ML20246B125
| ML20246B125 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 07/03/1989 |
| From: | Morgan W COMMONWEALTH EDISON CO. |
| To: | Murley T Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20246B128 | List: |
| References | |
| 0191T:2, 191T:2, NUDOCS 8907070206 | |
| Download: ML20246B125 (4) | |
Text
{{#Wiki_filter:m gy,Sj: f V p' H/ J'Commonw::cith Edison Mp fy-) ~ -{ .l 4 72 West Adams Street. Chicago, Illinois 6 7g Address Reply to: Post Offee Box 767 ?'- . -_ N -* Chicago, Illinois 60690 - 0767 - 4 4 I e July 3, 1989- ~ f g Dr. Thomas.E..Murley, Director Office of Noclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555' i
Subject:
LaSalle County Station Units 1 and 2 Supplements to Application for Amendment to'Facl11ty Operating Licenses NPF-11 and NPF Diesel Generator. Technical Specifications NRC DockeL Nos. 50-373.End 50-374 ll^ ' References (a): C.H. Allen letter to U.S. NRC dated July 28, 3967. j. l ,.E. Morgan letter to T.E. Murley dated i '(b): W l' November 2, 1988. 1
Dear Dr.lMurley:
,p preferences 'a) and (b) submitted Commonwealth Edispn's. request for an ( amendment' to Facility Operatihg Licenses NPF-11 and NPF-18, Appendix A, Technical Specifications. The purpose of this amendment request was to ' clarify.the Diesel Generator Technical Specification wording which had been determined to be ambiguous. 1 The following submittal is being transmitted at your staff's request to: provide more detailed information in the Technical Specification bases con- 'cerning application of the footnotes and, additionally, it amends the Technical
- Specifications to clarify the diesel generator loading requirements.
l I l ) 9907070206 890703 PDR ADOCK 05000373 P PDC
T.E. Murley July 3, 1989 Attachment A provides an introduction and discussion. Attachment B provides copies of the changes to be made to the Facility Operating License. Commonwealth Edison has reviewed this docmnent and finds that no significant hazards exists. This review is documented in Attachment C. Attachment D provides the LaSalle County Station SSER (NUREG-0519), Pages 16-1 and 16-2, which supports this snendment request. If you have any additional questions regarding this matter, plence contact this office. Very truly yours, OW. SV) W. E. Morgan g Nuclear Licensing Administrator 3m Attachments cc P.C. Shemanski - Project Manager, NRR A.B. Davis - Regional Administrator, RIII Senior Resident Inspector - LaSalle County Office of Nuclear Facility Safety - IDNS 01917 1-2
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ATIACIRHMI A f j BACKGROUND _AHQ_ DISCUSSION y i EACKGRQUNR A question'concerning interpretation of the technical specification requirements.for the frequency of fast starting and loading of the diesel b .g nerators from ambient conditions has been raised by the NRC. Technical Specifications 4.8.1.1.2.a.4 and 4.8.1.1.2.a.5 originally required a fast start and. loading'of the diesel generators in accordance with Table 4.8.1.1.2-1 (normally on a monthly basis). A footnote was added to the Unit I specifica-tions (prior to licensing) to relax these requirements such that a fast start ,and load would only be required semi-annually. The balance of the monthly . tests would include a warmup period, as recommended by the manufacturer to minimize the mechanical stress and wear, caused by fast starting and loading of the diesel generators. The question regards the ambiguity in the wording ' of the footnote which could be Interpreted to apply the relaxation to the 13 second start requirement in Technical Specification 4.8.1.1.2.a.4 only, and not to the 60 second load requirement in Specification 4.8.1.1.2.a.5. The station has always applied the footnote.to both surveillance requirements. On July 28, 1989, Commonwealth Edison submitted an snendment request (Reference (a))-to revise gie technical specifications accordingly'. Upon l review of the submittal, the NRC expressed some additional concerna about the wording and placement of the footnotes and requested that Commonwealth Edslon revise the footnote to further' clarify the issue. These changes were 1 submitted to the NRC on November 2, 1988 (Reference (b)). After. review of the latest submittal, the NRC requested that Commonwealth Edison provide; more detailed information in the Technical Specification bases, concerning application'of the footnotes and, in addition, that the Technical Specifications be amended to clarify diesel generator loading requirements. 1 l D HCUSSION The diesel generators are equipped with a pre-lubrication.sys: tem which maintains a continuous flow of oil to the diesel engine moving parts i g l while the engine is shutdown. The purpose of this system is to increase long { term diesel generator reliability by reducing the stress and wear caused by i frequent dry starting of the diesel generator. The diesel generator pre-l ' lubrication process may be accomplished either through, normal operation of the installed pre-lubrication system, or by manual pre-lubrication of the i diosel generator in accordance with manufacturers instructions. A l'ow speed start (idle start) of the diesel generator is not considered to be a means of ) ' pre-lubrication. It is proposed that the following footnote be placed in the ' Technical Specifications and identified with all surveillance which require diesel generator starts. i 1 01917:2 l-
3 a 1 i All planned diesel generator starts performed for the purpose of f. meeting these surveillance requirements, may be preceded by an engine l prelube period, as recommended by the manufacturer. Analysis has shown that testing which includes a semi-annual fast start of the diesel generators is sufficient to demonstrate the capability of the on-site AC power system to mitigate the consequences of the design basis event for the plant (i.e., large LOCA coincident with a loss-of-offuite power). All other engine starts, for the purpose of meeting the diesel generator surveillance requirements, may be preceded by a warm-up period of low speed L operation (idle start), and gradual loading procedures, as recommended by the I manufacturer, so that mechanical stress and wear on the diese] generators is minimized. It is proposed that the following footnote be placed in the technical specifications and identified with Technical Specification 4.0.1.1.2.a.4 and 5. Surveillance testing to verify the diesel generator start (13 second) and load (60 second) times from ambient conditions shall be performed I at least once per 184 days. All other engine starts performed for I the purpose of meeting these surveillance requirements may be l conducted in accordance with warm-up and loading procedures, as recommended by the manufacturer, so that mechanical stress and wear on the diesel generators is minimized. To further clarify the loading requirements, the NRC has requested that Commonwealth Edison specify in Technical Specification 4.8.1.1.2.a.5 an acceptable load band for diesel generator loading. Currently the technical specifications require that the diesel generator be loaded to a value greater than or equal to 2600 kW. The technical specification as written could result in routine overloading of the diesel generator. Therefore, it is proposed the l Technical Specification 4.8.1.1.2.a.5 be amended to allow a load range between 2400 kW and 2600 kW, for the surveillance. This is a sufficient load to verify diesel operability while providing operational flexibility and ensuring that the diesel generator is not routinely overloaded. The following footnote will also be added to the technical specifications to provide guidance during j application of the new load band. l
- Transients, outside of this load band, do not invalidate the surveillance tests.
Momentary transients outside of the load band due to changing bus conditions should not prevent satisfactorily assuring that the diesel meets I the surveillance requirements. l Based on the above discussion, it is proposed that the Unit 1 (NPT-11) and Unit 2 (Npr-18) technical sp ecifications be revised to include the changes ar described above and shown in Attachment B. 0191T 4 _ _ - _. _ _ _ _ - _}}