ML20070N706
| ML20070N706 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 04/28/1994 |
| From: | Hutchinson C ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-10, GNRO-94-00068, GNRO-94-68, NUDOCS 9405090098 | |
| Download: ML20070N706 (3) | |
Text
Enteigy Operations,Inc,
,ENTERGY mus fb.' G byn M3 39150 Ta 601437 2800
/
April 28, 1994 C.l1. Hutchinson i ava l nw r aem px % n j U.S. Nuclear Regulatory Commission Mail Station P1-37 l Washington, D.C. 20555 Attention: Document Control Desk
Subject:
Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 Grand Gulf Nuclear Station (GGNS)
Evaluation of Motor-Operated Valve (MOV) Dynamic Test Results GNRO-94/00068 Gentlemen:
l l
BACKGROUND: l l
On February 4, 1994, the Staff issued Inspection Report 50-416/94-01 detailing results of the Grand Gulf Nuclear Station l (GGNS) Motor-Operated Valve (MOV) Phase 2 Inspection, in which Unresolved Item (URI) 94-01-01 was identified. This issue l concerns prompt evaluation of dynamic test data and applicable l acceptance criteria.
On March 30, 1994, members of our staff met with NRC/NRR personnel to further discuss this issue and to present specific j details of GGNS' MOV testing and evaluation process. At the conclusion of the meeting, we believe the Staff agreed that our review of valve signatures for gross anomalies, combined with an initial review of dynamic traces for evidence of insufficient thrust margins (under dynamic conditions), and programmatic controls for identification, documentation, and evaluation of nonconformances, meets the intent of Generic Letter 89-10 guidance and recommendations relating to prompt evaluation of dynamic test data. GGNS was requested to provide written confirmation of these reviews for future Staff reference.
DISCUSSION:
The GGNS Motor-Operated Valve (MOV) Program is accomplished through written procedures that govern, both directly and indirectly, overall implementation of Generic Letter 89-10, and its supplements. For example, the plant's nonconformance program, which governs plant activities including MOV testing, requires all personnel to identify, report, and document n ..
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April 28, 1994 GNRO-94/00068 Page 2 of 4 deficiencies important to safety. This program, in conjunction I with our operability determination procedure, ensures that a I potentially degraded or non-conforming condition of plant l components and systems is evalutted for operability in a time ;
period commensurate with its safety significance.
l MOV implementing procedures provide details for proper installation and removal of diagnostic test equipment and specific requirements for acquisition of data during diagnostic testing (static and dynamic) of valves. These documents require technicians to review valve signatures for the presence of valve l and actuator anomalies / abnormalities. Technicians responsible i for acquiring valve signatures have received signature analysis training and are qualified to recognize any gross or otherwise obvious anomaly or abnormality. It is the technicians' responsibility to document gross anomalies / abnormalities during the data acquisition process.
During dynamic testing, the technician monitors the data acquired immediately after test strokes are completed. The technician is effectively reviewing the data for the presence of gross anomalies / abnormalities during this evolution.
Additionally, it is expected that signatures displaying anomalies / abnormalities on premature torque switch trip will be called to the attention of the engineer supervising the dynamic test. Following completion of dynamic valve strokes, the data is downloaded and then uploaded to a different storage test device.
This provides additional opportunity for the test engineer to view the dynamic signatures for presence of anomalies / abnormalities and/or obvious lack of adequate thrust margins (dynamic data is not necessarily transferred prior to valve return to service or post-static tenting). Furthermore, a static test is performed immediately following the dynamic test.
The data from the static test is additionally reviewed for anomalies / abnormalities. It is expected, that if valve / actuator damage were to occur during the dynamic test that it would also be evident in the static test.
Collectively, these actions provide ample assurance that gross anomalies / abnormalities or gross inadequacies in thrust margin are detected, documented, and handled in accordance with the plant's material nonconformance program. This program further ensures that the deficiency is evaluated for potential generic implications and that the component's operability is adequately addressed in a manner and time frame commensurete with its safety significance.
.P y
April 28, 1994 l GNRO-94/00068 Page 3 of 4 l
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CONCLUSION:
Upon completion of the above reviews, checks, and evaluation of MOV test data by trained and qualified technicians and engineers, GGNS meets the staff guidance for prompt evaluation of dynamic test data. The checks described above provide ample assurance that gross anomalies / abnormalities would be identified.
We trust this information will be sufficient to address and close URI 94-01-01. Please feel free to contact Jewel Summers (601) 437-2149 should you require further information.
Yours truly, v L CRH/JS/amb cc: Mr. R. H. Bernhard (w/a)
Mr. H. w. Keiser (w/a)
Mr. R. B. McGehee (w/a)
Mr. N. S. Reynolds (w/a)
Mr. H. L. Thomas (w/o)
Mr. Stewart D. Ebneter (w/a) l Regional Administrator )
U.S. Nuclear Regulatory Commission l Region II 101 Marietta St., N.W., Suite 2900 Atlanta, Georgia 30323 Mr. P. W. O'Connor, Project Manager (w/2)
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C. 20555 Mr. Thomas Scarborough Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C. 20555
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