ML17318A636
| ML17318A636 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 02/11/1980 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Dolan J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| References | |
| NUDOCS 8003190248 | |
| Download: ML17318A636 (9) | |
Text
TERA (2)
NSIC WGanmill LShao EReeves IE (4)
ACRS (16)
OELD TJCarter WRussell 4ISTRIBUTION:
Docket File NkR Rdg ORBgl Rdg JRMiller BGrimes RVollmer ASchwencer CParrish DWigginton Docket Nos. 50-315 and 50-316 (2)
NRC PDR (2)
L PDR DEisenhut RVol1mer FEBRUARY 1 1 ~
1
~MkgiYmuIQ'~g,~ goPg VIr. John Dolan, Vice President Indiana and fkichfgan Electric Company Post Office Box 18.
Bowling Green Station New York, New York 10004
Dear Nr'olan:
RE:
Containment Purging and Venting During Normal Operation By letter dated November 28, 1978, the Cottmfssfon (NRC) requested a'il licensees of operating reactors to respond to generic concerns about containment purging or venting during normal plant operation.
The generic concerns were twofold; (1)
Events had occurred where licensees oVerrode or bypassed the safety actuation isolation signals to the containment isolation valves.
These events were determined to be abnormal occurrences and reported to Congress in January 1979.
(2)
Recent licensing reviews have required tests or analyses to show that containment purge or vent valves would shut without,degrading con-tainment integrity during the +namfc loads of a design basis loss of coolant accident (DBA-LOCA).
The NRC position of the November 1978 letter requested that licensees take the following positive actiohs pending completion of the HRC review:
(1) prohibit the override or bypass of any safety actuation signal which would affect another safety actuation signal; the NRC Office of Inspection and Enforcement 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 exceed 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 (by test or by test and analysis) that containment isolation valves would shut under postulated DBA-LOCA condition.
The HRC 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 CSB 6-4, which have effectively classed the purge and vent valves as "active" invoking the operability assurance program of SRP 3.9.3.
l The HRC staff has made site visits to several,facflitfes, has met with licensees at Bethesda, tfaryland, and has held telecon conferences wfth mary other licensees and met with some valve manufacturers-During these discussions,,
the NRG staff has stressed that positive actions must be taken as noted above to assure that containment integrity would be maintained OFFICE P SURNAME DATE$..
NRC FORM 318 (9-76) NRCM 0240 AU.S. GOVERNMENT PRINTING OFFICE: 1979 289'369
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As a result of these actions, we have learned from sev'bral licensees that at least three valve vendors have reported that their valves may not'lose against the ascending differential pressure and the resulting ~amic loading 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 Ahich shows satisfacoi;y valve performance under the DBA-LOCA condition.
- Recently, a report under 10 CFR Part 21 was received by the NRC from the manu-facturer of butterfly valves which are installed in the primary containment at
- the Three Nile Island Unit 2 Nuclear Station.
These butterfly Rives are used
,, for purge and exhaust purposes and are required to operate during accident con-
- ditions.
The report discusses the)use of. an unqualified solenoid'alve for a
- =. Safety-related valve function which requires operation under accident conditions.
. 'The solenoid valve is used to'pilot control the pneumatic valve actuators which
'are installed on the containment ventilation butterfly valves at this facility.
'Your re-evaluation of valve performance for, conditions noted in the previous paragraph must consider the concerns idenfified in IE Bull~tin 79-01A.
='s the NRC review progresses, licensees which might have electrical override circuitry problems are being advised not to use the override and to take compen-satory interim oeasures to minimize the problem.
tI.
In light of the information gained during our reviews of your submittals as
-, jenumerated in your November 8, 1979 letter, we consider that your f'acility oper'
.'-ation meets the enclosed Interim Position except on Unit No. 1, Positiori,1{1.
-,=However, to ensure that you were kept fully informed, we previously provided you
.;- with our recently developed "Guidelines for Demonstration of Operability of
- ", Purge and Yent Yalves",
Ife are also providing the "Interim Position: which you should review to ensure Unit No.
1 conformance.
This letter in no),way relaxes
- - any existing licensing requirements.for Units No.
1 or No. 2.
Ue are in the process of completing the review of this issue for your facility.
We are
- ,. currently reviewing and developing our position on the non-safety grade 'radiation
, 'onitors in your facilities.
We also expect further requirements on Hie electrical override concern 'from the implementation of the Lessons Learned efforts.
Unt,'Ll we have completed our review, you are requested to commit to our Position 1 on Unit No. l.
Your commitment should be confirmed in writing and submitted within 10=,-;;
days upon receipt of this letter. If you have further questions, please let us know.
t' i/
Sincerely, OrIglnal'Sl ned By v;{
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Enclosure:
Interim Pob+tion Por A. Schwencer, Chief Operating Reactors Branch
)/1 Division of Operating Reactors TAC 10170/
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O UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 February ll, 1980 Docket Nos.
