ML20070D327
| ML20070D327 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 02/22/1991 |
| From: | Cottle W ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GNRO-91-00024, GNRO-91-24, NUDOCS 9102280204 | |
| Download: ML20070D327 (3) | |
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t February 22,1991 U.S. Nuclear Regulatory Commission Mail Station P1-137 Washington, D.C.
20555' Attention: Document Control Desk
SUBJECT:
Gr6nd Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Report'No. 50-416/90-25, dated 1/28/91(GNRI-91/00015)
GNRO-91/00024 Gentlemen:
Enterg Operations, Inc. hereby submits the reply to Notice of Violation 50-416 90-25-01.
Yours truly, w YC M' WTC/JS/cg attachment:- Reply to Notice of Violation 50-416/90-25-01 cc:
Mr. D. C. Hintz (w/a)
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. Mr. R. B. McGehee (w/a)-
Mr. N. S. Reynolds (w/a)
- Mr. H. L. Thomas (w/o)
Mr. J. L. Mathis (w/a) 1 Mr.StewartD.Ebneter(w/a)
-Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta St.,'N.W., Suite 2900 Atlanta, Georgia 30323-Mr. L. L. Kintner, Project Manager (w/a)
.0ffice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 11021 Washington, D.C.
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Attachment to GNR0-91/00024 Reply to Notice of Violation 50-416/90-25-01 Technical Specification 6.8.1.a requires that written procedures be established, implemented, and maintained covering activities recommended in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978.
Regulatory Guide 1.33, Revision 2, Appendix A, recommends procedures for the startup and shutdown of the reactor water cleanup system.
Integrated Operating Instructions (101) 03-1-01-1, Cold Shutdown to Generator Carrying Minimum Load, required the transfer from pre-pump to post-pump mode of operation for the reactor water cleanup system af ter reactor pressure reaches 100 psig.
Additionally, the procedure required placing the second RWCU pump in service at approximately 200 psig.
Contrary to the above, on November 24, 1990, operators failed to follow procedure 101 03-1-01-1 when transferring from pre-pump to post-pump mode of operation for the RWCU system, in that the transfer was made at 25 psig.
Also, the second RWCU pump was placed in service prior to reaching 200 psig reactor pressure.
This resulted in an isolation of RWCU.
1.
The Reason for The Violation The Reactor Water Cleanun (RWCU) System is susceptible to perturbations at rea or, essures less than 100 psig when both pumps are operating, j causing the system to isolate on high delta flow.
As a result of previous RWCU isolations, efforts were begun to make personnel aware of certain operating conditions that could cause flow peturbations.
Plant procedures were changed to provide adequate margin in the pump suction pressure to prevent system isolation. All licensed operations personnel were instructed on the significance of these changes and conditions in which an RWCU isolation could occur.
This violation occurred due to a licensed operator's failure to follow plant procedures.
Had the licensed operator referred to the applicable operating instructions, he would have realized that the transfer from pre-pump to post-pump modes, and placing the second pump in service, should not have been performed until the required reactor pressures were achieved.
Further investigations revealed that an inadequate pre-shift briefing was also a contributing factor, i.e., discussions on required hold points were not conducted by the responsible shift superintendents.
This incident was documented and reported in License Event Report (LER) Number 90-27-01.
V10L9025/SCMPFLR
Attachment to GNRO-91/00024 5
11.
The Corrective Steps That Have Been Taken And The Results Achieved Due to the nature of this incident (i.e., failure to follow procedures) the licensed operator involved was counselled and subsequent disciplinary actions taken.
Also, the responsible shift superintendents were counselled on the importance of conducting proper pre-snift briefings, 111.
The Corrective Steps That Will Be Taken To Avoid Further violation Entergy Operations, Inc. considers the actions taken in Section 11 adequate to preclude further violations.
IV.
The Date When Full Compliance Will Be Achieved Full compliance has been achieved.
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