ML17194B140
| ML17194B140 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/23/1982 |
| From: | Oconnor P Office of Nuclear Reactor Regulation |
| To: | Delgeorge L COMMONWEALTH EDISON CO. |
| References | |
| TASK-06-04, TASK-6-4, TASK-RR LSO5-82-06-085, LSO5-82-6-85, NUDOCS 8206300015 | |
| Download: ML17194B140 (5) | |
Text
Docket No. 5~237 LSOS-82-06-085
\\
Mr. L. *'oelGeorge Director of Nuclear Licensing Conunonwealth Edison Company Post Office Box 767 Chicago, Illinois 60690
Dear Mr. OelG.eorge:
June 23, 1982
SUBJECT:
SEP TOPIC VI-4i CONTAINMENT ISOLATION SYSTEM (ELECTRICAL)
FINAL SAFETY EVALUAtIPN REPORT FOR DRESDEN UNIT 2 The staff has determined that the scope of review and evaluation performed for multi-plant generic activity B-24 includes the electrical aspects of SEP Topic VI-4.
Additional review and evaluation is, therefore, not required.
Enclosed 1s a copy of our final evaluation of the ~~~ctrfcal portion of generic activity B-24 for Dresden Unit 2. This assessment compares your fac11 ity', as described in Docket No. 5~237, with the cr~teria ~urrently used by 1the regulatory staff for lfcensing*new fac11itje~.
We had intended ti>.considere~ny plant modifications necessary ~s a.result of the generic review during *):ltre'.f ntegrated assessment for your facfl ity 1n order to assure that backfft1:1ng decisfons would be made on a,<>onsfst~nt basis with other modifications which may be.required for other SEP. issues.
HoQever. based on the status of the ongoing review being generically con-ducted by the staff with the.BWR Owners Group for NUREG-0737 Item IUE.4. 2(7), it appears that this review may not be completed* before the integrated assessment for your facility. Those aspects of the implementations.
of II-E.4.2(7) that are known prior to the completion of the fotegrated as-sessme.nt w111 be considered to the exte"!t practicab1 e. Nevertheless, the 11-E.4. 2(7) review will be conducted i nd~peridently of SEP.
SEP Topic VI-4 1s therefore considered completed for the purpose of conducting the integrated assessment.
Sincerely,
[J6~igggJs;;~~~s~g~
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J Qrie;niei signe\\l 1'11'.
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ORAB~
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'C AD A:DL ORAB~u au W. 0 onnor, j1toject Manager G inas Tippolito Opera~tng Reactors Branch No. 5 611.1.,,v182 6/ ltY/82 Enc l:o*.suY.?e :
6/'>{ /82 Di vi s1on of L icensf ng
- See previous Concurrence As stated OFFICE. ************************
SURNAME~......cc:..w/.ancl
~
See next DATE........................
SEPB
- SEPB
- SEPB
- Rsctr*rr*.-or** ***********:.. ********** *************.........
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SEPB NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY' USGPO: 1981-335-960
Docket No. 50-237 LS05~82-Mr. L. De 1 George Dfrector of Nuclear L1censfng Conunonwealth Edf son Company Post Offf ce Box 767 Chicago, I11fno1s 60690
Dear Mr. DelGeorge:
SU8.JECT:
SEP TOPIC VI-4, CONTAINMENT ISOLATION SYSTEM (ELECTRICAL)
FINAL SAFffi EVALUATION. REPORT FOR DRESDEN UNIT 2 The staff has detenntned that the scope of review and evaluatfon perfonned for mu1 ti-plant generic actfvfty B-24 t ncludes the el ectrfcal aspects of SEP Topic VI-4.
Addftfonal revfew and evaluation ts. therefore, not required; Enclosed fs a copy of our ftnal evaluation of the el ectrfcal portfon of generfc actfvfty 8"!'24 fQr Dresden Unft 2.
Th1 s assessment compares your facility', as desert bed in Docket No. 50-237. wfth the ~a:tterfa currently used by the regulatory staff -for lfcensfng new facfl ttf es~
The staff has conc.luded.that the modfffcatfons described fn the Apr11 5, 1982 letter from T. J. ~ausch satisfy our criterfa for thfs topfc. Thfs assessment may be revfsed 1n the future ff your facflf ty design fs changed or 1 f NRC-crfterfa relating to this subject are modffied before the*
integrated assessment 1s completed.
Enclosure:
As stated cc w/enclosure:
See next. page
-S~PB OFFICE. ***
l : bl SURNAME
- 61
- i82.........
