ML14338A007
| ML14338A007 | |
| Person / Time | |
|---|---|
| Site: | Vogtle, Farley  |
| Issue date: | 12/16/2014 |
| From: | Shawn Williams Plant Licensing Branch II |
| To: | Pierce C Southern Nuclear Operating Co |
| Williams S | |
| References | |
| TAC MF4828, TAC MF4829, TAC MF4889, TAC MF4890 | |
| Download: ML14338A007 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 16,,2014 Mr. C. R. Pierce Regulatory Affairs Director Southern Nuclear Operating Company, 'Inc.
P. 0. Box 1295/Bin- 038 Birmingham, AL 35201-1295
SUBJECT:
JOSEPH M. FARLEY, UNITS 1 AND 2, AND VOGTLE, UNITS 1 AND 2-REQUEST FOR ADDITIONAL INFORMATION (TAC NOS. MF4828, MF4829, MF4889, AND MF4890)
Dear Mr. Pierce:
By letter dated Septemeber 17, 2014, the Southern Nuclear Operating Company, Inc. (SNC),
submitted a request to revise the Joseph M. Farley Nuclear Plant, Unit 1 and Unit 2, and the Vogtle Electric Generating Plant, Unit 1 and Unit 2, Technical Specification Surveillance Requirement 3.1.3.2 and TS 5.6.5 both related to the moderator temperature coefficient.
The U.S. Nuclear Regulatory Commission (NRC) staff has determined that additional information is needed as discussed in the Enclosure. We request that SNC respond within 45 days of the date of this letter. Please note that the NRC staff's review is continuing and further requests for information may be developed.
If you have any questions, please contact me at (301) 415-1009.
Sincerely, Shawn Williams, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos.: 50-348, 50-364, 50-424, 50-425 cc: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT TO REVISE TECHNICAL SPECIFICATIONS REGARDING MODERATOR TEMPERATURE COEFFICIENT SURVEILLANCE
. JOSEPH M. FARLEY NUCLEAR PLANT, UNIT 1 AND UNIT 2 VOGTLE ELECTRIC GENERATING PLANT. UNIT 1 AND UNIT 2 SOUTHERN NUCLEAR OPERATING COMPANY, INC.
DOCKET NOS. 50-348, 50-364, 50-424, 50-425 The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the Southern Nuclear Operating Company, Inc. (SNC), license amendment request dated Septemeber 17, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14267A030), to revise Technical Specification Surveillance Requirement 3.1.3.2 and TS 5.6.5. The NRC staff has reviewed the request and determined that additional information is necessary to complete the review.
- 1. On December 28, 2012, the NRC issued requests for additional information (RAis) for a similar license amendment request (LAR) at Beaver Valley Power Station (BVPS). In, SNC provided their responses to these RAis. Table 1 of Enclosure 9 provides a summary of statistics to compare PHOENIX-P/ANC and NEXUS/ANC results.
Though the PHOENIX-P/ANC and NEXUS/ANC results compare favorably to each other, they appear to differ significantly from the values found in Table 3-1 of WCAP-13749-P-A. Please discuss this discrepancy.
In this discussion, emphasis should be placed on the differences in the means and standard deviations between the two tables, particularly for the end-of-cycle (EOC) hot full power (HFP) moderator temperature coefficient (MTC). The discussion should present a statistical analysis of the datasets used to generate the two tables to explain whether or not the results presented belong to the same population.
The discussion should also address the deviation between measured and predicted critical boron throughout the cycle. Based on the statistics provided, many of the calculated values would apparently violate the generally:-used acceptance criterion of
+/- 50 ppm for comparison to measurements (as discussed in ANSI/ ANS-19.6.1, the PARAGON topical report WCAP-16045-P-A, and others).
- 2. The LAR states that the "FNP [Farley Nuclear Plant] and VEGP [Vogtle Electric Generating Plant] core design calculations are currently being transitioned from nuclear calculations that are performed with the PHOENIX-P lattice code to generate cross-section data to those that will be performed with the PARAGON lattice code."
Farley TS 5.6.5.b, the Core Operating Limits Report (COLR) reference list, includes references for PHOENIX-Pas well as the PARAGON and NEXUS methodologies.
Vogtle TS 5.6.5.b, on the other hand, does not include any of these references.
Enclosure In both sites' TS, WCAP-9272-P-A, 'Westinghouse Reload Safety Evaluation Methodology" is referenced for calculation of the moderator temperature coefficient.
WCAP-9272 states that "the values of all measured parameters are calculated using the design codes described in Table 3.1." Table 3.1 is a list of older neutronics codes, such as LEOPARD and TURTLE, which were in use at the time when WCAP-9272-P-A was
- first published in 1978. While the Vogtle and Farley Final Safety Analysis Reports (FSARs) include references to these older codes as well as newer codes like PHOENIX-P and ANC, they both indicate that the newer codes are used for core design.
- a. Please discuss how WCAP-9272-P-A is being used for calculation of the MTC limits for TS 3.1.3 when the codes being used for core design are not part of the WCAP-9272-P-A methodology.
- b. Please provide a justification for why the COLR reference list for Vogtle does not need to be updated to include PHOENIX-P, PARAGON, and/or NEXUS. This is
~
especially pertinent given that Farley submitted an LAR on August 14, 2012 (ADAMS Accession No. ML12227A884) specifically to include NEXUS in their COLR reference list.
ML14338A007 OFFICE NRR/LPLII-1/PM NRR/LPLII-1/LA NRR/LPLII-1/BC NAME SWilliams SFigueroa RPascarelli DATE 12/12/14 12/11/14 12/15/14