ML091030147

Request for Additional Information, License Amendment Request to Modify Technical Specification Section 5.6, Fuel Storage, and Add New TS 3/4 9.12, Spent Fuel (SFP) Pool Boron Concentration

ML091030147
Person / Time
Site:	Waterford
Issue date:	04/17/2009
From:	Kalyanam N Plant Licensing Branch IV
To:	Entergy Operations
Kalyanam N, NRR/DLPM, 415-1480
References
TAC MD9685
Download: ML091030147 (4)

Text

OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION WATERFORD STEAM ELECTRIC STATION, UNIT 3 LICENSE AMENDMENT REQUEST REGARDING FUEL STORAGE, SPENT FUEL BORON CONCENTRATION By letter dated September 17, 2008, as supplemented by letter dated February 26, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession Nos.

ML082660649 and ML090610134, respectively), Entergy Operations, Inc. (the licensee),

submitted an application to the U.S. Nuclear Regulatory Commission (NRC) requesting an amendment to modify Technical Specification (TS) 5.6, "Fuel Storage," and add new TS 3/49.12, "Spent Fuel Pool (SFP) Boron Concentration," to take credit for soluble boron in Region 1 (cask storage pit) and Region 2 (SFP and refueling canal) fuel storage racks for the storage of both Standard and Next Generation Fuel (NGF) assemblies.

Entergy submitted the application to revise the Waterford Steam Electric Station, Unit 3 (Waterford 3) licensing basis to reflect the new SFP criticality analysis. The licensee performed the new analysis to credit soluble boron in the fuel storage racks for both Standard and NGF.

The NRC staff has reviewed the application and determined that the following additional information is needed to complete the review:

1. Validation of the code, MCNP4a Appendix A of the Holtec Report No. HI-2084014, "Licensing Report for Waterford Unit 3 Spent Fuel Pool Criticality Analysis" (Attachment 3 to your application dated September 17,2008), discusses the validation of the three-dimensional Monte Carlo Code MCNP4a used in criticality calculations. To allow the NRC staff to evaluate the adequacy of the validation, please provide the following additional information:

a) In Section 2.1, you state that, "MCf\lP4a calculations used continuous energy cross-section data predominantly based on ENDF/B-V and ENDF/B-VI." Please explain how both libraries were used. Also, please identify what energy group data was used in the MCNP4a calculations?

b) Please identify the cross-section library and energy group used in the benchmark calculations.

c) Please identify any known problems associated with the libraries that may adversely affect the analysis.

d) Please document and justify the area of applicability for the benchmarks.

e) Please explain how the measurement uncertainties for the benchmarks were accounted for in the analysis.

Enclosure

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2. Validation of the code, CASMO-4 Please discuss the basis for not needing to apply any methodology uncertainties associated with the use of CASMO-4 to determine the relative reactivity differences for temperature variation, manufacturing tolerances, and depletion uncertainty.

3. Table 7.13 on page 46 of Holtec Report No. HI-2084014 The numbers do not add up for the 2 percent enrichment case in Table 7.13 (Le., MCNP calculated value plus the sum of biases and uncertainties do not equal 0.995). Please explain.

4. Soluble boron calculations In Attachment 1 to your letter dated February 26, 2009, you provided a revised Table 7.14. Please clarify if the rows "Normal Keff [effective multiplication factor] without Boron" and "Normal Keff with 600 ppm [parts per million] Boron" should indicate the MCNP calculated value. As presented, the values in these rows appear to include the sum of biases and uncertainties and appear inconsistent with the interpolated boron concentration values.

Please demonstrate the effect of soluble boron on the biases and uncertainties for the borated cases, beyond rack and fuel uncertainties. The staff acknowledges the information on rack and fuel uncertainties provided in the letter dated February 26, 2009.

ML091030147 *M"mor ed""

Itona I c hanges onlY I f rom sta ff RAI OFFICE NRR/LPL4/PM NRR/LPL4/BC NRRIDSS/SRXB NRR/LPL4/BC NRR/LPL4/PM NAME NKalyanam JBurkhardt GCranston* MMarkley NKalyanam DATE 4/17/09 4/14/09 03/27/09 4/17/09 4/17/09