ML20101M568
| ML20101M568 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 12/28/1984 |
| From: | Fay C WISCONSIN ELECTRIC POWER CO. |
| To: | Harold Denton, John Miller Office of Nuclear Reactor Regulation |
| References | |
| GL-83-28, TAC-53140, TAC-53141, NUDOCS 8501030151 | |
| Download: ML20101M568 (2) | |
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Msconsin Electnc rowca couraur 231 W. MICHIGAN, P.O. BOX 2046. MILWAUKEE, WI 53201 December 28, 1984 Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U.
S. NUCLEAR REGULATORY COMMISSION Washington, D. C.
20555 Attention:
Mr. J. R. Miller, Chief Operating Reactors, Branch 3 Gentlemen:
DOCKET NOS. 50-266 AND 50-301 REQUEST FOR ADDITIONAL INFORMATION RESPONSE TO GENERIC LETTER 83-28 REQUIRED ACTIONS BASED ON GENERIC IMPLICATIONS OF SALEM ATWS EVENTS POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 Additional information was requested by your November 23, 1984 letter regarding Generic Letter 83-28, Items 4.2.1 and 4.2.2, preventative maintenance program for reactor trip breakers and trending of reactor trip breaker parameters, based on your review of our November 7, 1984 response to Generic Letter 83-28 for the Point Beach Nuclear Plant, Units 1 and 2.
In response to your request that we confirm that our periodic maintenance program includes the twenty items at the specified intervals listed in your November 23, 1984 letter, the current Point Beach Nuclear Plant maintenance procedure used to maintain the reactor trip and bypass breakers, Routine Maintenance Procedure (RMP 26), Revision 1, addresses all items listed in your letter with the exception of verifying cell interlock operation.
Revision 2 of RMP 26 will include verification of cell interlock operation.
Revision 2 of RMP 26 is currently being reviewed prior to approval.
Approval is expected prior to the 1985 Unit 1 refueling outage when the next periodic maintenance is due to be performed on the Unit 1 reactor trip and bypass breakers.
The performance for all items of RMP 26 is on a refueling interval basis.
The refueling interval periodicity for all items is in accordance with the Westinghouse Generic Procedure for Reactor Trip Switchgear, Revision 0 dated October 14, 1983, which allows that
"... the semi-annual activities might be extended to 9-12 months if experience shows this to be sufficient provided that 200 breaker cycles are not exceeded during this interval."
Our experience with the reactor (Oh 8501030151 841228
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Denton December 28, 1984' trip and bypass breakers has demonstrated tha~t these devices are very reliable and that minimal correcti.ve maintenance is required.
The number of breaker cycles is not expected to exceed forty during the interval of operation between refueling outages.
Additionally, biweekly functional tests are performed on.the. reactor trip and bypass breakers.
Therefore, we consider the refueling interval periodicity for all items of the maintenance procedure to be justified.
The following information is provided in response to your request that we commit to the inclusion of trip force, i
breaker response time for undervoltage trip, and. breaker I
insulation resistance as trending parameters.
The Point Beach Nuclear Plant maintenance group trends the undervoltage trip attachment dropout voltage, as recommended by the. Westinghouse Generic Procedure for Reactor Trip Switchgear, Revision 0 dated October 14, 1983, as part of RMP 26 on a refueling interval basis.
The trip force and breaker response time for undervoltage trip are recorded and compared to the maximum acceptable values of'31 ounces and 10 cycles, respectively.
Since the trip force and breaker response time for undervoltage; trip are considered "go" or "no go" parameters, the recorded forces and response times are not trended.
Additionally, the breaker insulation is not meggared to trend breaker insulation resistance.
The breakers are cleaned, inspected for insulation cracks, and operated at less than one half of rated voltage.
Therefore, trending of insulation resistance is not considered necessary for the reliable operation of the breakers.
Please contact us if you have any questions regarding the above information.
Very truly yours, 7
Vice President-Nuclear Power C. W. Fay Copy to NRC Resident Inspector Subscribpd and sworn to before me this Jffdf da of December 1984.
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Notary Public, State of Wisconsin My Commission expires M /9U.
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