View source for BYRON 2023-0065, Unit 2 - Notification of Deviation from Electric Power Research Institute (EPRI) Topical Report MRP-227, Revision 1-A, Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guideline

{{Adams
| number = ML23321A080
| issue date = 11/17/2023
| title = Unit 2 - Notification of Deviation from Electric Power Research Institute (EPRI) Topical Report MRP-227, Revision 1-A, Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guideline
| author name = Welt H
| author affiliation = Constellation Energy Generation, LLC
| addressee name = 
| addressee affiliation = NRC/NRR, NRC/Document Control Desk
| docket = 05000454, 05000455
| license number = NPF-037, NPF-066
| contact person = 
| case reference number = BYRON 2023-0065
| document type = Letter type:BYRON
| page count = 1
}}

=Text=
{{#Wiki_filter:Constellation November 17, 2023 LTR:    BYRON 2023-0065 File:   10.101 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Unit 1 and Unit 2 Renewed Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455

==Subject:==
Notification of Deviation from Electric Power Research Institute (EPRI) Topical Report MRP-227, Revision 1-A, "Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guideline" In accordance with Appendix B, Section 8.1.c of Nuclear Energy Institute (NEI) 03-08, "Guideline for the Management of Materials Issues," Revision 4, Constellation Energy Generation, LLC (CEG) is notifying the U.S. Nuclear Regulatory Commission (NRC) that Byron Station, Unit 1 and Unit 2, have processed a deviation from a "Needed" requirement in EPRI Document MRP 227, Revision 1-A, "Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guideline," with appropriate justification and documentation.
MRP 227, Revision 1-A, Table 4-3, Item W6: "Baffle-Former Assembly; Baffle-Former Bolts" requires that Tier 4 plants perform baseline volumetric examinations of Baffle-Former Bolts no later than 35 effective full power years (EFPY), as stated in Table 4-3, Note 8. Based on the schedule the RVI examinations for Byron Units 1 and 2, the plant will exceed the EFPY requirement for performing these baseline examinations. Per the implementation requirements under Subsection 7.3 of MRP-227, Revision 1-A, there is a NEI 03-08 "Needed" requirement which states, "each commercial U.S. PWR unit shall implement the requirements of Tables 4-1 through 4-9 and Tables 5-1 through 5-3 for the applicable design."
Per NEI 03-08, "Needed" requirements or guidance are "to be implemented whenever possible but alternative approaches are acceptable". The deviation has been documented in accordance with CEG's corrective action program and approved by the appropriate levels of CEG management. Attachments 1 and 2 provide the deviation form and the technical justification, respectively.
In accordance with NEI 03-08, this letter is being transmitted for information only. CEG is not requesting any action from the NRC.
This letter contains no new regulatory commitments.

LTR: BYRON 2023-0065 November 17, 2023 Page 2 Please direct any questions you may have regarding this letter to Ms. Zoe Cox, Regulatory Assurance Manager, at (815) 406-2800.
Respectfully, Harris Welt Site Vice President Byron Generating Station HW/AH/JA/hh

==Attachment:==
1: ER-AA-4003 Attachment 2 - NEI 03-08 Deviation Form for Baffle-Former Bolts Volumetric Examination for Byron Units 1 and 2 and Braidwood Unit 2.
2: EC 639996 (Byron), Revision 1 and EC 640160 (Braidwood), Revision 0, Technical Evaluation for NEI 03-08 Deviation of Baffle-Former Bolts Volumetric Examinations for Byron and Braidwood.
cc:     Regional Administrator - NRC Region Ill NRC Senior Resident Inspector- Byron Station NRC Project Manager, NRR - Braidwood and Byron Stations Illinois Emergency Management Agency - Division of Nuclear Safety

