NLS2024070, Response to Integrated Inspection Report No. 05000298/2024003

From kanterella
Jump to navigation Jump to search
Response to Integrated Inspection Report No. 05000298/2024003
ML24340A107
Person / Time
Site: Cooper Entergy icon.png
Issue date: 12/04/2024
From: Dia K
Nebraska Public Power District (NPPD)
To:
Office of Nuclear Reactor Regulation, NRC Region 4, Document Control Desk
References
NLS2024070
Download: ML24340A107 (1)
v • d • e


Text

H Nebraska Public Power District NLS2024070 December 4, 2024 "Always there when you need us" U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Subject:

Response to Integrated Inspection Report No. 05000298/2024003 10 CFR 50.4 10 CFR 50.109 10 CFR 50.49 Cooper Nuclear Station, Docket No. 50-298, Renewed License No. DPR-46

Reference:

Letter from Nuclear Regulatory Commission to Nebraska Public Power District, Cooper Nuclear Station - Integrated Inspection Report 05000298/2024003 On September 30, 2024, the Nuclear Regulatory Commission (NRC) completed the 3rd Quarter 2024, Integrated Inspection at Cooper Nuclear Station (CNS). NRC inspectors documented two Non-Cited Violations (NCV) of very low safety significance (Green) and one Severity Level IV NCV (Reference).

In accordance with 10 CFR 50.4 and the NRC Enforcement Policy, Nebraska Public Power District (NPPD) hereby submits its basis for why NCV 05000298/2024003-01, "Failure to Maintain Environmental Qualification of Process Line Connections Associated with Safety-Related Instrumentation," as documented in the above Reference, should not have been issued against the requirements of 10 CFR 50.49.

NPPD believes that the NCV, as discussed in the attachment, represents a new NRC staff position that expands the 10 CFR 50.49(b) equipment qualification scoping requirements and would require CNS to establish qualification of purely mechanical equipment per the special treatments1 associated with 10 CFR 50.49. CNS's existing equipment qualification program for in-scope electric equipment is consistent with the NRC's regulations, regulatory guidance, and CNS's licensing basis. NPPD believes that the Performance Deficiency described in the NCV is not applicable to 10 CFR 50.49. NPPD also believes the Performance Deficiency associated with these mechanical process line connections should be assessed against the applicable 10 CFR 50, Appendix B Criteria.

1 10 CFR 50.49 imposes additional special treatments for certain electric equipment important safety to preclude environmentally induced common cause failures that could result in a loss of a safety function under design basis accident conditions. The imposition of this special treatment is directly related to the higher vulnerability of electric equipment to common cause failure because of exposure to harsh design basis accident conditions.

COOPER NUCLEAR STATION P.O. Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3811 http://www.nppd.com

NLS2024070 Page 2 of2 As discussed in the attachment, if the NRC staff determines that the Performance Deficiency is subject to 10 CFR 50.49, then it is requested that the NRC staff conduct a Backfit Analysis for the expansion of the scope of 10 CFR 50.49, as required by 10 CFR 50.109(a)(3). The attachment describes the basis for contesting the Performance Deficiency described in the NCV and the Backfit Claim.

There are no regulatory commitments contained in this submittal. If you have any questions please contact Linda Dewhirst, CNS Regulatory Affairs & Compliance Manager at ( 402) 825-5416.

Sincerely, Site Vice President

/mu

Attachment:

Contest of Non-Cited Violation 05000298/2024003-01, "Failure to Maintain Environmental Qualification of Process Line Connections Associated with Safety-Related Instrumentation," and Backfit Analysis cc:

Director of the Office of Nuclear Reactor Regulation w/attachment Director of the Office of Enforcement w/attachment Regional Administrator w/attachment USNRC - Region IV NRC Branch C Chief w/attachment US NRC - Region IV Cooper Project Manager w/attachment USNRC - NRR Plant Licensing Branch IV Senior Resident Inspector w/attachment USNRC-CNS NPG Distribution w/attachment CNS Records w/attachment

NLS2024070 Attachment Page 1 of22 Contest of Non-Cited Violation 05000298/2024003-01, "Failure to Maintain Environmental Qualification of Process Line Connections Associated with Safety-Related Instrumentation," and Backfit Analysis

NLS2024070 Attachment Page 2 of22 Table of Contents Executive Summary...................................................................................................................................... 3

1.

CONTEST OF NRC NCV 05000298/2024003-01.............................................................................. 5 1.1.

NRC Inspection Report 05000298/2024003................................................................................ 5 1.2.

NPPD Position.............................................................................................................................. 6 1.3.

NPPD Conclusion to Contest NCV.............................................................................................. 8

2.

BACKFIT CLAIM, NRC NON-CITED VIOLATION 05000298/2024003-01.................................. 9 2.1.

Background................................................................................................................................... 9 2.2.

NCV 05000298/2024003-01........................................................................................................ 9 2.3.

NPPD Position............................................................................................................................ 12 2.4.

Regulatory Requirements, Applicable Guidance and CNS Licensing Basis.............................. 13 2.4.1.

10 CFR 50.49...................................................................................................................... 13 2.4.2.

Department of Operating Reactors (DOR) Guidelines (Enclosure 4 to IEB 79-0lB)........ 13 2.4.3.

NUREG-0588..................................................................................................................... 14 2.4.4.

10 CFR 50 Appendix A, General Design Criterion 4 (GDC-4)......................................... 14 2.4.5.

10 CFR 50 Appendix B, Criterion III................................................................................. 15 2.4.6.

10 CFR 50.55a(h)............................................................................................................... 15 2.4.7.

Regulatory Guide 1.89, Revision 1.................................................................................... 15 2.4.8.

CNS Licensing and Design Basis....................................................................................... 16 2.4.9.

Summary and Conclusion................................................................................................... 18 2.5.

Change in NRC Staff Position Requires a Backfit Analysis...................................................... 19

3.

CONCLUSION.................................................................................................................................. 21

4.

REFERENCES................................................................................................................................... 21

NLS2024070 Attachment Page 3 of22 Executive Summary On September 30, 2024, the Nuclear Regulatory Commission (NRC) completed the 3rd Quarter, 2024, Integrated Inspection at Cooper Nuclear Station (CNS) as documented in Inspection Report 05000298/2024003, dated November 5, 2024 (Reference 4.1 ). NRC inspectors documented a performance deficiency associated with a Non-Cited Violation (NCV)05000298/2024003-01, "Failure to Maintain Environmental Qualification of Process Line Connections Associated with Safety-Related Instrumentation." The NCV was determined to be of very low safety significance (Green) and involved a failure to maintain Environmental Qualification (EQ) of thread sealants used in process line connections associated with safety-related instrumentation per the special treatments required by Title 10 Code of Federal Regulations 50.49 (10 CFR 50.49, Reference 4.2). The violation states that the "licensee is required to use qualified or to qualify thread sealant used in EQ equipment boundaries by one of the methods described in 10 CFR 50.49(+/-)."

