ML110200602

Request for Additional Information Spent Fuel Pool Rerack Amendment (ME1079)

ML110200602
Person / Time
Site:	Beaver Valley
Issue date:	01/24/2011
From:	Nadiyah Morgan Plant Licensing Branch 1
To:	Harden P FirstEnergy Nuclear Operating Co
Morgan Nadiyah, NRR/Dorl, 415-1016
References
TAC ME1079
Download: ML110200602 (8)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 24, 2011 1VIr. Paul A. Harden Site Vice President FirstEnergy Nuclear Operating Company Beaver Valley Power Station Mail Stop A-BV-SEB1 P.O. Box4, Route 168 Shippingport, PA 15077 SUB~IECT: BEAVER VALLEY POWER STATION, UNIT NO.2 - REQUEST FOR ADDITIONAL INFORMATION RE: SPENT FUEL POOL RERACK LICENSE AMENDMENT (TAC NO. ME1079)

Dear Mr. Harden:

By letter dated April 9, 2009, as supplemented by letters dated June 15, 2009, January 18, March 18, May 3, May 21, June 1, August 9, October 7, October 18, 2010, and January 5, 2011, FirstEnergy Nuclear Operating Company (the licensee) submitted a license amendment for Beaver Valley Power Station, Unit NO.2 (BVPS-2). The proposed amendment would modify Technical Specifications (TSs) to support the installation of high density fuel storage racks in the BVPS-2 spent fuel pool.

The Nuclear Regulatory Commission (NRC) staff is reviewing the submittals and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). The NRC staff is requesting a response to the RAI within 30 days of receipt.

The NRC staff considers that timely responses to RAls help ensure sufficient time is available for NRC staff review and contribute toward the NRC's goal of efficient and effective use of staff resources.

P. Harden -2 If you have any questions regarding this issue, please contact me at (301) 415-1016.

Sinc~~ly,

/7~diyah S. Morgan, Project Manager Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-412

Enclosure:

RAI cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE SPENT FUEL POOL RERACK LICENSE AMENDMENT FIRSTENERGY NUCLEAR OPERATING COMPANY FIRSTENERGY NUCLEAR GENERATION CORP.

OHIO EDISON COMPANY THE TOLEDO EDISON COMPANY BEAVER VALLEY POWER STATION, UNIT NO.2 DOCKET NO. 50-412 By letter dated April 9, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML091210251), as supplemented by letters dated June 15, 2009 (ADAMS Accession No. ML091680614) and January 18 (ADAMS Accession No. ML100191805), March 18 (ADAMS Accession No. ML100820165), May 3 (ADAMS Accession No. ML101260059), May 21 (ADAMS Accession No. ML101460057), June 1 (ADAMS Accession No. ML101610118), August 9 (ADAMS Accession No. ML102240256), October 7 (ADAMS Accession No. ML102860124), October 18,2010 (ADAMS Accession No. ML102940454), and January 5, 2011 (ADAMS Accession No. ML110110217), FirstEnergy Nuclear Operating Company (the licensee) submitted a license amendment for Beaver Valley Power Station, Unit NO.2 (BVPS-2). The proposed amendment would modify Technical Specifications (TSs) to support the installation of high density fuel storage racks in the BVPS-2 spent fuel pool (SFP). In order to complete the review, the Nuclear Regulatory Commission (NRC) staff needs the folloWing additional information:

1. RAI-15: The response to RAI-15 is adequate, but raises some additional questions.

a. Provide an explanation for the large differences between the predicted nuclear design report values and the corrected/measured soluble boron concentrations. The issue is that some reactor parameter, such as temperatures, power, and coolant flow rate, may be significantly different than what was used in the fuel depletion calculations. If core reactiVity is mispredicted by nearly 1% ~k-effective (k eff) , you may also be under predicting the reactiVity of the fuel in storage. The explanation of the misprediction should also address its impact on the analysis.

Enclosure

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b. The RAI-15 response includes the following statement:

A process will be established prior to receipt of the next reload batch of BVPS Unit 2 fuel to ensure that the design features and operating parameters of fuel used in the future at BVPS Unit 2 are consistent with the assumptions of the criticality analysis.

Which design features and operating parameters will be reviewed in the process? Will the "process" be reviewed by NRC staff prior to implementation?

