ML20024A361
| ML20024A361 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 06/08/1983 |
| From: | Larson C NORTHERN STATES POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| REF-SSINS-6820 IEB-83-03, IEB-83-3, NUDOCS 8306170134 | |
| Download: ML20024A361 (2) | |
Text
4 b/7/0 Northern States Power Company 414 Ncollet Mall Minneapohs. Minnesota 55401 Telephone (612) 330-5500 June 8, 1983 Mr. J. G. Keppler, Director Region III Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50-263 License No. DPR-22 The following is submitted in response to IE Bulletin 83-03.
A review was completed of the plant Pump and Valve In-Service Test (IST) program required by Section XI of the ASME Boiler and Pressure Vessel Code.
It was verified that the ten (10) valves governed by IET 83-03 are included in the present Section XI program for Monticello.
(Referent. letter dated August 12, 1982 from D. M. Musolf to Director, Office of Nuclear Resetor Regulation, titled Supplemental Information Concerning Inservice Testing Program.)
Following is a list of the ten (10) valves and a summary of their IST program requirements.
SW-101, 102, 103, 104 are two series pairs of check valves which prevent back-flow f rom the emergency service water supply for the ECCS pumps and room coolers to the service water header (see Attachment 1, Emergency Service Water System). Present piping configuration does not pe rmit verifying the closure of each valve. A modification will be completed by the end of the next refueling outage (1984) which will allow verification that each valve pair will shut to provide the necessary system barrier function. This will satisfy the reverse flow testing requirement of IEB 83-03.
There is no need for full stroke testing of these valves since their normal position is full open.
Following completion of the modification reverse flow testing will be performed during each refuel outage.
There are no known previous failures of these valves.
SW 15, 16, 17, 18 are two series pairs of check valves which prevent backflow f rom the emergency service water supply for the diesel generators into the service water header. Modifications will be completed by the end of the next refueling outage (1984) to allow verification of valve closure.
Closure or 8306170134 830608
,f 4h gf0 PDR ADOCK 05000263 G
PDR JUN 10 1983
NORTHERN CTATE'] POWER COMPANY J G Keppler, Dir of Region III June 8, 1983 Page 2 reverse flow testing will be performed during each refuel outage. These check valves will be full stroke exercised quarterly. There are no known previous f ailures of these valves.
ESW 1-1,1-2 are pump discharge check valves and are exercised quarterly under the Section XI program.
The valves were partially disassembled to manually full stroke exercise their discs during the 1982 refueling outage. The mechanical operability was found to be satisfactory and visual inspection showed each valve to be in good physical condition.
To satisfy IEB 83-03 requirements the valves will be disassembly-exercised every five (5) years.
If deficiencies are noted, they will be corrected and the above inspection process repeated each refueling outage until a satisfactory inspection is completed, upon which the disassembly-exercising will revert back to a five (5) year interval. There are no known previous failures of these valves.
ESW 4-1, 4-2 a re not governed by IEB 83-03.
During non-emergency conditions the valves are in the closed position.
If during an emergency condition the valves failed to open, the diesel generator would receive more emergency service water than if the valves functioned properly. However, the valves are included in Monticello'sSection XI program.
Following revisions to surveillance test procedures and installation of the described modifications during the next refueling outage (1984), all valves governed by IEB 83-03 will be tested in accordance with that bulletin.
Yours very tru (3
'W C. E. La son Director, Nuclear Generation CEL/kik cc G. Charnoff C. Brown i