ML20154D799

Forwards Documents Re Background Info on Util Violation of 10CFR50.44,per Request

ML20154D799
Person / Time
Site:	Pilgrim
Issue date:	07/24/1981
From:	Robert Carlson NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:	Wessman R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
Shared Package
ML20154D739	List: ML20154D737 ML20154D749 ML20154D775 ML20154D786 ML20154D799 ML20154D811 ML20154E181 ML20154E200 ML20154E235 ML20154E256 ML20195F929
References
FOIA-88-198 NUDOCS 8809160116
Download: ML20154D799 (6)

Text

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' .5,M 06 ket: 50-293 S: F01004888 g g4 NOTE TO: Richard Wessman. Chief. Enforcement Branch. IE FROM: Robert T. Carlson. Director. Enforcement and Investigation Staff. R!

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SUBJECT:

BOSTON EDISON COMPANY - PILGRIM RECOMMENDED ESCALATED ENFORCEMENT ACTION

! The enclosed documents are forwarded per your request for background information on the Pilgrim violation of 10 CFR 50.44.

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Robert T. Car *1 son. Director Enforcement and Investigation Staff

Enclosures:

! 1. SER 8/25/71

! 2. BEco Itr to 00L. 6/13/74 I 3. Ippolito ltr to Andognini. 3/14/79 4 Andognini Itr to Ippolito. 6/6/79 I

5. Andognint Itr to Ippolito. 10/19/79 l 6. Ippolito Itr to Andognini, 10/30/79

! 7. LER 81-021/01X-0, 6/16/81 i

! E. Novak memo to Moris t . 6/26/81

10. RI Daily Rpt. 7/31/80

11. RI Daily Rpt. 9/9/80 i

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August 25, 1971 i 1

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SAFETY EVALUATION SY Tilt i

. DIVISION OF REACTO. R LICENSING _.

U.S. ATOMIC ENERCY COMMISSION, t

IN THE MATTER OF i i \

50STON EDISON _COMPA Q ,

! eit.CRIM WUCLEAF. POWER STATION i DOCKET NO. 50-293  ;

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4.1.2 Co n t a,1,nfe,n,t, ,A,t no s p ,h e,r e, C,o n t,r o 1, Fo11 ovine a loss-of-coolant accident (IDCA), (a) hydrogen pas could be menerated inside thn orteary containment f rom a chemical reaction between the fuel rod claddina and steam (metal-water reaction), and (e) both hydroedn and oxymen would be menerated as a rasult of redi-olytic decoeposition of recirculatine coolant solutions. If a sufft-cient ascunt of the hydroren is generated and oxyeen is asa11able in stoichiometric quantities, the subsequent reaction of hydrogen with U  !

C oxygen at rates rapid enouth to lead to significant over-pressure 3 could lead to f ailure of the containnent to maintain low leakare integrity.

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The applicant croposes ventint of the containwnt as the corrective 3 seasure if the monitored hydrocen concentration inside the containeent shows sips of so, 9achine the lover flamability limits. The proposed  !

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ventine involves ournina containaent atmosphere with air and ventine in a controlled manner through the standby Ras treatment sys'eu to the . l I stack.  !!

We have concluded that a hydrogen control system should be provided.

La addition to the nurstne system pronosed be the apnitcant, to keen l C the hydrogen content within safe limits: 1.e., less than 4 volum l 3 percent. In its report on the Dresden 3 facility, the ACRS recosamended I

that a reasonable time period be allowed for the desten of such a system l

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and appropriate review by the reeulatory staf f. Special Report No.14 l subnitted for Dresden Unit 3 in response to our letter to Cosmnwealth l Edison Company dated December 22, 1970 provided additional information on post-accident covbustible eas control for Dresden Unit 3. This i

.f j Special Raport provides a conceptual desien of a flamability control i

system and a containnent atmosehere nonitorine system. As was the case for the Dresden Unit 3 facility. installation of a corbustible  ;

I eas control systers would require a chante in the desian of the Filaria f acility af ter the construction retnit had been issued, since we had not considered the problem of corbustibio sas can'.rol l

durine, our construction permit review of the Filaria aeotteation, we i

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evaluated this ratter in the lieht of 13 CTR 50.109 which states that

< 1 1 the Comission may require the backfittine of a f acility if it finds that such action will provide substantial additional protection which I is required for the public health and safetf. Our calculations in

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accordsace with AIC Safety Guide No. 7 on other similar plants has indicated that the production of hydrogen is auch that purains would be required within about 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> following a less-of-coolant accident.

I The radiolosteal consecuences from such releases usins the existine

! standby eas treateent system calculated by us for another sisitar plant i

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- 38 indicate that the incremental doses could be sienificant. Thus the capability to control the hydrogen concentration by pensures not requiring release to the environment with the present system would pro-i vide a eubstantial reduction in the total offsite doses that mieht '

result from the accident.

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We have concluded that the backfitting of the Pilgrim facility in -

I this regard will provide substantial additional protection required for i the public health and sa fety, but that the desian and installation of a

the systen need not be coseleted prior to issuance of an operatint I

license. We believt this action to be consistent with the advice of l the ACR$ as given on the Dresden 3 facility, i.e., that action should i i be achieved on a reasonable time basis. We will require the applicant to submit the derailed desirn and schedule for the installation and testing of a cet inment atmosphere senitorina system and control system to meet the desipn basis riven in Safety Guide 7. ,

The prir.ary containment will be provided with an inert atmosphere of nitrogen durina reactor sever operation, keepine the containtient atm-sphere oxygen concent ration less than 5?. by weteht. in order to ministre I t

the possibility of the combustion of tydroten evolwd from a strcontum-I j water reaction durine the first few minutes following a loss-of-coolant accident. i The inert atnoschere will also extend the time available to cope with the hedromen evolved fron radiolvsis of the ortmtv coolant.

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. 5 Ve recomise that inertinr makes insnection and repair of the orieary

.4 tysten core difficult and believe that it is erudent to permit short o

l t term personnel access to the drvve11 for leak inspections durine l

l startup/ hot standby periods when the primary systen is at or near rated l

l operatine temperature and pressure. Accordinely, a 24-hour transition l

I period is permitted to inert subsequent to inspections and the place-ment of the reactor in the Rm ?bde, and to deinert durine operation ,

l prior to a shutdown without stanificantly af fecting plant safety, j i

i Containment inerting has been requirnd for all nrevious boilinr water  ;

reactor pressure suppression containwnts. We conclude that the inerting system for the Pilerim Station provides additional plant safety !

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which outaeiphs the operational restrictions that may re s ul t .

l 4.1.3 teolation Valves ,

The basic function of all primry containment isolation valves is to trovide containeent intenrity between the erinary coolant system stes- l sure bondary or the containment atrosphere and the environs in the l l

event of accidents or sin 11ar equionent failures. Where necessary the valves are provided with valve operators, and these valves are auto-matica11y closed when the sensors detect certain accident or faulted conditions. The consequences of ecstulated pipe f ailures both inside l and outside the containment have been evaluated. For exanole, the operational aspects of the main steam line isolation valves for a l

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