NRC-15-0081, License Renewal Application Update for the Boraflex Monitoring Program

License Renewal Application Update for the Boraflex Monitoring Program

ML15268A454
Person / Time
Site:	Fermi
Issue date:	09/24/2015
From:	Kaminskas V DTE Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-15-0081
Download: ML15268A454 (19)

Text

Vito A. Kaminskas Site Vice President DTE Energy Company 6400 N. Dixie Highway, Newport, JVII 48166 Tel: 734.586.6515 Fax: 734.586.4172 Email: kaminskasv@dteenergy.com 10 CFR 54 September 24, 2015 NRC-15-0081 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington DC 20555-0001

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) DTE Electric Company Letter to NRC, "Fermi 2 License Renewal Application," NRC-14-0028, datedApril24, 2014 (ML14121A554)

3) DTE Electric Company Letter to NRC, "Response to NRC Request for Additional Information for the Review of the Fermi 2 License Renewal Application- Set 13," NRC-15-0008, dated January 26,2015 (ML15026A624)

4) DTE Electric Company Letter to NRC, "Response to NRC Request for Additional Information for the Review of the Fermi 2 License Renewal Application- Sets 23, 24, and 26," NRC-15-0031, datedAprillO, 2015 (ML15110A342)

5) NRC Letter, "Fermi 2 - Issuance of Amendment Re: Spent Fuel Pool Rerack (TAC No. MA7233)," dated January 25, 2001 (ML010310205)

Subject:

Fermi 2 License Renewal Application Update for the Boraflex Monitoring Program The purpose of this letter is to provide the NRC with an update to the Fermi 2 License Renewal Application (LRA) related to the Boraflex Monitoring Program as shown in .

In Reference 2, DTE Electric Company (DTE) submitted the License Renewal Application (LRA) for Fermi 2. In References 3 and 4, DTE responded to requests for additional information (RAis) on the Boraflex Monitoring Program. Upon further discussion with the NRC staff, DTE has decided to no longer credit the Boraflex

US NRC NRC-15-0081 Page 2 Monitoring Program during the period of extended operation. DTE's current licensing basis includes NRC-approved License Amendment No. 141 (Reference 5) that authorizes DTE to replace Boraflex neutron-absorbing storage racks with Boral neutron-absorbing storage racks. Two phases of the replacement were completed in 2001 and 2007. The third phase, which would replace the remaining Boraflex racks with Boral racks, has not yet been implemented.

One new commitment is being made in this submittal:

Consistent with the current licensing basis, DTE commits to implementation of the Boraflex rack replacement approved in Amendment No. 141 prior to September 20, 2024, or the end of the last refueling outage prior to March 20, 2025, whichever is later, so that the current Boraflex panels in the spent fuel pool will not be required to perform a neutron absorption function during the period of extended operation.

If, based on further analyses and subject to any necessary NRC approvals, DTE identifies an alternative to implementation of the rack replacement approved in Amendment No. 141 that can be completed in a timely manner, this commitment will be revised accordingly. As addressed in RIS 2014-06, "Consideration of Current Operating Issues and Licensing Actions in License Renewal," dated May 5, 2014, changes to the current licensing basis that occur after the renewed license is approved, may be subject to 10 CFR 54.37 (b) reporting requirements, but do not affect review of the license renewal application.

This new commitment for license renewal is provided in LRA Table A.4 Item 5, Boraflex Monitoring, as indicated in Enclosure 1.

Should you have any questions or require additional information, please contact Lynne Goodman at 734-586-1205.

I declare under penalty of petjury that the foregoing is true and correct.