Nebraska Public Power District (NPPD) has reviewed the broad base of regulatory requirements, guidance, and related industry standards, as well as the CNS plant specific licensing basis ( e.g., 10 CFR 50.49, Regulatory Guide (RG) 1.89 (Reference 4.3), Generic Letter (GL) 82-09 (Reference 4.4), relevant Institute of Electrical and Electronics Engineers (IEEE) standards, etc.). This includes the applicable CNS EQ Safety Evaluation Reports (SERs) that were developed and approved by the Office of Nuclear Regulatory Regulation (NRR) in 1981 and 1985 as a part of the original licensing for compliance with 10 CFR 50.49. The 1981 and 1985 SERs concluded the CNS program and its alignment to the applicable regulations, standards, and guidance was in compliance with 10 CFR 50.49.

NPPD's review of the current CNS program found it to be consistent with the CNS program reviewed under the final NRR EQ SER (Reference 4.19), and that the mechanical thread sealants used in the process line connections, are outside the scope of electric equipment that is subject to the special treatments of 10 CFR 50.49. This determination is based upon the scope of electric equipment subject to 10 CFR 50.49, as defined in 10 CFR 50.49(b)(l), (b)(2), and (b)(3), the Statements of Consideration for 10 CFR 50.49 [48 FR 2729 Jan. 21, 1983], the review of the scoping methodology used to establish the CNS program, and concluded that of the list of in-scope electric equipment complied with 10 CFR 50.49 as reflected in the final EQ SER in 1985.

The licensing process utilized in the development of the NRR EQ SERs for compliance with 10 CFR 50.49, required that the licensee submit the methodology used to select the individual pieces of in-scope electric equipment based upon the scope of 10 CFR 50.49(b). The licensee was then required to use this methodology to generate a Master Equipment List (MEL) which defined the in-scope electric equipment that would be subject to the requirements of 10 CFR 50.49. The final NRR EQ SER concluded that the selection methodology, and revision 2 of the MEL that was submitted on April 24, 1984, complied with 10 CFR 50.49.

The instrument process sensing lines are part of Instrument Loops that contain mechanical and electrical components such as valves, threaded pipe connections, electrical transmitters/switches, electric cables, square rooters, indicators, etc. All of the equipment contained in these Instrument Loops are subject to the standard design treatments like the 10 CFR 50 Appendix A General Design Criteria (GDC's, Reference 4.12), 10 CFR 50 Appendix B Criterion (Reference 4.13) and 10 CFR 50.55a (Reference 4.14).

Only the electrical equipment in the Instrument Loop that meets the scoping criteria of 10 CFR 50.49(b) is subject to the additional special treatments of 10 CFR 50.49(+/-). The instrument process sensing line threaded connections do not meet the scoping criteria of 10 CFR 50.49(b). A review of revision 2 of the

NLS2024070 Attachment Page 4 of22 CNS MEL confirms that standalone mechanical devices such as pumps, valves, process instrument tubing and manifolds, pump couplings, instrument racks, etc., were not included in the scope of 10 CFR 50.49.

Based on the information above, it was determined that Safety-Related mechanical equipment outside of the boundary of in-scope electrical equipment is not subject to the special treatments invoked by 10 CFR 50.49. Mechanical items that are not integral to the EQ component and perform a passive or active safety related function(s), are subject to the applicable technical and quality requirements imposed by the standard design processes and therefore, the NCV should not be cited against 10 CFR 50.49. The use of Teflon Tape in process sensing line threaded connections should be assessed against the general requirements applicable to Systems, Structures, and Components (SSCs) designed to accommodate the effects of environmental conditions, such as 10 CFR 50 Appendix A General Design Criteria ( or the Proposed-General Design Criteria for CNS), 10 CFR 50 Appendix B Criteria (III, XI, XVII), 10 CFR 50.55a, but not those of 10 CFR 50.49(+/-).

The NRC staff position presented in this NCV expands the boundaries of 10 CFR 50.49 and results in the need for a Backfit Analysis pursuant to 10 CFR 50.109(a)(3) (Reference 4.16). The basis for this conclusion is that NPPD established the boundaries of in-scope electric equipment subject to harsh environments during the licensing process for 10 CFR 50.49, which culminated in the Final CNS EQ SER that confirmed the CNS program compliance with 10 CFR 50.49 on January 30, 1985. That licensing action included reviews of the methodology for determination of in-scope electric equipment contained in the CNS EQ program as well as the contents of the CNS MEL for EQ. The MEL did not include mechanical devices that were outside the boundaries of the in-scope electrical equipment because they did not meet the scoping requirements of 10 CFR 50.49(b), and those mechanical devices were already subject to the requirements such as 10 CFR 50 Appendix A General Design Criteria, 10 CFR 50 Appendix B Criterion, and 10 CFR 50.55a.

NLS2024070 Attachment Page 5 of22

1. CONTEST OF NRC NCV 05000298/2024003-01 Failure to Maintain Environmental Qualification of Process Line Connections Associated with Safety-Related Instrumentation 1.1. NRC Inspection Report 05000298/2024003 Dated November 5, 2024, states NCV 05000298/2024003-01 as follows (emphasis added):

The inspectors identified a finding of very low safety significance (Green) and an associated non-cited violation of Title 10 of the Code of Federal Regulations 50.49, "Environmental Qualification of Electrical Equipment Important to Safety for Nuclear Power Plants," for the licensee's failure to properly maintain environmental qualification of process line joints within environmental qualification boundaries. Specifically, a non-qualified thread sealant was used on instrument line joints associated with nuclear instrumentation. The licensee is required to use qualified or to qualify thread sealants used in environmental qualification boundaries by one of the methods as described in Title 10 of the Code of Federal Regulations 5 0. 4 9. Because the finding was a very low safety significance (Green) and was entered into the licensee's corrective action program as CR-CNS-2024-03635 this violation will be treated as an NCV consistent with section 2.3.2 of the Enforcement Policy.

In describing this violation, NRC Inspection Report (IR) 05000298/2024-003, also stated:

During a walkdown of the plant, the inspectors identified significant use of Teflon tape on process lines to installed instruments that are required to be environmentally qualified in accordance with 10 CFR 50.49. Most examples identified were on pipe joints on the drain side of Rosemount Pressure transmitters and Barton instruments, upstream of closed isolation valves.

Teflon is known to degrade when exposed to high temperatures or radiation and is therefore not typically qualified for use in these environments.

The licensee justified the use of non-qualified sealant by defining a boundary between the EQ and non-EQ as the point of connection, or where the process line tubing threads into an EQ device.

Additionally, the licensee stated that the electrical transmitter, electrical conduit seal assembly, and thread sealant at the connection of the process line to the host transmitter are the only components within the bounds of their EQ program. The licensee does not have documentation adequately supporting the qualification of Teflon by testing or other acceptable methods.

The inspectors reviewed the following:

IEEE Standard 323-1974, "IEEE Standard for Qualifying Class IE Equipment for Nuclear Power Generating Stations, " defines interface as "a junction or junctions between a Class 1 E Equipment and another equipment or device." Additionally, section 6.3.1.3, which specifies connections used in type test procedures, states that "Equipment shall be connected in a manner that simulates its expected installation when in actual use unless an analysis can be performed and justified to show that the equipment's performance would not be altered by other means of connection. "Since the subject joints are located upstream of the isolation valves, degradation of the non-qualified thread sealant, which is not present in the EQ test configuration, caused by harsh conditions could result in leakage of the process fluid. This leakage could result in

NLS2024070 Attachment Page 6 of22 inaccurate instrument readings, thereby inhibiting the instrument from performing its safety function.

