ML17194A277
| ML17194A277 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/20/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Del George L COMMONWEALTH EDISON CO. |
| References | |
| TASK-15-20, TASK-RR LSO5-81-11-048, LSO5-81-11-48, NUDOCS 8111240720 | |
| Download: ML17194A277 (6) | |
Text
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Docket No. 50-23.7 LSOS-81 048
- Nove~ber 20, *198l
.:F' Mr.* L. Del George
( 1.
~ I Director of Nuclear Licensing Commonwealth Edison* Company
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- ~1\\V~
Post Office Box 767 Chicago, Illinois
- 60690
Dear Mr. Del George:
SUBJECT:
DRESDEN -2. *SEP TOPIC XV-20; RADIOLOGICAL CONSEQUENCES OF FUEL DAMAGING ACCIDENT L~
Commonwealth Edison (T. Rausch) letter dated October 15, 1981, transmitted for our review your safety analysis report (SAR) of SEP Topic xv.. 20.
Enclosed you will find our evaluation of this topic. The result of our staff's review indicates that the Dresden 2 plant is acceptably designed for controll fng and mftfgatfng the radiological ;:consequences of a fuel handling acciden~.
This evaluation will be a basic input to the integrated safety assessment for Dresden-2. unless you identify changes neede~ to reflect the as-built conditions at your facfl tty.
- The assessment may be revf sed 1n the future ff your facflfty*desfgn is changed or if the NRC criteria relating to this subject is. modified before t~e integrated assessment ts complete.
I
Enclosure:
As stated cc w/enclosure:
See next page 0111240720 81112P7 1 PDR ADOCK 050002~DR l
, p P1 Sincerely, Dennfs M.
Crut~hfield, Chief Operating Reactors Branch No.
Division of 1Licensf ng
- DL BHermann
_ wRussel 1 PO I Connor
' DCrutchfi el d GL as
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NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
Mr. L. DelG~orge cc Isham, Lincoln & Beale Counselors at Law One First National Plaza, 42nd Floor Chicago, Illinois 60603 Mr~ B. B. Stepherison Plant Superintendent
. Dresden Nuclear Power Station Rural Route #1 Morris, Illinois 60450 Natural Resources Defense Council 917 15th Street, N. W.
Washington, D. c. 20005 U. S. Nuclear Regulatory Commission Resident Inspectors Office Dresden Station RR #1 Morris, Illinois 60450 Mary Jo Murray Assistant Attorney General Environmental Control Division 188 W. Randolph Street Suite 2315 Chicago, Illinois 60601 Morris Public Library 604 Liberty Street Morris, Illinois 6045.:t--
Chairman Board of Supervisors of Grunqy County Grunqy County Courthouse
- Morris, Illinois 60450 John F. Wolf, Esquire 3409 Shepherd Street Chevy Chase, Maryland 20015 Dr. Linda w. Little 500 Hermitage Drive
- Ral~igh, North Carolina 27612 DRESDEN 2
- Docket No. 50-237
,i Illiriois Department of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704 U. S. Environmental Protection Agency Federal Activities Branch Region V Office ATTN:
EIS COORDINATOR 230 South Dearborn Street Chicago, Illinois
- 60604 Dr. ~arrest J. Remick 3.05 East Hamilton Avenue State College, Pennsylvania 16801 The Honorable Tom Corcoran United States House of Representatives Washington, D. C.
20515
- ~
-RESDEN, UNIT ;
XV-20 RADIOLOGICAL CONSEQUENCES OF FUEL DAMAGING ACCIDENTS...
- t; I.
INTRODUCTION The.safety objective of this topic *is to assu.re that the offsite doses
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from fuel damaging acc.idents as a result of fuel :*handling inside and out-t!
. side ~~ntainment are we 11 *within the guide 1 ine v~lues of 10 CFR Part 100.
