ML18058B172
| ML18058B172 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 10/21/1992 |
| From: | Masciantonio A Office of Nuclear Reactor Regulation |
| To: | Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| REF-GTECI-070, REF-GTECI-094, REF-GTECI-NI, TASK-070, TASK-094, TASK-70, TASK-94, TASK-OR GL-90-06, GL-90-6, TAC-M77368, TAC-M77438, NUDOCS 9210280253 | |
| Download: ML18058B172 (4) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 Docket No. 50-255 Mr. Gerald B. Slade Plant General Manager Palisades Plant Consumers Power Company 27780 Blue Star Memorial Highway Covert, Michigan 49043
Dear Mr. Slade:
October 21, 1992
SUBJECT:
PALISADES PLANT - STAFF REVIEW OF GENERIC LETTER 90-06, "RESOLUTION OF GENERIC ISSUE 70, 'POWER-OPERATED RELIEF VALVE AND BLOCK VALVE RELIABILITY,' AND GENERIC ISSUE 94, 'ADDITIONAL LOW-TEMPERATURE OVERPRESSURE PROTECTION FOR LIGHT-WATER REACTORS,' PURSUANT TO 10 CFR 50.54(f) 11 (TAC NOS. M77368 AND M77438)
By *letters dated December 26, 1990 and April 15, 1992, Consumers Power Company responded to Generic Letter (GL) 90-06.
The generic letter represented the technical resolution of two generic issues and included plant backfits which were cost-justified safety enhancements. Generic Issue (GI) 70 included upgrades in quality requirements, in-service testing requirements, and modified technical specifications for all pressurized water reactor facilities that incorporate power-operated relief valves (PORVs) and block valves in their design.
The intended purpose was to enhance the overall reliability of the PORVs and block valves so that they could better perform the safety functions identified in the generic letter. Generic Issue 94 included modified technical specifications for all Westinghouse and Combustion Engineering facilities to reduce the allowed outage time for an inoperable low-temperature overpressure protection (LTOP) channel and thus reduce the probability of overpressurization events during shutdown conditions.
The staff has reviewed your submittals and finds that you have deviated from the guidance in selected portions of the generic letter. It is the staff's position, that a regulatory analysis has been performed in accordance with 10 CFR 50.109(a)(3) and 50.109(c) which justifies the backfit. Therefore, absent any information that demonstrates that your facility is not bounded by the regulatory analysis that accompanied the generic letter, you are requested to resubmit a response that is in keeping with the intent of the generic letter.
The specific areas of concern are as follows.
The staff position requires the 18-month PORV stroke test to be performed during Mode 3 (HOT STANDBY) or Mode 4 (HOT SHUTDOWN) and in all cases prior to establishing conditions where the PORVs are used for low-temperature overpressure protection. Your submittal did not adequately meet this staff position.
9210280253 921021 PDR ADOCK 05000255 P
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Mr. G. October 21, 1992 The requirement to perform stroke tests of the PORVs during Modes 3 or 4 is a new position for some licensees. The basis for this position lies in the uncertainty introduced by stroke testing the PORVs at lesser system temperature conditions and then expecting them to perform adequately at operating system conditions. If this recommendation is not adopted, a sound technical basis should be provided (e.g., that such testing cannot be performed without significant system modifications or that the intent of such testing is accomplished by some other means}.
We note that one licensee has proposed the option to bench test the PORVs.
This would be acceptable, provided the tests are performed at conditions simulating Modes 3 or 4 conditions or greater and provided the proper reinstallation of the PORVs and controls is verified.
In another case, the staff accepted an argument from a licensee that the physical distance between the PORV and the pressurizer maintained the same temperature at the PORV in Modes 3, 4, or 5 such that there is no difference from the valve's perspective of testing in different Modes.
In this case, the facility had an air-operated PORV and was able to perform the PORV stroke test with the block valve closed such that the PORV would be primarily influenced by the ambient room conditions.
Additionally, the GL required that PORVs be stroke tested in all cases prior to establishing conditions where the PORVs are used for low-temperature overpressure protection.
Some licensees have interpreted this to mean that PORVs should be stroke tested during every shutdown and again during every start-up. This interpretation is inaccurate. Based on the IST program requirements, the PORVs should be tested no more frequently than every three months (unless valve maintenance is performed} to demonstrate operability.