50-315 and 50-316 Mr. John Dolan, Vice President Indiana and Michigan Electric Company Post Office Box 18 Bowling Green Station New York, New York 10004
Dear Mr. Dolan:
RE:
Containment Purging and Venting During Normal Operation By letter dated November 28, 1978, the Comnission (NRC) requested all licensees of operating reactors to respond to generic concerns about containment purging or venting during normal plant operation.
The generic concerns were twofold:
(1)
Events had occurred where licensees overrode or bypassed the safety actuation isolation signals to the containment isolation valves.
These events were determined to be abnormal occurrences and reported to Congress in January 1979.
(2)
Recent licensing reviews have required tests or analyses to show tha.
containment purge or vent valves would shut without degrading con-tainment integrity during the dynamic loads of a design basis loss of coolant accident (DBA-LOCA).
The NRC position of the November 1978 letter requested that licensees take the following positive actions pendi ng completion of the NRC review:
(1) prohibit the override or bypass of any safety actuation signal which would affect another safety actuation signal; the NRC Office of Inspection and Enforcement 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 exceed 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 (by test or by test and analysis) that containment isolation valves would shut under postulated 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 CSB 6-4, which have effectively classed the purge and vent valves as "active" invoking the operability assurance program of SRP 3.9.3.
The NRC staff has made site visits to several facilities, has met with licensees at Bethesda,
- Maryland, and has held telecon conferences with many other licensees and met with some valve manufacturers.
During these discussions, the NRC staff has stressed that positive actions must be taken as noted above to assure that containment integrity would be maintained in the event of a DBA-LOCA.
~W
~
Hr. John Dolan February ll 1980 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 loading 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 manu-facturer of butterfly "valves wh'ich are installed -in the. primary, containment at the Three Nile Island Unit 2 Nuclear Station.
These butterfly valves are used for purge and exhaust. purposes and are required to operate during accident con-ditions.
The report discusses the use of an unqualified solenoid valve for a safety-related valve function which requires operation under accident conditions.
The solenoid valve is used to pilot control the pneumatic valve actuators which are installed on the containment ventilation butterfly valves at this facility.
Your re-evaluation of valve performance for conditions noted in the previous paragraph must consider the concerns identified in IE Bulletin 79-01A.
As the NRC review progresses, licensees which might have electrical override circuitry problems are being advised. not to use the override and to take compen-satory interim measures to minimize the problem.
~
- In light of the information gained during our reviews of your submittals as enumerated in your November 8, 1,979 letter, we consider that your facility oper-ation, meets the enclosed Interim Position except on Unit No.
1, Position'l.
However, to ensure'that you were kept fully informed, we previously provided you with our recently developed "Guidelines for Demonstration of Operability of Purge and Vent Valves".
Me are also providing the "Interim Position:
which you should review to ensure Unit No.
1 conformance.
This letter in no way relaxes any existing licensing requirements for Units No.
1 or No. 2.
We are in the process of completing the review of th'is issue for your facility.
We are currently reviewing and developing our position on the non-safety grade radiation monitors in your facilities.
We also expect further requirements on the electrical override concern from the implementation of the Lessons Learned efforts.
Until we have completed our revieW, you are requested to commit to our Position 1 on Unit No.
- 1. 'our commitment should be confirmed in writing and submitted within 10
, days-upon receipt of this letter. If you have further questions, please let us know.
Sincerely Enclosure; Interim Position for Containment. Purge and Vent Valve Operation cc w/enclosure:
See next page r
A. Schwencer, Chief Operating Reactors Branch= 81 Division of Operating Reactors
Nr. John Dolan Indiana and Michigan Electric Company February 11, 1980 CC:
Mr. Pobert W. Jurgensen Chief Nuclear Engineer American Electric Power Service Corporation 2 Broadway New York, Hew York 10004 Gerald Charnoff, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
Washington, D. C.
20036 Citizens for a Better Environment 59 East Van Buren Street
- Chicago, I 11 inoi s 60605 Maude Preston Pal enske Memorial Library 500 Market Street St. Joseph, Michigan 49085 Mr. D. Shaller, Plant Manager Donald C.
Cook Nuclear'lant P. 0.
Box 458 Bridgman, Michigan
- 49106, Nr. Robert Masse Donald C.
Cook Nuclear Plant P. 0, Box 458 Bridgman, Michigan 49106
INTERIM POSITION FOR CONTAINMENT 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 operational, mode.
The revised restrictions can be established separately for each system.
1.
Wheneve'r 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 activity 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 most severe design basis accident flow condition loading and can close within the time limit stated in your Technical Specifications, design criteria or operating procedures.
The operability of butter-fly valves
- may, on an interim basis, be demonstrated by limiting the valve to be no more than 30'o 50'pen (90'eing full open).
The maximum opening shall be determined 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
mi nimum, 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.
n y where temperature and humi dity controls are not in the present design.