ER-AA-4003 Revision 6 ATTACHMENT 2 MDMP Deviation Form Page 1 of 3 Utility: Constellation Energy Generation (CEG), LLC Applicable Site(s) and Unit No.: Byron Units 1 and 2 and Braidwood Unit 2 Utility Contact(s):
Osvaldo Cru7 - Fleet PWR. Internals Program Engineer, Kemper Young - Fleet PWR lnternais Program Engineer, Issue Program (IP) activity or document:
lvlateria!s Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines (AfRP-227, Revision 1-A). EPRL Palo Alto, CA: 2019. 3002017168.
Scope/ Description of Deviation:
CEG is submitting this NE! 03-08 deviation for Byron Units 1 and 2 and Braidwood Unit 2 to perform the baseline volumetric e;,.._aminations of Baffle-Former Bolts (Bfl3s) no later than 36 effective full power years (EFPY). Byron Units l and 2 and Braidwood Unit 2 are scheduled to perform the Reactor Vessel Internals (R Vl) e:,:aminations in accordance with MRP-227. Revision l -A during the Spring 2026. Fall 2026. and Fall 2027 refueling outages, n:spectively. These e:,:arninations include the volumetric e:,:aminations of the BFBs. These plants are considered Tier 4 plants per NSJ\ L-16-1. Revision I.
MRP-227. Revision 1-A. Table 4-3. Item W6: .. Baffle-Former Assembly: Baffle-Former Bolts" requires that Tier 4 plants perform baseline volumetric ex.aminations of BFBs no later than 35 effectiw full power years (EFPY). as stated in Table 4-3. Note 8. Based on the schedule of the RVI ex.arninations for Byron Units 1 and 2 and Braidwood Unit 2, these plants will ex.ceed the EFPY requirement for performing these baseline examinations. Per the implementation requirements under Subsection 7.3 of MRP-227. Revision 1-A. there is a NE[ 03-08 .. Needed" requirement Vvhich states. **1:uch cnmm<!l"cial US PHR unit sher!!
imp/1:1111:nl 1/w rcquircmv11s of TaNe.1 11/im11gh 9 and Tah!cs 5-l r!zmugh 5-3/cJr the upp!icah!c clc1ign**. Per NE! 03-08. --Needed'" requirements or guidance arc **10 be' implcmc11!1:dwhcncvcrpossihlc Im! olrcnw!ivc appmaclz1:s We' accc1Jtabl1: .. Technical justification has been developed under EC 639996 and 640160 to deviate from the --Needed"" requirement above because it .. will no! he imp/cmcntcd 11"i1hin the linzc/mmc               in MRP-227. Revision 1-A.
Reason for Deviation:
This deviation is being submitted to e"\tencl the current requirement of 35 LFPY to 36 LFPY to bundle the baseline volumetric ex.arninations of BFBs with the rest of the R VI examinations to reduce person-rem exposure and outage complexity. The R VI examinations are being performed during outages with significantly longer durations than normally scheduled due to planned main turbine upgrades. These refueling outages are projected to occur at EFPYs greater than 35 but less than 36. J\s such. performing:
the volumetric examination ofBFBs during those outages with longer duration will allow more time to perform any necessary evaluations or repairs on the BFBs. thereby reducing outage extension risks. J\lso.
this provides site and vendor personnel with more time to complete the inspections. thereby reducing execution risks.
IR Number: 04 712854                        EC Number: 639996 (Byron) and 640160 (Braidwood)

ER-AA-4003 Revision 6 ATTACHMENT 2 MDMP Deviation Form Page 2 of3 Time Frame the Deviation will be in Effect:
The deviation will be in effect until the completion of the following outages for Byron Units l and 2 and Braidwood Unit 2:
Plant                 Outage                  Projected EFPY Byron Unit 1          BI R27 (Spring 2026)    35.95 l Byron Unit 2          B2R26 (Fall 2026)       35.814 Braidwood Unit 2      A2R26 (Fall 2027)       35.775 Deviation to this IP document is classified as: NEEDED 2023.10.31 Prepared By: Osvaldo Cruz _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
08:48:51 -05'00' (signdate)
Young, Kemper          DigitallysignedbyYoung, Kemper Joseph C orporate IP Pnmary     R
* epresentative: Kemper Young _     Joseph                 Date: 2023.10.31 09:51:38-04'00' (sign date)
Digitally signed by Murray, Murray, Pat rl(
* k Patrick Date:2023.10.311307:23 Byron and Braidwood Programs Manager: Patrick Murray                                        os*oo
                                                                 ----------------~
(sign date)
Asset Management Senior Manager: Gabriel Chavez _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
(sign date)
Coffey , La Uren Digitally      signed by Coffey, Lauren Date 2023.1101154841 -05'00' Centralized Programs Engineering Director: Lauren Coffey _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
(sign date)
Cunzeman,                Digitally signed by Cunzeman, Jonathan P.
Byron Site Engineering Director: Jonathan Cunzeman _ _ _ _ _P._ _ _ _ _ _ _ _ _ _ _ _ __
Jonathan                 Date 2023 11 06 08:59:38 -06'00' (sign date)
MacArtney,             Digitally signed by MacArtney, Steven Braidwood Site Engineering Director: Steven Macartney           Steven                 Date: 2023.11.06 17:37:08 -06'00' (sign date)