Cooper Procedure 14. 0. 6, revision 12, Instrument Tubing, valve, fitting, and thread lubricant guidelines, 11 section 16.2.1, states in part "Teflon tape should not be used in connections which come in contact with reactor system water.

11 This guidance was made effective in 1989, when the lack of viability of Teflon in harsh environments became known. Evaluation EE 1998-0009 identifies locations in the plant where Teflon was used and recommends replacing the thread sealant when maintenance activities disturb the affected joint.

The inspectors determined that the extent to which this guidance has been applied is not apparent, given that work orders associated with the disturbance of the applicable joints do not contain specific instruction on torque or thread sealant application, nor do the work orders contain guidance advising against the use of Teflon tape referenced in station Procedure 14. 0. 6.

Work orders associated with replacement of transmitters do not contain any specific guidance for disconnecting and reconnecting the instrument to process lines, relying on the use of the licensee's generic Lead Removal and Installation Maintenance Procedure 7.3.28.1. Additionally, Procedure 14. 0. 6 is an information use procedure and is not required to be reviewed by technicians prior to each applicable job.

Therefore, the inspectors, along with subject matter experts determined that the licensee has not demonstrated that instruments considered electric equipment important to safety satisfy the environmental qualification requirements when Teflon tape is used as a thread sealant on process line joint connections. As a result, the licensee has not demonstrated that these components could be relied upon to perform the required function for the specified mission time under design basis accident conditions.

1.2. NPPD Position NPPD has reviewed the broad base of regulatory requirements, guidance, and related industry standards, as well as the CNS plant specific licensing basis (e.g., 10 CFR 50.49, RG 1.89, GL 82-09, relevant IEEE standards, etc.). This includes the applicable CNS EQ SERs that were developed and approved by the NRR in 1981 and 1985 as a part of the ori'ginal licensing for compliance with 10 CFR 50.49. The 1981 and 1985 SERs concluded that the CNS program and its alignment to the applicable regulations, standards, and guidance complied with 10 CFR 50.49.

NPPD's review of the current CNS program found it to be consistent with the CNS program reviewed by the final NRR EQ SER, and that the mechanical thread sealants used in the process line connections, are outside the scope of electric equipment that is subject to the special treatments of 10 CFR 50.49. This determination is based upon the scope of electric equipment subject to 10 CFR 50.49, as defined in 10 CFR 50.49(b)(l), (b)(2), and (b)(3), the Statements of Consideration for 10 CFR 50.49 [48 FR 2729 Jan 21, 1983], the review of the scoping methodology used to establish the CNS program, and concluded that the list of in-scope electric equipment was compliant with 10 CFR 50.49, as reflected in the final EQ SER in 1985.

The licensing process utilized in the development of the NRR EQ SERs for compliance with 10 CFR 50.49, required that the licensee submit the methodology used to select the individual pieces of in-scope electric equipment based upon the scope of 10 CFR 50.49(b ). The licensee was then required to use this methodology to generate a MEL which defined the in-scope electric equipment that would be subject to the requirements of 10 CFR 50.49. The final NRR EQ SER

NLS2024070 Attachment Page 7 of22 concluded that the selection methodology, and revision 2 of the MEL that was submitted on April 24, 1984 complied with 10 CFR 50.49,.

While 10 CFR 50.49 does not provide specific guidance on how to determine the boundary between in-scope electric equipment and out-of-scope non-electric equipment ( only subject to standard design treatments), the historical understanding2 is that the process connections are considered out-of-scope non-electric equipment ( e.g., mechanical) and not subject to the special treatments of 10 CFR 50.49. A review of revision 2 of the CNS MEL confirms that standalone mechanical devices such as pumps, valves, process instrument tubing and manifolds, pump couplings, instrument racks, etc., were not included in the scope of 10 CFR 50.49.

The methodology used for determining the contents of the MEL was also found to be consistent with the NRC position/requirements delineated in Generic Letter 82-09 (GL 82-09), Question and Answer (Q&A) 2, which was issued during promulgation of the rules specified in 10 CFR 50.49 which states:

Q. For Equipment Qualification purposes, what constitutes all safety-related electrical equipment?

A. The Commission, in CLI-80-21, required the environmental qualification of only safety-related electrical equipment. Identification of the safety-related equipment installed at specific plants can be obtained from FSARs, Technical Specifications and other docketed correspondence settingforth NRC requirements or licensee commitments. Identification of safety-related equipment installed in harsh environments at specific plants must be supplied by the licensee. The necessity for upgrading nonsafety-related system to safety-related status will be the subject of other NRC reviews.

Additional reviews by NPPD were performed of applicable regulatory documents and industry standards associated with 10 CFR 50.49. These reviews also did not yield a specific definition of the individual boundaries for in-scope electrical equipment subject to 10 CFR 50.49(b). The most applicable of the documents reviewed would be Regulatory Guide 1.89, IEEE 279-1971 (Reference 4.5), IEEE 308-1970 (Reference 4.6), IEEE 308-1974 (Reference 4.7) and IEEE 323-1974 (Reference 4.8).

Regulatory Guide 1.89, Revision 1, Section C, stipulates that the procedures described by IEEE 323-1974 are an acceptable method for satisfying the Commission's regulations pertaining to qualification of electric equipment with the provisions provided. IEEE 323-1974 does not define the scope of 10 CFR 50.49. It is only an acceptable testing methodology that can be used to meet the requirements of 10 CFR 50.49(+/-).

In practice, the equipment boundary for in-scope electrical equipment is typically based on an understanding of the tested configuration of the equipment being qualified, The equipment boundary can vary depending on test specimen, what (if any) interfaces are included as part of the 2 The NRC's and industry's past actions are consistent with NPPD's understanding that certain non-electric (e.g.,

mechanical) equipment is not subject to 10 CFR 50.49. In the early 1980's, for example, the NRC Staff considered-but did not formally propose-rulemaking on the application of Mechanical Equipment Qualification.

Historical Understanding is based on the development process for compliance with 10 CFR 50.49 (e.g., IEB 79-018, CLl-80-21, DOR Guidelines, Generic Letter 82-09, CNS EQ SER's, etc.).

NLS2024070 Attachment Page 8 of22 test specimen and is usually established during the design of the test program. This approach provides flexibility along with the recognition of:

The size of the test chamber may limit the size of the test specimen or the ability to include ancillary or interfacing equipment. This can result in the need for multiple test programs.

Test specimens may not include the actual interfaces that are needed. For example, the test specimen may have the conduit entrance hard piped within the test chamber, which would warrant the use of a conduit seal to prevent the ingress of the accident environment within the equipment enclosure.

For electric equipment qualified by type testing, IEEE 3 23-197 4 addresses this variability by requiring that test specimen( s) be mounted and connected in a manner that simulates the expected installation when in actual use unless an analysis can be performed and justified to show that the equipment's performance would not be altered by other means of mounting or connection.

The instrument sensing line threaded connections discussed in this NCV are external to the in-scope electric equipment boundary and only have a safety function to maintain pressure boundary integrity. These instrument sensing line threaded connections are part of Instrument Loops that contain mechanical and electrical components such as valves, threaded pipe connections, electrical transmitters/switches, electric cables, square rooters, indicators, etc. The individual pieces of equipment in the Instrument Loops can be located in both harsh and mild environments.

