BYRON 2018-0014, Appeal to NRC Letter Upholding Disputed Violation Documented in Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/2017009, 05000455/2017009

Appeal to NRC Letter Upholding Disputed Violation Documented in Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/2017009, 05000455/2017009

ML18039A707
Person / Time
Site:	Byron
Issue date:	02/08/2018
From:	Kanavos M Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BYRON 2018-0014, IR 2017009
Download: ML18039A707 (11)

Text

z__:- Byron Generating Station

,EEz Exeton Generation www.exeloncorp.com February 8, 2018 LTR: BYRON 201 8-0014 Anne Boland Director, Office of Enforcement U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. SIN 50-454 and SIN 50-455

Subject:

Appeal to NRC Letter Upholding Disputed Violation Documented in Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/201 7009, 05000455/2017009

References:

1 Letter from R. C. Daley (U.S. Nuclear Regulatory Commission) to B. C.

Hanson (Exelon Generation Company, LLC), Byron Station, Units 1 and 2 -

Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/2017009, 05000455/2017009, dated June 29, 2017

2. Letter from M. Kanavos (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, Response to NRC Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/2017009, 05000455/201 7009, dated July 31 2017

3. Letter from K. G. OBrien (U.S. Nuclear Regulatory Commission) to B. C.

Hanson (Exelon Generation Company, LLC), Response to Disputed Non-Cited Violation Documented in Byron Station, Units 1 and 2 Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/201 7009, 05000455/201 7009, dated December 21 2017 In Reference 1 the U.S. Nuclear Regulatory Commission (NRC) identified a traditional enforcement Severity Level IV violation with an associated finding during the perlormance of the Evaluation of Changes, Tests, and Experiments inspection at Byron Station (Byron), which concluded June 1 201 7. The violation is associated with Byrons failure to provide a 10 CFR 50.59 written evaluation that provided the basis for the determination that a change to the surveillance frequencies of the emergency diesel generators described in the Update d Final Safety Analysis Report (UFSAR) did not require a license amendment.

February 8, 2018 Byron Letter 2018-0014 U.S. Nuclear Regulatory Commission Page 2 Exelon Generation Company, LLC (EGC) submitted the Reference 2 letter disputing the NRCs assessment and conclusions stated in Reference 1 In Reference 2, EGC documented the basis for the conclusion that a 1 0 CFR 50.59(d)(1) evaluation is not required because the associated change to the UFSAR satisfies 10 CFR 50.59(c)(4).

On December 21 201 7, the NRC issued its response to EGCs dispute in Reference 3, upholding the violation and associated finding. EGC has perFormed a detailed review of Reference 3 and the docketed history of the development and approval of NEI 04-10, Revisions 0 and 1, Risk-Informed Method for Control of Surveillance Frequencies, and NEI 99-04, Revision 0, Guidelines for Managing NRC Commitment Changes. EGC disagrees with the NRCs basis and justification for upholding the Byron non-cited violation. The attachment to this letter provides the EGC response and basis for further appeal of the violation and finding issued to Byron in Reference 1 and upheld in Reference 3.

Until this issue is resolved, Byron will continue to perlorm surveillances as currently listed and evaluated in the Surveillance Frequency Control Program, including those for emergency diesel generators. As noted in Reference 1 the disputed finding has been evaluated as very low safety significance.

In parallel with EGCs appeal, EGC has engaged with NEI to discuss the industrys interpretation of these programs to resolve differences and come to a mutually agreeable understanding of the NEI 04-10 process and implementation.

There are no regulatory commitments made within this letter. If you have any questions concerning this letter, please contact Mr. Douglas Spitzer, Regulatory Assurance Manager, at (81 5) 406-2800.