ER-AA-4003 Revision 6 ATTACHMENT 2 MDMP Deviation Form Page 3 of 3 We     It'   H
* Digitally signed by Welt, Harris Byron Site Vice President: Harris Welt arn s-06'00'2023.11.09 08:05:33 Date:
                                                            ----=-=-(.:;::s-:--1*g-n-;--
1d--;-a-te-:--)-----
B   'd rai woo d s ite Vice President: Gregory Gugle Gug le, Greg              Digitally signed byGugle,Greg Date:2023.11.0908:41:18 -o 6 ,00 ,
(sign/date)

EC 639996 (Byron), Revision 1 and 640160 (Braidwood), Revision 0 Technical Evaluation for NEI 03-08 Deviation of Baffle-Former Bolts Volumetric Examinations for Byron and Braidwood
: 1. Reason for Evaluation/Scope Byron Units I and 2 and Braidwood Unit 2 are scheduled to perform the Reactor Vessel Internals (RV!)
examinations in accordance with MRP-227, Revision I -A [ l] during the Spring 2026, Fall 2026, and Fall 2027 refueling outages, respectively. These examinations include the volumetric examinations of the Baffle-Former Bolts (BFBs), which are typically performed using the ultrasonic testing (UT) method.
These plants are considered Tier 4 plants per NSAL-16-1, Revision I [2].
Table 4-3 (Item W6) of MRP-227, Revision I-A [I] requires that Tier 4 plants perform baseline volumetric examinations ofBFBs no later than 35 effective full power years (EFPY), as stated in Note 8 of Table 4-3 [l]. Based on the schedule of the RV! examinations for Byron Units I and 2 and Braidwood Unit 2, these plants \viii exceed the EFPY requirement for performing these baseline examinations. Per the implementation requirements under Subsection 7.3 of MRP-227, Revision 1-A [I], there is a NE! 03-08 [3] '"Needed" requirement which states, each commercial U.S. PTVR unit shall implement the requirements of Tables 4-1 through 4-9 and Tables 5-1 through 5-3for the applicable design [ 1]. Per NE!
03-08 [3], *'Needed" requirements or guidance are to be implemented whenever possible but alternative approaches are acceptable. Technical justification shall be developed to deviate from the '"Needed" requirement above because it -will not be implemented within the timeframe ~pecified in MRP-227, Revision 1-A [I]. As such, a deviation is required to extend the current requirement of35 EFPY to 36 EFPY to bundle the baseline volumetric examinations of BFBs with the rest of the RV! examinations to reduce person-rem exposure and outage complexity. This evaluation serves as the technical justification for that deviation.
: 2. Detailed Evaluation Byron and Braidwood are Westinghouse 4-loop plants with neutron panels continuously operated with the baffle-former assembly in the uptlow configuration. As such, they are considered Tier 4 plants per NSAL-16-1, Revision I [2]. Each unit has a total of 832 BFBs made of Type 3 I 6 stainless steel material. The BFBs are located on the baffle plates and fasten the baffle plates to the former plates. The baffle plates are the vertical components that are next to the fuel when the core is in place. The baffle plates are supported by horizontal supports called former plates. These components compose the baffle-former assembly. The function of the baffle-former assembly is to maintain the fuel assembly structural integrity to ensure that the control rods insert, maintain a coolable core geometry, and ensure a core configuration that supports long-term reactor shutdown.
As shown in Table 4-3, MRP-227, Revision 1-A [I] requires a volumetric examination of 100% of the BFBs. The initial examination for Tier 4 plants is required by 35 EFPY, and subsequent examinations are required on a I 0-year interval unless significant degradation (2: 5% of BFBs with indications or clustering as defined in NSAL-16-1 Revision 1 [2]) is observed. With the current RV! examination schedule in place for Byron Units I and 2 and Braidwood Unit 2, these three units are projected to exceed 35 EFPY prior to performing the required baseline volumetric examinations of their BFBs. Table l shows the RV!
examination schedule for these units and the projected cumulative EFPY at which these examinations are scheduled to be performed. EFPY projections were made by adding 1.5 EFPY per 18-month fuel cycle from the accumulated EFPY values from the last refueling outage.
Page 1 of5

