ML19305C384
| ML19305C384 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/21/1980 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| 602, TAC-12890, NUDOCS 8003280471 | |
| Download: ML19305C384 (3) | |
Text
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TOLEDO File: 0017 l(()l$$()lQ Docket No. 50-346 License No. NPF-3 Serial No. 602 March 21, 1980 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. Robert W. Reid, Chief Operating Reactors Branch No. 4 Division of Operating Reactors
Dear Mr. Reid:
This is in response to your letter of February 23, 1980 on LWR primary coolant system pressure isolation valves. There are only four check valves applicable to your concern at the Davis-Besse Nuclear Power Station Unit 1 (DB-1).
The following itemizes responses consistent with your letter:
1.
A valve configuration at DB-1 includes two check valves in series with a motor operated valve. This falls under the " Event V isolation valve" configuration definition of a Class I boundary of high pressure piping
)nnecting primary coolant system (PCS) piping to low pressure sys em piping. The valves involved are CF-31, DH-77, CF-30 and DH-76,.tud shown on Figure 6-17 of the DB-1 Final Safety Analysis Report (l'SAR).
2.
As shown on Figure 6-17 of the FSAR, there is a continuous pressure surveillance by a computer alarm which alarms at pressures above 375 psig with both decay heat pumps off.
Since the motor operated valves, DHIA and DHlB are always open under normal conditions, the computer alarm continuously monitors the line pressure to check if there is any leakage in the check valves CF-30 and DH-76 in one LPI train and CF-31 and DH-77 in the other LPI train. The pressure monitoring in the two LPI traine are common to this computer alarm.
In addition to this alarm, there are pressure indicators PI 2882A and PI 2882B local to the valves DHIA and DHlB.
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THE TOLEDO EDISON COMPANY OlSON PLAZA 300 MADISON AVENUE TOLEDO. OHIO 43652 w oac so 4 7I
Docker No. 50-346 License No. NPF-3 Serial No. 602 In addition to the above monitoring, the following test requirements are established for the subject valves:
-(a) Testing capability for valves CF-30, CF-31, DH-76 and DH-77 is provided by a normally isolated bypass line as described in response to NRC Question 6.3.2 in the Davis-Besse Unit No. 1 FSAR. This test will be done at every refueling outage.
(b) In addition, Check Valves DH-76 and DH-77 are leak checked every plant startup per established plant procedures.
(c) As per the surveillauce requirements of the Station Technical Specification, the motor operated valves, DHlA and DHlB are verified per established surveillance test procedures at least once every 31 days to be in their correct (open) position.
The only case of lack of integrity of one of these check valves occurred on DH-77 in 1977. This valve's seat was found to be leaking. For details, reference Licensee Event Report (LER) #32-77-8.
In addition, Toledo Edison is in the process of updating our inservice testing requirement of our Valve Testing program to meet the requirements of the ASME Boiler & Pressure Vessel code, 1977 edition through summer 1978 addenda. This update program is presently scheduled for NRC submittal in May of this year.
The revised inservice testing requirements for these check valves will be to forward flow cycle the valves at cold shutdown (mode 5).
System operation precludes partial stroke testing during normal operation when reactor coolant system pressure is greater than the decay heat system design pressure.
Yours very truly,
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R. P. Crouse Vice President
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Nuclear RPC:TKR:TWH jh d/4-5 5l
e SUBMITTAL FOR THE DAVIS-BESSE NUCLEAR POWER STATION UNIT 1 FACILITY OPERATING LICENSE NPF-3 IN RESPONSE TO A 10 CFR 50.54(f)
REQUEST DATED FEBRUARY 23, 1980 This response is filed in accordance with 10 CFR 50.54(f) relating to Mr. Darrell G. Eisenhut's letter of February 23, 1980. This. deals with primary coolant system pressure isolation valves.
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= w-w by R. P. Crouse Vice President, Nuclear Sworn to and subscribed before me the twenty-first day of March, 1980.
Notary Pu e
ANNA MAE Ft GUSON Natary Pt.b:.c - State of Ohlo 1
My C:mmission Dpires Oct. 7.198r
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