Respecif Ily, Mark Kanavos Site Vice President Byron Station

Attachment:

Exelon Position Related to NEI 04-10 cc: NRC Regional Administrator, Region Ill NRC Director, Office of Enforcement NRC Director, Office of Nuclear Reactor Regulation NRC Senior Resident Inspector Byron Station

ATTACHM ENT Exelon Position Related to NEI 04-10

1. Introduction In the Reference 1 inspection report, the Nuclear Regulatory Commission (NRC) issued a Severity Level IV, Non-Cited Violation of 10 CFR 50.59, Changes, tests, and experiments, Section (d)(1) and an associated finding of very low safety significance (Green) to Byron Station (Byron) for failure to provide a written evaluation that provided the basis for the determination that a change did not require a license amendment. Specifically, Reference 1 stated that Byron failed to provide a basis for why a change to the surveillance frequency of the emergency diesel generators described in the Updated Final Safety Analysis Report (UFSAR) did not require prior NRC approval.

Following review of Reference 1 Exelon Generation Company, LLC (EGC) submitted the Reference 2 letter disputing the NRCs assessment and conclusions stated in the inspection report. In Reference 2, EGC documented the basis for the conclusion that a 10 CFR 50.59(d)(1) evaluation is not required because the associated change to the UFSAR satisfies 10 CFR 50.59(c)(4).

On December 21 201 7, the NRC issued the Reference 3 letter, which outlined the NRCs conclusions and rationale for upholding the Byron non-cited violation. EGC has performed a detailed review of Reference 3, as well as the docketed history of the development and approval of NEI 04-10, Revisions 0 and 1, Risk-Informed Method for Control of Surveillance Frequencies, and NEI 99-04, Revision 0, Guidelines for Managing NRC Commitment Changes. EGCs understanding and interpretation of some aspects of these programs is not consist with that of the NRC. Applying the NRC interpretation limits the efficiencies and benefits gained from incorporation of NEI 04-10 into the Technical Specifications, with no improvement in safety. Therefore, EGC further appeals the Byron non-cited violation and associated finding.

The information below describes EGCs interpretation of these programs, our understanding of how they work together, and the specific areas where EGC and the NRC may not be aligned.

2. EGC Review of NRCs December 21, 2017 Letter In the Reference 3 cover letter, the NRC summarizes the basis for concluding the Reference 1 non-cited violation was valid:

Specifically, the NRC-approved Surveillance Frequency Control Program recognizes 10 CFR 50.59 to be the governing change control process for any proposed change to UFSAR commitments associated with codes and standards. This handling of changes to UFSAR commitments is deliberately distinct and separate from the Surveillance Frequency Control Program in order to maintain sufficient safety margin by ensuring the proposed surveillance test frequency change is not in conflict with approved industry codes and standards.

The attachment to Reference 3 provides the details of the NRCs conclusion, which EGC understands to be based on two distinct but related positions. The two positions are:

1 . The NRC-approved NEI 04-1 0 program does not allow surveillance frequency changes that are different than or in conflict with industry codes and standards.

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ATTACHM ENT Exelon Position Related to NEI 04-10

2. Byron has a regulatory commitment to follow Regulatory Guide (RG) 1 .9 (and its referenced Institute of Electrical and Electronics Engineers (IEEE) Standard) related to the diesel generator surveillance frequencies.

EGO disagrees with these positions because they do not align with our understanding of the intent and allowance provided in NEI 04-10. The basis for EGOs interpretation and understanding is detailed below.

3. EGC Position NEI 04-10 and Industry Oodes and Standards EGO is not aligned with the NROs position that NEI 04-10 does not allow surveillance frequency changes that are different than frequencies stated in industry codes and standards.

In Reference 3, Affachment Section 4.4, the NRC discusses industry codes and standards (e.g.,

ASME and IEEE) and how they relate to the key safety principle of sufficient safety margin for risk-informed TS changes (documented in RG 1.177 and 1.174). The NRC concludes that NEI 04-10 evaluations performed by a licensee must ensure that the surveillance frequency change is not in conflict with approved industry codes and standards. This conclusion is based on review of the Byron Amendment Number 171 Safety Evaluation.

