ML12319A230

Response to Request for Additional Information - License Amendment Request for Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks

ML12319A230
Person / Time
Site:	Peach Bottom
Issue date:	11/13/2012
From:	Jesse M Exelon Generation Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
TAC ME7538, TAC ME7539
Download: ML12319A230 (7)

Text

10 CFR 50.90 November 13, 2012 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278

Subject:

Response to Request for Additional Information - License Amendment Request for Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks

References:

1) Letter from M. D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "License Amendment Request - Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks," dated November 3, 2011

2) Letter from J. D. Hughey (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 - Supplemental Information Needed for Acceptance of Requested Licensing Action RE: Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks (TAC NOS. ME7538 and ME7539)," dated December 14, 2011

3) Letter from M. D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "License Amendment Request - Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks," dated December 22, 2011

4) Letter from J. D. Hughey (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 - Request for Additional Information Regarding License Amendment Request for Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks (TAC NOS.

ME7538 and ME7539)," dated March 12, 2012

5) Letter from M. D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "Response to Request for Additional Information - License Amendment Request for Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks," dated April 4, 2012

U.S. Nuclear Regulatory Commission Response to Request for Additional Information License Amendment Request Spent Fuel Pool Rack Inserts November 13, 2012 Page 2

6) Letter from R. B. Ennis (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 - Request for Additional Information Regarding License Amendment Request for Use of Neutron Absorbing Inserts in Spent Fuel Pool Storage Racks (TAC NOS. ME7538 and ME7539)," dated April 18, 2012

7) Letter from M. D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "Response to Request for Additional Information -License Amendment Request for Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks," dated May 17, 2012

8) Letter from R. B. Ennis (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 - Request for Additional Information Regarding License Amendment Request for Use of Neutron Absorbing Inserts in Spent Fuel Pool Storage Racks (TAC NOS. ME7538 and ME7539)," dated May 22, 2012

9) Letter from M. D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "Response to Request for Additional Information - License Amendment Request for Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks," dated June 21, 2012

10) E-Mail from R. B. Ennis (U.S. Nuclear Regulatory Commission) to T. R. Loomis (Exelon Generation Company, LLC), "Draft RAI - PBAPS SFP Rack Insert LAR (TACs ME7538 & ME7539)," dated July 12, 2012

11) Letter from M. D. Jesse (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "Response to Request for Additional Information -License Amendment Request for Use of Neutron Absorbing Inserts in Units 2 and 3 Spent Fuel Pool Storage Racks," dated August 15, 2012

12) E-Mail from R. B. Ennis (U.S. Nuclear Regulatory Commission) to T. R. Loomis (Exelon Generation Company, LLC), " RE: Draft Revised RAI for Peach Bottom Spent Fuel Pool Rack Insert Amendment," dated November 12, 2012 In the Reference 1 letter, Exelon Generation Company, LLC (Exelon) requested a proposed change to modify the Technical Specifications (TS) to include the use of neutron absorbing spent fuel pool rack inserts for the purpose of criticality control in the spent fuel pools at Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. In References 2, 4, 6, 8, and

U.S. Nuclear Regulatory Commission Response to Request for Additional Information License Amendment Request SpentFueiPooiRacklnserts November 13, 2012 Page 3 10 the U.S. Nuclear Regulatory Commission requested additional information. References 3, 5, 7, 9, and 11 were our responses to those requests, respectively. In Reference 12, the U.S. Nuclear Regulatory Commission requested additional information. As a result of discussions with the U.S. Nuclear Regulatory Commission Staff, attached is our response to Requests for Additional Information (RAis) 42 and 43. We request implementation of the amendment within 60 days from approval.

Exelon has reviewed the information supporting a finding of no significant hazards consideration and the environmental consideration provided to the U.S. Nuclear Regulatory Commission in Reference 1. The additional information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. In addition, the additional information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.

There are no regulatory commitments contained in this submittal.

Should you have any questions concerning this letter, please contact Tom Loomis at (610) 765-5510.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 131h of November 2012.

Respectfully, Michael D. Jesse Director, Licensing and atory Affairs Exelon Generation Company, LLC

Attachment:

Response to Request for Additional Information .

cc: USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, PBAPS USNRC Senior Project Manager, PBAPS R. R. Janati, Bureau of Radiation Protection S. T. Gray, State of Maryland

ATTACHMENT Response to Request for Additional Information

Response to Request for Additional Information License Amendment Request Attachment Spent Fuel Pool Rack Inserts Page 1 Question 42:

Page 3 of Attachment 1 of the licensees submittal dated June 21, 2012 (ADAMS Accession No. ML12188A094), indicates that the minimum as-built areal density for the PBAPS Boraflex panels is 0.0235 g/cm2. However, page 2 of Attachment 2 of the same submittal states that the 0.0235 g/cm2 value is lower than the as-manufactured values for all PBAPS Boraflex panels.

Please confirm whether the 0.0235 g/cm2 value bounds the as-manufactured areal densities for all PBAPS Boraflex panels. In other words, confirm that the 0.0235 g/cm2 value can be used as a conservative initial assumed areal density for all PBAPS Boraflex panels.

Response

The Boron-10 areal density value of 0.0235 g/cm2 is a lower bound of all as-manufactured areal densities for PBAPS Boraflex panels and can be used as a conservative initial assumed areal density for all PBAPS Boraflex panels.