In summary, the staff maintains its position that the PORVs should be stroke tested during Modes 3 or 4 in order to verify the capability to function in an environment more representative of operating conditions.
In your revised response, discuss how PORV stroke testing provides assurance that the PORVs will perform all necessary safety functions adequately at the required system operating conditions.
The staff position for the resolution of GI 94 included the technical specification upgrades as presented in the generic letter. The staff review determined that you have significantly modified the staff position. The staff will not accept, without significant technical justification, statements that the maximum allowed outage time will not support flexible plant operations.
In addition,.the staff will not accept probabilistic risk assessment-based (PRA-based} arguments to expand allowable outage times. Only differences in plant hardware, relative to that assumed in the staff's cost/benefit analysis, will be considered. It is our position, that in view of the recently completed regulatory analysis supporting the proposed outage times, and the uncertainties inherent in PRA analyses, consideration of PRA-based arguments (which is tantamount to re-opening the issue} is not warranted.
- I*
v Mr. G. October 21, 1992 The intent of the resolution of GI 94 was to decrease the probability of cold overpressurization while in a water-solid condition by increasing the availability of the LTOP system.
Generic Issue 94 did not apply to Babcock &
Wilcox (B&W) facilities because they maintain a nitrogen bubble in the pressurizer and do not operate in a water-solid condition. Similarly, the staff would be receptive to extending the recommended 24-hour allowed outage time with an inoperable LTOP channel to 7 days provided the plant is not water-solid.
For such cases, the licensee must identify a pressurizer level which provides a level of protection against cold overpressurization comparable to that provided-by the nitrogen bubble in B&W facilities.
Therefore, based on the additional guidance provided above, you are requested to resubmit your response to the generic letter.
You are requested to respond within 60 days following receipt of this letter.
If you would like to further discuss these issues prior to your resubmittal, please feel free to contact me.
cc:
See next page DISTRIBUTION Docket file, NRC & LPDRs PD31 Rdg File BBoger JZwol inski LMarsh AMasciantonio MShuttleworth DPickett OGC ACRS ( 10)
Palisades P/F WShafer RII I Sincerely, Original signed *by Armando Masciantonio, Project Manager Project Directorate III-I Division of Reactor Projects - III/IV/V Office of Nuclear Reactor Regulations OFFICE LA:PD31*
PM:PD31 D:PD31 NAME MShuttleworth AMasciantonio:jkd LMarsh DATE 10/7/92
//)jJ'f/92
,o /)1/92 (O /l.. V92
- SEE PREVIOUS CONCURRENCE
Mr. Gerald B. Slade Consumers Power Company cc:
M. I. Miller, Esquire Sidley & Austin 54th Floor One First National Plaza Chicago, Illinois 60603 Mr. Thomas A. McNish, Secretary Consumers Power Company 212 West Michigan Avenue Jackson, Michigan 49201 Judd L. Bacon, Esquire Consumers Power Company 212 West Michigan Avenue Jackson, Michigan 49201 Regional Administrator, Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 Jerry Sarno Township Supervisor Covert Township 36197 M-140 Highway Covert, Michigan 49043 Office of the Governor Room 1 - Capitol Building Lansing, Michigan 48913 Mr. Patrick M. Donnelly, Director Safety and Licensing Palisades Plant 27780 Blue Star Memorial Highway Covert, Michigan 49043 U.S. Nuclear Regulatory Commission Resident Inspector Office Palisades Plant 27782 Blue Star Memorial Highway Covert, Michigan 49043 Palisades Plant Nuclear Facilities and Environmental Monitoring Section Office Division of Radiological Health Department of Public Health 3423 N. Logan Street P. 0. Box 30195 Lansing, Michigan 48909 Gerald Charnoff, Esquire Shaw, Pittman, Potts and Trowbridge 2300 N Street, N. W.
Washington DC 20037 Mr. David L. Brannen, Vice President Palisades Generating Company c/o Bechtel Power Corporation P. 0.
Box 2166 Houston, Texas, 77252-2166 Roy W. Jones, Manager Strategic Program Development Westinghouse Electric Corporation 4350 Northern Pike Monroeville, Pennsylvania 15146