SBK-L-12099, Supplement to LAR 11-04, Changes to the Technical Specifications for New and Spent Fuel Storage

Supplement to LAR 11-04, Changes to the Technical Specifications for New and Spent Fuel Storage

ML12136A126
Person / Time
Site:	Seabrook
Issue date:	05/10/2012
From:	Freeman P NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-12099, TAC ME7946
Download: ML12136A126 (37)

Text

NEXTera ENERG-Y.O, May 10, 2012 10 CFR 50.90 10 CFR 2.390 (Attachment 2)

SBK-L-1 2099 Docket No. 50-443 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Seabrook Station Supplement to LAR 11-04, Changes to the Technical Specifications for New and Spent Fuel Storage

References:

1. NextEra Energy Seabrook, LLC letter SBK-L-1 1245, "License Amendment Request 11-04, Changes to the Technical Specifications for New and Spent Fuel Storage,"

January 30, 2012

2. NRC letter "Seabrook Station, Unit No. 1 - Supplemental Information Needed for Acceptance of Requested Licensing Action Regarding License Amendment Request 11-04, Changes to the Technical Specifications for New and Spent Fuel Storage (TAC No. ME7946)," March 30, 2012 In Reference 1 NextEra Energy Seabrook, LLC (NextEra) submitted a request for an amendment to the Technical Specifications (TS) for Seabrook Station. The proposed change would revise the TS for new and spent fuel storage as the result of a new criticality analyses for the new fuel vault and the spent fuel pool.

In Reference 2, the NRC staff requested that NextEra supplement the application with additional information to enable the staff to make an independent assessment regarding the acceptability of the proposed amendment request in terms of regulatory requirements and the protection of public health and safety and the environment.

Awl NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874

United States Nuclear Regulatory Commission SBK-L-1 2099 / Page 2 The enclosed supplement to license amendment request 11-04 provides the information requested by the staff. Included in Attachment 1 to the supplement are revised TS pages that modify the wording of two notes that were added to the TS as part of the proposed change. The revised wording is an editorial change and does not alter the intent or meaning of the notes. The modification to the proposed change is administrative in nature and does not alter the conclusion in Reference 1 that the proposed change does not involve a significant hazard consideration pursuant to 10 CFR 50.92. to the supplement (Holtec Letter RRTI-2064-001) provides responses to items 1-7 and 9-10 in Reference 2. Attachment 2 contains information proprietary to Holtec International and is supported by an affidavit in Attachment 3 (Holtec Letter 2064-AFFI-02) signed by Holtec International, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b) (4) of Section 2.390 of the Commission's regulations. Accordingly, NextEra requests that the information that is proprietary to Holtec International be withheld from public disclosure in accordance with 10 CFR Section 2.390 of the Commission's regulations. Attachment 4 provides a non-proprietary version of the information contained in Attachment 2.

A copy of this letter has been forwarded to the New Hampshire State Liaison Officer pursuant to 10 CFR 50.91 (b).

Should you have any questions regarding this letter, please contact Mr. Michael O'Keefe, Licensing Manager, at (603) 773-7745.

Sincerely, NextEra Energy Seabrook, LLC.

Paul Freeman Site Vice President Enclosure cc: NRC Region I Administrator J. G. Lamb, NRC Project Manager, Project Directorate 1-2 W. J. Raymond, NRC Senior Resident Inspector

United States Nuclear Regulatory Commission SBK-L-12099 / Page 3 Mr. Christopher M. Pope, Director Homeland Security and Emergency Management New Hampshire Department of Safety Division of Homeland Security and Emergency Management Bureau of Emergency Management 33 Hazen Drive Concord, NH 03305 John Giarrusso, Jr., Nuclear Preparedness Manager The Commonwealth of Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702-5399

0 FPL Energy Seabrook Station AFFIDAVIT I, Paul Freeman, Site Vice President of NextEra Energy Seabrook, LLC hereby affirm that the information and statements contained within this supplement to License Amendment Request 11-04 are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

Sworn and Subscribed beforeje this

,/ "day of 2012 Paul Freeman

/ NotayK Public Site Vice President

Supplement to LAR 11-04, Changes to the Technical Specifications for New and Spent Fuel Storage Table of Contents Section Page Introduction 2 1.0 Responses to NRC Questions 3 2.0 Description of Revised Technical Specification Changes 17 3.0 References 18 Attachments Revised TS Pages Holtec Letter RRTI-2064-001 (Proprietary) Holtec Letter 2064-AFFI-02 Affidavit for Holtec Response Holtec Letter RRTI-2064-001 (Non-Proprietary)

I

Supplement to LAR 11-04, Changes to the Technical Specifications for New and Spent Fuel Storage

==

Introduction:==

By letter SBK-L-11245 dated January 30, 2012, (Reference 1) NextEra Energy Seabrook, LLC (NextEra) requested to amend the Seabrook Unit 1 Technical Specifications (TS). The proposed amendment will revise the TS for new and spent fuel storage as the result of a new criticality analyses for the new fuel vault (NFV) and the spent fuel pool (SFP).

On March 30, 2012, the NRC requested supplemental information (Reference 2) to support acceptance of the requested license amendment request (LAR) 11-04. Eleven questions were transmitted to NextEra.

The questions and the applicable NextEra responses are documented in Section 1.0.

In response to question # 9, a revision to two of the pages of the proposed TS submitted in Reference 1 is proposed. These TS changes are considered administrative changes and are discussed in Section 2.0.

2

1.0 Responses to NRC Questions:

The responses to questions 1-7 and 9-10 are provided in Attachment 2. The responses to question 8 and question 11 are provided below.

Request / Question #8

8. In Section 4.2.3.5.11 of HI-21144996 item number 8 lists the modeling of BORALTm blisters.

Provide the basis for the BORALTM blister model.

a. Include the data that supports the blister formation and growth rate.

b. Estimate at what time the BORAL TM blister model used in HI-21144996 will become non-limiting.

c. Describe how the BORALTM in the area of the blisters will respond during a seismic event; include the data that supports that discussion.

