ML19319C432
| ML19319C432 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/30/1978 |
| From: | Nocvak T Office of Nuclear Reactor Regulation |
| To: | Bosnak R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002140809 | |
| Download: ML19319C432 (3) | |
Text
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Di m ibution:
G Ac@t File 3 NRR R/F RSB R/F NAR 3 0 E73 T.Novak Docket !!o. 50-346 Siegel chron
!!D;GRNiDUM FOR:
R. J. Bosnak, Chief, Mechanical Engineering 3 ranch, OSS FRO't:
T. M. Tiovak, Chief, Reactor Systems Branch, DSS
SUBJECT:
EVALUATION OF DAVIS BESSE UNIT I SUC!ITT/L RECUESTI:iG REIIEF FP.0fi CERTAITi ASME CODE SECTI0ti V.I PUMP A"D VALVE Ill-SERVICE TESTI?;G REQUIRCiEITS - 00CKET N0. 50-345 RS3 has reviewed the sections of the sutaittal related to the ECC (i.e.,
decay heat removal, high and leu pressure injection) and the reactor coolant systems in-service insrection crogran. While the applicant's subnittal is generally acceptable, there are questions related to the catagorization and testing of sete of the valves identified in the sub-nittai which we have addressed in the attached enclosure.
"sesconse of the applicaat to these cuestions is neeced before the sub:nittal can te fully evaluated and accepted.
v-;. ; ! p.4 ay T.r wed Thoras.'t. Mcvah, Chief Reactor Systens Eranch Division of Systens Safety
Enclosure:
Cuestiens cc:
D. Ross G. Mazetis Oo 0
0 B. Siegel c) a O
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Contact:
Syron Siegel,ilRR 49-27341
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'/$ovak 03f78 db/ 30/78 03/30/78 NRC FORM 318 (9 76) NRCM 0240 W u. s. oovannaeumv reinvine orric s. is,o - eae.eaa eo o2 u o207 p
4 Questions en Davis Besee Unit 1 Submittal of June 27, 1977 1.
Valves DH9A & B (from the containment sump) are only exercised curing shutdown.
Justify why these valves cannot be exercised quarterly, similar to valves DH7A & B (from borated water storage tank).
2.
Explain why, on Table 4 for System 49 of the submittal, valve CH79 frcm borated water storage tank and valves DH54 and DH55 in the bypass lines around the decay heat pumps are not identified as Category E valves which are normally locked ocen.
3.
It is the RSB rosition that all the check valves in the ECCS lines that perform the function of isolation be classified as ASME IWV-2000 Category A/C. These valves for Davis Besse Unit i are classified in the submittal only as Catecorv C valves. To confirm the orotection offered by these valves. it must be ascertained that the valve discs are actually in place and capable of seating througrout the life of the plant.
Current operability tests only confirm that injection flow is possible, not that the check valves are still capable of performing their intended isolation function.
It is the RSB positicn that each of the cneck valves in the submittal which performs an isolation function in the ECCS lines must be individually leak tested and a testing program be provided.
It should be noted that a testing program which simply draws a suction on the low pressure side of the outermost check valves will not be acceptable.
This only verifies that one of the series check valves is fulfilling an isolation function.
Verification of isolation capability for each valve is required.
4.
There appear to be some inconsistencies between the cycling frequency of check valves and the mode during which cycling can be oerformed in Table 2 for the decay heat removal and low pressure injection systems.
a.
Explain why isolation check valves DH76, DH77, HP56, HP57, HPa8, HP49, HP58, HP59, HP50, and HP51, some of which are identical tyce valves in redundant locos, are not all specified as being testable under the same piant conditions.
(Some are specified as testable during cold shutdown while others can be tested during cold shutdown or refueling.)
b.
Valves DH81 and DH82 under " cycling frequency" are stated as only testable during shutdown; however, under the mode of " plant operation" any condition from startup through normal operation to shutdown is acceptable for testing.
Correct or explain this apparent discrepancy.
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'/alves CF23 and CF30 are stated under " cycling frequency" as testable only during shutdown; however, the plant condition during testing is specified as hot standby.
Correct or explain this discrepancy.
5.
Explain why valves HP1556 and HP35 in the bypass line to tne borated water storage tank frcn the high pressure injection pumps are not identified in the submittal for System 49.
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