ML20212E634
| ML20212E634 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/23/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18039A874 | List: |
| References | |
| NUDOCS 9909270079 | |
| Download: ML20212E634 (3) | |
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4 UNITED STATES f.
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NUCLEAR REGULATORY COMMISSION i
' t' WASHINGTON, D.C. 20555-0001 49.....,o SUPPLEMENT TO SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 259 TO FACILITY OPERATING LICENSE NO. DPR-52.
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' AND AMENDMENT NO. 218 TO FACILITY OPERATING LICENSE NO. DPR-68
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TENNESSEE VALLEY AUTHORITY l
BROWNS FERRY NUCLEAR PLANT. UNITS 2 AND 3 DOCKET NOS. 50-260 AND 50-296
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1.0 BACKGROUND
l On August 2,1999, the U.S. Nuclear Regulatory Commission issued Amendments Nos. 259 and 218 to Facility Operating License Nos. DPR-52 and DPR-68 for the Brov ns Ferry Nuclear j
Plant, Units 2 and 3, respectively.
The amendments changed the Technical Specification (TS) COMPLETION TIME for REQUIRED ACTION 3.8.1.B.4 for Units 2 and 3 from existing 7 days to 14 days. This permits an extension of the allowed outage time from 7 days to 14 days for an inoperable emergency diesel generator.
The staffs evaluation of the licensee's August 2,1999, application encompassed a review of information presented in the licensee's March 12,1997 application, and in letters dated March 30,1999, April 23,1999, and June 18,1999. The staff also considered information provided in the licensee's submittals dated June 19,1997 and August 15,1997 regarding a one-time extension of emergency diesel generator (EDG) allowed outage time (AOT) from 7 days to 14 days. The one-time extensions were approved as Amendment Nos. 250 and 209, respectively, for Units 2 and 3.
'2.0 ERROR IN SAFETY EVALUATION
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The Safety Evaluation enclosed with the August 2,1999, amendments encompassed both a deterministic and a probabilistic evaluation. The deterministic evaluation included a discussion of compensatory measures, incorrectly stating:
j 3.1.4 Compensatory Measures To limit other activities to minimize the potential for a loss of offsite power sources, and to maximize the availability of other onsite sources, the licensee implements the following compensatory measures during EDG maintenance l
outages:
(1) Ensures availability of an extra offsite power source available to the affected unit, above and beyond the two offsite sources reqded by the TS; i
9909270079 990923 PDR ADOCK 05000260 EUCLOSURE P
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' (2) Restricts work activities that could affect the ability to cross-tie the opposite EDG unit to the 4-kV shutdown board; and (3) Restricts work activities on the 500-kV switchyard and stop scheduling high risk switchyard maintenance.
The probabilistic evaluation in Section 3.2.2 correctly stated:
The licensee did not identify additional TS restrictions or compensatory measures required to avoid potential risk significant configurations during an EDG outage.
The compensatory measures identified in Section 3.1.4 of the August 2,1999, safety evaluation were commitments of the application dated June 19,1997 and applied only to the no-longer-effective one-time extension.
In preparing this supplement, the staff reconsidered the need for interim compensatory measures such as those specified in temporary Amendment Nos. 250 (Unit 2) and 209 (Unit 3).
The staff concluded that, with respect to the deterministic evaluation, and consistent with the probabilistic evaluation, no specific compensatory-measures commitment is necessary in conjunction with the additional 7-days AOT. This finding was based on the uniquely high degree of redundancy and flexibility of the Browns Ferry power distribution system. These redundancy and flexibility features include: a 500-kV switchyard with seven offsite power sources, a 161-kV switchyard with two offsite power sources, four EDGs per operating unit, and a bus tie board which provides shutdown board intertie capability among the eight EDGs.
3.0 CORRECTION This supplement resolves an error in the original August 2,1999, Safety Evaluation, clarifying the fact that the licensee has not committed to retain those specific compensatory measures that were applied to the one-time extension,.and confirms that this does not alter the conclusions of the August 2,1999, Safety Evaluation.
Principai ,ontributor: William O. Long, NRR Date: September 23, 1999 L
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Mr. J. A. Scalice BROWNS FERRY NUCLEAR PLANT Tennessee Valley Authority cc:
Mr. Karl W. Singer, Senior Vice President Mr. Mark J. Burzynski, Managar Nuclear Operations Nuclear Licensing l
Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place 4X Blue Ridge 1101 Market Street 1101 Market Street Chattanooga, TN 37402-2801 Chattanooga, TN 37402-2801 Mr. Jack A. Bailey, Vice President Mr. Timothy E. Abney, Manager Engineering & Technical Services Licensing and Industry Affairs Tennessee Valley Authority Browns Ferry Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Decatur, AL 35609 Mr. John T. Herron, Site Vice President Senior Resident Inspector Browns Ferry Nuclear Plant U.S. Nuclear Regulatory Commission Tennessee Valley Authority Browns Ferry Nuclear Plant P.O. Box 2000 10833 Shaw Road Decatur, AL 35609 Athens, AL 35611 General Counsel State Health Officer Tennessee Valley Authority Alabama Dept. of Public Health ET 10H RSA Tower - Administration 400 West Summit Hill Drive Suite 1552 Knoxville, TN 37902 P.O. Box 303017 Montgomery, AL 36130-3017 Mr. N. C. Kazanas, General Manager Nuclear Assurance Chairman Tennessee Valley Authority Limestone County Commission SM Lookout Place 310 West Washington Street 1101 Market Street Athens, AL 35611 Chattanooga, TN 37402-2801
- Mr. Robert G. Jones, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority
- P.O. Box 2000 Decatur, AL 35609 i
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