Response to 8a.

BoralTM absorber coupons, representing, and traceable to, the panels within six of the Seabrook racks, have been observed to form gas filled blisters in the aluminum clad. The blister volume directly displaces water from the flux trap resulting in diminished moderation and neutron absorption by the flux trap. The measured average coupon blister displacement volume over the entire coupon per unit area is compared to the program acceptance criterion of 45 mils to limit the accrued blister displacement within the bounds of the criticality analysis. More details of the monitoring program are provided in the response to Question 11.

The greatest measured blister displacement volume for the BoralTM coupons is depicted in the plot below.

Six BoralTM Coupon Examination campaigns of multiple coupons have been performed to date.

Examination techniques have evolved to improve blister volume measurement accuracy over this time.

Therefore the last three measurements of blister volume are used here to estimate future blister growth rate. The plot domain covers the history from the introduction of the BoralTM racks in the Seabrook SFP and extrapolates forward two cycles beyond the last coupon examination through Cycle 16. Itshould be noted that the A133 coupon results are obscured on the plot by the A144 and A132 data. A trend line for that coupon is not provided. The greatest measured coupon blister displacement volume occurred on coupon Al 12 during the Cycle 14 examination and was found to be 23.6 % of the 45 mil program acceptance criterion. This blister growth extrapolates to 29 % of the acceptance criterion at the end of Cycle 16.

3

The measured to predicted limiting blister displacement between the Cycle 13 & 14 differed by only 4%

indicating a reasonable degree of precision and confidence in the blister volume measurements.

1.1 *Six Lead BORAL Coupon Blister Volume vs. cycle 1 ý*A112 *A122 AA141 0 A144 zrA133 -A132 0.9 145 mil Uniform Void Limit = 3.8 in Blister Volume per Coupon 0 0.8 0.

Q 0 .7 23.6 % of Uniform Void Li

0) 0.6-E 0.5-

0) 0.4-LO 0.4-0.2 0.1 - -_

01 6 7 8 10 11 12 13 14 15 16 Fuel Cycle Response to 8b Seabrook BoralTM monitoring indicates significant variation in BoralTm Blister growth rate between different material lots as seen from the plot of different coupons provided above. Likewise it is too early in the Seabrook program to definitively project the long term factors that will drive the blister forming process to completion. Therefore, a relatively large acceptable blister volume of 3.8 cubic inches per coupon (45 mil uniform void over the surface of a coupon) has been accommodated within the new SFP Criticality Analysis. The coupon blister volume is measured and evaluated each fuel cycle. This measured value is extrapolated out to future cycles and compared to the limit to ensure operational conformance between measurements.

4

An estimate of the future margin to the blister limit should fall between a linear extrapolation of the latest blister volume measurements (constant growth rate) and an exponential fit of these same data. The linear extrapolation indicated the blister volume limit might be reached around Cycle 38 whereas the exponential projection would not be reached until late in extended license operating period. The exponential projection may indicate that the measured blister volume could approach an asymptotic maximum below the 3.8 cubic inches limit. But again, as indicated, these projections over many cycles are uncertain. Therefore regular BoralTM examinations are required by the Program to provide ample advance indication of blister growth that might approach the limit assumed within the SFP Criticality Analysis.

4-45 mil Uniform Void Limit = 3.8 in Blister Volume per Coupon -

3-.

OVt 2.5 . . -

E Extrapolation / P'"i 0)

D 1.5" C:  ! / Long Ter7 0o Extrapolation 0A 0:Z 29.0 % of Uniform Void 0 812 Limit @ Cycle 16 3 4A

-2:3.6 %of Uniform Void

• . 1 Lim it @ Cycle 14 *A 0.5 -"- - *=

i i -A

/6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 Fuel Cycle Response to 8c The Seabrook Spent Fuel Racks are designed and fabricated to satisfy the seismic qualifications as described within the UFSAR. BoralTM is an approved neutron absorber for use in Spent Fuel Racks. The bare cermet retains mechanical integrity within the blistered area. Given the geometry of the BoralTm and its encapsulation within the fuel racks it is improbable that a seismic event would result in a boron carbide loss (washout) or redistribution from within the seismically qualified racks. For gross boron carbide loss or redistribution to occur the cermet core material would have to be pulverized to a degree where the 5

resulting cermet particles are reduced to a size smaller than the tight clearance within the BoralTM encapsulation. The current observations from the BoralTM Monitoring Program, especially the neutron radiographic examination indicate no significant sign of cermet disruption or loss of mechanical strength in the BoralTM cermet due to blister formation. This is especially true in observations of dissected blisters on the coupon A131 (pictured on next page).

The response of blistered BoralTM to seismic excitation should consider the physical restraint of the BoralTM material within the seismically qualified rack structure. Additional consideration is required for the mechanical integrity retained by the bare cermet within the blistered area. BoralTM panels are positioned and contained within a 90 mil space between each cell wall a 20 mil stainless steel wrapper plate that is welded to the cell wall. The wrapper plate attachment to the cell wall allows water flow between the space containing the BoralTM Panel and the bulk SFP water volume. The coupon encapsulation is designed to be functionally similar to the BoralTM Panel encapsulation within the SFP racks.

The nominal thickness of non-blistered BoralTM is 75 mils leaving 15 mils total clearance between the BoralTM and the stainless steel encapsulation. Blisters will fill this clearance and restrain the BoralTM panel in place within the structural cell wall and the wrapper plate of the racks. The BoralTM core cermet is composed of 50% boron carbide and 50% aluminum where the aluminum forms a continuous, but slightly porous, matrix surrounding the individual boron carbide particles during the hot rolling production process. The boron carbide particles are mechanically captured but not chemically bound to the aluminum. The BoralTM clad is thin and very malleable when blisters are formed as indicated by the ability of the clad to stretch into a blister dome.

