ML19254F790
| ML19254F790 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/23/1979 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | Finfrock I JERSEY CENTRAL POWER & LIGHT CO. |
| References | |
| TASK-06-04, TASK-6-4, TASK-RR NUDOCS 7911190027 | |
| Download: ML19254F790 (5) | |
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October 23, 1979 Docket No. 50-219 Mr.1. R. Finfrock, Jr.
Vice President - Generation Jersey Central Power & Light Company Madison Avenue at Punch Bowl Road norristown, New Jersey 07960
Dear f1r. Finfrock:
RE: Containment Purging and Venting During Normal Operation By letter dateu Novemoer 29, 1978, the Commission (NRC) requested all licensees of operating reactors to respond to generic concerns about containraent pur9 ng or venting during normal plant operation. The 1
generic concerns were twofold:
(1) Events had occurrea wnere licensees overrode or bypassed the safety actuation isolation signals to the containment isolation valves.
These events were determined to De abnormal occurrences and reported to Consress in January 1979.
s) Recent licensing reviews have required tests or analyses to show that containitent purge or vent valves would shut without degrading con-toinuent integrity during the dynamic loaas of a design basis loss of coolant accident (USA-LOCA).
The hKC position of the liovencer 1978 letter requested that licensees taKe tne following positive actions pending completion of the NRC review:
(1) pranioit the cverride or Dypass of any safety actuation signal which would affect another safety actuation signal; the f;RC Office of Inspection ano Enforcet..ent would verify that administrative controls prevent improper manual defeat of safety actuation signals, and (2) cease purging (or venting) of containment or limit purging (or venting) to an absolute minimum, not to exceea 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per year. Licensees were requested to demonstrate (Oy test or by test and analysis) that containuent isolation valves would shut unoer postulatea DBA-LOCA condition. The NRC positions were amplified by citation (and an attached copy) of our Standard Review Plan (SRP) 6.2.4 Revision 1 and the associated Branch Technical Position cst 6-4, wnicn have effectively classed the purge and vent valves as
" active" invoking the operability assurance program of SRP 3.9.3.
The iiRC staff has maae site visits to several facilities, has met with licensees at Bethesda, inaryland, and has held telecon conferences with many otner licensees anc met with some valve manufacturers. During these ciscussions, the MC staff has stressed that positive actions uust ce taken as noteo above tu assure that containment integrity would oe maintained in the event of a UBA-LOCA.
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Mr. I. R. Finfrock, Jr.
2-2 October 23, 1979 As a result of these actions, we have learned from several licensees that at least three valve vendors have reported that their valves may not close against the ascending differential pressure and the resulting dynamic loadin9 of the design basis LOCA. All identified licensees who are affected have proposed to maintain the valves in the closed position or to restrict the angular opening of the valves whenever primary containment integrity is required until a re-evaluation is provided which shows satisfactory valve performance under the DBA-LOCA condition.
Recently, a report' under 10 CFR Part 21 was received by the NRC from the manufacturer of butterfly valves which are installed in the primary containment at the Three Nile Island Unit 2 Nuclear Station. These butterfly valves are usea for purge and exhaust purposes and are required to operate during accident conoitions. The report discusses the use of an unqualified solencio valve for a safety-relatea valve function which requires operation uncer acciaent concitions. The solenoid valve is used to pilot control the pneumatic valve actuators which are installed on tne containment ventilation butterfly valves at this facility.
Your re-evaluation of valve performance for conditions noted in the previous paragraph must consider tne concerns icentified in IE Bulletin 79-Ol A.
As the iiRC review progresses, licensees which might have electrical overrice circuitry proolems are being advised not to use the override anc to take coupensatory interin measures to minimize the problea.
In lignt of the inforuation gained during our reviews of your submittal udtec January 23, 1979, and the information citea above, we believe an interin commitment frou you is required at this tir.;e.
This is the case, even though you may have proposed Technical Specification changes or other long or short-tena measures, wnich we are reviewing. For your use, we have provided as an attachuent an interim NRC staff position.
