handled by a Site Emergency classification when area radiation monitors reach 1R/hr at the Unit 1 fuel 9
pool. This is consistent with new Generic EAL philosophy and EALS in place at our other Stations.
Question _Lt What are the Emergency Action Levels for a noble gas release at I
Dresden 17 Responset All Units at Dresden Station will be regarded equally with respect to noble gas releases.
Since all Unit stacks have system particulate lodine i
noble gas monitors and classification releases are related to dose rates, no distinction will be made between the Units.
i d
Implementation of the EAL changes will be accomplished during the implementation of the Generic EALS at Dresden which is targeted for March.
1989 contingent upon NRC acceptance of those EALS.
The initial review and modification process of the Corporate-wide Generic EALS will be started I
shortly at Dresden.
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Please address any questions that you or your staf f rnay have concerning this response to this office.
Respectfully, N
W l
W.E.ytorgan Nuclear Licensing Adrni.tistrator rf Attachments ces A. B. Davis Resident Inspector Dresden 5115K
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August 1,1979 Docket he. 5010 Mr. Cordell Reed Allistant Vice President Corronwealth (dison Co.mpaay Post Office km 767 Chicago,111tnois 60690 i
Lear Mr. Reed:
7,1977, we requested the Commonwealth Ed4 ton Company sy letter dated January 1 1he Reactor f a postulated fuel handling accident in to sutett an evaluation c involving he potential consequences of an attident Sutiding of Cresden 1.
1 the handling of spent fuol inside containnent had not been evaluetW previous dated March 18. 1977, you submitted en evaluation of for Dresden 1.
By lettereviewed your sutetttal and have concluded that although this accident. We have Pis are somewhat larger than estinted by you, they are exposure guidelines of 10 CFR Port 100 and are, therefore, the potential consequerc ep;ropriately within tne acceptable.
nluated the consequences of dropping the iW1 transfer We also indepeMontly ev The t fuel assembiles down the fuel transfer tube. single twndle cask Iceded with 16 spenident are core severe then the drop of t handling accident. The anstaptions used nd the conclusica consequences of this acc postulated in ycur fuel 10804 Safety that the potential consequences are acceptable are given in the e Evaluation.
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a.....,,. ' (.....c Dennis L. Ziemann, Chief Operating neesters trench d2 Division of Operating Rest ters inclosure:
Safety Evaluation cc w/ enclosure:
see next page
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Mr. Cordell Reed
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01 rector, Technical Assessnnt 1 sham, Lincoln 4 8eale 01visten Counselors at Law One First National Plaza, 42nd Floor Of fice of Radietten Pr4res Cn!cego, 111tnots 60603 (AW.459)
U. 5. Envirotusental Prt41petten Agency Mr. l. l. Stephensen Crystal Mall fl Plant Superintendent Arlington, Virginia IM40 Drescen huclear Power Station Rural toute el U. 5. Envirofunental Pr>tec tion Morris, 111tnots 60453 Agency U. 5. Nuclear Reguistory Cc mission Federal Activlties tranen Renton V Offi_g ATTN: Jtemy L. Isrker AT"N: 115 C00u0lkATOR P. O. 80 706 230 South CtWrn Street Mor.-is,1111 nots 60450 Chicap. tilinois 60404 Susan N. Sekuler Assistant Attorney Gent '41 K N C, Inc.
Environtsental Control O lvision ATTNt,;tenard E. Sch4ffstall 188 W. Randolph Street 1747 Pennsylvente Ave 9ue, N. W.
Suite 10$0 Suite 7315 Chicago. Illir.ois 60601 Washington, O. C.
20006 Norrts Public Library 404 Liberty 5treet Morris, Illinof s 60451 Chatru n losrd of $t,pervisors o" Grundy Cauity Grundy Conty Courtroule Morris, Illinois 6045-)
Departrient of Public Health ATTM; Chief, 01 vision of Nuclear Safety 535 Vest Jef ferson 5pringfielo, Illinois 62761 s
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?,1977. the staff requested the Conssonwtalth [dtlen o evaluate the previously unevaluated pot 6ntial const.
Sy letter dated January '
Conpany (the licensee)d Fuel Handling Accident Inside Containment (FMA!C5 at t
- ste sutruitted, in a letter dated March it.1EIn t an quences of a costulate Cresden Unit 1.
The lic llowing the evaluation of the FHAIC.the fuel pins in the equlyalent of a single fuel assm dropping of a fuel attenbly Cnto the top of tne core.Ps of this postulated accide d
he Exclusion Area loundary (CAS). The itsensee con.
l the potential consequenc 0.05 Rem whole body at tare well belcw the guide)1nes of 10 CFR Part 100.
cluded that these desas EVALUA110N I
1977 sulntttal and view of the licensee's March 18, d by the Itcensee are We have completed our reuquences of the accident postulate l
P 10 CFR part 100 and therefore are acceptable.
cencluded that the cens within the guidelines o r
ptations a fuel transfer basket is loadedl with 15 spent During the refueling opfuel assemblies and is then transported frem the north surp. to the fuel transfer Tailure of the tube and down the fuel transfer tuce using an overhead crane.
overbead crane during this operation could be a rore severe accident than Therefore, we analyzed the consequences of this l
accident assurting that all the pins in 16 fuel asse'tbites failed. The assumptions astred by the licenses.
The calculated poteettal doses and results of our analysis are given in Tab)e 1.
et, the (AB frci this af cident are 54 Rest thyroid and 0.4 Refs whole body dose.
7 Rens is within the guide 11nes of the 10.CFR Part 100 4
whole body doses are not controlling due to the decay The itntting dose of 50 Since.the refueling value of 1C0 Rom. The ettotects prior to fuel handling.
l crane is resitioned above the core or between the core and of the short 1tved rad-
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ifore this accident was not considered credible.
tastet during fuel han<
it.ssemir durinnaneuers in the inent fusi mi resunedj P onto tne core and ther P n damage to the dropped Cr target fuel assemblies, of drepping a 3,ent fu i in no Calculated fuel
.t.
(1) the limiting accident is the drop of the fully Our conclulfons are that:
loaded transfer basket deim the fuel transfer tube and (2) the postulated con-secuences of the limiting accident are within the guidellets of 10 CFA Part 100 and are, therefore, accepo,4 bl e.
ENVIILCNMENTAt. CON $10 ETAT!WS of an accident invc1ving the handling of spent fue)
The environrental impacts inside containment have been addressed in Section 7.1 of the Final Environmental State. ent (FES) dated Ncv inber 1973, for the operation of Dresden Nuclese Power t
Station Unit 1.
Date: August 1, 1979 9
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f F04 AND PatiNTI AL CONS:0V!NCF5 0F THE POSTU.ATED A$5tWPT]CNpDTII<
U f C ?eT$ AT THE rXCLU3 CN AREA 50VNDMY FUEL hA F 0il RE10EN STAT QN UN ;T l Assugi f ens t' Guldalce in Regulatory Gui<e 1.05 Power Level 700 Mwt Fuel l aposure Tine 3 yurs f
P ower Peaking Factor 1.5 f
(guiva lent Number of Assem-bli <s damaged 16 i
Mumber of Assemblies in 4M corn Char'.41 Filters available None Decay time before moving fuel 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1
0 2 hlwrs I/Q Valwe, Ex.
-4 3
nion Area losndary) clu wnd level releasa 1.0 x 10 Iset/m (gr 1
Dese$ Rt*
- Whole Body T_ hyret(_
Exclu11on Area loundary (EAl)
Conte@ences f rom Accidents les lde Centatant 56 04 r
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