Dissected coupon blister examinations clearly indicated the physiology and morphology of the BoralTM blisters. During blister formation the aluminum clad layer separates at clad-cermet interface where the rupture cross-section is half aluminum and half unbound boron carbide. During blister formation most of the cermet core remains intact as a ridged, though slightly irregular, surface within the clad blister dome.

A thin layer of boron carbide particulate is retained by the interior surface of the blister dome and only a few loose boron carbide particles have been observed within newly formed blisters. These cermet attributes, resulting from blister formation, are consistent within the observations of the BoralTM Monitoring Program even when the coupon clad has been striped from both sides of an affected area by opposing blisters. Within dissected blisters the bare cermet, comprised of boron carbide captured within its mal.Ieable aluminum matrix, appears mechanically sound When the blistered aluminum clad is removed from one or both sides of the BoralTM coupon.

The aluminum matrix can corrode and release boron carbide at a slow rate that should be detected by neutron radiography within the BoralTM Monitoring Program prior to significant degradation to the cermet that might challenge the BoralTM fracture toughness required to survive a seismic event.

6

Dissected BoralTM Coupon Blister A131 1 IBlister Dome (Clad) Cut Away Bare BoraMTM Core Cermet Material Numerous BoralTM coupon blisters have been examined over 6 campaigns at Seabrook Station. Of these blisters, that are either intact or vented to the coupon edge or through small corrosion pits, none indicate a loss or redistribution of the internal B1° areal density when examined via detailed neutron radiography and neutron beam attenuation. Since the boron carbide is held in place solely by the aluminum matrix of the cermet material, verification of the B13areal density and distribution is a strong indication that the aluminum matrix of the cermet material remains intact and resistant to boron carbide particulate redistribution or washout.

Question 11:

The staff would require the details of the BoralTM Monitoring Program in order to determine if the degradation/deformation of BoralTM will be properly monitored and mitigated. Please provide these details of the BoralTM Monitoring Program including the following:

a. Describe how the neutron-absorbing capacity will be monitored. Include a description of the parameters, calculations, frequency, and acceptance criteria.

b. If coupon testing will be used:

1. What is the location of coupons relative to the spent fuel racks?

2. How are the coupons mounted and are they fully exposed to the spent fuel pool water (both sides exposed or bolted to a wall)?

3. To demonstrate that the BoralTM integrity has been maintained, the staff requests the applicant to provide the test results for the coupons, including areal density measurements.

4. After removal from the pool for inspection are the coupons inserted back at the same locations in the pool?

5. Discuss the schedule/frequency for coupon removal and testing to demonstrate continued BoralTM performance.

7

6. How does this acceptance criteria account for potential degradation between surveillance periods?

7. Please describe the corrective actions that would be implemented if coupon test results are not acceptable.

8. Please discuss the correlation between measurements of the physical properties of BoralTM coupons and the integrity of the BoralTM panels in the storage racks.

Question 11 a.

Describe how the neutron-absorbing capacity will be monitored. Include a description of the parameters, calculations, frequency, and acceptance criteria.

Response a1 a

The Seabrook BoralTM Monitoring Program is based on examination of BoralTM coupons each cycle. A detailed review of the program is provided below in a narrative form as Background Information. A specific response to each question is also provided.

In summary, BoralTM coupons are examined each cycle to determine any physical change. The parameters reviewed and the method used to evaluate include:

Criterion A: BoralTM Coupon geometry (Total Blister Displacement Volume)

Criterion B: B10 areal density (Thermal Neutron Beam Attenuation)

Criterion C: B10 distribution (Neutron Radiography)

The acceptance criteria for the blister displacement volume is to maintain the blistering below the 45 mil analysis limit as projected from the measured data. The areal density acceptance criterion is to maintain the projected future value from the measured data above the required limit. It should be noted that for LAR 11-04, the required areal density is being lowered to 0.015 gm/cm2. The boron distribution

,Tequirement is to remain equally distributed.

Question 1lb.1:

What is the location'of coupons relative to the spent fuel racks?

Response 11 b. 1 Sixteen BoralTM Test Coupons on a Coupon Tree are located in a spent fuel rack cell, selected for each fuel cycle, and is surrounded by 24 newly discharged fuel assemblies at each core offload. The axial mid point of the coupon tree is positioned at the mid point of the adjacent fuel assemblies. The 24 fuel assemblies with the coupon tree at the center form a 5 x 5 array of rack cells referred to as the "nest".

Question 11 b.2:

How are the coupons mounted and are they fully exposed to the spent fuel pool water (both sides exposed or bolted to a wall)?

8

Response 11 b.2 The coupon encapsulation "jackets" mimic the presentation of the BoralTM panels within the actual racks with regard to materials, dimensions, orientation, mass, gamma heating and water intrusion so as to accurately represent the BoralTM panel response to the spent fuel pool environment.

The degree of similarity in encapsulation and presentation between the coupons and the actual racks is paramount to accurately determining BoralTM panel response and behavior both expected and unexpected. Also the Program is designed such that the coupon exposure to heat and radiation lead the Boralm contained in the actual racks.

Coupon encapsulation "jackets"were fabricated from 304 stainless steel to match the fuel rack construction. Likewise, similar to the racks, the 20 mil stainless steel wrapper and 1/16" backing plate are separated by a 0.90" spacer to allow for 15 mils total clearance between the jacket and the 75 mil BoralTM coupon (prior to blister formation). The jackets are fastened with stainless steel pop-rivets with similar spacing as the spot welds that attach the wrapper plates to the fuel rack cells. The BoralTM coupons, like the BoralTM panels within the racks, are not bolted or otherwise restrained but are free to move within the encapsulation (again prior to blister formation). This design allows pool water to flow into and around all Boral m coupon surfaces with similar convective and thermal hydraulic characteristics to the BoralTM panels of the fuel racks.

