ML20082R858
| ML20082R858 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 12/09/1983 |
| From: | Schroeder C COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20082R861 | List: |
| References | |
| 7763N, NUDOCS 8312130323 | |
| Download: ML20082R858 (5) | |
Text
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Commonwealth ECson l
' One First Nitional Plaza. Chicago. Ilhnois
(
7 Address Reply to. Post Othee Box 767 Chicago. Ilhnois 60690 N.
December 9.
1983 s
Mr. Harold R. Denton, Director Of fice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
LaSalle County Station Units 1 and 2 Request for An Exigent Change to NPF-ll Appendix A Technical Specifications Regarding Diesel Generator Fast Starts NRC Docket Nos. 50-373 and 50-374
Dear Mr. Denton:
The purpose of this letter is to request the following exigent change in Technical Specifications for LaSalle County Station Unit 1 and that the same change be incorporated into the original Unit 2 Technical Specifications.
CHANGE REQUEST NPF-11/83-06 Revise diesel generator specifications to require a " fast start" only once for each diesel generator each six months.
This proposed change is addressed in Attachment A and has received onsite and offsite review and approval.
Guidance for Technical Specification changes states:
" Exigent circumstances exist when a licensee and the NRC must act quickly and time does not allow a full 30-day notice...".
In this case, Commonwealth Edison Company believes that such action is warranted.
Commonwealth Edison Company is requesting that the LaSalle County Station Unit 2 original Technical Specifications, as part o f NPF-18, be issued to minimize " fast starts" on the diesel generators.
These changes which are being made for the purpose of minimizing mechani-cal stress and wear on the diesel generators, require a concurrent change in the Unit 1 NPF-ll Technical Specifications because diesel generators 0, lA, and 2A have surveillance required in accordance with both sets of Technical Specifications.
The 1B and 2B diesel generators are addressed only in the respective Unit 1 and the Unit 2 Technical Specifications.
IN ORDER TO ALLOW THIS STEP TOWARD LESS HARMFUL TESTING OF DIESEL GENERATORS TO BE 1AKEN IN THE PENDING UNIT 2 LICENSE ISSUANCE, AN EXIGENT UNIT 1 CHANGE IS NECESSARY.
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H. R. Denton December 9, 1983 Commonwealth Edison has reviewed this amendment request and has determined that no significant hazard consideration exists.
Our review is documented in Attachment B.
Pursuant to 10 CFR 170, this change reflects one example of a Class III amendment.
A remittance of $4,000 is, therefore, enclosed.
To the best of my knowledge and belief the statements contained herein and in the attachment are true and correct.
In some respects these statements are not based on my personal knowledge but upon infor-mation furnished by other Commonwealth Edison and contractor employees.
Such information has been reviewed in accordance with Company practice and I believe it to be reliable.
Commonwealth Edison is notifying the State of Illinois of our request for this amendment by transmittal of a copy of this letter and its attachments to the designated State Official.
If you have any que.=tions concerning this matter, please contact this office.
Enclosed please find three (3) signed originals and forty (40) copies of this letter and the enclosures.
Very truly yours,
/c /4/ QU)
C.
W. Schroeder Nuclear Licensing Administrator im Attachments cc:
Dr. A. Bournia NRC Resident Inspector - LSCS G. N.
Wright (State of Illinois)
SUBSCRIBED and SWOGN to befor me this 9_Mc day of Mzex/ux_.)
, 1983 ff44 tads 0 -
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-Notary Public 7763N
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ATTACHMENT A LaSalle County Station Technical Specification Change Request Units 1 and 2
SUBJECT:
Diesel Generator Testing Requirements REFERENCES (a):
LSCS Technical Specification 3.8.1.1 and 4.8.1.1.2.
(b):
Marked-Up Technical Specification Pages 3/4 8-1, 8-2, 8-3, 8-7 and B 3/4 8-1 for Unit 1 and Unit 2.