EC 639996 (Byron), Revision 1 and 640160 (Braidwood), Revision 0 Technical Evaluation for NEI 03-08 Deviation of Baffle-Former Bolts Volumetric Examinations for Byron and Braidwood Table 1 - RVI Examinations Schedule and EFPY Projections Last Outage      Last Outage      Examination  Projected EFPY Plant Date             EFPY             Outa~e Date  at Examination Byron Unit 1          Spring 2023      32.951           Spring 2026  35.951 Byron Unit 2          Fall 2023        32.814           Fall 2026    35.814 Braidwood Unit 2      Spring 2023      31.275           Fall 2027    35.775 The volumetric examinations of BFBs are intended to detect the potential cracking failure of the bolts due to irradiation-assisted stress corrosion cracking (IASCC) or fatigue. Most of the BFB degradation observed in the industry, and the worst of the degradation, has been found in plants that operate in the downflow configuration. The elevated degradation in those plants has been linked to the higher stresses on the BFBs due to the pressure differential caused by the downflow configuration. Plants with upflow configuration, like Byron Units 1 and 2 and Braidwood Unit 1, have lower differential pressure which causes lower stresses on the BFBs.
The most recent UT inspection results from the original and converted upflow plants that have performed their RV! examinations show very minimal BFB degradation (less than 1% of BFBs with indications and no clustering). These results as shown in Table 2.
Table 2 - Industry Results of Volumetric Examinations of BFBs for Tier 3 and 4 Plants Reactor Plant                           Config. Year     EFPY                                  UI Desi n                                          Ins .
Wolf            4-loop Upflow      2021     30.15      832 Creek      Neutron Panel Converted vc             3-loop Upflow      2021      32.3     1088 Summer       Neutron Panel
(-2008) 4-loop Callaway                          Upflow      2022     31.76      832     832                 0 Neutron Panel Point           2-loop        Converted 2022      42.2      728    728                  0 Beach 1      Thermal Shield       U flow 202                  The rest of 526 Point          2-loop         Converted                         (out 2023     42.89             202 Beach 2      Thermal Shield       Upflow                           of 728)                      ment issues Converted North           3-loop Upflow      2016     31.05     1088                         7 Anna 1      Thermal Shield (1996)
Beaver          3-loop         Converted 2022      -35      1088                        12 Valle I Thermal Shield            U flow Almaraz          3-loop Upflow      2022      34.5      960    957 2        Neutron Panel Note: SAT- Satisfactory, RI - Relevant Indication, UI - Un-inspectable Based on Table 2, none of the mentioned plants have ever come close to having BFB degradation that would threaten structural integrity of the baffle-former assembly. Furthermore, Wolf Creek and Callaway, Page 2 of5

