ML20113G194
| ML20113G194 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/18/1985 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | John Miller Office of Nuclear Reactor Regulation |
| References | |
| GL-83-28, NUDOCS 8501240277 | |
| Download: ML20113G194 (4) | |
Text
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BALTIMORE GAS AND ELECTRIC CHARLES CENTER.P.O. BOX 1475 BALTIMORE, MARYLAND 21203 ARTHUR E. LUNDVALL, JR.
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VtCE PntseDENT SUPPLY U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C. 20555 ATTENTION:
Mr. James R. Miller, Chief Operating Reactors Branch #3 Division of Licensing
SUBJECT:
Calvert Cliffs Nuclear Power Plant Units Nos.1 & 2; Docket Nos. 50-317 & 50-318 Supplemental Response to Generic Letter 83-28, " Required Actions Based on Generic Implications of Salem ATWS Events"
REFERENCES:
(a)
Letter from A. E. Lundvall, J r.,
to D.
G. Eisenhut dated November 5,1983, same subject.
(b)
Letter from A. E. Lundvall, J r.,
to D. G. Eisenhut dated February 29,1984, same subject.
(c)
Letter from 3.
R.
Miller to A.
E.
Lundvall, J r.,
dated December 14,1984, same subject.
Gentlemen:
f.
The enclosure provided herein constitutes our reply to the 30-day response requirements of Reference (c). References (a) and (b) forwarded our original response to the subject Generic Letter. also provides a scheduled date for the completion of
- specific items requested.
Should you have further questions regarding this reply, please do not hesitate to contact us.
Very truly yours,
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Mr. James R. Miller January 18,1985 Page 2 cc:
D. A. Brune, Esquire G. F. Trowbridge, Esquire D. H. Jaffe, NRC T. Foley, NRC
ENCLOSUREI RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION GENERIC LETTER 83-28 ITEMS 4.2.1 AND 4.2.2 ITEM 4.2.1 Periodic Maintenance Program for Reactor Trip Breakers.
NRC REQUEST 1.1 Provide a commitment to the six month maintenance activity interval or justification for any other proposed maintenance interval.
BG&E RESPONSE As stated in our response to Item 4.2.1 contained in Reference (a), we have a monthly surveillance test, a quarterly Preventive Maintenance (PM) and an annual Preventive Maintenance procedure.
We do not see a need at present to reduce our annual maintenance interval to a six month period. Maintenance Instruction GEI-50299El states:
... Periodic inspection of the circuit breaker is recommended at least once a year.
More frequent inspections are recommended if severe load conditions, dust, moisture, or other unfavorable conditions exist..."
Reactor trip breakers at Calvert Cliffs are not subject to unfavorable environmental conditions or severe load conditions.
Our reactor trip switchgear is located in an environmentally controlled space. We have found the annual maintenance interval to be satisfactory in conjunction with the monthly surveillance testing. Applicable portions of the annual preventive maintenance are performed on breakers that do not meet the monthly surveillance testing acceptance criteria.
Should conditions or _ test results warrant, the maintenance interval would be reduced appropriately for a given breaker.
NRC REQUEST 1.2 Confirm that the Reactor Trip Breaker periodic maintenance program includes the 13 items listed in Reference (c) at the specified interval or commit to their inclusion and provide a date by which they will be included.
BG&E RESPONSE Our monthly Surveillance Testing Procedure presently includes items 9,11 and 13. Our quarterly PM procedure, PM No.1(2)-58-E-Q-1, presently includes items 7 and 13. Our annual PM procedure, PM No.1(2)-58-E-A-1 currently includes items 1 through 9, and 11 through 13, with the exception of the insulation resistance checks in item 1.
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ENCLOSURE 1 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION GENERIC LETTER 83-28 ITEMS 4.2.1 AND 4.2.2 Item 10 is not a maintenance item, but does require vendor replacement of bearings. We are in the process of upgrading all our reactor trip breakers and spares to use the Mobil 28 lubricant by replacing the front frame assemblies. Once this is complete, there will be no need for maintenance procedures to address lubrication of the bearings.
Lubrication is not possible without replacing the bearings.
A one-time upgrade to Mobil 28 lubricant is all that is required.
We will rev;se our maintenance procedures by March 31,1985, to include any portions of items 1 through 9 and 11 through 13 not presently included. As stated in our response to NRC Request No.1.1, we will maintain our maintenance periodicity at an annual interval.
ITEM 4.2.2 Trending of Reactor Trip Breaker Parameters to Forecast Degradation of Operability.
NRC REQUEST 2.1 & 2.2 Provide a commitment to inclusion of trip torque, dropout voltage for undervoltage trip, and breaker insulation resistance as trending parameters. Identify the organization which will perform trend analysis, how often the analysis will be performed, and how the information derived from the analysis will be used to effect periodic maintenance.
BG&E RESPONSE Our annual preventive maintenance, PM No.1(2)-58-E-A-1, presently includes response time, trip torque, and dropout voltage for undervoltage trip as trending parameters. We will revise our PM procedure by March 31,1985, to include breaker insulation resistance checks.
Additionally, our quarterly preventive maintenance, PM No.1(2)-58-E-Q-1, presently Inc.ludes trip torque measurements as trending parameters.
Our Electrical and Controls Engineering Unit reviews all reactor trip breaker data for trending purposes. Time response is trended monthly, trip torque and dropout voltage are trended at least annually and more frequently if performed as part of corrective maintenance. Breaker insulation resistance data will be trended at least annually. All trending results are used to anticipate and identify potential problems, plan corrective maintenance, and recommend changes in maintenance intervals, if required.
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