Question 11 b.3:

To demonstrate that the BoralTM integrity has been maintained, the staff requests the applicant to provide the test results for the coupons, including areal density measurements.

Response lb.31 The BoralTM Monitoring Program has three acceptance criteria. The three criteria are coupon blister volume displacement, areal density and no change in the boron carbide distribution within a coupon. All acceptance criteria have been met by the most recent coupon examination performed during Cycle 14.

The results of the examinations are summarized below:

The maximum coupon blister displacement was found to be 1.53 in3/ ft2 representing a uniform void of 10.6 mils. This uniform void of 10.6 mils is 23.6% of the 45 mil limit. For the limiting coupon the blister volume growth and the proportionate change in uniform void were calculated to be 11.4 % (volume) for the previous 18-month cycle. This limiting volumetric growth rate indicates the uniform void is expected to be 11.8 mils, or 26 % of the 45 mil limit, at the Cycle 15 BoralTm examination. A margin equal to 74 % of the 45 mil limit is expected to remain at the next BoralTM examination.

The BoralTM B1° areal density was found to be greater than 0.023 gm/cm2 for all measurements, which is within the demonstrated acceptable range 0.022 to 0.025 gm/cm 2. The B1° margin for demonstrated acceptable range in areal density is 0.002 gm/cm2 above the specified limit of 0.020 gm/cm 2, the previous analysis limit. Reduction in B13 areal density has not been observed in the test coupons without dissected blisters. Therefore, adequate margin in B areal density exists until the next Boral examination. It must be noted that visual indications of aluminum corrosion on surveillance coupons indicates some amount of clad and boron carbide removal at levels below the lower limit of B10 areal density measurement sensitivity. TM This minimal reduction in localized B10 would have no impact on the performance of the Boral and is acceptable.

Neutron radiography indicated acceptable boron carbide distribution within the test coupons.

9

Question 11 b.4:

After removal from the pool for inspection are the coupons inserted back at the same locations in the pool?

Response 11b.4 I The coupons are returned to the coupon tree for continuing exposure after examination.

For a typical cycle, two or more coupons selected for examination are retrieved from the active SFP nest and dried toward the end of each fuel cycle. The coupon tree, without the coupons selected for examination, is returned to the active nest, typically within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, for continued exposure during the examination process. Post examination the selected coupons are encapsulated and the coupon tree is again retrieved from the active exposure nest. Inspected coupons are then reattached to the coupon tree and the tree is returned to a new SFP location designated for the new nest location for the pending core off-load. This pattern of exposure allows the coupon cermet to re-hydrate for about one month prior to resumed exposure at the next core off-load. This pattern of exposure and re-hydration approximates the exposure of the BoralTM racks that receive the full core off-load.

Question 11 b.5:

Discuss the schedule/frequency for coupon removal and testing to demonstrate continued BoralTM performance.

Response 11 b.5 The BoralTM coupon examination schedule, as described in Response 11 b.4, is once per cycle (currently

-18 months).

Question 11 b.6:

How does this acceptance criteria account for potential degradation between surveillance periods?

Response 1lb.6 The change in margins for blister volume & areal density respectively, are extrapolated forward to ensure compliance beyond the next examination. It should be noted that significant numbers of surveillances have been performed on the coupons and any degradation noted has been gradual. There is no evidence that would justify a sudden catastrophic failure assumption. Extrapolation forward of the coupons which are designed to lead the actual panel performance is the most reasonable approach to monitoring the degradation and is consistent with industry standards.

Criterion C, "Neutron radiography indication of acceptable boron carbide distribution within the test coupons" must be applied differently from the other criteria. The purpose of the neutron radiography is to detect any mal-distribution or change in areal density over the entire coupon that might not otherwise be identifiable from the visible surface features of the coupon. Once such an area of mal-distribution is detected by radiography it would then be evaluated for areal density by thermal neutron beam attenuation and Criterion B would be applied to determine material acceptability and margin.

10

Question 11 b.7:

Please describe the corrective actions that would be implemented if coupon test results are not acceptable.

Response 11 b.7 The BoralTM Monitoring Program makes provisions for Remedial Actions to maintain the spent fuel racks to within the assumptions of the criticality analysis and the viability of the Program. "Unacceptable test results" would result in a Condition Report (CR) within the Seabrook Corrective Action Program (CAP).

The course of action pursuant to the CR would be dependent on the specific nature of the coupon test results that are unacceptable and why. Potential actions, without knowing the specifics of the issue are difficult to document however it would be expected that verification of the test results in question would be the first action taken. If warranted, additional coupons could be tested. If unacceptable results are confirmed, the industry and the regulatory agencies would be informed. If criticality analysis parameters were challenged provisions might be made to take credit for SFP boron concentration, at least as a temporary measure. Restrictive fuel placement in the SFP might be a potential countermeasure. Rack repairs or replacement might be pursued or a license amendment rnmht be applied for depending on the nature and severity of the specific issue. Trending of regular Boral coupon examination data would allow time to anticipate an unacceptable result and develop contingency actions prior to exceeding specific acceptance criteria.

Question 11 b.8 Please discuss the correlation between measurements of the physical properties of BoralTM coupons and the integrity of the BoralTM panels in the storage racks.

Response 1lb.8 Correlation of the measured BoralTM coupon results to the condition of the poison panels within the spent fuel pool racks is paramount to the effectiveness of the Program. The following are the key attributes which provide the basis for correlating the BoralTM coupons to the BoralTM panels Program attributes that support coupon to rack correlation

1. Industry recommendations, promulgated by EPRI for Neutron Absorber Monitoring Coupons, were applied with regard to the size, number, encapsulation and presentation of such coupons to the spent fuel pool environment.

