ML19322C059
| ML19322C059 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Davis Besse  |
| Issue date: | 03/23/1976 |
| From: | Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Knop R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML19269F522 | List: |
| References | |
| NUDOCS 7912300014 | |
| Download: ML19322C059 (2) | |
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UNITED OTATES NUCLEAR HLGut.ATORY COMMISSION nrGION lit 799 ROOLLVELT RO AD GLEN [Lt.Y N, It.LINOIS 60137 March 23, 1976 R. C. Knop, Chief, Reactor Projects Section 1 VENT VALVE INSPECTION REQUIREMENTS - DAVIS-BESSE 1 The design and evaluations of the 14 inch diameter internals vent valves utilized in the Davis-Besse Unit I design are described in Sections 4.2.2.2.8, 4.2.2.3, and 4.2.2.4 of the FSAR. The description notes these valves will be fully open at a differential pressure between that shield.and the coolant the plenum assembly inside the core support annulus outside the shield of not more than 0.3 psig. The description also notes that these valves should start to open at a differential pressure of 0.15 psig.
(It is noted that Q.4.4.3 of the FSAR indicates that valves will be open at "about 0.5 psig".)
These valves are fitted with lif ting lugs which permit their exercising during periods when the vessel is open utilizing long handling tools.
Such periodic exercising is required every 18 months by Technical 4.4.10.1.2.b (Draf t Technical Specifications - Davis-Besse Specification Unit 1):
"Each internals vent valve shall be demonstrated OPERABLE at least once every 18 months by visua.' inspection and manual actuation."
During the review of preoperational test procedure TP 200.01, " Reactor Internals Vent Valve Removal and Replaceme: t, Exercise, and Inspection it was noted that one of the accept nce criteria for this test Test",
called for the opening force (using the exercising tool) to be in the range of 15-25 lbs. with the fully open force to be in the range of 75-100 lbs. This suggests that the ratio of opening to fully open Based on the force could be acceptable in the range of 1:3 to 1:7.
FSAR description and drawings of these valves, it would appear that a ratio of less than 1:2.5 would be appropriate.
In discussing the above with the licensee's staf f, I was informed that these acceptance criteria were recommended by B&W as being indicative of the experience obtained at other sites and are not directly related to the design criteria for the valves.
In light of the above, I recommend the following steps be taken:
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,s March 23. 1976 2-R. C. Knop i
I will inf orm the licensee that he should obtain suf ficient design information and acceptance criteria guidance from B&W to enable 1.
i g the the evaluation of the proper performance of these val will demonstrate their operability.
lleadquarters should be informed of this problem to determine if:
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Specific acceptance criteria should be included in the Davis-Besse Technical Specifications for the 18 month testing of a.
these valves.
Similar requirements exist or should be added to other B&W b.
facilities using internals vent valves.
d Unless I hear to the contrary, I will inform the licensee of the neeOth for additional information.
bring this matter to the attention of Headquarters.
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R. D. Martin Reactor Inspector Reactor Projects Section 1 e
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