EC 639996 (Byron), Revision 1 and 640160 (Braidwood), Revision 0 Technical Evaluation for NEI 03-08 Deviation of Baffle-Former Bolts Volumetric Examinations for Byron and Braidwood the two plants with the most similar designs to Byron and Braidwood. have the best BFB UT inspection results and did not find a single BFB with a RI. As such. the probability of significant BFB degradation(::.::
5% of BFBs with indications or clustering as defined in NSAL-16-1 Revision 1 [2]) at Byron Units I and 2 and Braidwood Unit 2 is very low based on industry operating experience and low relative stresses on the BFBs. Plus. Byron and Braidwood had never experienced fuel failures due to baffle-jetting, which is a well-known symptom of BFB degradation at Westinghouse-designed PW Rs. Therefore, performing the baseline volumetric examinations of the BFBs no later than 36 EFPY is prudent and will not be a safety concern.
The intent of the MRP-227, Revision 1-A guidance is to proactively inspect RVI components prior to them undergoing significant degradation. thereby adequately managing the aging of the components. With the RV! examination schedule for Byron Units 1 and 2 and Braidwood Unit 2 outlined in Table 1. these units will still meet this intent, as demonstrated by the technical justification in this evaluation.
: 3. Conclusions I Findings Based on Byron's and Braidwood's history ofno fuel failures due to baffle-jetting. good industry operating experience of BFB degradation for Tier 3 and 4 plants, and low relative stresses on their BFBs due to their upflow configuration. it is acceptable to perform the baseline volumetric examinations of the BFBs beyond 35 EFPY. but no later than 36 EFPY. Therefore. performing the baseline volumetric examinations of the BFBs no later than 36 EFPY will reduce person-rem exposure and outage complexity by bundling these with the rest of the RVI examinations while still providing an acceptable level of quality and safety.
: 4. References
[1]   MRP-227, Revision l-A, Materials Reliability Program PWR Reactor Internals Inspection and Evaluation Guideline.
[2]   NSAL-16-1, Revision 1, Baffle-Former Bolts.
[3]   NEI 03-08, Revision 4, Guideline for the Management of Materials Issues.
[4]   MRP 2014-009, 2014 Biennial Report of Recent MRP-227-A Reactor Internals Inspection Results.
[5]   MRP 2016-008, 2016 Biennial Report of Recent MRP-227-A Reactor Internals Inspection Results.
[6]   MRP 2018-025, 2018 Biennial Report of Recent MRP-227-A Reactor Internals Inspection Results.
[7]   MRP 2020-015, 2020 Biennial Report of Recent MRP-227-A Reactor Internals Inspection Results.
[8]   MRP 2022-017. 2022 Biennial Report of Recent MRP-227-A Reactor Internals Inspection Results.
[9]   MRP-227 Rev 1-A Reporting Tables for Westinghouse Plants, Point Beach Unit I U2R39.
[IO]  MRP Fall 2022 TAC Meeting. Operating Experience Technical Session. dated 11/15/2022.
[11]  BB-PBD-AMP-XI-M I 6A, Revision 3, Byron and Braidwood PWR Vessel Internals Bases Document.
[12]  TOOi BYR-23-006. Revision 0, Cycle Burnup Values for Byron Unit 1 Cycles I through 25.
[13]  TOOi BYR-23-029. Revision 0, Cycle Burnup Values for Byron Unit 2 Cycles I through 24.
[14]  EC 639058, Revision 0, Braidwood Unit 2 Cumulative Burnup in Effective Full Power Years Through Cycle 23 (A2R23 ).
[15]  F-2956 and L-2956, Revision 0, Byron and Braidwood Procurement Specification for PWR In-Vessel Inspections.
[16]  ER-AP-333. Revision 4, Pressurized Water Reactor Internals Management Program.
Page 3 of 5

EC 639996 (Byron), Revision 1 and 640160 (Braidwood), Revision 0 Technical Evaluation for NEI 03-08 Deviation of Baffle-Former Bolts Volumetric Examinations for Byron and Braidwood
[17] ER-AP-333-1001, Revision 4, Pressurized Water Reactor (PWR) Internals Program.
[18] ER-AA-40, Revision 4, Materials Degradation Management Program (MDMP).
[19] ER-AA-4001, Revision 6, Materials Degradation Management Program (MDMP) Implementation Guidance.
[20] ER-AA-4003, Revision 6, Materials Degradation Management Program (MDMP) Deviation Guidance.
[21] CC-AA-309-101, Revision 16, Engineering Technical Evaluations.
[22] HU-AA-12 I 2, Revision 13, Technical Task Risk/Rigor Assessment Pre-Job Brief, Independent Third Party Review, and Post-Job Brief.
: 5. Technical Review The detailed evaluation was verified correct, and the associated conclusions are deemed reasonable through independent review of the Technical Evaluation. The requirements of the HU-AA-1212 were reviewed and no independent third-party review \Vas required. A human performance briefing per HU-AA-1212 was completed on I 0/13/2023 by Jacky Shoulders in association with this document.
Since there are no configuration changes or plant modifications performed by this technical evaluation, it has been determined that a Design Attribute Review (DAR) is not warranted. The Programs Engineering Manager has concurred with this decision.
Preparer: Osvaldo Cruz                                    Signature: Electronicallv signed in PassPort Independent Reviewer: Kemper Young                        Signature: Electronicallv signed in PassPort Approver: Jacky Shoulders                                 Signature: Electronically signed in PassPort Page 4 of5

EC 639996 (Byron), Revision 1 and 640160 (Braidwood), Revision 0 Technical Evaluation for NEI 03-08 Deviation of Baffle-Former Bolts Volumetric Examinations for Byron and Braidwood Attachment 1 Baffle-Fornier Belt (St1ort}
Baffle-Former Bo!t (Long)
Bafflf-F 01mf1 Bolt,
( S.32 Location'\!
Figure 1 - Byron/Braidwood Units 1 and 2 Baffle-Former Bolts Page 5 of5}}