2. The response to RAI-29 may not be adequate. The second of the three figures that were provided might have a more reactive configuration. See the modified figure below:

The locations marked with "M" are the evaluated misload locations. It is not clear that an alternate 1 3 3 3 :2 1 1 :2 3 1 3 3 misload location, marked 1 3 3 3 2 2 '2 :2 3 1 3 3 "X", will not yield a higher 1 3 3 2 1 1 :2 3 1 3 3 "T

~  ! 2 ?II 2

'I 1 2 1 2 2

1 2

1 2

2

?II 1

2 IX 2 1 2

2 kejJvalue. The alternate locations have more type "3" fuel assemblies around 1 1. 1 1. 1 1 ... 1 1 1 - them than the originally III 2 1\1 :2 2 2 2 111 21X 2 evaluated locations. Type 3 3 3 :2 1 1 :2 1 3 3 3 3 fuel has a higher 3 3 3 :2 2 2 2 1 3 3 3

~ ~ ~ ... . 1 2 3 3 3 3 reactivity than the type 2 fuel.

a. Confirm that the kefffor the alternate misload location is bounded by the already evaluated misloads.

b. Figure 4.5.7, which did not exist in the original analysis and varies significantly from Figure 1.1, appears to show locations where an assembly could be placed between rack modules. If this is true, evaluate the soluble boron requirement for assemblies incorrectly placed in these non-storage locations.

c. Figure 4.5.7 seems to indicate that four fresh fuel assemblies will not be placed into the neighboring corners of four rack modules. Is this configuration prohibited? If so, how is this restriction captured in the TS?

3. RAI-33: This RAI focused on how the reactivity control penalty was calculated. The response leads to some additional questions.

a. The calculation of the reactivity control penalties was performed using CASMO. It does not appear that CASMO's ability to calculate/:::"keff penalties as used in the analysis has been validated. Provide the validation for using CASMO to calculate the /:::,.keff penalty.

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b. It looks like the reactivity control penalties were calculated using 2-D CASMO calculations. If this is true, this represents a significant simplification over the real 3-D problem. Provide justification for the use of 2-D calculations and provide data that supports this justification. If appropriate, incorporate and justify additional margin to cover the modeling simplification.

c. The IFBA penalty calculations were presented for only fuel with initial enrichments of 3, 3.8 and 5 weight percent (wt%). Provide the data and justify the use of the rather limited set of enrichments evaluated.

d. The IFBA penalty calculations were presented for only 100, 128, and 200 IFBA rod patterns. Justify not examining other patterns already used at Beaver Valley, which also include 32, 48, 64, and 80 IFBA rod patterns, and provide data that support this justification.

e. The analysis does not describe how the IFBA rods were modeled in CASMO. The IFBA coating is a very thin layer of a strong neutron absorber on the outside of the pellet.

Provide a description and justify how this was modeled in CASMO. The description should address the model geometry, and relevant CASMO solution parameters such as quadrature used.

f. Describe the experience and performance of modeling IFBA using CASMO. Have CASMO IFBA cross sections been used in reactor simulation for operating reactors? If so, provide data that shows how well the simulated power distributions and soluble boron agree with measurements.

g. The last seven lines of the CASMO IFBA depletion results in the RAI-33 response appear to be duplicates of the preceding seven lines. Was some other content intended?

4. RAI-34: Response is adequate. However, WABA rods were evaluated at only 2.6 and 3 wt%. It appears that the applicant does not intend to use WABAs in the future. This restriction should be captured in the "procedure" that will be used to screen future cycles.

5. RAI-38: Validation has been revised to address many of the issues and concerns. The following issues resulted from a review of the revised validation work:

a. Tables 7.1-8 and 7.2-8 include trending analysis results for multiple subgroups, but look at only EALF for the overall set, which is the critical experiment set used to derive the bias and bias uncertainty.

i. Trending analysis of the overall set should have also included enrichment, boron concentration, Plutonium (Pu) content {g Pu/(g U + g pun, and pin pitch. Provide supplementary trending analysis for the overall set. If the bias and bias uncertainty changes as a result of the supplementary trending analysis, update the criticality analysis to use the revised bias and bias uncertainty.

ii. Pu enrichment was listed in Tables 7.1-8 and 7.2-8, but was not defined. Provide the definition for "Pu enrichment."

