ML23270B966
| ML23270B966 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 09/27/2023 |
| From: | Jungmann B Ameren Missouri, Union Electric Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| ULNRC-068 13 | |
| Download: ML23270B966 (1) | |
Text
12Ameien Callaway Plant MISSOURI September 27, 2023 ULNRC-068 13 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-000 1 10 CFR 50.55a Ladies and Gentlemen:
DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.
RENEWED FACILITY OPERATING LICENSE NPF-30 10 CfR 50.55a(z)(1) REQUESTS FOR RELIEF FROM ASME OM CODE PUMP AND VALVE TESTING REQUIREMENTS FOR FIFTH 120-MONTH INSERVICE TESTING INTERVAL Pursuant to 1 0 CFR 50.55a(z)(1), Union Electric Company (Ameren Missouri) requests NRC approval of the enclosed (three) reliefrequests for the fifth 1 0-year inservice testing interval at the Callaway Energy Center (Callaway Plant). The Code Edition applicable to Callaway for its fifth inservice testing interval, which begins December 20, 2024, is ASME OM Code 2020. No Code Addenda are applicable to Callaway for its fifth inservice testing interval.
The enclosed relief requests are identified as
, PR-02, and PR-03. Relief requests PR-01 and PR-02 allow testing of the residual heat removal and centrifugal charging pumps, respectively, using installed pressure gauges which have a full-scale range that exceeds the Code requirement, but which can be compensated by applying appropriate calibration controls to the existing gauges. Reliefrequest PR-03 permits use of a test flow path for the boric acid transfer pumps, for which only differential pressure (in lieu of differential pressure and flow) will be measured but which will still provide an adequate means to assess pump performance.
Supporting information, including the justification for each request, is provided in the enclosed relief requests.
83 1 5 County Road 459 Steedman, I\\/1() 65077 ArnererthIissouri.coin
ULNRC-068 13 Page2of4 As indicated above, these reliefrequests support testing activities for which the applicable A$ME OM Code requirements will go into effect on December 20, 2024. Ameren Missouri therefore respectfully requests review and approval of these requests by that time.
This letter does not contain new commitments.
If there are any questions, please contact E. S. Smith at 3 14-225-1 7 1 1.
Sincerely, Brent L.
Senior Director, Nuclear Engineering
Enclosure:
10 CFR 50.55a Request Number PR-Ol 10 CfR 50.55a Request Number PR-02 1 0 CFR 50.55a Request Number PR-03 (with Attachment 1)
ULNRC-068 13 Page3of4 cc:
Mr. John Monninger Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1 600 East Lamar Boulevard Arlington, TX 76011-4511 Senior Resident Inspector Callaway Resident Office U. S. Nuclear Regulatory Commission
$201 NRC Road Steedman, MO 65077 Mr. M. Chawla Project Manager, Callaway Plant Office ofNuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop O$B1A Washington, DC 20555-000 1
ULNRCO68 13 Page4of4 Index and send hardcopy to QA File A160.0761 Hardcopy:
Certrec Corporation 6500 West Freeway, Suite 400 FortWorth,TX 76116 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)
Electronic distribution for the following can be made via Other Situations ULNRC Distribution:
F. M. Diya K. C. Scott W. A. Witt B. L. Jungmann T. A. Witt T. B. Elwood NSRB Secretary STARS Regulatory Affairs Mr. Jay Silberg (Pillsbury Winthrop Shaw Pittman LLP)
Ms. Kathleen McNelis (Public Service Commission)
Ms. Claire Eubanks (Public Service Commission)
Attachment to 1 0 CFR 50.55a Request Number PR-O1 ULNRC-06813 Page 1 of 2 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)
Alternative Provides Acceptable Level of Quality and Safety I
American Society of Mechanical Engineers (ASME) Code Components Affected Pump Description Code CM Code Number Class Category PEJOIA Residual Heat Removal Pump A 2
Gp A PEJO1 B Residual Heat Removal Pump B 2
Gp 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, General paragraph (b), Range, subparagraph (1) states, The full-scale range of each analog instrument shall be not greater than three times the reference value.
