ML17262B064
| ML17262B064 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/17/1992 |
| From: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
| To: | Andrea Johnson NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17262B063 | List: |
| References | |
| NUDOCS 9210280017 | |
| Download: ML17262B064 (2) | |
Text
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89 EAST AVENUE,,ROCHESTER N. Y. 14649-0001 TELEPHONE
,. AstErtCODETt6 5rt6 2700 August 17, 1992
])/ SEES IIPilll I1IIII'p(ii'flflllll AÃip ROCHESTER GAS AND ELECTRIC CORPORATION ROBERT'C. MECREDY Vice President Cinne Nucleer Production s Atee U.S. Nuclear Regulatory Commission Document Control Desk Attn:Allen R. Johnson PWR Project Directorate I-3 Washington, D.C.
20555
Subject:
Electrical (EDSFI)
Unresolved R.E.
Ginna Docket No.
Distribution System Functional Inspection Item 50-244/91-80-06 Nuclear Power Plant 50-244 Ref.(a):
(b)-
Letter from M.W.
- Hodges, NRC, to R.C.
- Mecredy, RG&E,
Subject:
Electrical Distribution System Functional Inspection Report No. 50-244/91-80, dated August 21, 1991 Letter from R.C.. Mecredy, RG&E, to M.W.
- Hodges, NRC,
Subject:
EDSFI Unresolved Items, dated July 17, 1992
Dear Mr. Johnson,
The Electrical Distribution System Functional Inspection Report, Reference (a), Section 2.8, identified an unresolved item involving protection coordination of motors at degraded voltage conditions while attempting to start or while operating in a service factor zone during an accident condition. Preliminary calculations were provided to demonstrate that there 'was 'o immediate cause for concern; RG&E indicated that a coordination analysis was being conducted to resolve this concern,and made a commitment tReference (b)] to complete the analyses for the 480 Vac and 4160 Vac breakers by the end of June and November 1992, respectively.
Our estiiilated completion dates fGrthese anal> ses were based on acquiring documented motor information calculations.
- However, we have now learned that in order to perform these calculations certain specific motor and load data information must be determined by'otor testing since the manufacturer's information is not available.
During the Spring 1992 refueling outage the safety-related 480 Vac motors were tested.
During the 1993 refueling outage the necessary 4160 Vac motors will be tested.
During the EDSFI the NRC was concerned, in particular, with overcurrent protection of the containment recirculation fans arid the service water pump motors.
Field testing performed during the 1992 refueling outage and subsequent modeling shows that a greater margin of safety exists than that which was calculated during the time of the inspection.
Specifically, the starting currents and 9210280017 921016 PDR ADOCK 05000244 PDR
times are less than previously had been assumed.
In addition, field testing and analysis to date has shown that these motors are loaded less than had been assumed.
The combination of these findings has increased the margin between the full load current and the lower band of the breaker pickup current.
The 480 Vac coordination analysis for the safety-related motors is approximately 80O complete and the 4160 Vac coordination analysis will require input from planned.
motor testing during the 1993 refueling outage before it can be completed.
As a result, completion of both of these analyses is scheduled by June 30, 1993.
Very truly yours, GAHN244 Robert C. Mecredy xc:= Mr. Allen R. Johnson (Mail Stop 14D1)
Project Directorate I-3 Washington, D.C.
20555 U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA.
19406 U.S.
NRC Ginna Senior Resident Inspector