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b. The critical experiment set should have been evaluated to determine if some of the experiments include significant features that are not present in the BVPS-2 safety analysis cases and that could impact the bias and bias uncertainty. For example, some of the Haut Taux de Combustion (HTC) phase 3 and 4 experiments include neutron absorbers and/or reflectors that are not present in the safety analysis models. Evaluate the impact on the bias and bias uncertainty of including critical experiments that vary significantly from the safety analysis cases.

c. The HTC configurations that were used included some configurations that Section 3.2 of NUREG/CR-6979 recommended not be used. Explain and justify the use of these configurations.

d. Neither the revised report nor the revised validation provided in Appendix E address the applicability of the validation to the BVPS-2 criticality safety analysis. This should be done by comparing and contrasting the ranges of parameters in the BVPS-2 safety analysis and in the set of critical experiments. Such parameters might include enrichment, pin pitch, soluble boron concentration, Pu content, EALF, fuel forms, absorber materials, etc. Note that Table 9-1 in Appendix E appears to be presenting a comparison of the validation with some generic criticality analysis. The design application column in this table is not BVPS-2 specific. Provide a BVPS-2 specific analysis of the applicability of the validation set.

e. The analysis should identify any validation gaps (e.g. missing materials, nuclides, and model features, etc.) and address what additional margin, if any is needed to cover such gaps. For example, is margin needed to cover fission product k eff validation?

-5 REFERENCES

1. FENOC Letter L-09-086, "License Amendment Request No.08-027, Unit 2 Spent Fuel Pool Rerack," dated April 9. 2009 (ADAMS Accession No. ML091210251).

2. FENOC Letter L-09-162, "Additional Technical Information Pertaining to License Amendment Request No.08-027 (TAC No. ME1079)," dated June 15, 2009 (ADAMS Accession No. ML091680614).

3. FENOC Letter L-1 0-001, "Response to Request for Additional Information for License Amendment Request No.08-027, Unit 2 Spent Fuel Pool Rerack (TAC No. ME1079)"

dated January 18, 2010 (ADAMS Accession No. ML100191805).

4. FENOC Letter L-10-082, "Response to NRC Staff Request for Additional Information Regarding Criticality Analyses Supporting a Spent Fuel Pool Rerack for Unit 2 (TAC No.

ME1079)," dated March 18, 2010 (ADAMS Accession No. ML100820165).

5. FENOC Letter L-10-121, "Response to Request for Additional Information for License Amendment Request No.08-027 (TAC No. ME1079)," dated May 3, 2010 (ADAMS Accession No. ML101260059).

6. FENOC Letter L-1 0-151, "Response to Request for Additional Information for License Amendment Request No.08-027 (TAC No. ME1079)," dated May 21, 2010 (ADAMS Accession No. ML101460057).

7. FENOC Letter L-1 0-130, "Remainder of Responses to NRC Staff Request for Additional Information Regarding Unit 2 Spent Fuel Pool Rerack Criticality Analyses (TAC No.

IVlE1 079)," dated June 1, 2010 (ADAMS Accession No. ML101610118).

8. FENOC Letter L-1 0-235, "Response to Request for Additional Information for License Amendment Request No.08-027, Unit 2 Spent Fuel Pool Rerack (TAC No. ME1079),"

dated August 9,2010 (ADAMS Accession No. ML102240256).

9. NRC Letter dated June 11,2010, "BEAVER VALLEY POWER STATION, UNIT NO.2 REQUEST FOR ADDITIONAL INFORMATION RE: SPENT FUEL POOL RERACK LICENSE AMENDMENT (TAC NO. IVlE1079)" (ADAMS Accession No. ML101380546).

10. RS-001, Review Standard for Extended Power Uprates, Section 3.1.1.1., "Full Cooling System Capability Evaluation," of Attachment 2 to Matrix 5 of Section 2.1, Revision 0, December 2003.

11. 20M-20A.AAC, Fuel Pool Purification Trouble, Revision 4.

12. 20M-20A.AAA, Fuel Pool Cooling Trouble, Revision 6.

ML110200602 *See memo dated 1/12/2011 OFFICE DORLILPLI-1/PM DORLILPLI-1/LA DSS/SRXB/BC DORLILP -

NAME I\JMorgan SLittie TUlyses*

NSalgado (JBoska for)

. . _ - _ . _ ~

DATE 1/24/11 1/24/11 1/12/2011 1/24/11