E(~,;Q71;:r;* 2015 Vito A. Kaminskas Site Vice President Nuclear Generation

Enclosures:

1. Fermi 2 License Renewal Application Revisions for the Boraflex Monitoring Program

US NRC NRC-15-0081 Page 3 cc: NRC Project Manager NRC License Renewal Project Manager NRC Resident Office Reactor Projects Chief, Branch 5, Region III Regional Administrator, Region III Michigan Public Service Commission, Regulated Energy Division (kindschl @michigan.gov)

Enclosure 1 to NRC-15-0081 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF -43 Fermi 2 License Renewal Application Revisions for the Boraflex Monitoring Program to NRC-15-0081 Page 1

Background

The Fermi 2 License Renewal Application (LRA) submitted in April2014 included a Boraflex Monitoring Program. The Boraflex Monitoring Program described in LRA Section B.l.3 was based on NUREG-1801,Section XI.M22, Boraflex Monitoring. The program included areal B-1 0 density measurement testing of the spent fuel storage racks, such as BADGER testing, at a frequency of at least once every five years during the period of extended operation. As described in the "Operating Experience" subsection of LRA Section B.1.3, DTE had already performed BADGER testing in October 2013. In RAI B.l.3-1, the NRC staff requested the report documenting the October 2013 BADGER testing. DTE provided the BADGER report in response to RAI B.l.3-1 on January 26,2015 by letter NRC-15-0008. After reviewing the BADGER report, the NRC asked follow-up RAI B.l.3-1a. DTE responded to RAI B.l.3-1a on AprillO, 2015 by letter NRC-15-0031. In LRA Section B.l.3 and these RAI responses, DTE explained that the BADGER testing showed degradation of the Boraflex and described corrective actions. The NRC staff subsequently indicated that there were still questions regarding Boraflex degradation that were not resolved by the RAI responses.

Impact on LRA As a result of the DTE commitment made in the cover letter for this enclosure, the Boraflex panels will no longer be required to perform a neutron absorption function during the period of extended operation. Therefore, DTE will not credit the Boraflex Monitoring Program during the period of extended operation. LRA Sections 2.3.3.4, 3.3.2.1.4, A.l.3, B.l.3, and LRA Tables 3.3.1 (Item 3.3.1-51), 3.3.2-4, A.4 (Item 5), B-1, B-2, and B-3 are revised to no longer credit the Boraflex Monitoring Program. All of the neutron-absorbing material that will be credited for neutron absorption during the period of extended operation will be managed by the existing Neutron-Absorbing Material Monitoring Program. For consistency with NUREG-1801 Section XI.M40, LRA Sections A.1.27 and B.l.27, and LRA Table 3.3.1 (Item 3.3.1-102) are revised to cover all neutron-absorbing material other than Boraflex (i.e. including, but not limited to, Boral). The LRA revisions associated with the changes discussed above are shown on the following pages. Additions are shown in underline and deletions are shown in strike-through.

Note that previous changes made to these same LRA sections made in previous letters are not shown in underline or strike-through such that only the new changes due to the items above are shown as revisions. The LRA revisions are provided in the order that they would appear in the LRA.

to NRC-15-0081 Page 2 2.3.3.4 Fuel Pool Cooling and Cleanup Fuel Service and Handling Equipment The fuel service and handling equipment system codes (system codes F11, F12, F13, F14, F15, F16, F17, F19) consist of equipment used for moving fuel during refueling and other outage inspections and tasks as well as spent fuel storage. With the exception of system code F16 (reactor vessel fuel storage equipment), the few components that are classified as safety-related (the RPV head strongback [system code F13] the dryer and separator sling [system code F13], and a plug for the "fuel servicing equip gamma scan collimator" [system code F11 ]), are not mechanical system components. (For scoping discussion of lifting devices and plugs, see Section 2.4.1, Reactor/Auxiliary Building and Primary Containment).

The purpose of the reactor vessel fuel storage equipment system (system code F16) is to provide storage for spent fuel. There are two types of high-density spent fuel storage racks (Holtec and Oat) being used. The Oat racks use Boraflex as a neutron absorber; the Holtec racks use Boral. The structural support of fuel provided by the stainless steel racks and the neutron absorption performed by Boraflex and Boral are intended functions in accordance with 10 CFR 54.4(a)(1 ). DTE's current licensing basis includes an NRC-approved license amendment (Amendment No. 141) that allows for replacement of the Boraflex with Boral. This modification consisted of several phases, with the final phase not yet being implemented. DTE has committed to implementation of the Boraflex rack replacement approved in Amendment No. 141 prior to September 20, 2024, or the end of the last refueling outage prior to March 20, 2025, whichever is later. Following the completion of spent fuel pool modifications prior to the period of extended operation, the current Boraflex in the spent fuel storage racks will not be credited for the intended function of neutron absorption. System code F16 also includes the nonsafety-related new fuel racks, which provide structural support for new fuel.

to NRC-15-0081 Page 3 3.3.2.1.4 Fuel Pool Cooling and Cleanup System Aging Management Programs The following aging management programs manage the aging effects for the fuel pool cooling and cleanup system components.

