ML24296B190

10 CFR 50.55a Requests for the Fifth Ten-Year Interval Inservice Testing Program

ML24296B190
Person / Time
Site:	Wolf Creek
Issue date:	10/22/2024
From:	Boyce M Wolf Creek
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
000652
Download: ML24296B190 (1)

Text

Michael T. Boyce Vice President Engineering October 22, 2024 000652 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Reference:

1) Letter from USNRC, dated May 15, 2015, from M. T. Markley, USNRC, to A. C. Heflin, WCNOC, Wolf Creek Generating Station - Request for Relief Nos. 4PR-01, 4PR-02, and 4VR-02 for the Fourth 10-Year Inservice Testing Program Interval (TAC No. MF4992, MF4993, and MF4994), ADAMS ML15134A002

2) Letter from USNRC, dated August 10, 2015, from M. T. Markley, USNRC, to A. C. Heflin, WCNOC, Wolf Creek Generating Station -

Request for Relief Nos. 4VR-01 and 4GR-01, and 4VR-02 for the Fourth 10-Year Inservice Testing Program Interval (TAC No. MF4991 and MF5005), ADAMS ML15216A229

Subject:

Docket No. 50-482: 10 CFR 50.55a Requests for the Fifth Ten-Year Interval lnservice Testing Program Commissioners and Staff:

Pursuant to 10 CFR 50.55a(z)(1), Wolf Creek Nuclear Operating Corporation (WCNOC) requests Nuclear Regulatory Commission (NRC) approval of 10 CFR 50.55a requests 5PR-01 and 5VR-01 for the Fifth Ten-Year Interval of the WCNOC lnservice Testing (IST) Program.

Attachment I provides 10 CFR 50.55a Request Number 5PR-01, which requests an alternative to the requirements of American Society of Mechanical Engineers (ASME) Code for Operations and Maintenance of Nuclear Power Plants (OM Code) ISTB-3510(b)(1) as they pertain to the Centrifugal Charging Pump suction pressure gauge requirements. This request has been approved for the current IST interval as 4PR-02, as stated in Reference 1.

Attachment II provides 10 CFR 50.55a Request Number 5VR-01 requesting an alternative to the requirements of ASME OM Code Appendix I, 1-1410 pertaining to the Set Pressure Measurement Accuracy for two relief valves. This request has been approved for the current IST interval as 4VR-01, as stated in Reference 2.

WCNOC requests approval of the proposed 10 CFR 50.55a Requests by August 21, 2025, to have in place prior to the start of WCNOCs Fifth Ten-Year Program Interval which begins September 4, 2025.

000652 Page 2 of 2 This letter contains no commitments. If you have any questions concerning this matter, please contact me at (620) 364-8831 x8687, or Dustin Hamman at (620) 364-4204.

Sincerely, Michael T. Boyce MTB/jkt Attachment I: 10 CFR 50.55a Request Number 5PR-01 Attachment II: 10 CFR 50.55a Request Number 5VR-01 cc:

A. N. Agrawal (NRC), w/a S. S. Lee (NRC), w/a J. D. Monninger (NRC), w/a Senior Resident Inspector (NRC), w/a WCNOC Licensing Correspondence ET 24-000652, w/a

Attachment I to 000652 Page 1 of 3 Attachment I 10 CFR 50.55a Request Number 5PR-01 Request for Alternative to Centrifugal Charging Pump Suction Pressure Gauge Range Requirements

Attachment I to 000652 Page 2 of 3 10 CFR 50.55a Request 5PR-01 Centrifugal Charging Pump Suction Pressure Gauge Range Requirements Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Alternative Provides Acceptable Level of Quality and Safety

1. ASME Code Component(s) Affected PBG05A Centrifugal Charging Pump A Group A PBG05B Centrifugal Charging Pump B Group A

2. Applicable Code Edition and Addenda ASME OM Code, Operation and Maintenance of Nuclear Power Plants, 2020 Edition, no Addenda

3. Applicable Code Requirement ISTB-3510(b)(1) - The full-scale range of each analog instrument shall be not greater than three times the reference value.