(c):
Memorandum for Power System Branch from Reliability and Risk Assessment Branch dated February 4, 1983, " Frequency of Diesel Generator Fast Start Surveillance Testing by Technical Specifications Requ'.rements."
BACKGROUND:
Reference (a) specifies the requirement for testing the diesel generators.
These requirements specify that the diesel generator be started quickly.
These quick starts place unnecessary mechanical stress and wear on the diesel engine.
In reference (c) the subject of relaxation of fast start surveillance test frequency was investigated and found to be unlikely to impact risk adversely.
DISCUSSION:
To reduce the nicchanien1 stress and wear on the diesel generators while still maintaining assurance that the diesel will perform its design function when required, the requirements to fast start the diesel should be reduced to semiannually (184 days).
Rapid startup engine wear is caused by large dynamic forces and heterogeneous component heating.
The diesel generator will still be started at the same frequency as required by reference (a) to meet the surveillance requirements but these starts will be preceded by an engine prelube period and/or other warmup procedure recommended by the manufacturer so that mechanical stress and wear on the diesel engine is minimized.
This change will increase the reliability of the standby diesel generators since the large number of fast starts will be reduced while the fast start capability will be verified by the semi-annual fast start.
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2-2 DISCUSSION (Cont'd)
The diesel generator starts per Table 4.8.1.1.2-1 will have no time requirements associated with them.
These tests will verify correct generator voltage and frequency and after a warmup period will be syncronized to the grid and i
loaded to 2600 kw for 60 minutes but the 13 second (or 60 seconds) time requirements will not apply for these starts.
Even though these starts have no start time requirements they will be considered to meet the valid test requirement by Reg. Guide 1.108.
The semi-annual (184 days) fast starts will have time requirements as presently required by Technical Specifications 4.8.1.1.2a.4 and 5.
The semi-annual fast starts will~be from ambient conditions without a prior warming up procedure.
In addition, since the warmup procedure will require additional manpower to perform and because it requires additional time to complete the surveillance requirements for slow starts, the time to complete action statements of e?
3.8.1.1 must be increased.
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CONCLUSION:
Commonwealth Edison believes that this change should be added to the Unit 2 Technical Specification prior to license issue and be addea to the Unit 1 Technical Specification by license admendment as an exigent change.
The changes to both documents need to be made at the same time because three of the LaSalle County Station's five diesel generators are contained in both Technica: Specif1-cations and therefore identical surveillance requirements must be maintained to eliminate unnecessary diesel generator starts to satisfy two different Technical Specifica. ions.
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4 ATTACHMENT B Significant Hazards Consideration f
i Commonwealth Edison has evaluated the proposed Technical Specification amendment and determined that it does not represent a significant hazards consideration.
Based on the criteria for defining a significant hazards consideration established in 10 CFR 50.92, operation of LaSalle County Station Unit 1 in accordance with the proposed amendment will not:
1)
Involve a significant increase in the probability or consequences of an accident previously evaluated because the reliability of the diesel generators will be increased due to decreased wear and stress on the diesel engine while verifying the fast start on a semi-annual basis.
The issue has been previously analyzed in reference (c) and found to be "unlikely to impact risk adversely."
2)
Create the possibility of a new or different kind of accident from any accident previously evaluated because the same surveillances are performed and only tne time period has changed.
The failure of a diesel generator is analyzed in the FSAR.
3)
Involve a significant reduction in the margin of safety because the overall reliability of the diesel generators will be maintained and no reduction in availability of the diesel generators will be made.
Based on the preceding discussion, it is concluded that the proposed change clearly falls within all acceptable criteria with respect to the system or component, the consequences of previously evluated accidents will not be increased and tne margin of safety will not be decreased.
Therefore, based cn the guidance provided in Federal Registar and the criteria established in 10 CFR 50.92(e), the proposed change does not constitute a significant hazards consideration.
7763N
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