II. REVIEW CRITERIA Section* 50.34 of 10 CFR Part 50, "Contents of Applications: Technical
- Information," requires that each app,1 ic~nt for a ';construction permit or operating licenseprovide an analysis and evaiua~ifon of the*design and i,
performance of structures, systems, and components of the facility with the objective of assessing the risk to public he~lth iiand safety resulting from
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operation of the facility.* A fuel handling accident in the fuel *handling and storage facility resulting in damage to fuel 'cladding and subsequent
. release of radioactive material is one of the pos:~ulated accidents.used to t;
evaluate the adequacy of these structures, system's, and components with respect to the public health and.safety.*
In addition, 10 CFR Part 100 provid~s offsite radjologica~ consequence
. -r; guidelines for reactor siting against which calcu~ated accident* consequences I
may be compared.
III.RELATED SAFETY TOPICS Topic II-2.C, "Atmospheric Transport and Diffus.ion Characteristics for Accident Analysis" prov1des the meteorological da~a. used for calculating the offsite dose consequences.
The review of the fuel damaging accidents_ did no,t consider fuel damage as a result of drops of the spent fuel cask or other,heavy objecti which can* be carried either over an open reactor vessel or tHe spent fuel pool. Review of the dr:;.;:s cf casks and heavy objects is covered, in two SEP Topics,.IX-2, "Overhead Handling Systems-Cranes~ and XV-21, "~pent Fuel Cas~ Drop Accidents."
IV.
REVIEW GUIDELINES I
Accidents resulting from the movement of fuel inside secondary containment.
were reviewed following the assumptions and-procedures outlined in Standard Re~iew Plant (S_RP) Section 15. 7.4 and Regulatory Guide 1 ~25~ The d0;se to an individu~l from a postulated fuel handling acci~ent should be **well within" the exposure guide 1 ines of 10 CFR Part 100.
(W~ole. body doses are also~
examined but are not controlling due to the decay of the short-lived radio-isotopes prior to fuel handling.) This is based on the probability of this event rel_ative to other events which a.re evalua~ed against 10 CFR Part 100 exposure guidelines. The review considers single failure, seismic design and equipment qualification only when the potential consequenc~s might exceed the guide 1 ines of 10 CFR Part 100 in the*. absence of containment
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I isolation and effluent filtration. The system design is considered to be acceptable if the limiting doses are well withifl the 10 CFR 100 guidelines.
V.
EVALUATION The assumptions used in this evaluation are summarized. in Table XV-20-1.
The fuel handling accident was considered assu~ing *that filters with an effic_iency_of 90% for elemental iodine were used an~ that the fuel was
- damaged 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s* after shutdown, a limitin~ tnyroid dose at the exclusion area boundary of about 3 Rem was calculated.
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The plant's Technical Specificatiorys r~lated to_:fuel handling in the *
- secondary containment provide for the required filtration of radioiodines *
. That is, all standby gas treatment system filtets in two redundant trains ~
. are required to be operable when itradiated fuel is handled in:th~ buildihg~.
The su.rveiliance requirements are sufficient to:*provide reasonable assurance that the efficiency will be as high as the 90% assumed in the-staff's cal cul at ions.
VI.
CONCLUSIONS
- .The limiting dose for the fuel handling acciden~ inside secondary containment
. indicates that the system is adequately designed-to mitigate the consequences of this type of accident.
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~ TABLE xv~20-1
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ASSUMPTIONS MADE IN ANALYSIS'. OF THE FUEL
. HANDLING ACCIDENTS INSIDE AND ou:rs~DE CONTAINMENT
- 1. Reactor Power 2527 MWthermal
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- 2. Clad failure of all rods in 2 assemblies. {724 assemblies in core)
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- 3. Re leas!: of gap i.nventory of a 11 failed rods:
10% I.
- 4. Peaking Factor 1~2*
10% Noble Gas 30% 85Kr s.* Meteorological conditions corresponding to a ground le~el release X/Q of 2.6 x 10-4 sec/m3 at the Exclusion Area Boundary,.
{See Topic II-2.c). *
- 6. 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> irradiated fuel cooldown time.
- Peaking factor of 1:2 used for more than ~ne damaged fl,lel assembly.
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