Surveillance frequencies identified in industry codes and standards, and their impact and role within the NEI 04-10 Surveillance Frequency Oontrol Program (SFOP), was the subject of considerable discussion and review by the NRC during the NEI 04-10 (Revisions 0 and 1) approval and the Limerick pilot approval.1 These docketed letters and NRC documents form a clear NRC position that surveillance frequencies in industry codes and standards çg be changed through the SFCP, as detailed below. NEI 04-10 was intended to reduce burden and improve efficiencies, not constrain changes and drive additional License Amendment Requests.

During NRC review of NEI 04-10, Revision 0, the NRC asked in an RAI to Provide deterministic criteria in the basis document that would be used to approve revisions to surveillance frequencies that are based on approved Oodes and Standards...The guidance of RG 1.174 states that sufficient safety margins are maintained when codes and standards...

(e.g., IEEE). .are met. This RAI referenced the Limerick LAR as an example. The NEI response to the RAI stated:

We believe that the risk informed methods used to establish surveillance intervals under NEI 04-10 will provide an appropriate technical basis for intervals. .The risk methods proposed are consistent with the NRC policy and regulatory practice, meet PRA technical adequacy requirements,. .address all aspects ofthe integrated decision making process of Regulatory Guide 1.174, and will in fact provide a much more robust technical basis for surveillance intervals than that which currently exists. .The NRC notes that Regulatory Guide 1 1 74 references the use of codes and standards to establish and maintain adequate safety margins. We are in agreement with this concept, and note that compliance will be maintained with the vast majority of IEEE Standard 387(and other relevant standards), including those elements that are technically relevant 1

The Limerick pilot license amendment request (LAR) was reviewed in parallel with the NROs approval of NEI 04-10. Limerick was used to provide specific insights and interpretations to support final NEI 04-10 development and the associated NRC approval.

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ATTACHM ENT Exelon Position Related to NEI 04-10 to maintenance of safety margins (e.g, design and maintenance practices, test methods, etc). We do not believe Regulatory Guide 1 .1 74 infers that every aspect of codes and standards must always be met to establish sufficient safety margin. We believe that the deterministic criteria. .that would be used to approve revisions to surveillance frequencies that are based upon approved Codes and Standards suggested by NRC in the RAI are in fact already contained in the steps of the process. These include a thorough evaluation of vendor recommendations, performance history, maintenance practices, industry codes and standards, all of which are considered by the plant expert panel in conjunction with the risk information.

As part ofthis RAI response, Step 7 of the NEI 04-10 methodology was revised and resubmitted to provide additional clarity and direction with regard to test intervals specified in applicable industry codes and standards. This included the step that Any deviations from STls

[surveillance test intervals] specified in applicable industry codes and standards currently committed to in the plant licensing basis shall be reviewed and documented consistent with the considerations specified within this step (Step 7).

Based on this RAI response, it is clear thatthe NEI 04-10 methodology is technically sound and provides a comprehensive review (including consideration of applicable industry codes and standards), and that the aggregate expert panel review of the specific NEI 04-10 evaluation is a more robust assessment which can justify surveillance frequencies different than those contained in the codes and standards described in the plant licensing basis.

The NRC safety evaluation approving NEI 04-10, Revision 0, goes into detail with regard to the key safety principle of maintaining sufficient safety margin. Much of the NRCs discussion reiterates the language of the RAI response, noting that SSCs design, operation, testing methods, and acceptance criteria specified in applicable codes and standards will continue to be met as described in the licensing basis since these are not affected by changes to the surveillance frequency. The safety evaluation also directly addresses STls associated with industry codes, standards, and NRC regulatory guides:

The present surveillances, STIs, and acceptance criteria were established over a 40-year history of industry consensus standards development, e.g. in the form of Institute of Electrical and Electronics Engineers (IEEE) standards, and regulatory endorsementthrough the regulatory guide process. The proposed NEI 04-1 0 methodology will allow a licensees independent decisionmaking panel (IDP) to alter STIs to a frequency different from those recommended in previously-approved consensus standards and RG processes.

The surveillance requirements themselves are not to be changed and will continue to be performed in accordance with the applicable RG or topical report, as appropriate. However, associated STIs may be modified in accordance with the licensee-controlled program.