All of the equipment contained in these Instrument Loops are subject to the standard design treatments like the 10 CFR 50 Appendix A GDC's, 10 CFR 50 Appendix B Criterion and 10 CFR 50.55a. Only the electrical equipment in the Instrument Loop that meets the scoping criteria of 10 CFR 50.49(b) is subject to the additional special treatments of 10 CFR 50.49(f). The instrument sensing line threaded connections do not meet that criteria.

1.3. NPPD Conclusion to Contest NCV This violation should not be cited against 10 CFR 50.49 because mechanical process sensing line connections do not meet the scoping criteria of 10 CFR 50.49(b). The use of Teflon Tape in process sensing line threaded connections should be assessed against the general requirements applicable to SSCs designed to accommodate the effects of environmental conditions, such as 10 CFR 50 Appendix A GDC ( or the Prop'osed-General Design Criteria for CNS), 10 CFR 50 Appendix B Criterion (III, XI, XVII), 10 CFR 50.55a, but not those of 10 CFR 50.49(f).

The NCV represents a change in NRC Staff position regarding in-scope electric equipment qualification boundaries by extending the application of 10 CFR 50.49 beyond the in-scope electric equipment out to mechanical devices that are upstream and downstream of the in-scope electric equipment. The Commission's regulations and CNS' s Licensing Basis are clear that there is no requirement to apply the special treatments of 10 CFR 50.49 to mechanical equipment that is not an integral part of the in-scope electric equipment.

NLS2024070 Attachment Page 9 of22

2. BACKFIT CLAIM, NRC NON-CITED VIOLATION 05000298/2024003-01 This is a New Staff Position Which Requires a Backfit Analysis 2.1. Background On September 30, 2024, the NRC completed the 3rd Quarter 2024 Integrated Inspection at CNS as documented in Inspection Report 05000298/2024003, dated November 5, 2024. NRC inspectors documented NCV 05000298/2024003-01. The NCV was determined to be of very low safety significance (Green) involving a failure to maintain Environmental Qualification of thread sealants used in process line connections associated with safety-related instrumentation per the special treatments required by 10 CFR 50.49. The violation states that the "licensee is required to use qualified or to qualify thread sealant used in EQ equipment boundaries by one of the methods described in Title 10 CFR 50.49(f)."

2.2. NCV 05000298/2024003""01 "Failure to Maintain Environmental Qualification of Process Line Connections Associated with Safety-Related Instrumentation," NCV, Green. The following is the entire violation as presented in the Inspection Report:

The inspectors identified a finding of very low safety significance (Green) and an associated non-cited violation of Title 10 of the Code of Federal Regulations 50.49, "Environmental Qualification of Electrical Equipment Important to Safety for Nuclear Power Plants, "for the licensee's failure to properly maintain environmental qualification of process line joints within environmental qualification boundaries. Specifically, a non-qualified thread sealant was used on instrument line joints associated with nuclear instrumentation. The licensee is required to use qualified or to qualify thread sealants used in environmental qualification boundaries by one of the methods as described in Title JO of the Code of Federal Regulations 50.49.

==

Description:==

During a walkdown of the plant, the inspectors identified significant use of Teflon tape on process lines to installed instruments that are required to be environmentally qualified in accordance with 10 CFR 50.49. Most examples identified were on pipe joints on the drain side of Rosemount Pressure transmitters and Barton instruments, upstream of closed isolation valves.

Teflon is known to degrade when exposed to high temperatures or radiation and is therefore not typically qualified for use in these environments.

The licensee justified the use of non-qualified sealant by defining a boundary between the EQ and non-EQ as the point of connection, or where the process line tubing threads into an EQ device. Additionally, the licensee stated that the electrical transmitter, electrical conduit seal assembly, and thread sealant at the connection of the process line to the host transmitter are the only components within the bounds of their EQ program. The licensee does not have documentation adequately supporting the qualification of Teflon by testing or other acceptable methods.

The inspectors reviewed the following:

IEEE Standard 323-1974, "IEEE Standard for Qualifying in-scope Equipment for Nuclear Power Generating Stations, " defines interface as "a junction or junctions between a in-scope Equipment and another equipment or device." Additionally, section 6.3.1.3, which specifies connections used in type test procedures, states that "Equipment shall be connected in a manner

NLS2024070 Attachment Page 10 of 22 that simulates its expected installation when in actual use unless an analysis can be performed and justified to show that the equipment's performance would not be altered by other means of connection." Since the subject joints are located upstream of the isolation valves, degradation of the non-qualified thread sealant, which is not present in the EQ test configuration, caused by harsh conditions could result in leakage of the process fluid. This leakage could result in inaccurate instrument readings, thereby inhibiting the instrument from performing its safety function.

Cooper Procedure 14. 0. 6, revision 12, "Instrument Tubing, valve, fitting, and thread lubricant guidelines," section 16.2.1, states in part "Teflon tape should not be used in connections which come in contact with reactor system water. " This guidance was made effective in 1989, when the lack of viability of Teflon in harsh environments became known. Evaluation EE 1998-0009 identifies locations in the plant where Teflon was used and recommends replacing the thread sealant when maintenance activities disturb the affected joint.

The inspectors determined that the extent to which this guidance has been applied is not apparent, given that work orders associated with the disturbance of the applicable joints do not contain specific instruction on torque or thread sealant application, nor do the work orders contain guidance advising against the use of Teflon tape referenced in station Procedure 14. 0. 6.

Work orders associated with replacement of transmitters do not contain any specific guidance for disconnecting and reconnecting the instrument to process lines, relying on the use of the licensee's generic Lead Removal and Installation Maintenance Procedure 7.3.28.1. Additionally, Procedure 14. 0. 6 is an information use procedure and is not required to be reviewed by technicians prior to each applicable job.

Therefore, the inspectors, along with subject matter experts determined that the licensee has not demonstrated that instruments considered electric equipment important to safety satisfy the environmental qualification requirements when Teflon tape is used as a thread sealant on process line joint connections. As a result, the licensee has not demonstrated that these components could be relied upon to perform the required function for the specified mission time under design basis accident conditions.

Performance Assessment:

Performance Deficiency: Title 10 CFR 50.49, "Environmental Qualification of Electrical Equipment Important to Safety for Nuclear Power Plants, " section (f) requires that each item of electric equipment important to safety must be qualified by one of four methods listed in the regulation. The inspectors determined the licensee's failure to maintain equipment required to be environmentally qualified is reasonably in the licensee's ability to foresee and correct and therefore a performance deficiency. This resulted in no assurance that these components could be relied upon to perform the required function for the specified mission time under design basis accident conditions.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the licensee failed to ensure environmentally qualified thread sealants were used on all process connections, whose failure could result in the failure of the instrument.

NLS2024070 Attachment Page 11 of 22 Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix A, 'The Significance Determination Process (SDP) for Findings At-Power. " Using exhibit 2, "Mitigating Systems Screening Questions, " the inspectors determined this finding to be of very low safety significance (Green) because it was a deficiency affecting the design or qualification of equipment, but the equipment maintained its probabilistic risk assessment (PRA) functionality.

Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.

Enforcement:

Violation: Title JO CFR 50.49, "Environmental Qualification of Electrical Equipment Important to Safety for Nuclear Power Plants, "section (I) requires that each item of electric equipment important to safety must be qualified by one of the following methods:

(1) testing an identical item of equipment under identical conditions or under similar conditions with a supporting analysis to show that the equipment to be qualified is acceptable (2) testing a similar item of equipment with a supporting analysis to show that the equipment to be qualified is acceptable (3) experience with identical or similar equipment under similar conditions with a supporting analysis to show that the equipment to be qualified is acceptable

( 4) analysis in combination with partial type test data that supports the analytical assumptions and conclusions Contrary to the above since 1989 to September 30, 2024, the licensee failed to qualify thread sealant used on process line connections with environmentally qualified instruments by one of the following methods:

(1) testing an identical item of equipment under identical conditions or under similar conditions with a supporting analysis to show that the equipment to be qualified is acceptable (2) testing a similar item of equipment with a supporting analysis to show that the equipment to be qualified is acceptable (3) experience with identical or similar equipment under similar conditions with a supporting analysis to show that the equipment to be qualified is acceptable (4) analysis in combination with partial type test data that supports the analytical assumptions and conclusions Specifically, the licensee has numerous safety-related transmitters, installed in multiple systems with non-qualified thread sealant installed in process connections to environmentally qualified instruments, which may inhibit the environmentally qualified instruments from performing their intended function under the environmental conditions described by JO CFR 50.49.

NLS2024070 Attachment Page 12 of 22 Enforcement Action: This violation is being treated as a non-cited violation, consistent with section 2.3.2 of the Enforcement Policy.

2.3. NPPD Position Nuclear power plant equipment important to safety must be able to perform its safety function( s) throughout its installed life. The NRC' s regulations in 10 CFR Part 50 require that important to safety SSCs in a nuclear power plant be designed to accommodate the effects of environmental conditions (i.e., remain functional under postulated accident conditions) and that design control measures such as testing be used to check the adequacy of design. These general requirements are contained in:

General Design Criteria (GDC) 1, 2, 4, and 23 contained in 10 CFR 50, Appendix A Criterion III, "Design Control" contained in 10 CFR 50, Appendix B Criterion XI, "Test Control" contained in 10 CFR 50, Appendix B Criterion XVII, "Quality Assurance Records contained in 10 CFR 50 Appendix B, and 10 CFR 50.55a, Codes and Standards These requirements are applicable to both electrical and mechanical equipment located inside of Primary Containment as well as outside in Secondary Containment.

10 CFR 50.49 imposes additional special treatments for certain electric equipment important safety to preclude environmentally induced common cause failures that could result in a loss of a safety function under design basis accident conditions. The imposition of this special treatment is directly related to the higher vulnerability of electric equipment to common cause failure because of exposure to harsh design basis accident conditions. As delineated in the Statements of Consideration for §50.49 [48 FR 2730, January 21, 1983] (Reference 4.9), the scope of the final rule covers that portion of equipment important to safety commonly referred to as "safety-related (which the Commission interprets as essentially "Class IE" equipment defined in IEEE 323-1974), and non-safety related electric equipment whose failure under postulated environmental conditions could prevent satisfactory accomplishment of required safety functions by safety-related equipment. Also covered in the scope of the final rule is certain post-accident monitoring equipment specified as "Category 1 and 2" in Revision 2 of Regulatory Guide 1. 97, "Criteria for Accident Monitoring Instrumentation for Nuclear Power Plants."

As discussed in Sections 1.2 and 1.3 above, the instrument sensing line threaded connections discussed in this NCV are external to the in-scope electric equipment boundary and only have a safety function to maintain pressure boundary integrity. These instrument sensing line threaded connections are part of Instrument Loops that contain mechanical and electrical components such as valves, threaded pipe connections, electrical transmitters/switches, electric cables, square rooters, indicators, etc. The individual pieces of equipment in the Instrument Loops can be located in both harsh and mild environments. All of the equipment contained in these Instrument Loops are subject to the standard design treatments like the 10 CFR 50 Appendix A GDC's, 10 CFR 50 Appendix B Criterion and 10 CFR 50.55a. Only the electrical equipment in the Instrument Loop that meets the scoping criteria of 10 CFR 50.49(b) is subject to the additional special treatments of 10 CFR 50.49(f). The instrument sensing line threaded connections do not meet the criteria.

The NCV represents a change in NRC Staff position regarding in-scope electric equipment qualification boundaries by extending the application of 10 CFR 50.49 beyond the in-scope

NLS2024070 Attachment Page 13 of 22 electric equipment out to mechanical devices that are upstream and downstream of the in-scope electric equipment. The Commission's regulations and CNS' s Licensing Basis are clear that there is no requirement to apply the special treatments of 10 CFR 50.49 to mechanical equipment that is not an integral part of the in-scope electric equipment.

2.4. Regulatory Requirements, Applicable Guidance and CNS Licensing Basis This section summarizes the applicable regulatory requirements, codes and standards, and CNS' s Licensing Basis that define or provide guidance on the equipment that is subject to the requirements of 10 CFR 50.49.

2.4.1.

10 CFR 50.49 Environmental Qualification of Electrical Equipment Important to Safety for Nuclear Power Plants 10 CFR 50.49 was written to provide specific programmatic requirements for a qualification program and documentation for certain electrical equipment important to safety that must perform their important to safety function during or following exposure to harsh design basis conditions, and thus is a special treatment requirement. Section 50.49(b) specifically defines the electric equipment important to safety as follows:

50.49(b)(l) - Safety-related electric equipment. This equipment is relied upon to remain functional during and following design basis events to ensure -

A. The integrity of the reactor coolant pressure boundary; or B. The capability to shut down the reactor and maintain it in a safe shutdown condition; or C. The capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposures comparable to the guidelines in§ 50.49(a)(J), § 50.67(b)(2), or§ 100.11, as applicable.

50.49(b)(2) - Non-safety related electric equipment whose failure under postulated environmental conditions could prevent the satisfactory accomplishment of safety functions specified in subparagraphs (b)(J)(i) (A) through (C) of paragraph (b)(l) by the safety-related equipment 50.49(b)(3) - Certain post-accident monitoring equipment.

2.4.2.

Department of Operating Reactors (DOR) Guidelines (Enclosure 4 to IEB 79-0lB)

By Commission Memorandum and Order CLI-80-21 (Reference 4.11), the NRC ordered that the DOR Guidelines form the environmental qualification requirements for safety-related electrical equipment that all plants with operating licenses as of May 23, 1980, must meet to satisfy General Design Criterion 4. The DOR Guidelines (Reference 4.10) were contained in IEB 79-0lB, Enclosure 4, and were entitled "Guidelines for Evaluating Environmental Qualification of Class 1 E Electrical Equipment in Operating Reactors."

The DOR Guidelines provided the guidelines and criteria that the staff used to evaluate the adequacy of licensee responses to Bulletin 79-01 B.

NLS2024070 Attachment Page 14 of 22 Section 2.0 of the DOR Guidelines contains a statement that "However, all of the operating reactors are required to comply with the General Design Criteria specified in Appendix A of 10 CFR 5 0. " The intent of the DOR Guidelines is to provide a basis for judgements required to confirm that operating reactors comply with GDC-4.

