ML26023A151
| ML26023A151 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 01/28/2026 |
| From: | Ilka Berrios Plant Licensing Branch III |
| To: | Ferneau K Indiana Michigan Power Co |
| Wall S | |
| References | |
| EPID L-2026-LLR-0000 | |
| Download: ML26023A151 (0) | |
Text
January 28, 2026 Ms. Kelly J. Ferneau Executive Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106
SUBJECT:
DONALD C. COOK NUCLEAR PLANT, UNIT NOS. 1 AND 2 - ISSUANCE OF ALTERNATIVE REL-PP1 ASSOCIATED WITH PUMP INSERVICE TESTING (EPID L-2026-LLR-0000)
Dear Ms. Ferneau:
By letter dated December 30, 2025 (Agencywide Documents Access and Management System Accession No. ML25364A335), Indiana Michigan Power Company (I&M, the licensee) submitted a request for the use of an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), associated with pump inservice testing (IST) for the Donald C. Cook Nuclear Plant, Unit Nos. 1 and 2 (CNP).
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee requested to use the proposed alternative in request REL-PP1 on the basis that complying with the requirements of the ASME Code would result in hardship without a compensating increase in the level of quality and safety. The ASME OM Code requires vibration measurements to be taken on each accessible pump-bearing housing for centrifugal pumps.
The proposed alternative would allow vibration measurements to be taken at the outboard motor bearing for the boric acid storage tank transfer pumps at CNP.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the subject request and concludes, as set forth in the enclosed safety evaluation, that I&M has adequately addressed the requirements in 10 CFR 50.55a(z)(2). Therefore, the NRC staff approves the use of REL-PP1 for the Sixth IST interval at CNP.
All other ASME OM Code requirements for which relief was not specifically requested and approved remain applicable.
K. Ferneau If you have any questions, please contact the Senior Project Manager, Scott Wall, at 301-415-2855 or e-mail at Scott.Wall@nrc.gov.
Sincerely, Ilka Berrios, Acting Chief Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316
Enclosure:
Safety Evaluation cc: Listserv ILKA BERRIOS Digitally signed by ILKA BERRIOS Date: 2026.01.28 10:31:09 -05'00'
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUEST REL-PP1 INDIANA MICHIGAN POWER COMPANY DONALD C. COOK NUCLEAR PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-315 AND 50-316
1.0 INTRODUCTION
By letter dated December 30, 2025 (Agencywide Documents Access and Management System Accession No. ML25364A335), Indiana Michigan Power Company (I&M, the licensee) submitted to the U.S. Nuclear Regulatory Commission (NRC) a request for the use of an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), associated with pump inservice testing (IST) for the Donald C. Cook Nuclear Plant, Unit Nos. 1 and 2 (CNP).
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee requested to use the proposed alternative in request REL-PP1 on the basis that complying with the requirements of the ASME Code would result in hardship without a compensating increase in the level of quality and safety.
2.0 REGULATORY EVALUATION
The NRC regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, state, in part:
Throughout the service life of a boiling or pressurized water-cooled nuclear power facility, pumps and valves that are within the scope of the ASME OM Code must meet the inservice test requirements (except design and access provisions) set forth in the ASME OM Code and addenda that become effective subsequent to editions and addenda specified in paragraphs (f)(2) and (3) of this section
[10 CFR 50.55a] and that are incorporated by reference in paragraph (a)(1)(iv) of this section [10 CFR 50.55a], to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The regulations in 10 CFR 50.55a(z) state, in part, that alternatives to the requirements in paragraphs (b) through (h) of 10 CFR 50.55a may be authorized by the NRC if the licensee demonstrates that: (1) the proposed alternative provides an acceptable level of quality and safety, or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request and the NRC to authorize the alternative requested by the licensee.
3.0 TECHNICAL EVALUATION
The information provided by the licensee in support of the request for an alternative to ASME OM Code requirements, as incorporated by reference in 10 CFR 50.55a, has been evaluated and the bases for NRC staffs conclusion are documented below.
3.1 Licensees Alternative Request REL-PP1 ASME OM Code Components Affected In its submittal, the licensee requested to use an alternative to the applicable ASME OM Code requirements for the pumps listed in Table 1.
Table 1 Pump Number Pump Name ASME OM Code Group Pump Type 1-PP-46-1 Boric Acid Storage Tanks Transfer Pump #1 A
Centrifugal 1-PP-46-2 Boric Acid Storage Tanks Transfer Pump #2 A
Centrifugal 2-PP-46-3 Boric Acid Storage Tanks Transfer Pump #3 A
Centrifugal 2-PP-46-4 Boric Acid Storage Tanks Transfer Pump #4 A
Centrifugal Applicable Code Editions and Addenda For the Sixth IST interval, the CNP IST program is based on the 2022 Edition of the ASME OM Code as incorporated by reference in 10 CFR 50.55a.
Applicable Code Requirements The ASME OM Code, Subsection ISTB, Inservice Testing of Pumps in Water-Cooled Reactor Nuclear Power Plants - Pre-2000 Plants, paragraph ISTB-3540, Vibration, (a), states:
On centrifugal pumps, except vertical line shaft pumps, measurements shall be taken in a plane approximately perpendicular to the rotating shaft in two approximately orthogonal directions on each accessible pump-bearing housing.
Measurement shall also be taken in the axial direction on each accessible pump thrust bearing housing.
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Reason for Request===
The licensee states that the only accessible point for taking axial vibration measurements is the outboard motor bearing. It is unsafe to monitor the axial direction vibration on the inboard pump bearing due to the proximity of the rotating shaft, and there is no position in monitoring the outboard pump bearing housing because of the presence of heat tracing. Modifications to the coupling shield to allow access were attempted. However, the modified shield did not provide sufficient clearance to allow individuals performing the measurement to safely place their hands near the rotating shaft.
