RNP-RA/03-0043, Additional Information Regarding Adequacy of Delayed Offsite Power Circuit

Additional Information Regarding Adequacy of Delayed Offsite Power Circuit

ML030980016
Person / Time
Site:	Robinson
Issue date:	04/04/2003
From:	Baucom C Progress Energy Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RNP-RA/03-0043, TAC M97957
Download: ML030980016 (2)

Text

12) Progress Energy Serial: RNP-RA/03-0043 APR 0 4 2003 United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261/LICENSE NO. DPR-23 ADDITIONAL INFORMATION REGARDING ADEQUACY OF DELAYED OFFSITE POWER CIRCUIT (TAC NO. M97957)

Ladies and Gentlemen:

Carolina Power and Light (CP&L) Company, now doing business as Progress Energy Carolinas (PEC), Inc., is submitting this letter to provide additional information regarding the adequacy of the delayed offsite power circuit for H. B. Robinson Steam Electric Plant (HBRSEP),

Unit No. 2.

By letter dated February 14, 1997, the NRC staff requested information regarding the adequacy of the delayed offsite power circuit for HBRSEP, Unit No. 2. The requested information was provided by HBRSEP, Unit No. 2, letter dated March 27, 1997, with supplemental information having been provided by letters dated September 2, 1997, and October 30, 1997.

By letter dated September 10, 1998, the NRC staff summarized the results of an August 17, 1998 meeting with CP&L personnel regarding the status of unit auxiliary transformer backfeeding. In that letter, the NRC staff requested that HBRSEP, Unit No. 2, submit information to address items raised in the NRC staff's safety evaluation, dated June 10, 1997, which evaluated the adequacy of the delayed offsite power circuit for HBRSEP, Unit No. 2. By letter dated October 15, 1998, HBRSEP, Unit No. 2, provided the requested information.

Within the October 15, 1998 letter and at the August 17, 1998 meeting, HBRSEP, Unit No. 2, described activity timelines associated with establishing the backfeed alignment and provided the results of activities performed during Refueling Outage (RO)-18 to validate time estimates for certain tasks that are required in support of establishing the backfeed. Specifically, the October 15, 1998 letter stated that, assuming a Station Blackout (SBO), "the time required to establish backfeed with the current as-built configuration of the electrical distribution system has been estimated to be 221 minutes [3 hours and 41 minutes] after the event," which is within the four (4) hour time period identified in the Updated Final Safety Analysis Report (UFSAR). While it was not practical or feasible during RO-18 to validate time estimates for each aspect of the Progress Energy Carolinas, Inc.

3581 West Entrance Road Hartsville, SC 29550 \

United States Nuclear Regulatory Commission Serial: RNP-RA/03-0043 Page 2 of 2 backfeed evolution, a number of the required actions were walked down and time validated, when possible, or estimated when the action could not be performed. These actions included the hanging of main and auxiliary transformer clearances/tag-outs, the disconnecting of main generator links, the installation of jumpers and removal of clearances/tag-outs, and certain switching operations.

Subsequent to RO-18, additional actions have been taken to review, validate, and modify, as appropriate, the procedure and associated timelines for establishing the backfeed alignment. This includes the walk down and time validation of certain aspects of the backfeed evolution during RO-19 and RO-20. While these efforts have resulted in a minor modification to the backfeed procedure and associated timelines, HBRSEP, Unit No 2, has confirmed through these walk downs and time validation activities that the backfeed alignment can continue to be accomplished within the four (4) hour time period identified within the UFSAR. The previously completed minor modification to the backfeed procedure and associated timelines, and any potential future changes in this area, have been and will be controlled in accordance with the Emergency Operating Procedures program and the requirements of 10 CFR 50.59.

If you have any questions concerning this matter, please contact me.

Sincerely, C. T. Baucom Supervisor - Licensing/Regulatory Programs CTB/ctb c: Mr. L. A. Reyes, NRC, Region II Mr. C. Patel, NRC, NRR NRC Resident Inspector, HBRSEP