2. The coupons are serialized and traceable to the actual BoralTM production lots incorporated into the Seabrook spent fuel racks.

3. The Seabrook Coupon Program commenced when the BoralTM rack were first placed in the SFP.

4. The coupon encapsulation "jackets" mimic the presentation of the BoralTM panels within the actual racks with regard to materials,- dimensions, mass, orientation and water intrusion so as to accurately represent BoralTM response to the spent fuel pool environment.

5. Sixteen (16) coupons are encapsulated and mounted, four to a side, on a custom coupon "tree" or rack for exposure to the maximum thermal & gamma conditions within the actual fuel rack call. The Program is designed such that the coupon exposure to heat and radiation lead BoralTM contained in the actual racks. The BoralTM coupon tree is retrieved from the spent fuel pool late in each fuel cycle where it has been exposed to the pool environment since the last examination. The coupon tree resides in a spent fuel rack cell which is surrounded, at each core off-load with the 24 highest burnup discharge fuel assemblies.

11

6. The discharge assemblies are arranged two deep around the coupon tree to form a 25 cell array referred to as the coupon nest. A different nest location within the SFP is typically selected for each core off-load to avoid repeated high exposure to the same area of the racks and to minimize fuel handling. This also allows the coupon exposure to lead that accrued by the racks.

7. Selected coupons are removed from their encapsulation, dried in a silica gel desiccator and given preliminary inspection to check gross coupon condition prior to the detailed contractor examination. Drying the coupons within a silica gel desiccator arrests extraneous corrosion that might occur during examination while the coupon are removed from the SFP and not representative of the corrosion process occurring within the SFP racks. Drying within a silica gel also voids extraneous coupon blister formation and coupon damage associated with heat or vacuum drying.

8. The selected coupons are shipped to an inspection contractor for detailed examination and testing as defined by Seabrook examination specification. The Seabrook BoralTM subject matter expert typically participates in person, at the inspection contractor facility, to remain cognizant of examination methods and to recommend specific follow-up examination based on current results and findings.

9. The measured to predicted limiting blister displacement between the Cycle 13 & 14 differed by only 4% indicating a reasonable degree of precision and confidence in the blister volume measurements. There have been no discernable changes in areal density or B10 distribution.

Background Information:

Seabrook BoralTM Monitoring Program

Description:

This Program was initiated as an engineering "good practice" upon the initial introduction of Boral spent fuel pool storage racks at Seabrook Station in 1998. No regulatory guidance or commitments for BoralTM monitoring were imposed at the time. However, general industry recommendations, promulgated by EPRI for Boraflex Monitoring Coupons, were applied with regard to the size, number, encapsulation and presentation of such coupons to the spent fuel pool environment. Twenty-four (24) BoralTM coupons (13" x 6.5" x 0.075") were obtained for the Seabrook BoralTM Monitoring Program. The coupons are serialized and traceable to the actual BoralTM production lots incorporated into the Seabrook spent fuel racks.

Sixteen (16) coupons are encapsulated and mounted, four to a side, on a custom coupon "tree" or rack for exposure to the spent fuel pool. The BoralTM coupon tree is located within Region 1 of the SFP Eight additional coupons were designated as control coupons and maintained as dry archive specimens. The coupon encapsulation "jackets" mimic the presentation of the BoralTM panels within the actual racks with regard to materials, dimensions, mass, orientation and water intrusion so as to accurately represent BoralTM response to the spent fuel pool environment.

The degree of similarity in encapsulation and presentation between the coupon tree and the actual racks is paramount to accurately demonstrating BoralTM response and behavior both expected and unexpected.

Also as, indicated herein, the Program is designed such that the coupon exposure to heat and radiation are intended to lead BoralTM contained in the actual racks. Most importantly, all the BoralTM coupons were fabricated from material that is traceable to heat lots incorporated into the racks.

12

BoralTM Coupon Tree 13

BoraITM Coupon Encapsulation

'/2" erifcation Hole 0.02" 304 SS Wrapper Plate .- I i  !

0.09" 304 SS Window Frame Spacer Rivet & Attachment Screw Holes I

The BoralTM coupon tree is retrieved from the spent fuel pool late in each fuel cycle where it has been exposed to the pool environment since the last examination. The coupon tree resides in a spent fuel rack cell which is surrounded at each core off-load with the 24 highest burnup discharge fuel assemblies. The discharge assemblies are arranged two deep around the coupon tree to form a 25 cell array referred to as the coupon nest. A different nest location within the SFP is typically selected for each core off-load to avoid repeated high exposure to the same area of the racks and to minimize fuel handling. This also allows the coupon exposure to lead that accrued by the racks. Two to nine selected coupons are removed from the coupon tree for examination near the end of each fuel cycle. The coupon tree with the remaining coupons is returned to the nest for continued exposure.

The selected coupons are removed from their encapsulation, dried in a silica gel desiccator and given preliminary inspection to check gross coupon condition prior to the detailed contractor examination. This preliminary inspection serves to check, and photographically document, the overall coupon dimensions, blister changes and clad conditions prior to contractor examinations. The selected coupons are then shipped to an inspection contractor for detailed examination and testing as defined by Seabrook examination specification. The Seabrook BoralTM subject matter expert typically participates in person, at the inspection contractor facility, to remain cognizant of examination methods and to recommend specific follow-up examination based on current results and findings.

The neutron-absorbing capacity of the flux trap within the Seabrook spent fuel racks is dependent on the BoralTM & flux trap geometry, the B10 areal density and distribution within the BoralTM panels as well as the water density and boric acid concentration of the spent fuel pool. The water density and boric acid concentration of the spent fuel pool are independent of Boral and therefore not addressed herein.