===4.
Reason for Request===
Pursuantto 10 CFR 50.55a, Codes and standards, paragraph (z)(1), an alternative is proposed to the above-noted 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 for the Residual Heat Removal (RHR) pumps.
The range of the installed analog discharge pressure gauges for the RHR pumps is 0
- ZOO psig. Because the reference values for pump discharge pressure during lnservice Testing are less than 234 psig, the instrument range exceeds the requirement of ISTB-3510(b)(1).
Pump discharge pressure indication is used along with pump suction pressure indication to determine pump differential pressure. Discharge pressure reference values for the RHR pumps during Inservice Testing are between 200 psig and 234 p51g. Based on ISTB 3510(b)(1), this would require as a maximum, a gauge with a range of 0 to 600 psig (3 X 200 psig) to bound the lowest reference value for discharge pressure. Applying the accuracy requirement of +/- 2% for the quarterly Group A test, the resulting inaccuracies due to discharge pressure effects would be +/- 12.0 psig (0.02 X 600 psig).
Attachment to 10 CFR 50.55a Request Number PR-O1 ULNRC-06813 Page 2 of 2
===5.
Proposed Alternative and Basis for Use===
As an alternative, for the Group A quarterly test, Callaway Energy Center will use the installed analog discharge pressure gauge (0 to ZOO psig) calibrated to less than or equal to
+/- 1.7% such that the inaccuracies due to discharge pressure will be less than that required by the Code (+/- 12.0 psig). The error associated with the discharge gauge would then be no greater than +/- 1 1.9 psi (ZOO X 0.01 7). Use of the installed discharge pressure gauge calibrated to less than +/- 2% (+/- 1.7%) is equivalent in terms of Code compliance for the measurement of discharge pressure.
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.
===6.
Duration of Proposed Alternative===
The proposed alternative will be utilized for the entire fifth 1 20-month 1ST Program Interval, which is scheduled to begin on December 20, 2024, and end on December 1 9, 2034.
===7.
Precedents===
I Letter from M. Markley (U. S. Nuclear Regulatory Commission) to F. Diya (Ameren Missouri), Callaway Plant, Unit 1
- Requests for Relief PR-0J through PR-06, Alternatives to ASME OM CODE Requirements for lnservice Testing for the Fourth Program Interval (TAC Nos. MF2784, MF2785, MF2786, MF2787, MF2788, and MF2789), dated July 15, 2014 (ADAMS Accession No. ML14178A769) 2.
Letter from D. Terao (U. S. Nuclear Regulatory Commission) to C. Naslund (Ameren Missouri), Callaway Plant, Unit 1
- RE: Request for Relief from Code Pump Testing Requirements for Third 10-Year Inservice Testing Interval (TAC Nos. MC8173, MC8174, AND MC8175), December 20, 2005 (ADAMS Accession No. ML053560192) 3.
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 1 0-Year Inservice Testing Interval Regarding Boric Acid Transfer Pump Testing Instrumentation (CAC Nos. MF9526 and MF9527), dated August 29, 2017 (ADAMS Accession No. ML17213A863) 4.
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)
Attachment to 1 0 CFR 50.55a Request Number PR-02 ULNRC-06813 Page 1 of 2 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)
Alternative Provides Acceptable Level of Quality and Safety American Society of Mechanical Engineers (ASME) Code Components Affected Pump Description Code CM Code Number Class Category PBGO5A Centrifugal Charging Pump A 2
Gp B PBGO5B Centrifugal Charging Pump B 2
Gp B
===2.
Applicable Code Edition and Addenda===
ASME OM Code, Operation and Maintenance ofNuclear Power Plants, 2020 Edition, no Addenda
===3.
Applicable Code Requirement===
ISTB-3510, General, paragraph (b), Range, subparagraph (1) states, 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)(J), an alternative is proposed to the above-noted 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 B testing for the centrifugal charging pumps.
The range of the installed analog suction pressure gauges for the centrifugal charging pumps is 0
- 150 psig. Because the reference values for suction pressure during Inservice Testing are less than 50 psig, the instrument range exceeds the requirement of ISTB-351 O(b)(1).
