ML20046A493
| ML20046A493 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 07/22/1993 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9307280193 | |
| Download: ML20046A493 (2) | |
Text
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BALTIMORE F
GAS AND 4
- ELECTRIC 1650 CALVERT CUFFS PARKWAY. LUSOY, M u
357-4702 ROBERT E. DENTON Vict PatsioENT NUCLEAR ENERGY (410) 260-4455 July 22,1993 U. S. Nuclear Regulatory Commission Washington,DC 20555 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Revision to License Amendmeat Request; Onsite Power Distribution Systems. AC Distribution - Operating
REFERENCE:
(a)
Letter from R. E. Denton (BG&E) to NRC Document Control Desk, dated April 1,1993, License Amendment Request; Onsite Power Distribution Systems, A.C. Distribution - Operating The referenced lettet requests a 48-hour Allowed Out-of-Service Time (AOT) when a 120 Volt AC vital bus is being powered from the inverted backup bus. This AOT extension from the current 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 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 a 24-hour AOT for this condition. In order to maintain consistency with this standard, we hereby revise our request to reflect a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AOT. Attached is a revised " Insert A" for Attachments (1) and (2) of the referenced submittal.
The justification for a 24-hour AOT is the same as the justification for a 48-hour AOT. Changing the
- j requested AOT from 48 to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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.
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l 9307280193 930722 0
POR ADOCK 05000317 2 P
' Document Control Desk
^
July 22,1993 Page 2 e
' Should you have any questions regarding this matter, we will be pleased to discuss them with you.
N truly yours, -
i
.i
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]M k
STATE OF MARYLAND :
a TO WIT :
.3 COUNTY OF CALVERT I hereby certify that on the J4.Y day of h L-
,19H, 3re me, the subscriber, a Notary Public of the State of Maryland 66~ and for,/'a /mit.
AC -
i personally appeared Robert E Denton, bcing duly sworn, and states that he is Vice Pdsident of the 4
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 to the best of his knowledge, information, and belief; and that he.was authorized to provide thel i
response on behalf of said Corporation.
he b e e dg.,
WITNESS my Hand and Notarial Seah Notary Public
/
a My Commission Expires:
/, /99M' U
fate' RED,73DM/bdm/ dim Attachments: As Stated cc:
D. A. Brune, Esquire f
J. E. Silberg, Esquire i
R. A. Capra, NRC D. G. Mcdonald, Jr., NRC -
T. T. Martin, NRC P. R. Wilson, NRC ci R. I. Mclean, DNR J. H. Walter, PSC 1
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