• Bolting Integrity

• Boraflex Monitoring

• External Surfaces Monitoring

• One-Time Inspection

• Neutron-Absorbing Material Monitoring

• Water Chemistry Control - BWR to NRC-15-0081 Page4 Table 3.3.1 Summary of Aging Management Programs for the Auxiliary Systems Evaluated in Chapter VII of NUREG-1801 Table 3.3.1: Auxiliary Systems Aging Further Item Aging Effect/ Management Evaluation Number Component Mechanism Programs Recommended Discussion 3.3.1-51 Boraflex spent Reduction of Chapter XI.M22, No GeRsisteRt 1NitR ~JblR~G ~ 8G~.

fuel storage neutron-absorbing "Boraflex +Re eliaR§e iR A=~ateFial racks: neutron- capacity due to Monitoring" !3Fei38Fties aREl FeEll::letieR ef absorbing boraflex Rel::ll:FeR a8seFI3iR§ eapaeity ef sheets (PWR), degradation tRe @eFafle* speRt ft:~el steFa§e spent fuel Fael.;: Re!::ltFeR al3seFI3iR§ slieets storage racks: e*f3eseEl te tFeateEl vJateF \*Jill 13e neutron- A=JaRa§ed sy tRe @emfle*

absorbing MeRiteFiR§ PFe§FaA=J. This item sheets (BWR) was not used. The current exposed to Boraflex neutron-absorbing treated borated sheets exQosed to treated water, treated water in the SQent fuel storage water racks will not be credited for neutron absorQtion during the Qeriod of extended OQeration.

Therefore, the Boraflex in the SQent fuel storage racks will not Qerform a license renewal intended function.

to NRC-15-0081 PageS Table 3.3.1: Auxiliary Systems Aging Further Item Aging Effect! Management Evaluation Number Component Mechanism Programs Recommended Discussion 3.3.1-102 Bora!; boron Reduction of Chapter XI.M40, No Consistent with NUREG-1801.

steel, and other neutron-absorbing "Monitoring of The change in material materials capacity; change in Neutron- Absorbing properties and reduction of (excluding dimensions and Materials other neutron-absorbing capacity of Boraflex) spent loss of material due than Boraflex" the aluminum/boron carbide fuel storage to effects of SFP spent fuel storage rack racks: neutron- environment neutron-absorbing sheets absorbing materials exposed to treated sheets (PWR), water will be managed by the spent fuel Neutron-Absorbing Material storage racks: Monitoring Program.

neutron-absorbing sheets (BWR) exposed to treated borated water, treated water

Enclosure 1 to NRC-15-0081 Page 6 Table 3.3.2-4 Fuel Pool Cooling and Cleanup System Summary of Aging Management Evaluation Table 3.3.2-4: Fuel Pool Cooling and Cleanup System Aging Effect Aging Component Intended Requiring Management NUREG- Table 1 Type Function Material Environment Management Programs 1801 Item Item Notes Neutron Neutron Aluminum/ Treated water Change in Neutron- VII.A2.AP- 3.3.1- A absorber absorption boron (ext) material Absorbing 236 102 carbide properties Material Monitoring Neutron Neutron Aluminum/ Treated water Loss of Neutron- VII.A2.AP- 3.3.1- A absorber absorption boron (ext) material Absorbing 236 102 carbide Material Monitoring Neutron Neutron Aluminum/ Treated water Reduction in Neutron- VII.A2.AP- 3.3.1- A absorber absorption boron (ext) neutron Absorbing 236 102 carbide absorption Material capacity Monitoring Ne~:~treR ~Jel:ltFOR BoreR +FeateEI wateF GFiaR§leiR- Boraflex \Ill A0 A 07 3.3.~ A

