ML20057A843
| ML20057A843 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/08/1993 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9309160018 | |
| Download: ML20057A843 (4) | |
Text
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SALTIMORE GAS AND i
ELECTRI 1650 CALVERT CUFFS PARKWAY LUSBY, MARYLAND 20657-4702 ROBERT E. DENTON VICE PRESIDENT NUCLEAR ENERGY (4io) reo-44ss September 8,1993 U. S. Nuclear Regulatory Commission Washington,DC 20555 A'ITENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant i
Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 l
Revision to License Amendment Request; Onsite Power Distribution l
Systems. AC Distribution - Operatine I
REFERENCES:
(a)
Ixtter from R. E. Denton (BG&E) to Document Control Desk (NRC), dated April 1,1993, License Amendment Request; Onsite Power Distribution Systems, A.C. Distribution - Operating (b)
Letter from R. E. Denton (BG&E) to Document Control Desk (NRC), dated July 22, 1993, Revision to License Amendment Request; Onsite Power Distribution Systems, AC Distribution -
Operating References (a) and (b) request a 24-hour Allowed Out-of-Service Time (AOT) when a 120 volt AC vital bus is being powered from the inverter backup bus. This AOT extension from the current i
8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was justified based upon: 1) the increased reliability of the vital bus when using the backup bus; 2) the requested AOT is shorter than the AOT for an inoperable diesel generator which has a similar safety significance; and 3) the low probability of a loss-of-offsite power during the extended period.
NUREG-1432, " Standard Technical Specifications - Combustion Engineering Plants," allows 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to power an inoperable AC vital bus from its backup power supply (a constant voltage source l
transformer). Our proposed change would allow 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to make this alignment. In order to maintain consistency with the standard, we hereby revise our request. Attached is a revised
" Insert A" for Attachments (1) and (2) of Reference (a).
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Reducing the time allowed to power an inoperable 120 volt vital AC bus from its backup power supply does not change the arguments or conclusions of the " Determination of Significant Hazards" section of the original submittal and the request is still considered to not involve a significant hazard.
140085 N[
9309160018 930908 PDR ADOCK 05000317
.P PDR ELL
l Document Control Desk September 8,1993 Page 2 Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours,
)
1 STATE OF MARYLAND :
- TO %IT:
l COUNTY OF CALVERT :
I hereby certify that on the
[ day of %Mber'
,193, before me, the subscriber, a Notary Public of the State of Maryland iri and for Ca lueet Counf t/
personally appeared Robert E. Denton, being duly sworn, and states that he is Vice President of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the foregoing response for the purposes therein set forth; that the statements made are true and correct l
to the best of his knowledge, information, and belief; and that he was authorized to provide the response on behalf of said Corporation.
I WITNESS my Hand and Notarial Scal:
YbEIcIle to.1/1/2 Notary Public 9
k /998 My Commission Expires:
My Date
/
RED /BDM/bdm/bjd
Attachment:
As stated cc:
D. A. Brune, Esquire J. E. Silberg, Esquire l
R. A. Capra, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC P. R. Wilson, NRC R. I. McLean, DNR J. H. Walter, PSC l
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ATTACHMENT REVISED " INSERT A" FOR REFERENCE (A)
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INSERT A 9
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ACTION:
a.
With less than the above complement of 4160 and 480-volt A.C. busses OPERABLE,
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i restore the inoperable bus to OPERAHLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least IIOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SIIUTDOWN within the following j
30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
. i b.
With less than the above complement of 120-volt A.C. vital busses OPERAHLE, s
either:
1.
Restore the de-energized vital bus to OPERABLE status by re-energizing the vital bus from its associated inverter within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least IIOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SIIUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />;
]
OR 2.
Power the vital bus from the associated backup bus within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Rest' ore the vital bus to OPERABLE status by re-energizing the vital bus from its associated inverter within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least IIOT STANDHY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SIIUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
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