Section 3.0 of the DOR Guidelines specifically covers the identification of Class lE equipment that are needed to achieve emergency reactor shutdown, containment isolation, reactor core cooling, containment and reactor heat removal, and the prevention of significant release of radioactive material to the environment. Typical systems included in PWR and BWR reactor designs to perform these functions for the most severe LOCA or MSLB condition are listed in Appendix A. More detailed descriptions of the Class 1 E equipment installed at specific plants can be obtained from FSARs, Technical Specifications, and emergency procedures.

Section 5.2.2 of the DOR Guidelines provides considerations related to the test specimen.

The test specimen should be the same model as the equipment being qualified. The type test should only be considered valid for equipment identical in design and material construction to the test specimen. Any deviations should be evaluated as part of the qualification documentation.

2.4.3.

NUREG-0588 Interim Staff Position on Environmental Qualification of Safety-Related Electrical Equipment (Reference 4.15)

On May 23, 1980, Commission Memorandum and Order CLI-80-21 endorsed the positions in the "For Comment" version ofNUREG-0588 as the interim positions that shall be satisfied until the "final" positions are established in rulemaking. These interim positions, which were used to verify conformance to GDC-4, supplement the requirements found in the 1971 and 1974 versions of IEEE Standard 323.

The introduction section ofNUREG-0588 clarifies that for cases where the DOR Guidelines do not provide sufficient detail, but NUREG-0588 Category II does, NUREG-0588 will be used as part of their evaluation of operating reactors.

2.4.4.

10 CFR 50 Appendix A, General Design Criterion 4 (GDC-4)

Environmental and dynamic effects design basis Criterion 4 - Environmental and dynamic effects design bases. Structures, systems, and components important to safety shall be designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents.

These structures, systems, and components shall be appropriately protected against dynamic effects, including the effects of missiles, pipe whipping, and discharging fluids, that may result from equipment failures and from events and conditions outside the nuclear power unit. However, dynamic effects associated with postulated pipe ruptures in nuclear power units may be excluded from the design basis when analyses reviewed and approved by the Commission demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis for the piping.

NLS2024070 Attachment Page 15 of 22 Consistent with Criterion III of 10 CFR 50 Appendix B, the design requirements of GDC-4 include the selection, procurement, and use of materials capable of performing under the postulated service conditions coupled, where needed, with testing, analysis, or other methods to confirm this design capability.

2.4.5.

10 CFR 50 Appendix B, Criterion III Design Control Requires measures to be established for the selection and review for suitability of application of materials, parts, equipment, and processes that are essential to the safety-related functions of the structures, systems and components. The design control measures shall provide for verifying or checking the adequacy of design, such as by the performance of design reviews, using alternate or simplified calculational methods, or by the performance of a suitable testing program. The verifying or checking process shall be performed by individuals or groups other than those who performed the original design, but who may be from the same organization. Where a test program is used to verify the adequacy of a specific design feature in lieu of other verifying or checking processes, it shall include suitable qualifications testing of a prototype unit under the most adverse design conditions. Design control measures shall be applied to items such as the following: reactor physics, stress, thermal, hydraulic, and accident analyses; compatibility of materials; accessibility for inservice inspection, maintenance, and repair; and delineation of acceptance criteria for inspections and tests.

2.4.6.

10 CFR 50.55a{h)

Protection and safety systems Section 50.55a(h)(2) incorporates by reference the requirements in either IEEE 279-1968, "Proposed IEEE Criteria for Nuclear Power Plant Protection Systems," IEEE 279-1971, "Criteria for Protection Systems for Nuclear Power Generating Stations," or IEEE 603-1991, "IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations." Within these IEEE standards are special treatment requirements. Specifically, Sections 4.3 and 4.4 of IEEE-279 and Sections 5.3 and 5.4 of IEEE-603 contain quality and equipment qualification requirements. IEEE 279-1968 or IEEE 279-1971 applies to plants with construction permits issued after January 1, 1971, but before May 13, 1999.

For plants with construction permits issued before January 1, 1971, protection systems must be consistent with their licensing basis or may meet the requirements of IEEE 603-1991.

Subsection VIl-1. 7 of the CNS USAR states that the design of the protection systems conforms to the "Proposed Criteria for Protection Systems for Nuclear Power Generating Stations (IEEE 279)," as described in NEDO-10139, "Compliance of Protection Systems to Industry Criteria: General Electric BWR Nuclear Steam Supply System."

2.4.7.

Regulatory Guide 1.89, Revision 1 Environmental Qualification of Certain Electric Equipment Important to Safety for Nuclear Power Plants This regulatory guide describes a method acceptable to the NRC staff for complying with

§ 50.49 of 10 CFR Part 50 with regard to qualification of electric equipment important to

NLS2024070 Attachment Page 16 of 22 safety for service in nuclear power plants to ensure that the equipment can perform its safety function during and after a design basis accident.

Specific requirements pertaining to qualification of certain electric equipment important to safety are contained in§ 50.49, "Environmental Qualification of Electric Equipment Important to Safety for Nuclear Power Plants," of 10 CFR Part 50. Section 50.49 requires that three categories of electric equipment important to safety be qualified for their application and specified performance and provides requirements for establishing environmental qualification methods and qualification parameters. These three categories are (1) safety-related electric equipment (Class IE), (2) non-safety-related electric equipment (non-Class 1 E) whose failure under postulated environmental conditions could prevent satisfactory accomplishment of safety functions by safety-related equipment, and (3) certain post-accident monitoring equipment. This regulatory guide applies only to these three categories of electric equipment important to safety.

Regulatory position C.1 further reinforces that Section 50.49, "Environmental Qualification of Electric Equipment Important to Safety for Nuclear Power Plants," of 10 CFR Part 50 is specific to safety-related electric equipment (Class IE) as defined in paragraph 50.49(b)(l), non-safety related electric equipment whose failure under postulated environmental conditions could prevent satisfactory accomplishment of the safety functions performed by safety-related equipment, as well as certain post-accident monitoring equipment specified as RG 1.97 Category 1 or Category 2 variables.

2.4.8.

CNS Licensing and Design Basis The regulatory objective of the CNS EQ Program is to demonstrate station compliance with the requirements set forth in 10 CFR 50.49 as described USAR Chapter VII, Section

1. 7.2 and the EQ Program Basis Document. USAR subsection VII-1. 7.2 states, "The CNS Environmental Qualification (EQ) program meets the requirements of 1 0CFR50.49 for electrical equipment important to safety. This equipment consists of (1) Electric equipment relied upon to remain functional during and following design basis events to ensure the integrity of the reactor coolant pressure boundary, the capability to shut down the reactor and maintain it in a safe shutdown condition, and the capability to prevent or mitigate the consequences of accidents that could result in potential offeite exposures comparable to the J0CFRJ00 or J0CFR50.67 guidelines. (2) Nonsafety-related electric equipment whose failure under postulated environmental conditions could prevent satisfactory accomplishment of safety functions. (3) Certain post-accident monitoring equipment as determined per the guidelines of Regulatory Guide 1.97. "

The criteria for the selection of the equipment in the EQ Program is based on those systems and components required to achieve or support emergency reactor shutdown, containment isolation, reactor core cooling, containment heat removal, core residual heat removal, or the prevention of significant release of radioactive material to the environment.