... ,,..,,.,

absorber absoFptioR carbiEle / fextt material .§.+

~ ~~~:

"'-' '::I elastemeF ,..,y~,..,~v+:~~

rv-v

,..,

F"'~

Ne~:~tmR ~ BoreR +reateEI 'Jvater -o~~ ~-~-:~,..,

'--"'--' v Beraflex Vll./\2./\ 87 3.3.~ A absorber absorption carbiEie / fextt Re~:~tl=en MoniteriR§l .§.+

elastomer absorption

,.......,....,...,,...:+.

'--'!--'*'-'"

to NRC-15-0081 Page 7 A.1.3 Boraflex Monitoring Program The Boraflex Monitoring Program is an existing program to manage the Boraflex material affixed to the spent fuel storage racks. This program is currently reguired by Technical Specification 5.5.13 and includes activities implemented in response to NRC GL 96-04 to assure that the reguired five percent sub-criticality margin is maintained. The Boraflex currently in the spent fuel racks will not be credited for neutron absorption during the period of extended operation and therefore this aging management program will not be relied upon during the period of extended operation. All of the neutron-absorbing material to be credited during the period of extended operation will be managed by the Neutron-Absorbing Material Monitoring Program in Section A.1.27.

Tho Boraflex Monitoring Program manages the aging effect of reduction in neutron absorbing capacity (change in material properties) in the Boraflex material affb(Qd to spent fuel racks. /\

monitoring program for tho Boraflox panels in tho spent fuel storage racl<s is implemented to assure that no unexpected degradation of tho Boraflox material compromises the criticality analysis in support of tho design of spent fuel storage racks. Tho program uses tho RACKLIFE computer predictive code to calculate tho gamma dose absorbed by and tho amount of boron carbide loss from tho Boraflox panels. Tho program includes (a) quarterly sampling and analysis for silica levels in the spent fuel pooHivator and trending tho results by using tho RACKLIFE code, (b) performing periodic physical measurements and neutron attenuation testing of surveillance coupons, and (c) areal B 10 density measurement testing of the spent fuel storage racks, such as Beron 10 /\real Density Gage for Evaluating Racks (Bl\DGER) testing, at a frequency of at least once every five years. This program, implemented in response to NRC GL 96 04, assures that the required five percent sub criticality margin is maintaifl-04 The Boraflex Monitoring Program will be enhanced as follows.

@ Revise Boraflox Monitoring Program procedures to include areal B 10 density measurement testing of the spent fuel storage racks, such as BADGER testing, at a frequency of at least once every five years.

This enhancement vvill be implemented prior to tho period of extended oporatioR.

to NRC-15-0081 Page 8 A.1.27 Neutron-Absorbing Material Monitoring Program The Neutron-Absorbing Material Monitoring Program provides reasonable assurance that degradation of the neutron-absorbing material§ (Sh9:.._Boral) used in spent fuel pools that could compromise the criticality analysis will be detected. The program relies on periodic inspection, testing, and other monitoring activities to assure that the required five percent sub-criticality margin is maintained during the period of extended operation. The program monitors loss of material and changes in dimension, such as blisters, pits, and bulges that could result in a loss of neutron-absorbing capability. The parameters monitored include physical measurements and geometric changes in test coupons. The frequency of testing will be based on the condition of the neutron-absorbing material, justified with plant-specific and industry operating experience, prior to the period of extended operation, at a minimum of once every ten years in the period of extended operation. The approach to relating measurement results of the coupons to the spent fuel neutron-absorber materials considers the spent fuel loading strategy. In the event that a loss of neutron-absorbing capacity is anticipated based on coupon testing, additional testing will be performed to ensure the sub-criticality requirements are met.

The Neutron-Absorbing Material Monitoring Program will be enhanced as follows.

• Prior to the period of extended operation, revise Neutron-Absorbing Material Monitoring Program procedures to establish an inspection frequency, justified with plant-specific operating experience, of at least once every ten years, based on the condition of the neutron-absorbing material.