However, TM the BoralTM & flux trap geometry TM and the B10 areal density and distribution are direct attributes of Boral evaluated within the Boral Monitoring Program. Gross changes to the coupon length and width are checked in the preliminary inspection and found to be currently unchanged. However, BoralTM blister formation has resulted in BoralTM exceeding the material thickness specification of 0.075" +/- .005" assumed in the spent fuel rack specification. The potential effect of gas filled blister displacement of water within the flux trap is monitored as a function of maximum blister displacement volume measured on the BoralTM coupons. The inspection contractor measures the height and area of each blister on the selected coupons and calculates the specific blister and total coupon displacement volume using a spherical section model of each blister. This data produces a total blister count & displacement volume for each coupon.

The neutron-absorbing capacity of the flux trap within the Seabrook spent fuel racks is dependent on the magnitude and distribution of the B10 areal density. The B10 areal density distribution is evaluated by high resolution-digital neutron radiography. Any change or irregularity observed in the neutron radiograph wouia be designated for evaluation by thermal neutron beam attenuation measurement of B10 areal density at the specific area in question. Otherwise, areas of interest, such as blisters or corrosion pits will be selected for neutron beam attenuation measurement.

Photo microscopy is also applied during the detailed contractor examination to evaluate corrosion pits and other anomalies to detect the onset of boron carbide shedding and other material degradation that might lead to diminished B'° areal density or degradation. Such areas can then also be considered by the.Seabrook BoralTM subject matter expert for neutron beam attenuation measurement.

The Program acceptance criteria are applied to the following three critical attributes results.

1. BoralTM Coupon geometry (Total Blister Displacement Volume)

2. B10 areal density (Thermal Neutron Beam Attenuation)

3. B10 distribution (Neutron Radiography) 15

ADolication of ProQram Original AcceDtance Criteria* to Cycle 14 Exam Results The BoralTM Monitoring Program acceptance criteria are satisfied by the Cycle 14 examination results as evaluated below.

Criterion A Evaluation: The maximum coupon blister displacement was found to be 1.53 in 3/ ft2 representing a uniform void of 10.6 mils. This uniform void of 10.6 mils is 23.6% of the 45 mil limit. For the limiting coupon the blister volume growth and the proportionate change in uniform void were calculated to be 11.4 % (volume) for the previous 18-month cycle. This limiting volumetric growth rate indicates the uniform void is expected to be 11.8 mils, or 26 % of the 45 mil limit, at the Cycle 15 BoraITM examination. A margin equal to 74 % of the 45 mil limit is expected to remain at the next BoralTM examination.

TM 102 Criterion B Evaluation: The Boral B areal density was found to be greater than 0.023 gm/cm , which is within the demonstrated acceptable range 0.022 to 0.025 gm/cm 2. The B13margin for demonstrated acceptable range in areal density is 0.002 gm/cm2 above the specified limit of 0.020 gm/cm 2 . Reduction in B areal density has not been observed in the test coupons without dissected blisters. Therefore, adequate margin in B1° areal density exists until the next BoralTM examination. However, visual indications of aluminum corrosion on surveillance coupons indicate clad and boron carbide removal at levels below the lower limit of B10 areal density measurement.

Criterion C Evaluation: Neutron radiography indicated acceptable boron carbide distribution within the test coupons.

• Note: LAR 11-04 will allow Criterion B to be revised for a lower B10 areal density limit of 0.015 gm/cm2 to increase margin by 0.005 gm/cm2.

The change in criteria margins are extrapolated forward in time to ensure compliance to, or beyond, the next examination.

The BoralTM Monitoring Program makes provisions for Remedial Actions to maintain the spent fuel racks to within the assumptions of the criticality analysis and the viability of the Program. "Unacceptable test results" would result in a Condition Report within the Seabrook Corrective Action Program (CAP). The course of action pursuant to the CR would be dependent on the specific nature of the coupon test results that are unacceptable and why. Trending of regular BoralTM examination data allows time to anticipate an unacceptable result and develop contingency actions prior to exceeding specific acceptance criteria.

16

2.0 Description of Revised Technical Specification Changes

• Figure 5.6-1 Note 1 - Allowable Storage Pattern Region 1. The proposed TS submitted with LAR 11-04 is as follows:

There are no interface limitations within Region 1 between rack modules or within racks; however, each assembly must meet the burnup requirements of each 2x2 array that it resides within.

The proposed new wording is as follows:

There are no interface limitations within Region 1 between rack modules or within racks. Each cell is a part of up to four 2x2 arrays, and each cell must simultaneously meet the requirements of all those arrays of which it is a part.

Justification: This change clarifies the requirement for placement of the fuel to simultaneously meet the requirements of each 2x2 array. This clarification is considered an administrative change. There is no change in the intention of the Note. Each assembly was expected to meet the requirements of each 2x2 array it is a part (or within). The wording change is to add clarity to this requirement.

• Figure 5.6-2 Note 1 -Allowable Storage Patterns Region 2. The proposed TS submitted with LAR 11-04 is as follows:

The storage arrangements of fuel within a rack module may contain more than one pattern.

There are no interface limitations within Region 2 between rack modules or within racks; however, each assembly must meet the burnup requirements of each 2x2 array that it resides within.

The proposed new wording is as follows:

The storage arrangements of fuel within a rack module may contain more than one pattern.

There are no interface limitations within Region 2 between rack modules or within racks. Each cell is a part of up to four 2x2 arrays, and each cell must simultaneously meet the requirements of all those arrays of which it is a part.

Justification: This change clarifies the requirement for placement of the fuel to simultaneously meet the requirements of each 2x2 array. This clarification is considered an administrative 17

change. There is no change in the intention of the Note. Each assembly was expected to meet the requirement of each 2x2 array it is a part (or within). The wording change is to add clarity to this requirement.

The proposed revised TS pages are provided in Attachment 1.

3.0 References

1. Seabrook Station License Amendment Request 11-04, "Changes to the Technical Specifications for New and Spent Fuel Storage," SBK-L-1 1245, January 30, 2012.