2.4.8.1.

CNS Updated Safety Analysis Report (USAR) VII-1.7.2 The CNS Environmental Qualification (EQ) program meets the requirements of J0CFR50.49 for electrical equipment important to safety. This equipment consists of (1) Electric equipment relied upon to remain functional during and

NLS2024070 Attachment Page 17 of 22 2.4.8.2.

2.4.8.3.

following design basis events to ensure the integrity of the reactor coolant pressure boundary, the capability to shut down the reactor and maintain it in a safe shutdown condition, and the capability to prevent or mitigate the consequences of accidents that could result in potential offeite exposures comparable to the 10CFRl00 or 10CFR50.67 guidelines. (2) Nonsafety-related electric equipment whose failure under postulated environmental conditions could prevent satisfactory accomplishment of safety functions. (3) Certain post-accident monitoring equipment as determined per the guidelines of Regulatory Guide 1.97.

In accordance with the requirements of 10CFR50.49, a Master Equipment List (MEL) of all electrical equipment covered by the regulation is maintained. The equipment items have been catalogued by location in the plant, as a basis for identification of normal service and accident environments under which the equipment must function. The MEL provides summary information identifying each EQ item and its characteristics and environmental requirements.

Original CNS electrical equipment that falls under the scope of the EQ Rule has been environmentally qualified using the methodology described in the "Division of Operating Reactors Guidelines for Evaluating Environmental Qualifications of Class lE Electrical Equipment in Operating Reactors" (DOR Guidelines), in accordance with 10CFR50.49(k). Replacement components and new EQ equipment are qualified in accordance with Regulatory Guide 1. 89, Revision 1, in accordance with 10CFR50.49(l).

CNS USAR VII-1.7 The design of protection systems conforms to the "Proposed Criteria for Protection Systems for Nuclear Power Generating Stations (IEEE-279)5, "as described in NEDO-1013 9, "Compliance of Protection Systems to Industry Criteria: General Electric BWR Nuclear Steam Supply System. " Category I instrumentation and Class lE electrical equipment conform to IEEE-344-1971, "IEEE Guide for Seismic Qualification of Class 1 E Electrical Equipment for Nuclear Power Generating Stations, " or to Revision 3 of the Generic Implementation Procedure (GIP-3) as modified and supplemented by the US.

Nuclear Regulatory Commission Supplemental Safety Evaluation Report (SSER)

No. 2 and SSER No. 3.

Conformance to ABC Proposed General Design Criteria USAR Appendix F Criterion 23 - Protection Against Multiple Disability for Protection Systems "The effects of adverse conditions to which redundant channels or protection systems might be exposed in common, either under normal conditions or those of an accident, shall not result in loss of the protection function. "

These systems are designed to provide the required protection as long as necessary and in the presence of the most severe conditions which would be

NLS2024070 Attachment Page 18 of 22 encountered. This includes conditions resulting from transients and accidents for which the protective action is required. Protection System electrical equipment that is located in a harsh environment has been environmentally qualified as required by 10CFR50. 4 9.

CNS is committed to conformance with 1971 GDC 22 for the safety-related actuation instrumentation of the Reactor Building Ventilation Radiation Monitoring System.

Criterion 26 - Protection Systems Fail-Safe Design "The protection systems shall be designed to fail into a safe state or into a state established as tolerable on a defined basis if conditions such as disconnection of the system, loss of energy (e.g., electric power, instrument air), or adverse environments (e.g., extreme heat or cold,jire, steam, or water) are experienced."

Systems essential to the protection functions are designed to fail-safe in their most probable failure modes. Thus, a systematic or environmentally caused failure will be detectable and will not compromise the protective function of the system.

CNS is committed to conformance with 1971 GDC 23 for the safety-related actuation instrumentation of the Reactor Building Ventilation Radiation Monitoring System.

Criterion 42 - Engineered Safety Features Components Capability Requires that "Engineered safety features shall be designed so that the capability of each component and system to perform its required function is not impaired by the effects of a loss-of-coolant accident. The components which are required to function following a design basis loss-of-coolant accident are designed to withstand the most severe forces and environmental effects resulting from the accident. "

Commission Memorandum and Order CLJ-80-21 backfitted the DOR Guidelines for the environmental qualification of Class 1 E equipment as a means to confirm that the equipment conformed to the requirements ofGDC-4 of 10 CFR 50 Appendix A.

2.4.9.

Summary and Conclusion The scope of the EQ final rule is defined in § 50.49(b) and is specific to electric equipment important to safety. The Statement of Considerations for 10 CFR 50.49 [ 48 FR 2729 Jan. 21, 1983] establishes that the EQ final rule is specific to electric equipment.

Safety-Related mechanical equipment outside of the equipment boundary of in-scope electrical equipment is not subject to the special treatments invoked to 10 CFR 50.49.

Mechanical equipment that performs a passive or active safety related function(s) are subject to the applicable technical and quality requirements imposed by the standard design treatments.

NLS2024070 Attachment Page 19 of 22 The scope of 10 CFR 50.49 defines the requirements for an EQ program and does not apply to mechanical equipment outside the boundary of electric equipment subject to that regulation. While the scope of equipment covered is addressed, 10 CFR 50.49 does not explicitly describe, define, or delineate the individual equipment boundaries or interfaces of in-scope electrical equipment. This conclusion is supported by review of IEEE 323-1974, which also does not define individual equipment boundaries for in-scope electric equipment. For 10 CFR 50.49 qualification purposes, the individual equipment boundary is established based on the physical configuration of the test specimen and is usually established during the design of the test program.

2.5. Change in NRC Staff Position Requires a Backfit Analysis Section 50.109(a)(l) of Title 10 of the Code of Federal Regulations provides the following definition ofbackfitting:

Backfitting is defined as the modification of or addition to systems, structures, components, or design of a facility; or the design approval or manufacturing license for a facility; or the procedures or organization required to design, construct or operate a facility; any of which may result from a new or amended provision in the Commission's regulations or the imposition of a regulatory staff position interpreting the Commission's regulations that is either new or different from a previously applicable staff position after:

(iii) The date of issuance of the operating license for the facility for facilities having operating licenses; NRR Office Instruction, LIC-202, "Procedures for Managing Plant-Specific Backfits and 50.54(+/-) Information Requests," Revision 2 (LIC-202, Reference 4.18), Section 1 sets forth the Commission policy regarding backfits. In pertinent part:

The Backfit Rule, Title JO of the Code of Federal Regulations (JO CFR) 50.109, governs the requirements for baclifitting of nuclear power plants. It requires that the Nuclear Regulatory Commission (NRC) justify each backfit with either a backfit analysis or a documented evaluation. The term baclifit is used in these procedures to denote modification of or addition to (1) systems, structures, components, or design of a facility; (2) the design approval or manufacturing license for a facility; (3) the procedures or organization required to design, construct, or operate a facility if the modification or addition results from a new or amended provision in the Commission rules or from the imposition of a regulatory staff position interpreting the Commission rules that is either new or different from a previously applicable staff position. To be considered a backfit, these new or different positions must be taken after certain dates specified in 50.109(a)(l)(i-vii).