• Revise Neutron-Absorbing Material Monitoring Program procedures to perform trending of coupon testing results to determine the rate of degradation. Ensure the predicted boron-1 0 areal density will be sufficient to maintain the subcritical conditions required by technical specifications until the next coupon test.

Enhancements will be implemented prior to the period of extended operation.

to NRC-15-0081 Page 9 A.4 LICENSE RENEWAL COMMITMENT LIST Implementation No. Program or Activity Commitment Source Schedule 5 Boraflex Monitoring ~nl=lanee geFafle* MeniteFiR§ ~FO§FaFfl as felle'Ns: Prior to A.1.3

a. ~evise goFafle* Menitmin§ ~FO§FaFfl pmeeEl!:lFos te September 20, incl!:lEle areal g 10 Elensity Ff!eas!:lreFflent testin§ of tl=le 2024, or the end spent f!:lel stora§e raeks, s!:lcl=l as gf\QG~~ testin§, at a of the last freEJ!:lency of at least once every fh;e yeaFs. refuelinq outaae lmQiement the Boraflex rack reQiacement aQgroved in [prior to March 20.

Amendment No. 14 i so that the current Boraflex Qanels in 2025 whichever the SQent fuel QOOI will not be reguired to Qerform a neutron is later.

absorption function durina the period of extended operation.

to NRC-15-0081 Page 10 Table B-1 Aging Management Programs Program Section New or Existing 8oraflex Monitoring 8.1.3 Existing:

• This ex1st1ng program Will not be used dunng the penod of extended operation.

Table B-2 Fermi 2 Aging Management Program Correlation with NUREG-1801 Programs NUREG-1801 Number NUREG-1801 Program Fermi 2 Program This NUREG-1801 program will not be credited during the period XI.M22 8oraflex Monitoring of extended operation. Se~afle*

MeRitefiR§ [8.1.3]

Table B-3 Fermi 2 Program Consistency with NUREG-1801 NUREG-1801 Comparison Consistent with Programs with Plant-Program NUREG- Programs with Exception to NUREG-Name 1801 Enhancement 1801 Specific 8oraflex X X Monitoring:

• This ex1st1ng program w1ll not be used during the penod of extended operat1on.

to NRC-15-0081 Page 11 8.1.3 BORAFLEX MONITORING The Boraflex Monitoring Program is an existing program to manage the Boraflex material affixed to the spent fuel storage racks. This program is currently required by Technical Specification 5.5. i 3 and includes activities implemented in response to NRC GL 96-04 to assure that the required five percent sub-criticality margin is maintained. The Boraflex currently in the spent fuel racks will not be credited for neutron absorption during the period of extended operation and therefore this aging management program will not be relied upon during the period of extended operation. All of the neutron-absorbing material to be credited during the period of extended operation will be managed by the Neutron-Absorbing Material Monitoring Program in Section B. i .27.

Tho Boraflex Monitoring Program manages tho aging effect of reduction in neutron absorbfA-§ capacity (chango in material properties) in the Boraflex material affixed to spent fuel racl<s. /\

~§ffifn for the Boraflex panels in the spent fuel storage racks is implemented to assure that no unexpected degradation of the Beraflex material compromises the criticality analysis in support of tho design of spent fuel storage racks. The program uses the R/\CKLIFE computer predictive cede to calculate the gamma dose absorbed by and tho amount of boron carbide loss from tho Boraflex panels. Tho program includes (a) quarterly sampling and analysis for silica levels in tho spent fuel pool water and trending tho results by using the RACKLIFE cede, (b) performing periodic physical measurements and neutron attenuation testing of surveillance coupons, and (c) areal B i 0 density moasUfOmnt testing of tho spent fuel storage racl<s, such as BADGER testing, at a frequency of at least once every five years.

r.A+s--program, implemented in response to NRC GL 96 04, assures that tho required five percent sub criticality margin is maintained.

The Boraflox Monitoring Program, with enhancement, is consistent with tho program described in NUREG i 801,Section XI.M22, Boraflox Monitoring.