In NEI 04-10, Step 7, Identify Qualitative Considerations to be Addressed (by the IDP), technical justification will be provided for changes to the STIs found in committed industry standards. Consideration of committed industry standards and the current revisions of those standards will be documented. The NRC staff 3 of 9

ATTACHMENT Exelon Position Related to NEI 04-10 finds this acceptable due to the rigorous review and documentation required to justify an STI change related to an industry code or standard.

This safety evaluation section concludes that sufficient safety margins are maintained by the NEI 04-10 methodology and the key safety principle of RG 1.177/1.174 is satisfied. Much of the above language was also included with the Limerick safety evaluation approving NEI 04-10 for use.

Soon after NEI 04-10, Revision 0, was approved, NEI submiffed Revision 1 making it applicable to all reactor types and including a discussion on how to address staggered test frequencies.

The vast majority of the Revision 0 methodology was maintained. The NRC subsequently approved Revision 1 In the discussion related to maintaining sufficient safety margins, the Revision 1 safety evaluation did not go into as much detail, but did reaffirm the conclusion of the Revision 0 safety evaluation, stating:

The design, operation, testing methods, and acceptance criteria for SSCs, specified in applicable codes and standards (or alternatives approved for use by the NRC) will continue to be met as described in the plant licensing basis (including the final safety analysis report and bases to TS), since these are not affected by changes to the surveillance frequency. Similarly, there is no impact to safety analysis acceptance criteria as describe in the plant licensing basis.

Thus, safety margins are maintained by the proposed methodology, and the third key safety principle of RG 1 1 77 is satisfied.

In summary, the Reference 3 position thatthe approved NEI 04-10 methodology does not allow licensees to modify surveillance frequencies different than specified in industry codes or standards is not consistent with the documented NRC review and approval of NEI 04-10. The safety margin that is provided by industry codes and standards is not reliant on the specified frequencies; the NEI 04-10 methodology determines more robust and technically-justified frequencies than those stated in industry codes and standards. It is clear to EGC that the robust NEI 04-10 methodology was approved to allow changes to surveillance frequencies stated in RGs, codes and standards without the need for a license amendment.

Reciulatory Commitments The NRCs position in Reference 3, with regard to regulatory commitments, is inconsistent with how NEI 04-10 evaluates codes and standards. This NRC position significantly broadens the interpretation of a regulatory commitment described in NEI 99-04 and thus eliminates the stated intent and benefit of NEI 04-10 and TS 5.5.19. In Reference 3, the NRC states that the SF

[surveillance frequency] changes themselves were not changes to the facility or procedures as described in the UFSAR. Thus, the 10 CFR 50.59 obligation did not apply . . . Byron Station TS 5.5.19 Amendment 171, requires Revision 1 of NEI 04-10 as the governing change process for the SF changes. EGC agrees that surveillance frequency changes are made using the SFCP, as appropriate.

Further, EGC and the NRC are aligned thatthe NEI 04-10 process evaluates regulatory commitments made to the NRC. As stated in Reference 3:

That is, this process [Revision 1 of NEI 04-10] is not specified as the governing change process to evaluate changes to NRC commitments made in support of 4 of 9

ATTACHMENT Exelon Position Related to NEI 04-10 SF changes. Specifically, Revision 1 of NEI 04-10, Step 1, requires checking for NRC commitments related to the proposed SF change. When commitments are identified, Steps 2 through 4 require changing the commitments using a method acceptable to the NRC prior to changing the SF if the commitments could be changed. .Revision 1 of NEI 04-10 emphasizes that Evaluating changes to the NRC commitments is a separate activity based on a method acceptable to the NRC for managing and changing regulatory commitments, e.g., NEI 99-04.

This NRC description is consistent with EGCs interpretation and understanding of the NEI 04-10 process regarding evaluations of regulatory commitments.

However, EGC disagrees with the NRCs conclusion that the Byron UFSAR embodies a formal, explicit regulatory commitment related to diesel generator surveillance test interval I frequency.