Furthermore, a baclifit is plant-specific when it involves the imposition of a position that is unique to a particular plant.

NUREG 1409, Backfitting Guidelines, Section 2.1.1 (Reference 4.17), provides that "[t]he scope of the rule includes all design and hardware aspects of systems, structures, and components as well as supporting activities reflected by procedures and organization."

LIC-202, Appendix B,Section I provides that a staff position constitutes a backfit if it meets the following criteria:

NLS2024070 Attachment Page 20 of22 A staff position may be a proposed baclifit if it would cause a licensee to change the design, construction, or operation of a facility from that consistent with already applicable regulatory staff positions as described below.

A staff position, as described above, is a proposed baclifit if it is first made known to the licensee after certain important design, construction, or operation milestones involving NRC approvals of various kinds have been reached. A new or revised staff position will be considered a baclifit:

After the date of issuance of the operating license (for the facility or facilities having operating licenses); or LIC-202, Appendix B,Section I further provides a definition of "applicable regulatory staff positions," as follows:

Applicable Regulatory Staff Positions: The term "applicable regulatory staff positions" is used in these procedures to denote those requirements, commitments, or positions specifically imposed on a licensee or committed to by a licensee when the plant-specific backfit is identified:

Legal requirements, as in regulations, orders, and plant licenses (including amendments, conditions, technical specifications). Some regulations have update features built into them;for example, JO CFR 50.55a, "Codes of Standards." Such update features are applicable as described in the regulation.

NRC staff positions that explicitly interpret the more general regulations and that are approved and stated in such documents as standard review plans (SRPs), branch technical positions, regulatory guides, generic letters, and bulletins, and to which a licensee has previously committed or upon which a licensee has previously relied.

Positions contained in these documents are not considered applicable regulatory staff positions with respect to a particular licensee unless the staff has, in a previous licensing or enforcement action, identified to the licensee part or all of the position.

The NCV represents a change in NRC Staff position regarding in-scope equipment qualification scoping per 10 CFR 50.49(b). The Commission's regulations, and the CNS Licensing Basis with respect to 10 CFR 50.49 is clear that there is no requirement to qualify mechanical equipment that is outside the boundaries of the in-scope electrical equipment subject to 10 CFR 50.49(b).

This staff position represents a significant expansion of the regulatory requirements associated with 10 CFR 50.49. This expansion in scope would require that a significant number of items would have to be added to the list of the equipment in the CNS EQ program. For reference, there are currently over 1500 pieces of in-scope electric equipment, each with the potential for multiple mechanical devices ( valves, tubing, fittings, etc.) in the associated Instrumentation Loops, and the addition of this equipment would require CNS establish qualification for this additional mechanical equipment. This would require testing, development of qualification packages, potential modifications to the plant, revision of plant documentation, etc.

The instrument line threaded connections that are subject to harsh environments are currently addressed by standard design treatments like the General Design Criteria, 10 CFR 50 Appendix B

NLS2024070 Attachment Page 21 of 22 Criterion, 10 CFR 50.55a. The regulatory precedence and licensing basis ramifications of this new NRC staff position would be significant to CNS and the rest of the industry if the NCV remains applicable to 50.49.

3. CONCLUSION NPPD believes that the NCV represents a new NRC staff position that expands the 10 CFR 50.49(b) equipment qualification scoping requirements and would require CNS to establish qualification of purely mechanical equipment per the special treatments associated with 10 CFR 50.49. CNS's existing equipment qualification program for in-scope electric equipment is consistent with the NRC' s regulations, regulatory guidance, and CNS' s licensing basis. NPPD believes that the Performance Deficiency described in the NCV is not applicable to 10 CFR 50.49. NPPD also believes the Performance Deficiency associated with these mechanical process line connections should be assessed against the applicable 10 CFR 50, Appendix B Criteria.

If the NRC staff determines that the Performance Deficiency is subject to 10 CFR 50.49, then it is requested that the NRC staff conduct a Backfit Analysis for the expansion of the scope of 10 CFR 50.49, as required by 10 CFR 50.109(a)(3).

The NRC staff position presented in this NCV expands the boundaries of 10 CFR 50.49 and results in the need for a Backfit Analysis pursuant to 10 CFR 50.109(a)(3). The basis for this conclusion is that NPPD established the boundaries of in-scope electric equipment subject to harsh environments during the licensing process for 10 CFR 50.49, which culminated in the Final CNS EQ SER that confirmed the CNS program compliance with 10 CFR 50.49 on January 30, 1985. That licensing action included reviews of the methodology for determination of in-scope electric equipment contained in the CNS EQ program as well as the contents of the CNS MEL for EQ. The MEL did not include mechanical devices that were outside the boundaries of the in-scope electrical equipment because they did not meet the scoping requirements of 10 CFR 50.49(b), and those mechanical devices were already subject to the requirements of General Design Criteria, 10 CFR 50 Appendix B Criterion, and 10 CFR 50.55a.

4. REFERENCES 4.1. COOPER NUCLEAR STATION - INTEGRATED INSPECTION REPORT 05000298/2024003, November 5, 2024 4.2.

10 CFR 50.49, "Environmental Qualification of Electric Equipment Important to Safety for Nuclear Power Plants" 4.3.

Regulatory Guide (RG) 1.89, "Environmental Qualification of Certain Electric Equipment Important to Safety for Nuclear Power Plants," Revision 1 4.4.

Generic Letter (GL) 82-09, "Environmental Qualification of Safety-Related Electrical Equipment," April 20, 1982 4.5.

IEEE 279-1971, "Criteria for Protection Systems for Nuclear Power Generating Stations" 4.6.

IEEE 308-1970, "Criteria for Class IE Electric Systems for Nuclear Power Generating Stations"

NLS2024070 Attachment Page 22 of22 4.7.

IEEE 308-1974, "" Criteria for Class 1E Electric Systems for Nuclear Power Generating Stations 4.8.

IEEE 323-1974, "Qualifying Class 1E Equipment for Nuclear Power Generating Stations" 4.9.

Statements of Consideration for 10 CFR 50.49 [48 FR 2729 Jan. 21, 1983]

4.10. DOR Guidelines (Enclosure 4 to IEB 79-01B), "Guidelines for Evaluating Environmental Qualification of Class 1 E Electrical Equipment in Operating Reactors" 4.11. NRC Memorandum and Order CLI-80-21, "Petition for Emergency and Remedial Action" 4.12. 10 CFR 50 Appendix A, "General Design Criteria for Nuclear Power Plants" 4.13. 10 CFR 50 Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants" 4.14. 10 CFR 50.55a, "Codes and Standards" 4.15. NUREG-0588, "Interim Staff Position on Environmental Qualification of Safety-Related Electrical Equipment" 4.16. 10 CFR 50.109, "Backfitting" 4.17. NUREG-1409, "Backfitting Guidelines" 4.18. LIC-202, Procedures for Managing Plant-Specific Backfits and 50.54(f) Information Requests 4.19. ML20106F796 CNS Final EQ Safety Evaluation Report, Dated 1-30-1985

Retrieved from "https://kanterella.com/w/index.php?title=NLS2024070,_Response_to_Integrated_Inspection_Report_No._05000298/2024003&oldid=5450168"