The follmving enhancement 'Nill be implemented prior to tho period of extended operation.

cg,.,.......,...,+ 1\$/f., ~:::, .~ .~+

3. Parameters Monitored or Revise Boraflex Monitoring Pro§raFR-fJfGceduros to Inspected ffic-ludo areal--8-:l 0 density measurement tostiRg of the 4.---Dotection of Aging Effects spent fuel stora§o racks, such as BADGER testing, at r::.

~.

1\nr..-.i+r.Yinr< r,nrl OY,-,nrlinr< ..., hr>r< '"""' , f ,.t lc.-,c-t Anr-n ,..,. *nYl filln .to.-.YC' to NRC-15-0081 Page 12 The follo'Ning examples demonstrate ho'N the Boraflex Monitoring Program \Viii be effective in managing the effects of aging during the period of extended operation.

"' In response to NRC IN 87 43, National Nuclear Corporation completed a "blaclmess test" on March 28, 1992. Approximately one third of tho Boraflox panels in tho Fermi 2 spent fuel rad<:s had developed cracks and small gaps. Slovv scan test measurements provided data as to tho axial distribution of gaps and tho size of gaps. Both the size measurements and observed axial distribution are consistent 'Nith similar measurements in other racks of the same design at other plants. Analyses vvero performed to shovv that adequate subcritical margin vvas maintained.

"' NRC Generic Letter 96 04, "Boraflex Degradation in Spent Fuel Pool Storage Racks,"

requested evaluation of tho condition of tho Boraflox in tho spent fuel racks. Tho response addressed the results of testing and committed to using R/\CKLIFE to model tho Fermi 2 fuel racl<s and monitoring rack exposure and pool silica to identify degradation of Boraflox.

• In 1998, Boraflex coupons vvere tested at Pennsylvania State University in accordance with Fermi 2 procedures, Technical Spoc-i#eations, and UFSAR Section 9.1.2.4. This testing showed that tho coupons that acquired tho largest dose had more shrinkage than allovved by the acceptance criteria. The criticality analysis wa-s-~t-ed to account fOf this increased shrinkage, and the UFSAR analysis on shrinl<age was revised.

• In 2009, the silica level in the spent fuel pool 1.vas found at a level above that observed in previous cycles. Preparations were initiated to perform BADGER testing, which 'Nas performed in October 20"1 3.

"' In 2011, coupon testing was performed on four Borafle)( surveillance coupons at Pennsylvania State University. All applicable test criteria for tho coupons vvoro satisfied by the coupons.

"' In 2012, NRC IN 2012 13 Vias rovimvod regarding surveillance programs and corrective actions at Turkey Point and Peach Bottom 'JVith regards to Boraflox degradation monitoring. Based on the rovimv, revisions 'Nero made to inputs so that RACKLI FE will j3f0Vido more conservative calculations. *

"' In October 2013, BADGER testing '.Vas performed on sixty Beraflox panels in the spent fuel racks. There vvere three panels that fell belevv the limit. A criticality sensitivity analysis shmved margin in these panels' results to \Vhat is needed to maintain tho required five percent sub criticality margin. Actions 'Nero tal\en to preclude placing fuel in the cells adjacent to the throe panels. 1\ corrective action document vvas written to evaluate impacts of tho BI\DGER testing results on tho Beraflex Monitoring Pro§:lram.

The history of identification of degradation and initiation of corrective action prior to loss of intended function, along vvith identification of program deficiencies and subsequent corrective actions, provide assurance that tho Boraflox Monitoring Program vvill remain effective. The application of proven monitoring methods provides reasonable assurance that tho effects of aging vvill be managed such that components vvill continue to perform their intended functions consistent with the current licensing basis through tho period of extended operation.

