ML20086T587
| ML20086T587 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 12/31/1991 |
| From: | Gates W OMAHA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20086T590 | List: |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM LIC-91-337R, NUDOCS 9201060340 | |
| Download: ML20086T587 (2) | |
Text
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December 31, 1991 Omaha Public Power District L10 91-337R M4 South 16th Street Mall Omaha. Nete.ka C3102 2247 402/63G 2000 U. S. Nuclear kegulatory Commission Attn: Document Control Desk Mail Station Pl 137 Washington, DC 20555
References:
1.
Docket No. 50 285 2.
Letter from OPPD (W. G. Gates) to NRC (Document Control Desk) dated July 1, 1991 (LIC-91-182R)
Centlemen:
SUBJECT:
Completion of Power Operated Relief Valve (PORV) Block Valve Prototype Steam Blowdown Testing in order to close out remaining NUREG 0737, item II.D.) issues for fort Calhoun Station (FCS), Omaha Public Power District (OPPD) connitted to purchase a prototype PORV block valve from the original manufacturer and in Reference 2, to perform steam blowdown testing by December 31, 1991.
This testing was to
" qualify" the in-plant PORV block valves for isolating steam blowdown flow through a " stuck open" PORV.
Accordingly, enclosed is OPPD's preliminary data report on the test conducted by WYLE Laboratories.
In October 1991, the test valve was procured from CRANE-ALOYC0, Inc.
The block valve actu* tor used in the test was configured to duplicate the existing POR3 block va'.ve actuators.
Since a 7 1/2 ft-lb motor used on the in-plant block valve actuators could not be procured, it was necessary to utilize a 10 ft-lb Limitorque motor on the test valve actuator (see Report Section 8.5 for justification). Mobilux EP 1 was used as the stem lubricant on the test PORV block valve because OPPD will begin using Mobilux EP-1 for stem lubrication on the in-plant PORV block valves during the 1992 refueling outage.
Presently, Never-Seez NG-165 is used as the stem lubricant on the in-plant PORV block valves.
Additionally, the calculation (see Report Section 8.5) assunned no lubrication between the actuator stem nut and valve stem.
The test valve, actuator and motor were sent to WYLE Laboratories in Norco, California for steam bl;t9down testing during the week of November 18, 1991.
Based on the enclosed preliminary report, it was concluded that:
1.
Sufficient margin exists at the actuator torque switch trip for the installed PORV block valves to perform their safety function of isolating steam blowdown flow through a " stuck open" PORV.
2.
The steam blowdown test conditions adequately bounded the design basis conditions of the PORV block valves installed at FCS.
3.
The prototype test valve and actuator adequately duplicated the PORV block valves installetat FCS.
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O. S. Nuclear Regulatory Commission LIC-91-337R Page 2 OPPD concludes that the in plant PORY block valves will stroke closed in 10 seconds (or less) under the maximum expected differential pressure and flow conditions and therefore meet their most severe design basis function.
All remaining NUREG 0737, item !!.D.) issues have therefore been addressed by this testing. However, please note that since the report from WYLE Laboratories which will finalize the data is not expected until fepruary 1, 1992, all conclusions and data presented in the enclosed report are considered preliminary. To allow sufficient time for review of the WYLE Laboratories report, OPPD's final report will be submitted by April 1.,
1992.
If you should have any questions, please do not hesitate to contact to.
Sincerely, W /5. M W. G. Gates Division Manager Nuclear Operations WGG/sel Enclosure c:
LeBoeuf, Lamb, Leiby & MacRae R. D. Martin, NRC Regional Administrator, Region IV D. L. Wigginton, NRC Senior Project Manager R. P. Mullikin, NRC Senior Resident inspector J. T. Larkins, Project Director