2. NRC letter to Seabrook Station, "Seabrook Station, Unit No. 1 - Supplemental Information Needed for Acceptance of Requested Licensing Action Regarding License Amendment Request 11-04, Change to Technical Specifications for New and Spent Fuel Storage (TAC No. ME7946)," March 30, 2012.

18

Attachment I Revised TS Pages

Figure 5.6-1 ALLOWABLE STORAGE PATTERN REGION 1 (See Notes 1 and 2)

Pattern "A" See Definition 1 RC RC 1 2 RC RC 2 1 DEFINITIONS:

1. Allowable pattern is Reactivity Class (RC) 1 or fuel of lower reactivity checkerboarded with RC 2 or fuel of lower reactivity. Minimum burnup for RC 1 and 2 is defined in Table 5.6-1 as a function of nominal initial central zone enrichment. Diagram is for illustration only.

NOTES

1. There are no interface limitations within Region 1 between rack modules or within racks. Each cell is a part of up to four 2x2 arrays, and each cell must simultaneously meet the requirements of all those arrays of which it is a part.

2. Replacement of any fuel assembly by an empty water hole, non-fuel hardware or fuel rod storage basket is acceptable.

SEABROOK - UNIT 1 5-14 Amendment No.

Figure 5.6-2 ALLOWABLE STORAGE PATTERNS REGION 2 (See Note 1)

Pattern "B" Pattern "C" Pattern "D" RCS3 RC 3 RCS4 RC4 RCS5 RC 5 RCCA RCCA RC 3 RC 3 RC 4 RC 4 RCCA RC 5 KC See Definition 1 See Definition 2 See Definition 3 DEFINITIONS

1. Allowable pattern is Reactivity Class (RC) 3 or fuel of lower reactivity in each of the 2x2 array locations combined with two RCCAs placed in any two locations within the 2x2 array. Minimum burnup for RC 3 is defined in Table 5.6-1 as a function of nominal initial central zone enrichment and cooling time. Replacement of any fuel assembly (with or without an RCCA) by an empty water hole, non-fuel hardware or fuel rod storage basket is acceptable. Diagram is for illustration only.

2. Allowable pattern is Reactivity Class (RC) 4 or fuel of lower reactivity in each of the 2x2 array locations with one RCCA placed anywhere in the 2x2 array. Minimum burnup for fuel RC 4 is defined in Table 5.6-1 as a function of nominal initial central zone enrichment and cooling time. Replacement of any fuel assembly (with or without an RCCA) by an empty water hole, non-fuel hardware or fuel rod storage basket is acceptable. Diagram is for illustration only.

1

3. Allowable pattern is Reactivity Class (RC) 5 in each of the 2x2 array locations. Minimum burmup for RC 5 is defined in Table 5.6-1 as a function of nominal initial central zone enrichment and cooling time. Replacement of any fuel assembly by an empty water hole, non-fuel hardware or fuel rod storage basket is acceptable. Diagram is for illustration only.

NOTES

1. The storage arrangements of fuel within a rack module may contain more than one pattern. There are no interface limitations within Region 2 between rack modules or within racks. Each cell is a part of up to four 2x2 arrays, and each cell must simultaneously meet the requirements of all those arrays of which it is a part.

SEABROOK - UNIT 1 5-15 Amendment No.

Attachment 3 Holtec Letter 2064-AFFI-02 Affidavit for Holtec Response

Umm EM Holtec Center, 555 Lincoln Drive West, Marlton, NJ 08053 H O LTEC INTERNATIONAL Telephone (856) 797-0900 Fax (856) 797-0909 Holtec International Document ID 2064-AFFI-02 AFFIDAVIT PURSUANT TO 10 CFR 2.390 I, Thomas V. Fitzpatrick, being duly sworn, depose and state as follows:

(1) I have reviewed the information described in paragraph (2) which is sought to be withheld, and am authorized to apply for its withholding.

(2) The information sought to be withheld is information provided with Holtec letter 2064003, specifically Holtec RRTI-2064-001, which contains Holtec Proprietary information and is appropriately marked as such. The following Acceptance Review questions and responses are considered proprietary: Q3, Q4, Q5, Q6, Q7, Q9 and Q10.

(3) In making this application for withholding ofproprietary information of which it is the owner, Holtec International relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 USC Sec. 552(b)(4) and the Trade Secrets Act, 18 USC Sec. 1905, and NRC regulations 10CFR Part 9.17(a)(4), 2.390(a)(4), and 2.390(b)(1) for "trade secrets and commercial or financial information obtained from a person and privileged or confidential" (Exemption 4). The material for which exemption from disclosure is here sought is all "confidential commercial information", and some portions also qualify under the narrower definition of "trade secret", within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission, 975F2d871 (DC Cir. 1992), and Public Citizen Health Research Group v. FDA, 704F2d1280 (DC Cir. 1983).

1 of 5

Holtec International Document ID 2064-AFFI-02 AFFIDAVIT PURSUANT TO 10 CFR 2.390 (4) Some examples of categories of information which fit into the definition of proprietary information are:

a. Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by Holtec's competitors without license from Holtec International constitutes a competitive economic advantage over other companies;

b. Information which, if used by a competitor, would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product.

c. Information which reveals cost or price information, production, capacities, budget levels, or commercial strategies of Holtec International, its customers, or its suppliers;

d. Information which reveals aspects of past, present, or future Holtec International customer-funded development plans and programs of potential commercial value to Holtec International;

e. Information which discloses patentable subject matter for which it may be desirable to obtain patent protection.

The information sought to be withheld is considered to be proprietary for the reasons set forth in paragraph 4.b, above.

