ML20151L011
| ML20151L011 | |
| Person / Time | |
|---|---|
| Issue date: | 08/05/1997 |
| From: | Mayfield M NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Wessman R NRC (Affiliation Not Assigned) |
| Shared Package | |
| ML20151L015 | List: |
| References | |
| NUDOCS 9708060215 | |
| Download: ML20151L011 (1) | |
Text
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l August 5, 1997 1
l MEMORANDUM TO: Richard H. Wessman, Chief
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Mechanical Engineering Branch Division of Engineering, NRR FROM: Michael E. Mayfield, Chief Electrical, Materials, and Mechanical Engineering Branch Division of Engineering Technology, RES l
SUBJECT:
FINAL REPORT ON "RESULTS OF PRESSURE LOCKING AND THERMAL BINDING TESTS OF GATE VALVES," INEL 96/0382, 1 JUNE 1997 I I
l The attached report contains the results of the pressure locking and thermal binding tests that I were conducted at the Idaho National Engineering and Environmental Laboratory (INEEL). The tests were performed on two different gate valve designs to determine their susceptibility for pressure locking and thermal binding under simulated operating and event scenarios. The l effects of leakage from the valves' bonnets and the influence of entrapped air pockets in the i bonnets on pressure locking were also investigated.
The results show that these two valves are susceptible to pressure locking under rapid depressurization accident scenarios. These valves are also susceptible to thermally induced i pressure locking, particularly when there is no leakage from the bonnets. Leakage can be prevented when the internal bonnet pressure is sufficient to force the discs against the seats to seal the valves. The effects of air pockets, up to 2% of the valve volume, delayed the onset of pressure locking in these valves but did not prevent it from occurring.
l Thermal binding of the discs due to shrinkage of the valve bodies and internals during cool- I down caused slight increases in extraction forces for both valves. l These results have been reviewed by members of your staff and all comments have been resolved. It is expected that the results will subsequently be included in a NUREG report for issuance in 1998.
If you have any questions on the report, please contact Gerald Weidenhamer (301-415-6015) of my staff.
Attachment:
As stated
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Distribution: . .
Reading File (LCS)
Branch Reading File h6hOVt Document Control Desk Pubhc Document Room DOCUMENT NAME: G:WVEIDENHA\FINALRPT.PL To recohre e copy of thisAubent, indicate in the box: "C' = Copy without attachment / enclosure 'E" - Copy with attachment / enclosure "N" = No copy OFFICE EMMEB(/ W l C SC\EMMEB Q b l CTEMMEB [ #' il l l l NAM b G.WeideMamer J.Vora @ F# M.Moyfield W, u T_
DATE'llgt 1 / 3 r /97 6"} / D97 f) / Q l /97 OFFICIAL RECORD COPY RES File Code:
9700060215 970005 1 PDR ORG EXIINEL
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