The process fer review of future plant specific and industry operating experience for aging management programs is discussed in Section 8.0.4.

to NRC-15-0081 Page 13 Tho Boraflox Monitoring Program has been effective at managing tho aging effect of roductieR in neutron absorbing capacity in tho Boraflox material affixed to spent fuel racks. Tho Boraflox Monitoring Program provides reasonable assurance that effects of aging are managed such that applicable components will continue to perform their intended functions consistent vvith tho current licensing basis through the period of extended operation.

to NRC-15-0081 Page 14 B.1.27 NEUTRON-ABSORBING MATERIAL MONITORING Program Description The Neutron-Absorbing Material Monitoring Program provides reasonable assurance that degradation of the neutron-absorbing material§ (g,g,_Boral) used in spent fuel pools that could compromise the criticality analysis will be detected. The program relies on periodic inspection, testing, and other monitoring activities to assure that the required five percent sub-criticality margin is maintained during the period of extended operation. The program monitors loss of material and changes in dimension such as blisters, pits, and bulges that could result in a loss of neutron-absorbing capability. The parameters monitored include physical measurements and geometric changes in test coupons. The frequency of testing will be based on the condition of the neutron-absorbing material, justified with plant-specific and industry operating experience, prior to the period of extended operation, at a minimum of once every ten years in the period of extended operation. The approach to relating measurement results of the coupons to the spent fuel neutron-absorber materials considers the spent fuel loading strategy. In the event that a loss of neutron-absorbing capacity is anticipated based on coupon testing, additional testing will be performed to ensure the sub-criticality requirements are met.

NUREG-1801 Consistency The Neutron-Absorbing Material Monitoring Program, with enhancements, is consistent with the program described in NUREG-1801,Section XI.M40, Monitoring of Neutron-Absorbing Materials Other than Boraflex.

Exceptions to NUREG-1801 None Enhancements The following enhancements will be implemented prior to the period of extended operation.

Element Affected Enhancement

4. Detection of Aging Effects Prior to the period of extended operation, revise Neutron-Absorbing Material Monitoring Program procedures to establish an inspection frequency, justified with plant-specific operating experience, of at least once every ten years, based on the condition of the neutron-absorbing material.

5. Monitoring and Trending Revise Neutron-Absorbing Material Monitoring Program procedures to perform trending of coupon testing results to determine the rate of degradation.

Ensure the predicted boron-1 0 areal density will be sufficient to maintain the subcritical conditions required by technical specifications until the next coupon test.

to NRC-15-0081 Page 15 Operating Experience The following examples of operating experience demonstrate that the Neutron-Absorbing Material Monitoring Program will be effective in managing the effects of aging on the function of the neutron-absorbing materials in the spent fuel racks containing Boral.

• In 2010, a Boral test coupon was found with numerous blisters (18 on the front side and 16 on the back side). One of the blisters on the front was 2.1 inches in diameter.

Blisters can potentially result in fuel assembly binding during insertion or withdrawal from the fuel storage racks. An evaluation determined these blisters did not affect the neutron-absorbing properties of the Boral. The inspection procedure was revised to require a blister characterization if blisters are observed on the Boral coupon and to require an inspection of the Boral capsule for any deformation that would be caused by blisters.

• Based on operating experience presented at an Electric Power Research Institute (EPRI) Neutron Absorber User Group (NAUG) meeting, procedure enhancements were made in 201 0 regarding Bora I coupon surveillance. Also, an assessment of the blister resistance of the Boral based on testing of a coupon was performed.

• A Boral coupon test was performed in 2013 at Pennsylvania State University. Non-destructive examination was performed on coupon YD61 0122-1-7. The coupon was in good overall condition with several very small blisters. All acceptance criteria were met.

The history of identification of degradation and initiation of corrective action prior to loss of intended function, along with identification of program enhancements, provides assurance that the Neutron-Absorbing Material Monitoring Program will remain effective. The continued application of these proven monitoring methods provides assurance that the effects of aging will be managed such that components will continue to perform their intended functions consistent with the current licensing basis through the period of extended operation.

The process for review of future plant-specific and industry operating experience for aging management programs is discussed in Section 8.0.4.

Conclusion The Neutron-Absorbing Material Monitoring Program has been effective at ensuring that the required five percent sub-criticality margin is maintained. The Neutron-Absorbing Material Monitoring Program provides reasonable assurance that the effects of aging on the neutron-absorbing material§ (Bora!) will be managed to ensure the intended function can be maintained in accordance with the current licensing basis through the period of extended operation.