ML20094K056
| ML20094K056 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 03/12/1992 |
| From: | Cottle W ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GNRO-92-00029, GNRO-92-29, NUDOCS 9203180095 | |
| Download: ML20094K056 (4) | |
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March 12, 1992 U.S. Nuclear Regulatory Commission Mail Station P1-137 Washington, D.C.
20555 Attention:
Document Control Desk
SUBJECT:
Grand Gulf Nuclear Str.lon Unit 1 Docket No. 50-416 License No. NPF-29 Report No. 50-416/92-04-01 dated February 11, 1992 (GNRI-92/00026)
GNR0-92/00029 Gentlemen:
Entergy Operations, Inc. hereby submits the response to Notice of Violation 50-416/92-04-01.
Yours truly, w T~~hX WTC/RR:cg attachment cc: Mr.D.C.Hintz(w/a)
Mr. J. L. Mathis (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)
Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta St., N.W., Suite 2900 Atlanta, Georgia 30323 Mr. P. W. O'Connor, Project Manager (w/a)
Office of Nuclear Reacter Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3 7
Washington, D.C.
20555
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Attachment to GNRJ-92/00029 Notice of Violation 92-04-01 Technical Specification 6.8.1.a, in concert with Appendix A of Regulatory Guide 1.33, requires that unit shutdown procedures be implementad. Integrated Operating Instruction 03-1-01-3 (Revision 36), Plant Shutdown, requires, in step 5.13.2, that surveillance of the rod block function of the source range monitors be performed before decreasing reactor power below range 3 of the intermediate range monitors.
Contrary to the above, on December 30, 1991, shutdown procedures were not implemented in that at approximately 1:15 a.m.
reactor power was reduced to range 1 on the intermediate range monitors prior to performance of step 5.15.2 of Integrated Operating Instruction 03-1-01-3 (Revision 36).
I.
Admisrion or_ Denial of the Alleged Violation Entergy Operations, Inc. admits to this violation.
II.
The Reason for the Violation, If Admitted During a shutdown for an outage on the reactor recirculation water pump, the control rods were driven to their prescribed positions and preparations were made to perform the control red withdrawal block surveillance for the source range monitors (SRMs).
The insertion of rods was suspended and the surveillance was commenced.
Approximately twenty minutes later, the neutron flux decreased below range 3 on the intermediate range monitors (IRMs).
The surveillance was completed approximately thirty minutes af ter commencement of the test.
Prior to the completion of the test, a brief re-criticality occurred due to the temperature decrease of the moderator. As reported in LER 91-016, the performance of the shift operating crew was commendable in anticipating, recognizing and controlling the re-criticality. As a result, the event posed no adverse effects on plant safety or the ability of operable plant safety systems to perform their intended functions.
VIO 92-04-01 l
Attachment to GNRO-92/00029 The completion of the surveillance was delayed due to problems with the SRM surveillance procedure. When the neutron flux is above range three as indicated on the'IRMs or the count rate is greater than 100 counts per second (cps) on the SRMs, all SRM rod withdrawal block alarms are bypassed; therefore, no alarm came in during the performance of the surveillance.
Although-an obscure note in the procedure insinuated that tha alarms were bypassed, the remainder of the procedure led the operators to expect alarms due to the test. 'lhe lack of alarms led to some confusion and a
delay in completing the surveillance.
Upon further investigation, it was determined that similar confusion concerning alarm status had been experienced in the past when performing the SRM surveillance.
Operations personnel felt that the Technical Specifications required performance of the SRM surveillance prior to dropping below range 3 on the IRMs and, therefore, procedure changes to alleviate the problem could not be pursued.
Technical Specification 3/4.3.6, which governs the SRM surveillance, is itself confusing and can be difficult to interpret.
After further review of the Technical Specification and consultation with NRC Region II personnel, it was determined that the Technical Specification as written does allow performance of the SRM surveillance below IRM range 3 such that the rod withdrawal block alarms would not be bypassed.
The procedural constraint requiring completion of the SRM surveillance above IRM range 3 was based on an incorrect-interpretation of Technical Specification 3/4.3.6.
The root cause for this violation is attributed to a poorly constructed Technical Specification which led to the inadequate survaillance procedure.
III. The Corrective Steos Which Have been Taken and the Results Achieved
-A.
The Integrated Operating Procedure (IOI) was changed to delete the 1RM range 3 constraint.
B.
Additionally, the surveillance procedure was changed to be compatible with the IOI. Below IRM range 3,
the SRM rod withdrawal block alarms will be enabled, which is consistent with procedures and ope ator expectations.
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VIO 92-04-01 l-l l
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Attachment to GNRO-92/00029
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tag _j;Lqrrective' Steps Which Will Be Taken To Preclude FJrther Violation.
A.-
Technical' Specification 3/4.3.6 is being reviewed to identify changes necessary to clarify when the SRM
- surveillance; should - be performed and identify other clarifications _which may be helpful in avoiding similar i
confusions.
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V.
Date When Full qpapliance'Will Be Achieved Changes to Technical Specification 3/4'.3.6 will be submitted
' by May 1, 1992.
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