DATE. ************************
NRC FORM 318 (10-80) NRCM 0240 Sincerely, Paul W. O'Connor, Project Manager Operating Reactors Branch No. 5 Dfvtsfon of Licensing OFFICIAL RECORD COPY USGPO: 1981-335-960
- f <?-.. ~,I
~1 Mr. L. Del George cc Robert G. Fitzgibbons Jr.
Isham, Lincoln & Beale Counselors at Law Three First National Plaza Suite 5200 Chi~ago, Illinois 60602 Mr. Doug Scott Plant Superintendent Dresden Nuclear Power Station Rural Route #1 Merri~. Illinois 60450
- The Honorable Tom Corcoran United States House of Representatives Washington, o. c. io515
- u *. s. Nuclear Regulatory Commission Resident Inspectors Office Dresden Station RR 11 Morris, Illinois 60450 Mary Jo Murray Assistant Attorney General Environmental Control Division 188 W. Randolph Street Suite 2315 Chicago, Illinois 60601 Chainnan Board of Supervisors of eGrundy County Grunay*tounty Courthouse Morris, Illinois 60450 John F. Wolf, Esquire 3409 Shepherd Street Chevy Chase, Maryland 20015 Dr. Linda W. Little 500 Hennitage Drive Raleigh, North Carolina* 27612 Judge Forrest J. Remick
.The Carriage House - Apartment 205 2201 L Street, N. W.
Washington, o. c.
20037 Dresden 2 Docket No. 50-237 Revised 5/19/82 lllinois*oepartment of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704 U. S. Environmental Protection Agency Federal Activities Branch Region V Office ATTN:
Regional Radiation Representative 230 South Dearborn Street Chicago, Illinois 60604 James G. Keppler, Regional Administrator Nuclear Regulatory Commission, Region Ill 799 Roosevelt Street Glen Ellyn, Illinois 60137
REVISED SAFETY EVALUATION REPORT DRESDEN UNITS 2 AND 3 OVERRIDE OF CONTAINMENT PURGE ISOLATION TOPIC:
VI-4, Containment Isolation System I.
INTRODUCTION Instances have been reported at nuclear power plahts where the intended automatic closure of the contail"ITlent purge/ventilation valves during a postulated accident would not have occurP.ed because the safety actuation signals were inadvertently overriden and/or blocked, due to design deficien-cies. These instances were detennined to constitute an Abnonnal Occurrence
(#78-5).
As a follow-up action, NRR issued a generic letter requesting each licensee to take certain actions.
II.
EVALUATION The report enclosed with Mr. Crutchfield's December 15, 1981.letter to Mr. L. Del George titled, "Electrical, Instrumentation and Control Aspects of the Override of Containment Purge Valve Isolation," (EGG 1183-4199) was prepared for us by EG&G, San Ramon as part of our technical assistance contract program.
The report provides their technical evaluation of the design compliance with NRC provided criteria. The report is applicable to Dresden Units 2 and 3 because they are similar plants.
As a result of that report, the staff concluded that the electrical portion of this topic was not satisfactory in these plants because the containment ventilation and purge was not isolated automatically by a high radiation signal. Although our contractor noted that.there was no system level manual initiation of Group II isolation, the staff did not require a modi-fication because of the fact that there are only a few valves that connect to containment atmosphere and they are nonnally closed.
Subsequent to the issuance of our December 15, 1981 safety evaluation, the plants were modified to provide a 1 out of 2 Group II isolation on high radiation in the Torus (100 R/HR) and a system level manual 1n1t1at1on of Group II isolation. Drawings 12E2501 and 12E8552 (changes Wand 0 respec.:.
tively} show the: implementation of these modifications.
We had intended to consider any plant modifications necessary as a result of the generic review during the integrated assessment for your facility in order to assure that backfitting decisions would be made on a consistent basis with other modifications which may be required for other*SEP issues.
However, based on the status of the ongoing review being generically con-ducted by the staff with the BWR Owners Group for NUREG-0737 Item II-E.4.2. (7), it appears that this review may not be completed before the integrated assessment for your facility. Those aspects of the implementa-tions of II-E.4.2. (.7) that are known prior to the completion of the integrated assessment will be considered to the extent practicable. Never-theless, the II-E.4.2. (7) review will be conducted independently of SEP.
- III.
CONCLUSION SEP Topic VI-4 is considered complete for the purpose of conducting the integrated assessment.