Page 3 of Attachment 1 of the June 21, 2012 submittal should have stated that the areal density value of 0.0235 g/cm2 bounds the minimum as-built value of areal density of the PBAPS Boraflex panels. This is consistent with the discussion on Page 2 of Attachment 2 of the June 21, 2012 submittal, which remains accurate. None of the results or conclusions of the rack insert LAR are impacted by the modification to this language.

Question 43:

In the application dated November 3, 2011, the licensee proposed the following license condition in support of the proposed amendment:

Storage cells in spent fuel storage rack modules without NETCO-SNAP-IN rack inserts will be placed into one of three categories: Unrestricted, Restricted, and Unusable.

a) Unrestricted will be cells whose minimum panel Boron-10 areal density is greater than or equal to 0.0140 g/cm2. Unrestricted cells may contain fuel assemblies up to a maximum in-core cold reactivity of 1.235.

b) Restricted will be cells whose minimum panel Boron-10 areal density is between 0.0140 g/cm2 and 0.0112 g/cm2. Restricted cells will only contain PBAPS Units 2 and 3 General Electric (GE) 7x7 and GE14 fuel assemblies (maximum in-core cold reactivity of 1.217).

c) Unusable will be cells whose minimum panel Boron-10 areal density is less than or equal to 0.0112 g/cm2. Unusable cells will be administratively controlled to remain empty of any fuel assembly.

Assuming that the response to RAI-42 confirms that the 0.0235 g/cm2 value is a conservative initial assumed areal density for all PBAPS Boraflex panels, the NRC staff proposes that the following license condition be implemented in support of the proposed amendment in lieu of the license condition shown above:

Response to Request for Additional Information License Amendment Request Attachment Spent Fuel Pool Rack Inserts Page 2 Proposed License Condition 2.C(14) for Unit 2 (14) Spent Fuel Pool Criticality Considerations a) Use of spent fuel pool storage cells without NETCO-SNAP-IN rack inserts shall be restricted as follows:

1) Minimum panel Boron-10 areal density of a storage cell shall be greater than or equal to 0.014 grams per square centimeter to store fuel assemblies with the maximum in-core cold k-infinity of up to 1.235. The minimum panel Boron-10 areal density shall be evaluated by assuming that the panel areal density was initially equal to a value of 0.0235 grams per square centimeter.

2) A storage cell shall not contain any fuel assembly if the minimum panel Boron-10 areal density of a storage cell is less than 0.014 grams per square centimeter.

The minimum panel Boron-10 areal density shall be evaluated by assuming that the panel areal density was initially equal to a value of 0.0235 grams per square centimeter.

b) Until the installation of NETCO-SNAP-IN rack inserts are completed in the Peach Bottom Unit 2 spent fuel pool, Boraflex degradation shall be monitored analytically every 6 months.

c) Boraflex degradation shall be monitored by in-situ testing in the Peach Bottom Unit 2 spent fuel pool no later than December 31, 2014, unless installation of the NETCO-SNAP-IN rack inserts for Unit 2 have been completed prior to this date.

d) Installation of NETCO-SNAP-IN rack inserts shall be completed by December 31, 2016.

Proposed License Condition 2.C(14) for Unit 3 (14) Spent Fuel Pool Criticality Considerations a) Use of spent fuel pool storage cells without NETCO-SNAP-IN rack inserts shall be restricted as follows:

1) Minimum panel Boron-10 areal density of a storage cell shall be greater than or equal to 0.014 grams per square centimeter to store fuel assemblies with the maximum in-core cold k-infinity of up to 1.235 (except as noted in a.3 below for restricted cells). The minimum panel Boron-10 areal density shall be evaluated by assuming that the panel areal density was initially equal to a value of 0.0235 grams per square centimeter.

2) A storage cell shall not contain any fuel assembly if the minimum panel Boron-10 areal density of a storage cell is less than 0.014 grams per square centimeter (except as noted in a.3 below for restricted cells). The minimum panel Boron-10 areal density shall be evaluated by assuming that the panel areal density was initially equal to a value of 0.0235 grams per square centimeter.

Response to Request for Additional Information License Amendment Request Attachment Spent Fuel Pool Rack Inserts Page 3

3) For the period up to December 31, 2013, cells whose minimum panel Boron-10 areal density is between 0.014 grams per square centimeter and 0.0112 grams per square centimeter may be used as restricted cells. Restricted cells will only contain Peach Bottom Unit 3 GE14 fuel assemblies with an assembly average burnup of greater than 44,000 megawatt days per metric ton. The minimum panel Boron-10 areal density shall be evaluated by assuming that the panel areal density was initially equal to a value of 0.0235 grams per square centimeter.

b) Until the installation of NETCO-SNAP-IN rack inserts are completed in the Peach Bottom Unit 3 spent fuel pool, Boraflex degradation shall be monitored analytically every 6 months.

c) Boraflex degradation shall be monitored by in-situ testing in the Peach Bottom Unit 3 spent fuel pool no later than December 31, 2013, unless installation of the NETCO-SNAP-IN rack inserts for Unit 3 have been completed prior to this date.

d) Installation of NETCO-SNAP-IN rack inserts shall be completed by December 31, 2016.

Please confirm whether the licensee agrees to the above license conditions. If so, please provide the revised proposed license conditions in a docketed supplement to the application.

Response

Exelon agrees to the above license conditions.