ML20045H382
| ML20045H382 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 07/07/1993 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9307200149 | |
| Download: ML20045H382 (3) | |
Text
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BALTIMORE GAS AND ELECTRIC n
1650 CALVERT CUFFS PARKWAY. LUSBY, MARYLAND 20657-4702
'13ERT C. DENTON July 7,1993 Vect PRE $10ENT NUCttAR ENER0f (4ao) 260-44S5 U. S. Nuclear Regulatory Commission Washington, DC 20555 A'ITENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Modification to Our Station Blackout Rule Response
REFERENCES:
(a)
Letter from Mr. R. E. Denton (BG&E) to NRC Document Control Desk, dated May 7,1993, Response to the Station Blackout Ru'e (b)
Letter from Mr. D. G. Mcdonald, Jr. (NRC) to Mr. G. C. Creel (BG&E), dated February 12, 1991, Response to Station Blackout Rule - Calvert Cliffs Nuclear Power Plant, Units 1 and 2, TAC Numbers 68525 (Unit 1) and 68526 (Unit 2)
(c)
Letter from Mr. R. E. Denton (BG&E) to NRC Document Control Desk, dated April 7,1993, Emergency Diesel Generator Project -
Diesel Generator Qualification Report, Revision 1 Gentlemen:
As stated in Reference (a), we have changed our response to the station blackout rule (10 CFR 50.63). Instead of installing two safety-relat'A emergency diesel generators (total o'five for the site), we are now going to install one safety-related diesel generator and one non-safety-related alternate AC power source. As described below, we are still in compliance with the station blackout rule requirements. We request the NRC review and approve this change to our station blackout rule response.
EXISTING EMERGENCY DIESEL GENERATOR CONFIGURATION Calvert Cliffs is a two-unit site. He present emergency AC power configuration has one emergency diesel generator (EDG) dedicated to each unit with a third EDG (shared) that is connectable to one safety bus in either unit. The EDGs are 4160 volt, 3-phase diesel generators with a nominal continuous rating of 2500 kw each. He three EDGs are physically separated and electrically isolated from each other. If one of the three dicscis fails to start or carry load, the system continues to provide electrically-independent channels of emergency power to the plant.
Based on tbc guidancc wided in Reg Guide 1.155 and NUMA.RC 87-00, we have determined our coping duration category the esisting diesel generator configuration. We are a P2 offsite power group, an EAC group of t and have targe' reliability of 0.975. Therefore, our required coping 9367EOOIW '9307o7 0p w
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Document C(mtrol Desk July 7,'l993 Page 2 duration category is eight hours with our current diesel generator configuration (three diesel generators).
DIESEL GENERATOR INSTAILATION As required by NUMARC Station Blackout Initiative 1, we are undertaking actions to reduce our risk due to station blackout. We are reducing the required coping duration to four hours by installing an additional Class 1E diesel generator (bringing the site total to four). In addition, we are also installing an alternate AC power source which will meet the criteria provided in NUMARC 87-00, Appendix B and Regulatory Guide 1.155, Appendix A.
To elaborate further, the addition of another Class 1E diesel generator to our site will result in two dedicated diesel generators per unit. This changes our EAC group from D to C (one diesel generator out of two required to safely shutdown the unit). Then, based on an offsite power group of P2, an EAC group of C, and a target reliability of 0.975, our required coping category is four hours, assuming the new Class 1E diesel generator is installed. We have performed a coping analysis for four hours. The NRC has reviewed and approved (Reference b) c. station blackout response based on our ability to cope with a station blackout for four hours (AC-independent).
In addition, we plan to ado a non-Class 1E diesel generator to our site. It is 5000 kw, SACM diesel generator identical to the une procured for the safety-related application. The dicscl generator and its auxiliaries are procured safety related, however, they will be installed in a non-safety-related building and they will not be maintained as safety related. A testing program identical to the one described for the safety-related SACM diesel generator (Reference c) will be imposed on the non-safety-related diesel generator. He exception to this testing program involves the testing required to verify the automatic start and loading features of the diesel generator. Although non-safety-related, it will have the capability to power the safe shutdown loads on either unit during a station blackout.
It will be designed to meet the criteria of NUMARC 87-00, Appendix B. Quality assurance will be in accordance with the criteria of Regulatory Guide 1.155, Appendix A. This diesel will be manually started and loaded during a stati = 1: %ckout, therefore, we consider it to be capable of responding to a station blackout within one he Adequate information has been preauusly provided, and approval granted for our four-hour coping capability (Reference b).
We recognize, however, that additional information concerning the capabilities and configuration of our non-safety-related (Alternate AC) diesel generator is required before its adequacy can be determined. That information will be provided in a future submittal.
STATION lilACKOUT RESPONSE PROCEDURES f
Emergency Operating Procedure - 7, Station Blackout, describes the actions required to respond to a station blackout. These actions consider the guidance given in Section 4.2.1 of NUMARC 87-00.
Currently, EOP-7 addresses a coping scenario because we do not have alternate AC capability installed yet. The procedure will be changed as the Class 1E diesel generator and the Alternate AC source are installed.
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Document Control Desk July 7,1993 Page 3 i
CONCI,USiON We request the NRC review and approve our response to the station blackout rule based on the revised scope described above. This new dicsci configuration supports both a four-hour coping duration determination as an AC independent plant and a one-hour coping duration as an alternate AC plant. Additional information will be provided for both the safety-related and the non-safety-related diesel generators. This information can be used by the NRC to approve the adequacy of these diesel generators for their intended purposes.
Should you have any questions regarding this matter, we will be pleased to discuss them with you, ry truly yours, h
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RED / PSF /psCdim/bjd cc:
D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC P. R. Wilson, NRC R. I. McIran, DNR J. H. Walter, PSC l
.