In adaition, our recently developea " Guidelines for Demonstration of Operability of Purse and Vent Valves" were provided by separate letter to licensees of each operating reactor. This letter in no way relaxes any existing licensing requirements for your facility.
Because of the potential adverse effects on the public health and safety whicn could result from the postulated, DBA-LOCA while operating with open purge or vent valves, we believe your prompt response to this letter is required.
In accordance with 10 CFR 50.54(f), you are requested 1353 297
J Mr. I. R. Finfrock, Jr. October 23, 1979 to inform us in writing within 45 days of receipt of this letter of your comraitment to operate in confonaance with the enclosed interim position and to provioe us with infonaation which demonstrates that you have initiated the purge and vent valve operability verification on an.. expedited basis. The infonnation provided in your response will enaole us to determine whether or not your license to operate Oyster Creek Nuclear Generating Station should be modified, suspended, or revoked.
Sinc erely, (N w,s f -l inn,ta~
b Dennis L. Ziema Chief Operating Reactors Branch #2 Division of Operating Reactors
Enclosure:
Interiu Position for Containuent Purge and Vent Valve Operation cc: w/erclosure See next page 1353 298
Mr. I. R. Finfrock, Jr. October 23, 1979 1
cc w/ enclosure:
G. F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N. W.
Washington, D. C.
20036 GPU Service Corporation ATTN: Mr. E. G. Wallace Licensing Manager 260 Cherry Hill Road Parsippany, New Jersey 07054 Anthony Z. Roisman Natural Resources Defense Council 917 15th Street, N. W.
Washington, D. C.
20005 Steven P. Russo, Esquire 248 Washington Street P. O. Box 1060 Tons River, New Jersey 08753 Joseph W. Ferraro, Jr., Esquire Deputy Attorney General
~ State of New Jersey Departrent of Law and Public Safety 1100 Payrond Boulevard Newark, New Jersey 07012 Ocean County Library Brick Township Branch 401 Chanbers Bridge Road Brick Town, New Jersey 08723 1353 299
INTERIM POSITION FOR CONTAINfENT PURGE AND VENT VALVE OPERATION PENDING RESOLUTION OF ISOLATION VALVE OPERABILITY Once the conditions listed below are met, restrictions on use of the containment purge and vent system isolation valves will be revised based on our review of your responses to the November 1978 letter justifying your proposed operat'fonal mode. The revised restrictions can i e established separately for each system.
1.
Whenever the containment integrity is required, emphasis should be placed on operating the containment in a passive mode as much as possible and on limiting all purging and venting times to as low as achievable.
To justify venting or purging, there must be an established need to improve working conditions to perform a safety related surveillance or safety related maintenance procedure.
(Examples of improved working conditions would include deinerting, reducing temperature *, humidity *,
and airborne at.tivity sufficiently to permit efficient performance or to significantly reduce occupational radiation exposures), and 2.
Maintain the containment purge and vent isolation valves closed whenever the reactor is not in the cold shutdown or refueling mode until such time as you can show that:
a.
All isolation valves greater than 3" nominal diameter used for containment purge and venting operations are operable under the raost severe design basis accident flow condition loading and can close within the time lirait stated in your Technical Specifications, design criteria or operating procedures. The operability of butter-fly valves raay, on an interin basis, be demonstrated by limiting the valve to be no more than 30 to 50 open (90 being full open). The maximuu opening shall be detenoinec in consultation with the valve supplier. The valve opening must be such that the critical valve parts will not be damaged by DBA-LOCA loads and that the valve will tend to close when the fluid dynamic forces are introduced, and b.
Modifications, as necessary, have been made to segregate the containment ventilation isolation signals to ensure that, as a minimum, at least one of the automatic safety injection actuation signals is uninhibited and operable to initiate valve closure when any other isolation signal may be blocked, reset, or overridden.
- Only wnere temperature and humidity controls are not in the present design.
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