(5) The information sought to be withheld is being submitted to the NRC in confidence. The information (including that compiled from many sources) is of a sort customarily held in confidence by Holtec International, and is in fact so held. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by Holtec International. No public disclosure has been made, and it is not available in public sources. All disclosures to third parties, including any required transmittals to the NRC, have been made, or must be made, pursuant to regulatory provisions or 2 of 5

Holtec International Document ID 2064-AFFI-02 AFFIDAVIT PURSUANT TO 10 CFR 2.390 proprietary agreements which provide for maintenance of the information in confidence. Its initial designation as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set forth in paragraphs (6) and (7) following.

(6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge.

Access to such documents within Holtec International is limited on a "need to know" basis.

(7) The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist or other equivalent authority, by the manager of the cognizant marketing function (or his designee), and by the Legal Operation, for technical content, competitive effect, and determination of the accuracy of the proprietary designation.

Disclosures outside Holtec International are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary agreements.

(8) The information classified as proprietary was developed and compiled by Holtec International at a significant cost to Holtec International. This information is classified as proprietary because it contains detailed descriptions of analytical approaches and methodologies not available elsewhere. This information would provide other parties, including competitors, with information from Holtec International's technical database and the results of evaluations performed by Holtec International. A substantial effort has been expended by Holtec International to develop this information. Release of this information would improve a competitor's position because it would enable Holtec's competitor to copy our technology and offer it for sale in competition with our company, causing us financial injury.

3 of 5

Holtec International Document ID 2064-AFFI-02 AFFIDAVIT PURSUANT TO 10 CFR 2.390 (9) Public disclosure of the information sought to be withheld is likely to cause substantial harm to Holtec International's competitive position and foreclose or reduce the availability of profit-making opportunities. The information is part of Holtec International's comprehensive spent fuel storage technology base, and its commercial value extends beyond the original development cost. The value of the technology base goes beyond the extensive physical database and analytical methodology, and includes development of the expertise to determine and apply the appropriate evaluation process.

The research, development, engineering, and analytical costs comprise a substantial investment of time and money by Holtec International.

The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial.

Holtec International's competitive advantage will be lost if its competitors are able to use the results of the Holtec International experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions.

The value of this information to Holtec International would be lost if the information were disclosed to the public. Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive Holtec International of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing these very valuable analytical tools.

4 of 5

Holtec International Document ID 2064-AFFI-02 AFFIDAVIT PURSUANT TO 10 CFR 2.390 STATE OF NEW JERSEY )

) ss:

COUNTY OF BURLINGTON)

Mr. Thomas V. Fitzpatrick, being duly sworn, deposes and says:

That he has read the foregoing affidavit and the matters stated therein are true and correct to the best of her knowledge, information, and belief.

Executed at Marlton, New Jersey, this 2 4 th day of April, 2012 Thomas V. Fitzpatrick Holtec International Subscribed and sworn before me this ,'/ day of

• 2012.

MARIA C.MASSI NOMWYPUBLIC OF NEW JERSEY M, 4-ommissfon Expires April 25,2015 5 of 5

Attachment 4 Holtec Letter RRTI-2064-001 (Non-Proprietary)

Response to Request for Technical Information (RRTI

Request I Question I

1. The criticality code validation was not included. The validation is indicated as being in several references. Those references are required for the review to begin.

a. Reference 5, "Nuclear Group Computer Code Benchmark Calculations," Holtec Report HI-2104790 Revision 0, January 2011.

b. Reference 6, "Sensitivity Studies to Support Criticality Analysis Methodology," Holtec Report HI-2104598 Revision 1, October 2010.

c. Reference 7, "Lumped Fission Product and Pm148m Cross Sections for MCNP," Holtec Report HI-2033031 Revision 2, January 2011.

Response to 1 The following requested references have been submitted to the Nuclear Regulatory Commission:

a. Reference 5, "Nuclear Group Computer Code Benchmark Calculations," Holtec Report HI-2104790 Revision 0, January 2011 has been submitted to the Nuclear Regulatory Commission in the letter from T. Fitzpatrick (Holtec) to T. Orf (Nuclear Regulatory Commission) (Serial:1867005, June 17, 2011) "Request for Holtec Reports HI-2033031 "Lumped Fission Product and Pm148m Cross Sections for MCNP and HI-2104790 "Nuclear Group Computer Code Benchmark Calculations"

b. Reference 6, "Sensitivity Studies to Support Criticality Analysis Methodology," Holtec Report HI-2104598 Revision 1, October 2010 has been submitted to the Nuclear Regulatory Commission in support of the Beaver Valley Power Station Unit #2 (BPVS-2) re-rack application, Docket Number#: 50-412, License Number#: NPF-73.

c. Reference 7, "Lumped Fission Product and Pm148m Cross Sections for MCNP," Holtec Report HI-2033031 Revision 2, January 2011 has been submitted to the Nuclear Regulatory Commission in the letter from T. Fitzpatrick (Holtec) to T. Orf (Nuclear Regulatory Commission) (Serial: 1867005, June 17, 2011) "Request for Holtec Reports HI-2033031 "Lumped Fission Product and Pm148m Cross Sections for MCNP and HI-2104790 "Nuclear Group Computer Code Benchmark Calculations" Request / Question 2

2. In Section 3.2.2 of HI-21144996 it states, "...and the initial source was usually specified as uniform over the fueled regions (assemblies)." When wasn't the initial source specified as uniform over the fueled regions and why?

Response to 2 The source has been confirmed to be specified as uniform over the fueled regions for all calculations.

Therefore, the sentence is poorly worded and "usually" can be ignored.

I

Request I Question 3 3.

Response to 3 Request I Question 4

.4.

Response to 4 2

Request I Question 5 a.

b.

C.

Response to 5 Response to 5.a.

Response to 5.b.

_Response to 5. c..

3

Request / Question 6 6.

Response to 6 Request I Question 7 R7.

Response to 7 4

Request I Question 9 9.

Response to 9 Vs4~.

--- 4 Request I Question 10

-J Response to 10 5