ML19305E245

Responds to IE Bulletin 80-01 Re Operability of Automatic Depressurization Sys Valve Pneumatic Supply.Automatic Depressurization Accumulator Sys Uses soft-seat Design Lift Check Valves Mfg by Dragon Valves,Inc

ML19305E245
Person / Time
Site:	Cooper
Issue date:	01/16/1980
From:	Pilant J NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
IEB-80-01, IEB-80-1, NUDOCS 8004230192
Download: ML19305E245 (2)

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January 16, 1980 Mr. Karl V. Seyfrit, Director U.S. Nuclear Regulatory Commission Office of Inspection & Enforcement Region IV 611 Ryan Plaza .

Suite #1000 Arlington, Texas 76011 Subj ect: Response to IE Bulletin 80-01

Dear Mr. Seyfrit:

This letter is written in response to IE Bulletin 80-01, Operability of ADS Valve Pneumatic Supply. The following items are the Nebraska Public Power District (NPPD) responses to the licensee actions described in the subject bulletin.

Item 1 Determine if your facility has installed hard-seat check valves to isolate the ADS accumulator system from the pneumatic supply system.

The ADS accumulator system for Cooper Nuclear Station (CNS) uses soft-seat design lift check valves manufactured by Dragon Valves, Incorporated. The' seat material is BUNA-N.

Item 2 Determine if periodic leak tests have been performed on your ADS accumulator systems to assure. emergency pneumatic supply for the FSAR-required number and duration of valve operations.

The ADS accumulators were tested in November, 1973 during the CNS preop-erational testing. The tests were designed to verify that each accumulator could actuate the associated relief valve at least five times upon loss of air supply to the system. This would meet system requirements described in the FSAR. All check valves, accumulators, and associated piping performed satisfactorily at that time.

Periodic leak testing of the ADS accumulators has not been required by Technical Specifications or other plant surve111suce schedules. Conse-quently, no testing of the ADS accumulators has been performed since the preoperational tests.

Item 3 Review seismic qualifications of the ADS pneumatic supply system:

(a) from accumulator system isolation check valve to ADS valve operator, (b) from isolation valve outside containment up to ADS accumu-lator check valve.

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Mr. Karl V. Seyfrit January 16, 1980 Page 2.

Item 3 (Cont'd)

(a) At CNS the accumulators, piping, and check valves associated with the ADS pneumatic supply are Seismic Class I.

(b) The piping from the isolation valve outside containment to the ADS accumulator check valve is built to Seismic Class I criteria.

Item 4 Based upon determination of Items 1, 2, and 3 above, evaluate operability of the ADS for the conditions under which it is required to be operable including a seismic event. If operability cannot be established, adhere to appropriate Technical Specifi-cation action statement.

Our response to Item 1 above indicates that the ADS pneumatic check vaD+a at CNS are different in kind than those which caused problems at Peach Bottom 2. Our Item 2 response indicates that the check valves operated correctly after installation. Consequently, we have no reason to believe that these check valves will fail to perform their safety function. Our response to Item 3 above indicates that the integrity of the essential portion of the system will be maintained under all possible adverse con-ditions including a design basis seismic event. On the basis of the above information, we consider the ADS pneumatic system at CNS operable and capable of performing its safety function as described in the FSAR.

We recognize that the check valves have not been tested since November,1973.

Consequently, we hereby commit to testing the ADS accumulator system to assure that the system performs as described in the FSAR. The testing will be done on a once-per-cycle basis beginning with our next refueling outage. The successful testing of the accumulator system will provide increased assur-ance that the ADS pneumatic system is operable.

Iter 5 Provide an immediate notification to the NRC in the event the ADS is found to be inoperable.

Not applicable.

Should you have any questions regarding this response, please contact me.

Sincerely yours, M

, . Pilant Director of Licensing and Quality Assurance JMP:WEC:cmk