ML20212J661
| ML20212J661 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/19/1987 |
| From: | Allen C COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION (ADM) |
| Shared Package | |
| ML20212J664 | List: |
| References | |
| RTR-NUREG-1032 2530K, NUDOCS 8701280264 | |
| Download: ML20212J661 (5) | |
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Reply to: Post Omco Box Chca00, 767 Hlinois vf Chca00, Hlinois 60800 0767 January 19, 1987 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 i-
Subject:
LaSalle County Station Units 1 and 2 Proposed Amendments to Technical Specification for Facility Operating
- Licenses NPF-11 and NPF To Allow One Unit Operation with "O" DG OOS for Specified Required Surveillances WRC Docket No. 50-373 and 50-374 References (a)
- W. R. Butler letter to D. L. Farrar dated November 13, 1985 Issuance of Am. No. 16 to NPF-18.
(b): H. L. Massin letter to H. R. Denton dated August 23, 1985.
(c): H. L. Massin letter to H. R. Denton dated
- August 28, 1986.
- (d)
- ..C. M. Allen letter to H. R. Denton dated October 14, 1986.
(e): Draft NUREG-1032 concerning Station Blackouts.
, (f): UFSAR Figures 8.1-1 an 8.1-2.
Dear Sir:
Pursuant to 10 CFR 50.90, Commonwealth Edison proposes to amend Appendix A, Technical Specification, to Facility Operating Licenses NPF-11 and NPF-18. These amendment changes are being submitted for your staff's review and approval to permit continued operation of one unit for up to 7 days with "O" D.G. out-of-service. This would apply only during the performance of preplanned preventative maintenance activities involving the 18 month inspection and/or the 10 year fuel tank cleaning. Also included in this request is the elimination of previous footnotes from temporary Technical Specification revisions.
Attachment A provides background and discussion. The proposed revised Technical Specification page changes are enclosed in Attachment B.
The attached change has received both On-Site and Off-Site review and approval. We have reviewed this amendment request and find that no significant hazards consideration exists. This review is documented in Attachment C. \
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H. R. Denton January 19, 1987 Attachments D and E are copies of references (a) and (b). They are provided as a convenience for your Staff's review of this proposal.
Commonwealth Edison is notifying the State of Illinois of our request for this amendment by transmitting a copy of this letter and attachments to the designated State Official.
Please note that your approval of this change is required EEl or to scheduling of the required surveillances. Commonwealth Edison requests that you consider this be a high priority item, to be concluded at the earliest possible date.
Please direct any questions you may have concerning this matter to this office.
A fee remittance in the amount of $150.00 is enclosed in compliance with 10 CFR 170.
Ve y truly yours, I ww C. M. Allen Nuclear Licensing Administrator klj Attachments cc: Dr. A. Bournia Regional Administrator - RIII Resident Inspector - LSCS M. C. Parker - IDNS SUB IIBED AND Sy to bef E me this / day of /ldtMw , 1987 o D1 - 00h
Notary Pu$lic 2530K
ATTACHMENT A TECHNICAL SPECIFICATION CHANGE REQUEST LASALLE COUNTY STATION UNITS 1 AND 2 BACKGROUND AND DISCUSSION This proposal requests that Section 3.8.1.1 of the Unit 1 and 2 Technical Specifications be revised to allow the continued operation of one unit, for a period of 7 days, while the common plant Division 1 diesel generator (O DG) is out of service for the performance of Technical Specification surveillance requirements 4.8.1.1.2d.1 and/or 4.8.1.1.2f.1, without requiring:
- 1. The offsite A.C. electrical power sources and the other operable diesels to be testing immediately and every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, thereafter. (Tech Spec 3.8.1.1, Action a)
- 2. The operating unit to be shutdown after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> when the O DC is taken out of service for performance of the above surveillances. (Tech Spec 3.8.1.1, Action a)
These changes would only be applied to cases involving pre-planned preventive maintenance activities. Experience has shown that performance of surveillance requirement 4.8.1.1.2d.1, which involves disassembly and inspection of the diesel generators, requires longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Also it is anticipated that it will take longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to complete surveil-lance requirement 4.8.1.1.2f.1, which involves draining and cleaning of the diesel fuel oil storage tanks. With this change the station will be able to complete these surveillances with one unit in cold shutdown, refuel model or
-defueled, and the other unit in operation. Under the current Technical Specification action statement requirements, the operational unit could be required to be shutdown after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> which could result in a large economic loss to the company. In the past, surveillance requirement 4.8.1.1.2d.1 was performed during periods which both units were shutdown or by performing the surveillance in parts which could be completed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> . As the diesel generators accumulate more run time the types of reconmended preventive maintenance become more involved making it more difficult to complete this surveillance within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Even if the surveillance is t performed in parts which can be completed in less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, the total j time the diesel generator is unavailable will exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> overall.