Misalignment on the definition of a regulatory commitment has been a consistent theme throughout the industry and was recognized by NRC Office of the Inspector General as recently as 201 1 when it noted in its audit of licensee commitments that the definition and use of commitments were not consistently understood throughout the NRC and industry. EGC does not consider the specific discussion in the UFSAR referencing RG 1 .9 or the associated IEEE Standard to be an explicit regulatory commitment within the UFSAR.

Beyond the specific example for diesel generator surveillance frequency, the NRCs discussion in Reference 3 implies that the entire UFSAR is a regulatory commitment. Reference 3 states:

Because these statements were embodied in the UFSAR, they were submitted in writing on the docket to the NRC in accordance with 1 0 CFR 50.71 Maintenance of records, making reports. Therefore, the NRC staff determined these explicit statements were NRC commitments.

In the above statement, the NRC concluded a regulatory commitment existed because the discussion related to compliance with RG 1 .9 is a statement in the UFSAR and the UFSAR as a whole was submitted to the NRC on the docket. This interpretation of what constitutes a regulatory commitment is a significant broadening of the definition of a regulatory commitment governed by NEI 99-04, Revision 0.

NEI 99-04, Revision 0, defines a Regulatory Commitment as an explicit statement to take a specific action agreed to, or volunteered by, a licensee and submiffed in writing on the docket to the NRC. It further states that a Regulatory Commitment is an intentional undertaking by a licensee to (1) restore compliance with regulatory requirements, or (2) complete a specific action to address an NRC issue or concern (e.g., generic letter, bulletin, order, etc.). The statements in Appendix A of the UFSAR related to Regulatory Guide 1 .9 are not explicit statements to take specific actions, are not intentional undertakings to restore compliance with regulatory requirements, and are not intentional undertakings to complete a specific action to address an NRC issue or concern (e.g., generic letter, bulletin, order, etc.). Per NEI 99-04, Revision 0, the statements in Appendix A of the UFSAR related to RG 1 .9 are not explicit regulatory commitments. This conclusion is consistent with EGCs Commitment Management Program and was included in the most recent Byron UFSAR bi-annual submittal (Reference 10),

submitted in accordance with 1 0 CFR 50.71 (e)(4), with the statement there are no commitments made in this document.

While Appendix A of the UFSAR states that the Licensee complies with IEEE Standard 387-1984..., this statement does not constitute a regulatory commitmentto follow Regulatory 5 of 9

ATTACHM ENT Exelon Position Related to NEI 04-10 Guide 1 .9. Rather, this discussion in the UFSAR is simply part of the licensing basis. A detailed review of the Byron licensing basis has not identified any explicit, written, docketed statement agreed to by Exelon to take the specific actions required by the Regulatory Guide.

Since there is no regulatory commitment as described in NRC and industry guidance, Exelon does not agree with the NRCs premise that the SFCP evaluation was not perFormed in accordance with IS 5.5.19 and NEI 04-10 requirements.

Moreover, the implication that all UFSAR statements are regulatory commitments contradicts the hierarchical structure described in SECY 98-224, Staff and Industry Activities Pertaining to the Management of Commitments made by Power Reactor Licensees to the NRC. SECY 98-224 presented four levels that differentiated Mandated Licensing Basis Documents (e.g.,

UFSAR) as separate and distinct from Regulatory Commitments. The hierarchy was listed as (1) Obligations, (2) Mandated Licensing Basis Documents, (3) Regulatory Commitments, and (4) Non-Licensing Basis Information. The NRC staff stated that a regulatory commitment is appropriate for matters in which the staff has a significant interest but which do not warrant either a legally binding requirement or inclusion in the updated FSAR. . . This additional detail further clarifies the distinction between regulatory commitments and the contents of the UFSAR.

Prior to the approval of the NEI 04-10 program into the Byron Technical Specifications (TS), the diesel generator surveillance frequencies were explicitly stated and controlled by the TS. The contents of TS, including specific surveillance frequencies, are obligations that document legally binding requirements. Because the TS surveillances are obligations, there was no need for Byron to also make, or the NRC to require, a regulatory commitment related to the TS mandated surveillance requirements, including surveillance frequencies.