Pump suction pressure indication is used along with pump discharge pressure indication to determine pump differential pressure. Suction pressure reference values for the centrifugal charging pumps during Inservice Testing are between 30 psig and 45 psig.
Based on ISTB-351 O(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 B pump test, the resulting inaccuracies due to suction pressure effects would be +/- I.8 psig (0.02 X 90 psig).
1.
Attachment to 10 CFR 50.55a Request Number PR-02 ULNRC-06813 Page 2 of 2
===5.
Proposed Alternative and Basis for Use===
As an alternative, for the Group B quarterly test, Callaway Energy Center will use the installed analog suction pressure gauge (0 to 1 50 psig) calibrated to less than or equal to +/- I.2% such that the inaccuracies due to suction pressure will be less than that required by the Code (+/- 1.8 psig). The error associated with the suction gauge would then be no greater than +/- 1.8 psi (150
- 0.01 2). Use of the installed suction pressure gauge calibrated to less than +/- 2% (+/- I.2%) is equivalent in terms of Code compliance for the measurement of suction pressure.
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.
===6.
Duration of Proposed Alternative===
The proposed alternative will be utilized for the entire fifth 120-month 1ST Program Interval, which is scheduled to begin on December 20, 2024, and end on December 1 9, 2034.
===7.
Precedents===
1 Letter from M. Markley (U. S. Nuclear Regulatory Commission) to F. Diya (Ameren Missouri), Callaway Plant, Unit I
- 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 1 5, 2014 (ADAMS Accession No. MLJ41 78A769) 2.
Letter from D. Terao (U. S. Nuclear Regulatory Commission) to C. Naslund (Ameren Missouri), Callaway Plant, Unit I
- RE: Request for Relief from Code Pump Testing Requirements for Third 1 0-Year Inservice Testing Interval (TAC Nos. MC81 73, MC81 74, AND MC81 75), December 20, 2005 (ADAMS Accession No. ML053560192) 3.
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 I 0-Year Inservice Testing Interval Regarding Boric Acid Transfer Pump Testing Instrumentation (CAC Nos. MF9526 and MF9527), dated August 29, 2017 (ADAMS Accession No. ML17213A863) 4.
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 lnservice 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)
Attachment to 1 0 CFR 50.55a Request Number PR-03 ULNRC-06813 Page 1 of 4 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(1)
Alternative Provides Acceptable Level of Quality and Safety 1.
American Society of Mechanical Engineers (ASME) Code Components Affected Pump Description Code CM Code Number Class Category PBGO2A Boric Acid Transfer Pump A 3
Gp A PBGO2B Boric Acid Transfer Pump B 3
Gp A
===2.
Applicable Code Edition and Addenda===
ASME OM Code, Operation and Maintenance ofNuclear Power Plants, 2020 Edition, no Addenda
===3.
Applicable Code Requirement===
ISTB-51 21, Group A Test Procedure, subparagraph (c) states, Where it is not practical to vary system resistance, flow rate and pressure shall be determined and compared to their respective reference values.
Table ISTB-3000-1, Inservice Test Parameters, indicates which parameters must be measured for the preservice, Group A, Group B, and comprehensive tests.
===4.
Reason for Request===
Pursuantto 10 CFR 50.55a, Codes and standards, paragraph (z)(1), an alternative is proposed to the above-noted testing requirements of the ASME CM 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 for the Boric Acid Transfer pumps.
The normal test loop for the subject pumps consists of suction from the applicable Boric Acid Tank and discharge through a mini-flow recirculation line back to the Boric Acid Tank; however, flow measuring instrumentation is not installed in this flow path. Installing permanent flow instrumentation would require a costly system modification. The most suitable location for use of a temporary ultrasonic flow meter (UFM) has numerous small bore instrument lines interfering with the use of a ladder to reach the applicable Boric Acid Transfer piping. Callaway would also have to implement new and more costly calibration requirements for the UFM equipment.