Therefore, this proposal does not reduce diesel availability. We have
! concluded that the proposed change will not endanger the health and safety l of the public provided that the following conditions are met before the 0 l diesel generator is taken out of service for completien of surveillance
- requirements 4.8.1.1.2d.1 and/or 4.8.1.1.2f.1
- 1. One of the units must be in cold shutdown, the refueling mode or defueled.
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- 2. Within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to remove of the O diesel generator from service, surveillance requirements 4.8.1.1.la and 4.8.1.1.2a.4 must be successfully completed for the offsite power circuits and for the 1A and 2A diesel generators.
- 3. No maintenance is performed on the offsite power circuits or the 1A and 2A diesel. generators while the O diesel generator is out of service.
- 4. Technical Specification surveillance requirement 4.8.1.1.la is performed daily.
S. The control circuit for the unit cross-tie circuit breakers between buses 142Y and 242Y are temporarily modified to allow the breakers to be closed with a diesel generator feeding one of the buses.
In the event that the above conditions cannot be met, the appropriate Technical Specification action s.atement requirements will be met.
I The first condition minimizes the exposure period with one diesel generator inoperable and the consequences of Loss of Offsite Power (LOOP) transient. The next three conditions reduce the probability that an ESF bus will be without power, and the last condition helps to ensure that power will be available to at least one of the ESF buses following a LOOP event.
The proposed Technical Specification changes are justifiable for the following reasons:
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- 1. The probability that a station blackout will occur during any 7 day period is extremely unlikely.
- 2. The operating unit can be. safely shutdown following a LOOP transient even if one of the remaining diesel generators fails to start.
l The chances that a station blackout will occur is negligible due to l the high reliability of the Commonwealth Edison Company transmission network, the LaSalle switchyard, and its diesel generators. Based on operational experience, the reliability of these systems is considerably higher than the industry average. The average nuclear power plant experiences about one LOOP event every ten years (Reference (e)). Part of the reason for our high reliability is that the switchyard is designed so that a single failure cannot cause a LOOP. The switchyard is connected to four 345 KV transmission l
lines and is arranged in a ring-bus configuration with ten circuit breakers l (Reference (f)). Thus, any system fault or equipment failure is quickly located and isolated.
The LaSalle diesel generators also have a higher than average reliability. The average emergency diesel generator has a reliability of 0.98 (Reference (f)), and those at LaSalle Station have a reliability that exceeds 0.98. As indicated by station records, the diesel generators have been started over 450 times with only three valid failures, since the start of 1984.
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The-justification for these changes was previously accepted by the NRC for a similar change to the Unit 2 Technical Specifications (Reference (a)) and is currently under consideration by the NRC for a change to the Unit 1 Technical Specifications (Reference (d)). These changes involved an amendment to the Units 1 and 2 Technical Specifications to allow one unit to operate for a period of thirty days with a diesel generator in the other unit out-of-service for the installation of a lube oil modification. The documentation provided in References (a), (b) and (c) also supports this proposed Technical Specification change request (see Attachments D and E).
This proposal also requests the deletion of the following temporary Technical Specification changes made to the Unit 1 (NPF-11) and Unit 2 (NPF-18) Technical Specifications. These temporary changes are no longer needed and deletion of the changes will not endanger to the health and safety of the public:
- 1. Remove the footnotes "*" and "1", at the bottom of page 3/4.8.la, of the Unit 2 Technical Specifications, which were inserted (Amendment 16) to allow operation of Unit 2 while the diesel generator pre-lube modification was being installed on the Unit 1 diesel generators. Since these modifications have been completed on Unit 1, this temporary change is no longer needed.
I 2. Remove the footnote "*", at the bottom of page 3/4.8-4, of the Unit 1 Technical Specifications which was inserted (Amendment 24) as a one-time-only extension of 18 month interval surveillance requirement 4.8.1.1.2d. The Unit 1 first refuel outage has been completed and the surveillances, for which the time extension was granted, have been successfully completed.
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- 3. Remove the footnote "*", at the bottom of page 3/4.8-4, of the Unit 2 Techncial Specifications which was inserted (Amendment 13) as a one-time-only extension of 18 month int;rval surveillance requirement 4.8.1.1.2d. The Unit 1 first refuel outage has been completed and the surveillances, for which the time extension was granted, have been successfully completed.
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