4. Reason for Request Pursuant to 10 CFR 50.55a, "Codes and standards," paragraph (z)(1), an alternative is proposed to the instrumentation requirements of the ASME OM Code. The basis of the request is that the proposed alternative would provide an acceptable level of quality and safety. Specifically, this alternative is requested for Group A testing of the Centrifugal Charging pumps.

The installed suction pressure gauge range of the Centrifugal Charging Pumps is 0 - 150 psig. The reference values for suction pressure during Inservice Testing are between 30 and 40 psig. As a result, the instrument range exceeds the requirement of ISTB-3510(b)(1).

5. Proposed Alternative and Basis for Use Pump suction pressure is used along with pump discharge pressure to determine pump differential pressure. Suction pressure reference values for the Centrifugal Charging Pumps during Inservice Testing are between 30 psig and 40 psig. Based on ISTB-3510(b)(1), this would require as a maximum, a gauge with a range of 0 to 90 psig (3 X 30 psig) to bound the lowest reference value for suction pressure. Applying the accuracy requirement of +/- 2

% for the quarterly Group A pump test, the resulting inaccuracies due to pressure effects would be +/- 1.8 psig (0.02 X 90 psig).

As an alternative, for the Group A quarterly test, Wolf Creek Nuclear Operating Corporation (WCNOC) will use the installed suction pressure gauge (0 to 150 psig) calibrated to less than or equal to +/- 1.2 % such that the inaccuracies due to pressure will be less than or equal to

Attachment I to 000652 Page 3 of 3 that required by the Code (+/- 1.8 psig). Use of the installed pressure gauge calibrated to less than or equal to +/- 1.2 % is equivalent in terms of measuring differential pressure.

Although the permanently installed suction pressure gauges are above the maximum range limits of ASME OM Code ISTB-3510(b)(1), they are within the accuracy requirements and are therefore suitable for the test. Reference NUREG 1482 Revision 3, Section 5.5.1.

Using the provisions of this relief request as an alternative to the specific requirements of ISTB-3510(b)(1) identified above will provide adequate indication of pump performance and continue to provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(z)(1), relief is requested from the specific ISTB requirements identified in this request.

6. Duration of Proposed Alternative This proposed alternative will be utilized for the entire Fifth Inservice Testing interval which will begin September 4, 2025, and conclude on September 3, 2037.

7. Precedents Letter from M. T. Markley (U.S. Nuclear Regulatory Commission) to A. C. Heflin, WCNOC, Wolf Creek Generating Station - Request for Relief Nos. 4PR-01, 4PR-02, and 4VR-02 for the Fourth 10-Year Inservice Testing Program Interval (TAC No. MF4992, MF4993, and MF4994), dated May 15, 2015 (ADAMS Accession No. ML15134A002).

Letter from M. Markley (U.S. Nuclear Regulatory Commission) to F. Diya (Ameren Missouri),

Callaway Plant, Unit 1 - Requests for Relief PR-01 through PR-06, Alternatives to ASME OM CODE Requirements for Inservice Testing for the Fourth Program Interval (TAC Nos.

MF2784, MF2785, MF2786, MF2787, MF2788, and MF2789), dated July 15, 2014 (ADAMS Accession No. ML14178A769).

Letter from J. G. Danna (U.S. Nuclear Regulatory Commission) to M. L. Richey (Beaver Valley Power Station), " Beaver Valley Power Station, Unit No. 1 - Requests for Alternatives and Requests for Relief Re: Fifth 10-Year Inservice Testing Program Interval (CAC Nos.

MF8332, MF8334, MF8336, MF8337, MF8340, MF8342, MF8344, MF8346, MF8348, MF8350, MF8351, MF8353, MF8354, MF8355, and MF8357)," dated June 26, 2017 (ADAMS Accession No. ML17159A442).

Letter from U. Shoop (U.S. Nuclear Regulatory Commission) to M. Nazar (Florida Power &

Light Company), "Turkey Point Nuclear Generating Unit Nos. 3 and 4 -Safety Evaluation for Relief Request No. PR-03, for the Fifth 10-Year Inservice Testing Interval Regarding Boric Acid Transfer Pump Testing Instrumentation (CAC Nos. MF9526 and MF9527)," dated August 29, 2017 (ADAMS Accession No ML17213A863).