The mini-flow recirculation line contains a locked throttle valve set to allow for the minimum pump recirculation flow (approximately 1 5 gpm). The throttled position of this valve is important to provide for the minimum recirculation flow necessary to protect the pump while minimizing the diversion of flow from the primary discharge path to the Charging system to allow for immediate boration in emergency conditions. Unlocking and adjusting the throttle valve on a quarterly basis for lnservice Testing would create the potential for mis-positioning of the throttle valve and thus an adverse effect on system capability. Based on this, the mini-flow recirculation line is considered a fixed resistance flow path.
Attachment to 1 0 CFR 50.55a Request Number PR-03 ULNRC-06813 Page 2 of 4 4.
Reason for Request (Coj)
An alternate test circuit is available in which the flow rate may be measured; however, this flow path requires injection of highly concentrated boric acid solution into the reactor coolant system.
During the quarterly Group A test at normal power operations, this test is highly impractical since severe power level fluctuations would be created which could cause a trip of the reactor.
Performing this test at cold shutdown intervals would also result in excessive boration of the reactor coolant system resulting in potential difficulties and delays in restarting the plant.
===5.
Proposed Alternative and Basis for Use===
As an alternative to measuring differential pressure and flow during the Group A quarterly test, only the differential pressure will be measured and compared to its reference value.
Additionally, vibration measurements will be recorded and compared to their reference values.
The Group A test will be performed using the recirculation flow path shown on Attachment 1, with the throttle valve remaining in its locked position. The reference value is approximately 112 psig at an estimated flow rate of 15 gpm. At 15 gpm, the pump curves exhibit a small degree of slope/linearity, although not nearly as linear as the 75 gpm flow rate during the biennial comprehensive pump test. Because the throttle position of the applicable globe valve (BGV2O9/210) remains in its locked position, the flow rate for the quarterly testing is essentially a fixed value. The lack of flow measurement during quarterly testing does not prevent the detection of pump degradation. With the system resistance fixed, flow can be assumed to be constant and pump degradation may be detected by comparing successive measurements of pump differential pressure. Based on this, it is not warranted to install additional instrumentation to provide for flow measurement.
During the comprehensive pump test when flow may be measured, full spectrum vibration analysis will be performed, which is beyond the vibration analysis required by the Code. The vibration measurements will be recorded and compared to their reference values. Thus, when performing the comprehensive pump test, all required parameters will be measured and compared to their reference values. The performance of full spectrum analysis, in addition to continued Group A quarterly and comprehensive testing, will ensure that an accurate assessment of pump health and operational readiness is determined.
Using the provisions of this relief request as an alternative to the specific requirements of ISTB identified above will provide adequate indication of pump performance and continue to provide an acceptable level of quality and safety.
===6.
Duration of Proposed Alternative===
The proposed alternative will be utilized for the entire fifth I 20-month 1ST Program Interval, which is scheduled to begin on December 20, 2024, and end on December 1 9, 2034.
Attachment to 10 CFR 50.55a Request Number PR-03 ULNRC-068 1 3 Page 3 of 4 7.
Precedent 1
Letter from M. Markley (U. S. Nuclear Regulatory Commission) to F. Diya (Ameren Missouri), Callaway Plant, Unit 1
- Requests for Relief PR-O1 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 1 5, 201 4 (ADAMS Accession No. ML14178A769) 2.
Letter from D. Terao (U. S. Nuclear Regulatory Commission) to C. Naslund (Ameren Missouri), Callaway Plant, Unit 1
- RE: Request for Relief from Code Pump Testing Requirements for Third 1 0-Year Inservice Testing Interval (TAC Nos. MC81 73, MC81 74, AND MC81 75), December 20, 2005 (ADAMS Accession No. ML053560J 92)
Attachment to ULNRC-068 13 10 CFR 50.55a Request Number PR-03 Page4of4 Attachment I Boric Acid Transfer Pump Test Diagram Charging Pump Suction LO.
Locked Throttled Minimum Flow Recirc Line BGVI 48(166)
BGV1 55(167)
BGV147(1 65)
From other Boric Acid Boric Acid Transfer Transfer PumpA(B)
PumpA(B)