ML040700295

RAI, Limiting Conditions for Operations, Increase Completion Time

ML040700295
Person / Time
Site:	Farley
Issue date:	03/11/2004
From:	Sean Peters NRC/NRR/DLPM/LPD2
To:	Stinson L Southern Nuclear Operating Co
Peters S, NRR/DLPM, 415-1842
References
TAC MC1007
Download: ML040700295 (6)

Text

March 11, 2004 Mr. L. M. Stinson Vice President - Farley Project Southern Nuclear Operating Company, Inc.

Post Office Box 1295 Birmingham, Alabama 35201-1295

SUBJECT:

JOSEPH M. FARLEY NUCLEAR PLANT, UNIT 1 REQUEST FOR ADDITIONAL INFORMATION RE: REQUEST FOR TECHNICAL SPECIFICATION CHANGES DC SOURCES - OPERATING (TAC NO. MC1007)

Dear Mr. Stinson:

By letter dated September 19, 2003, Southern Nuclear Operating Company requested amendments to the Technical Specifications (TS) for Farley Nuclear Plant, Unit 1, that would revise TS Limiting Conditions for Operation 3.8.4, DC Sources - Operating, for the remainder of operating cycle 19. Specifically, the proposed TS change would increase the Completion Time for the 1B Auxiliary Building direct current electrical power system inoperability due to an inoperable battery to allow for on-line replacement of individual cells. The Nuclear Regulatory Commission technical staff has reviewed the application and has determined that additional information is required, as identified in the Enclosure.

We discussed these issues with your staff on March 1, 2004. Your staff indicated that you would attempt to provide your response by April 1, 2004.

Please contact me at (301) 415-1842, if you have any other questions on these issues.

Sincerely,

/RA/

Sean E. Peters, Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-348

Enclosure:

As stated cc w/encl: See next page

ML040700295 OFFICE PDII-1/PM PDII-1/LA PDII-1/SC NAME SPeters CHawes JNakoski DATE 3/10/04 3/10/04 3/11/04 REQUEST FOR ADDITIONAL INFORMATION SOUTHERN NUCLEAR OPERATING COMPANY, INC.

JOSEPH M. FARLEY NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-348 The Nuclear Regulatory Commission (NRC) staff has reviewed the licensees submittal dated September 19, 2003, regarding proposed changes to the Technical Specifications (TS) for the 1B Auxiliary Building direct current electrical power system. The NRC staff has identified the following information that is needed to enable the continuation of its review.

1. Regulatory Guide (RG) 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, Section 2.2.1, Defense in Depth, indicates that the proposed TS change request should maintain defense against potential common cause failures. In the cover letter of the submittal and on Page 1 of Enclosure 1, the licensees request states that the cells in battery bank 1B appear to be aging. Please address the following issues:

a. What are the average, minimum, and maximum ages of the cells in each battery bank?

b. Are there indications of aging in the other battery banks?

c. Has a root cause analysis been performed? If so, are there any indications of common-cause failures?

2. As discussed in RG 1.177, Section 2.3.3.1, Detail Needed for TS Changes, please provide the following numerical reliability data for the battery banks. For each value, identify the source of the data (e.g., plant-specific data). Summarize the methods used to convert raw data into final parameter estimates (e.g., maximum likelihood estimates, Bayesian methods):

a. Failure probability - Indicate if this value is based on a failure-on-demand probability (binomial model) or derived using a standby failure rate (Poisson model). If the latter, provide the time between tests.

b. Average unavailability due to maintenance during Mode 1 - Indicate if this value only considers corrective maintenance, or all maintenance.

c. Probability of common-cause failure - Indicate what model (e.g., beta factor) was used to make the estimate.

3. As presented in RG 1.177, Section 2.3.4, Assumptions in AOT and STI Evaluations, please provide the following details about how the incremental conditional core damage probability and incremental conditional large early release probability values were calculated:

a. Were the risk impacts based on the change in average core damage frequency/large early release frequency (CDF/LERF) using the mean outage Enclosure

times for the current and proposed completion time? If so, provide the value and basis for the increased battery bank unavailability due to maintenance. If the risk impacts were estimated using a zero-maintenance state as the base case (i.e.,

the risk impacts were estimated using risk meter software), please state so.

b. What truncation limits were used for accident sequence solution?

c. What are the base case importance measures (Fussell-Vesely and risk achievement worth) for battery bank 1B?

4. As discussed in RG 1.177, Section 2.4, Acceptance Guidelines for TS Changes, and RG 1.174, Sections 2.2.4, Acceptance Guidelines, and 2.2.5, Comparison of PRA Results with the Acceptance Guidelines, please provide the base case CDF, change in CDF ( CDF), base case LERF, and change in LERF ( LERF).

5. As presented in RG 1.177, Section 2.3.2, Scope of the PRA for TS Change Evaluations, and RG 1.174, Sections 2.2.5.4, Completeness Uncertainty, and 2.2.5.6, Comparisons with Acceptance Guidelines, do the estimated numerical risk impacts include the contributions from internal floods and external events such as fires, earthquakes, etc.? If not, please provide a qualitative discussion of the risk impacts from these types of events.

6. In Enclosure 1, Page 4, the licensees request states, There is reasonable assurance that risk-significant equipment configurations will not occur... and Increases in risk ...

will be managed. Please provide additional detail so that a decision concerning satisfaction of the Tier 2 guidance in RG 1.177, Sections 2.3, Evaluation of Risk Impact, and 2.4, Acceptance Guidelines for TS Changes, (second item) can be reached. Has a systematic search been made for risk-significant equipment configurations when battery bank 1B is out of service? What, if any, compensatory measures are proposed?

7. In Enclosure 1, Page 3, the licensees request states that the probabilistic risk assessment (PRA) was reviewed against NEI 00-02 in August 2001. As discussed in RG 1.177, Section 2.3.1, Quality of the PRA, and RG 1.174, Sections 2.2.3.3, PRA Technical Acceptability, and 2.5, Quality Assurance, please provide the Category A and B review findings and address the following items:

a. Indicate what progress has been made over the past two years towards resolving these findings, and what work remains to be finished.

b. Summarize changes to design and operational practices made since the review was completed that have an impact on PRA elements, but that have not yet been incorporated into the PRA model.

Joseph M. Farley Nuclear Plant cc:

Mr. Don E. Grissette William D. Oldfield General Manager - SAER Supervisor Southern Nuclear Operating Company Southern Nuclear Operating Company Post Office Box 470 P. O. Box 470 Ashford, Alabama 36312 Ashford, Alabama 36312 Mr. B. D. McKinney, Licensing Manager Southern Nuclear Operating Company Post Office Box 1295 Birmingham, Alabama 35201-1295 Mr. M. Stanford Blanton Balch and Bingham Law Firm Post Office Box 306 1710 Sixth Avenue North Birmingham, Alabama 35201 Mr. J. B. Beasley, Jr.

Executive Vice President Southern Nuclear Operating Company Post Office Box 1295 Birmingham, Alabama 35201 State Health Officer Alabama Department of Public Health 434 Monroe Street Montgomery, Alabama 36130-1701 Chairman Houston County Commission Post Office Box 6406 Dothan, Alabama 36302 Resident Inspector U.S. Nuclear Regulatory Commission 7388 N. State Highway 95 Columbia, Alabama 36319