8. References NUREG 1482, Guidelines for Inservice Testing at Nuclear Power Plants, Rev 3.

Attachment II to 000652 Page 1 of 3 Attachment II 10 CFR 50.55a Request Number 5VR-01 Request for Alternative to Set Pressure Measurement Accuracy

Attachment II to 000652 Page 2 of 3 10 CFR 50.55a Request 5VR-01 Set Pressure Measurement Accuracy Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)

Alternative Provides Acceptable Level of Quality and Safety

1. ASME Code Component(s) Affected Valve No.

Class Category ENV0058 2

C ENV0106 2

C

2. Applicable Code Edition and Addenda ASME OM Code, Operation and Maintenance of Nuclear Power Plants, 2020 Edition, no Addenda

3. Applicable Code Requirement Mandatory Appendix I, I-1410 - Set-Pressure Measurement Accuracy. Test equipment (e.g.,

gages, transducers, load cells, calibration standards) used to determine valve set-pressure, shall have an overall combined accuracy not to exceed +/-1% of the indicated (measured) set-pressure.

4. Reason for Request Pursuant to 10 CFR 50.55a, Codes and Standards, paragraph (z)(1), relief is requested from the requirement of ASME OM Code, Mandatory Appendix I, I-1410. The basis of the relief request is that the proposed alternative would provide an acceptable level of quality and safety.

ENV0058 and ENV0106 - These vacuum relief valves must open to provide vacuum protection of the spray additive tank. This function prevents the tank from collapsing in the event of a failure of the discharge isolation valves to close while the tank is empty, and the pumps are operating. This condition could cause a vacuum to be created within the tank.

The valve is set to relieve vacuum at 0.98 psig vacuum.

Typically, vacuum relief valves are designed to relieve at significantly low differential pressures. For the subject valves, the set pressures are as follows:

Spray Additive Vacuum Relief Valves 2 Hg (0.98 psig)

Attachment II to 000652 Page 3 of 3 Instrument accuracies to meet the Code requirements would therefore be 0.0098 psig.

Pressure instrumentation that provides this level of accuracy for this application is not commercially available and not typically maintained by a power plant facility. As a result, the instrument accuracy range will exceed the requirements of Mandatory Appendix I, I-1410.

5. Proposed Alternative and Basis for Use The functional requirement of a vacuum relief valve is only relevant in the opening direction.

The closure function is generally irrelevant or passive - the valve remains closed to maintain the system boundary (e.g. loss of system inventory). For these subject valves, there is not a concern for premature opening. During normal operations, system pressure acts to maintain the valve closed.

Therefore, Wolf Creek Nuclear Operating Corporation (WCNOC) will establish a set point range such that the lower limits for opening of the valves will allow considerable margin without affecting the valves performance with respect to the system requirements. The instrument accuracy and target setpoint for these valves will be established such that the overall combined accuracy specified in the test procedures will limit the actual set pressure to 1% above the stamped set pressure.

Using the provisions of this relief request as an alternative to the specific requirements of Mandatory Appendix I, I-1410, as identified above, will provide adequate assurance of valve set pressure performance with respect to system functional requirements. Therefore, pursuant to 10 CFR 50.55a(z)(1) relief is requested from the specific Appendix I requirements identified in this request.

6. Duration of Proposed Alternative This proposed alternative will be utilized for the entire Fifth Inservice Testing interval which will begin September 4, 2025, and conclude on September 3, 2037.

7. Precedents Letter from USNRC, dated March 21, 2006, from D. Terao, USNRC, to R.A. Muench, WCNOC, Wolf Creek Generating Station - Relief Requests for the Third 10 -Year Pump and Valve Inservice Testing Program (TAC Nos. MC8210, MC8212, MD0383, and MD0384),

(ADAMS Accession No. ML060550447)

Letter from USNRC, dated August 10, 2015, from M. T. Markley, USNRC, to A. C. Heflin, WCNOC, Wolf Creek Generating Station - Request for Relief Nos. 4VR-01 and 4GR-01, and 4VR-02 for the Fourth 10-Year Inservice Testing Program Interval (TAC No. MF4991 and MF5005), (ADAMS Accession No. ML15216A229)