The Byron UFSAR recognizes that the TS obligations govern diesel generator surveillance tests. UFSAR Section 8.3.1 .1 .2.2 related to diesel generators states Surveillance testing is specified in the Technical Specifications and meets the recommendations of the diesel generator manufacturer and applicable NRC guides, with exceptions noted. See Appendix A for the further discussion of Regulatory Guide 1 .9. This section, and the discussion in Appendix A, is included in the UFSAR as a description of how the plant design, qualification, and testing meets the recommendations of the Regulatory Guide, and therefore is part of Byrons licensing basis. However, this discussion does not constitute a written, docketed regulatory commitment to perform specific tests at specific frequencies because a regulatory commitment was not necessary due to the existing TS obligation. The TS obligation in existence when the UFSAR description was written obviated the need for a regulatory commitment, demonstrating that the UFSAR language was never intended to be a regulatory commitment.

EGC recognizes that the UFSAR discussion of Regulatory Guide 1 .9 and associated IEEE Standard is part ofthe Byron licensing basis that is evaluated as part ofthe NEI 04-10 methodology. However, as discussed above, these codes and standards, and their impact on surveillance frequency changes, are evaluated in Step 7 of NEI 04-10. The docketed correspondence during the NEI 04-10 development and approval process clearly demonstrates how Step 7 was to be used to address insights from regulatory guides, codes and standards.

In summary, statements within the UFSAR, in and of themselves, are not regulatory commitments. Byron station does not have a regulatory commitment to Regulatory Guide 1.9.

Regarding the diesel generator SFCP evaluation performed, no regulatory commitment to maintain a certain surveillance test interval exists for Byron Station. The only legally binding requirementfor surveillance frequencies is the TS, which the TS 5.5.19 provision allows the licensee to change. Therefore, the first four steps of NEI 04-1 0, Revision 1 were periormed 6 of 9

ATTACHM ENT Exelon Position Related to NEI 04-10 correctly and the stated compliance to an industry standard was properly evaluated as part of Step 7 of NEI 04-10. A 50.59 evaluation to change a regulatory commitment was not required prior to continuing, and completing, the SFCP evaluation.

4. Conclusion The SFCP uses an approved methodology to evaluate and revise surveillance frequencies.

Applying the NRC interpretation outlined in Reference 3, the methodology cannot be used without an initial License Amendment Request if the UFSAR discusses RGs, industry codes, and standards; even though the approval of the NEI 04-10 methodology evaluates and supports changes to surveillance frequencies different from those in approved consensus standards and RGs. This interpretation limits the efficiencies and benefits gained from incorporation of NEI 04-10 into the Technical Specifications, with no improvement in safety; while creating an unnecessary burden for the licensee and NRC by necessitating numerous needless LARs.

EGO continues to dispute the Byron violation and associated finding. As described above, NEI 04-10 does allow surveillance frequency changes that are different than or in conflict with industry codes and standards. If upheld, the NRCs position on this issue would significantly alter the scope of the SFCP in a manner inconsistent with the programs original intent.

Additionally, EGO disputes that the Byron UFSAR contains any regulatory commitment for diesel generator surveillance frequency. Simply because the UFSAR contains statements referring to Regulatory Guide 1 .9 does not transform those statements into regulatory commitments. Thus, EGO properly administered NEI 04-10 and no evaluation under 10 CFR 50.59 was necessary for the surveillance frequency change.

5. Clarification and Correction In Reference 3, the NRC relied, in part, on two documents to support its position that the Byron UFSAR contains regulatory commitments. First, the NRC noted that EGO Procedure ER-AA 425-1002, Engineering Evaluation of Proposed Surveillance Test Interval Changes, implies the UFSAR is a commitment. ER-AA-425-1002, describes the documents that EGO should review when checking for regulatory commitments under Step 1 of NEI 04-10. The procedure states:

Examples of commitments within Exelon include but are not limited to the following...:

1. UFSAR

2. Commitment Tracking Data Base

3. General Electric Service Information Letters (GE SILs)

4. Westinghouse technical bulletins

5. Vendor Manuals

6. System Manager or Program Engineer files

7. Insurance Review (NEIL, ANI)

When read in context, it is clear thatthis language from ER-AA-425-1002 is not meant to suggest that the entire UFSAR itself is a regulatory commitment, just like a vendor manual or technical bulletin would not constitute a regulatory commitment. Rather, the procedure simply lists documents where regulatory commitments may be found, and therefore, should be reviewed under Step 1 An Issue Report (IR #04101653) has been initiated documenting this 7 of 9

ATTACHMENT Exelon Position Related to NEI 04-10 administrative ambiguity, with an action to clarify the procedure regarding which licensing basis documents should be searched for regulatory commitments.

Second, the NRC also identified inconsistentterminology used in the SFCP evaluation BY 003. The SFCP evaluation states that Byron is committed to RG 1 .9, with some exceptions.

In this context, the term committed refers to the stated compliance with RG 1 .9 being part of Byron Stations Licensing Basis. An Issue Report (IR #04101694) has been initiated documenting this inconsistency in that the use of commitment in BY-13-003 is not meant to imply a regulatory commitment as defined in NEI 99-04. The resolution of this issue may include a revision to the SFCP evaluation and procedure revisions to clarify the use of terminology.

6. References 1 . Letter from R. C. Daley (U.S. Nuclear Regulatory Commission) to B. C. Hanson (Exelon Generation Company, LLC), Byron Station, Units 1 and 2 Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/2017009, 05000455/2017009, dated June 29, 2017

2. Letter from M. Kanavos (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, Response to NRC Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/2017009, 05000455/2017009, dated July 31, 2017

3. Letter from K. G. OBrien (U.S. Nuclear Regulatory Commission) to B. C. Hanson (Exelon Generation Company, LLC), Response to Disputed Non-Cited Violation Documented in Byron Station, Units 1 and 2 Evaluation of Changes, Tests, and Experiments Baseline Inspection Report 05000454/201 7009, 05000455/201 7009, dated December 21 2017 ,

4. NEI 04-10, Risk-Informed Technical Specifications Initiative 5B, Risk-Informed Method for Control of Surveillance Frequencies, Revision 1 April 2007 (MLO71 360462)

5. Letter from H. Hieh (NRC) to T. Pietrangelo (NEI), Final Safety Evaluation for Nuclear Energy Institute (NEI) Industry Guidance Document NEI 04-10, Revision 0, Risk-Informed Technical Specifications Initiative 5B, Risk-Informed Method for Control of Surveillance Frequencies, dated September 28, 2006 (ML062700012)

6. Letter from H. Hieh (NRC) to B. Bradley (NEI), Final Safety Evaluation for Nuclear Energy Institute (NEI) Topical Report (TR) NEI 04-1 0, Revision 1 Risk-Informed Technical Specification Initiative 5B, Risk-Informed Method for Control of Surveillance Frequencies, dated September 1 9, 2007 (ML072570267)

7. Nuclear Energy Institute NEI 96-07, Guidelines for 10 CFR 50.59 Evaluations, Revision 1, dated November 2000 (ML003771157)

8. U.S. NRC Regulatory Guide 1.187, Guidance for Implementation of 10 CFR 50.59, Changes, Tests, and Experiments, dated November 2000 (ML003759710)

9. Volume 64, Federal Register, Page 53588 (64FR53588), dated October 4, 1999 8 of 9

ATTACHM ENT Exelon Position Related to NEI 04-10

10. Letter from D. M. lmburgia (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, Updated Final Safety Analysis Report (UFSAR), Revision 16 Updated Fire Protection Report (FPR), Amendment 27, dated December 15, 2016.

1 1 U.S. NRC SECY-98-224, Staff and Industry Activities Pertaining to the Management of Commitments made by Power Reactor Licensees to the NRC, dated September 28, 1998

12. Nuclear Energy Institute NEI 99-04, Guidelines for Managing NRC Commitment Changes, Revision 0, dated July 1999 9 of 9