Proposed Alternative and Basis for Use The licensee proposes to measure axial vibration at the outboard motor bearing for the pumps listed in Table 1. The vibration limits contained in ASME OM Code, Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria, will be applied to the vibration levels monitored at the outboard motor bearing during both the Group A and comprehensive test.
The licensee stated that although the axial vibration measurement would now include the noise from the motor, that contribution would be minimal because the pump is directly coupled to the motor, and all significant axial contributors to vibration should originate from the pump.
Duration of Proposed Alternative The licensee requested the alternative to be approved for the Sixth IST interval of the CNP IST Program that is currently scheduled to begin on July 1, 2026.
3.2 Staff Evaluation The boric acid storage tanks transfer pumps have a safety requirement to pump a boric acid solution from the boric acid storage tank to the suction of the charging pumps. The ASME OM Code requires that the vibration measurements for centrifugal pumps be taken in the axial direction on each accessible pump thrust bearing housing. The licensee states that it is unsafe to monitor the axial direction vibration on the inboard pump bearing housing due to the proximity of the rotating shaft and access to the outboard pump bearing housing is impeded by heat tracing. Modifications to the coupling shield were attempted to allow access, but they were not successful in providing sufficient clearance to allow individuals taking vibration measurements to safely place their hands near the rotating shaft. This condition is considered to be a hardship with regard to performing the OM Code-required vibration measurement.
The licensee proposes to take axial vibration measurements on the outboard motor bearing and apply the vibration acceptance criteria given in ASME OM Code Table ISTB-5121-1. Although the axial vibration measurement would now include noise from the motor, that contribution would be minimal, considering that the pump is directly coupled to the motor and all significant axial contributors to vibration should originate from the pump. ASME OM Code, Subsection ISTB, paragraph ISTB-6200, Corrective Action, requires that if the measured test parameter values fall within the alert range of Table ISTB-5121-1, the frequency of testing shall be doubled until the cause of the deviation is determined and the condition is corrected, or an analysis of the pump is performed.
Based on its evaluation, the NRC staff has determined that requiring the licensee to meet the axial vibration measurement location requirement in the ASME OM Code for the boric acid storage tank transfer pumps at CNP would result in hardship without a compensating increase in the level of quality and safety. It is noted that the NRC staff previously authorized this alternative request for CNP for the Fifth IST interval in a letter dated February 4, 2016 (ML16032A031).
The NRC staff finds that the proposed vibration measurement location in the axial direction in Alternative Request REL-PP1 for the boric acid storage tank transfer pumps at CNP is acceptable and provides reasonable assurance of operational readiness of the pumps listed in Table 1, above, to perform their safety function.
The NRC staff notes that the applicable Code of Record for the CNP Sixth IST interval is the 2022 Edition of the ASME OM Code, as incorporated by reference in 10 CFR 50.55a. The CNP Sixth IST interval is scheduled to begin on July 1, 2026. The ASME OM Code (2022 Edition),
Subsection ISTA, General Requirements, paragraph ISTA-3120, Inservice Examination and Test Interval, as incorporated by reference in 10 CFR 50.55a, requires that licensees implement 10-year intervals for their IST programs. ASME OM Code Case OMN-31, Alternative to Allow Extension of ISTA-3120 Inservice Examination and Test Intervals from 10 to 12 Years, is conditionally accepted in Revision 5 to Regulatory Guide 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code, which the licensee could voluntarily implement to extend their IST intervals from 10 to 12 years, if they satisfy the conditions on its use. The NRC regulations in 10 CFR 50.55a allow licensees to implement the same ASME OM Code as their Code of Record for two successive IST program intervals. Therefore, the licensee of CNP could implement the 2022 Edition of the ASME OM Code, as incorporated by reference in 10 CFR 50.55a, for both the Sixth and Seventh IST intervals required by the ASME OM Code, Subsection ISTA, paragraph ISTA-3120.
4.0 CONCLUSION
As set forth above, the NRC staff finds that the proposed alternative provides reasonable assurance that the affected components are operationally ready. The NRC staff finds that complying with the specified ASME OM Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all the regulatory requirements set forth in 10 CFR 50.55a(z)(2).
Therefore, the NRC staff authorizes the use of REL-PP1 for the Sixth IST interval at CNP, which is currently scheduled to begin on July 1, 2026.
All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject request remain applicable.
Principal Contributor: Yuken Wong, NRR Scott Wall, NRR Date: January 28, 2026
SUBJECT:
DONALD C. COOK NUCLEAR PLANT, UNIT NOS. 1 AND 2 - ISSUANCE OF ALTERNATIVE REL-PP1 ASSOCIATED WITH PUMP INSERVICE TESTING (EPID L-2026-LLR-0000) DATED JANUARY 28, 2026 DISTRIBUTION:
PUBLIC RidsNrrDorlLpl3 Resource RidsRgn3MailCenter Resource RidsNrrLASLent Resource RidsAcrs_MailCTR Resource RidsNrrPMDCCook Resource RidsNrrDexEmib Resource YWong, NRR Accession No.: ML26023A151
- via memorandum NRR-028 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DNRL/NPHP/BC*
NAME SWall SLent SBailey DATE 1/23/2026 1/26/2026 1/21/2026 OFFICE NRR/DORL/LPL3/BC (A)
NRR/DORL/LPL3/PM NAME IBerrios Swall DATE 1/28/2026 1/28/2026 OFFICIAL RECORD COPY