ML24344A077
| ML24344A077 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 12/12/2024 |
| From: | David Wrona Plant Licensing Branch II |
| To: | Coffey B Florida Power & Light Co |
| Buckberg, P. NRR/DORL 415-1383 | |
| References | |
| EPID L-2024-LLR-0029 | |
| Download: ML24344A077 (1) | |
Text
December 12, 2024 Robert Coffey Executive Vice President, Nuclear and Chief Nuclear Officer Florida Power & Light Company Mail Stop: EX/JB 700 Universe Blvd.
Juno Beach, FL 33408
SUBJECT:
TURKEY POINT NUCLEAR GENERATING, UNIT NOS. 3 AND 4 - PROPOSED ALTERNATIVE TO THE REQUIREMENTS OF THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS OPERATION AND MAINTENANCE CODE (EPID L-2024-LLR-0029)
Dear Robert Coffey:
By letter dated April 17, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24108A091), Florida Power and Light Company (FPL) (the licensee) submitted Alternative Request PR-02 to the U.S. Nuclear Regulatory Commission (NRC) proposing the use of an alternative to specific inservice testing (IST) requirements in the 2020 Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Operation and Maintenance of Nuclear Power Plants, 2020 Edition (ASME OM Code) for Turkey Point Nuclear Generating (Turkey Point), Unit Nos. 3 and 4, associated with the Sixth 10-year Interval IST Program.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR)
Section 50.55a(z)(1), Acceptable level of quality and safety, the licensee requested to use the proposed Alternative Request PR-02 on the basis that the alternative provides an acceptable level of quality and safety.
The NRC staff has reviewed the subject request and concludes, as set forth in the enclosed safety evaluation, that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(1). Therefore, the NRC staff authorizes the use of Alternative Request PR-02, at Turkey Point, Unit No. 3, during the Sixth Interval IST Program, which is scheduled to begin on February 22, 2025, and end on February 21, 2035, and at Turkey Point, Unit No. 4, Sixth Interval IST Program, which is scheduled to begin on April 15, 2025, and end on April 14, 2035.
All other ASME OM Code, Section IST requirements for which an alternative was not specifically requested and authorized remain applicable, including third-party review by the authorized nuclear inservice inspector.
If you have any questions, please contact Perry Buckberg (NRCs licensing project manager for Turkey Point) at (301) 415-1383 or Perry.Buckberg@nrc.gov.
Sincerely, David Wrona, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-250 and 50-251
Enclosure:
Safety Evaluation cc: Listserv DAVID WRONA Digitally signed by DAVID WRONA Date: 2024.12.12 16:25:14 -05'00'
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PROPOSED ALTERNATIVE REQUEST PR-02 SIXTH INTERVAL INSERVICE TESTING PROGRAM FLORIDA POWER AND LIGHT COMPANY TURKEY POINT NUCLEAR GENERATING, UNIT NOS. 3 AND 4 DOCKET NOS. 50-250 AND 50-251
1.0 INTRODUCTION
By letter dated April 17, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24108A091), Florida Power and Light Company (FPL) (the licensee) submitted Alternative Request PR-02 to the U.S. Nuclear Regulatory Commission (NRC) proposing the use of an alternative to specific inservice testing (IST) requirements in the 2020 Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Operation and Maintenance of Nuclear Power Plants, 2020 Edition (ASME OM Code) for Turkey Point Nuclear Generating (Turkey Point), Unit Nos. 3 and 4, associated with the Sixth 10-year Interval IST Program.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(z)(1), Acceptable level of quality and safety, the licensee requested to implement Alternative Request PR-02 on the basis that the proposed alternative would provide an acceptable level of quality and safety in lieu of certain requirements in the ASME OM Code as incorporated by reference in 10 CFR 50.55a for specific valves at Turkey Point.
The Turkey Point, Unit No. 3, Sixth IST Program interval is scheduled to begin February 22, 2025, and is scheduled to end on February 21, 2035. The Turkey Point, Unit No. 4, Sixth IST Program interval is scheduled to begin April 15, 2025, and is scheduled to end on April 14, 2035. The licensee proposed that Alternative Request PR-2 be authorized for the Sixth IST Interval Program at Turkey Point, Unit Nos. 3 and 4.
2.0 REGULATORY EVALUATION
2.1 Regulations The NRC regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, state, in part, that, 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 [10 CFR 50.55a](f)(2) and (3) of this section and that are incorporated by reference in paragraph [10 CFR 50.55a](a)(1)(iv) of this section, to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The NRC regulations in 10 CFR 50.55a(z), Alternatives to codes and standards requirements, state:
Alternatives to the requirements of [10 CFR 50.55a](b) through (h) or portions thereof may be used when authorized by the Director, Office of Nuclear Reactor Regulation. A proposed alternative must be submitted and authorized prior to implementation. The applicant or licensee must demonstrate that:
(1) Acceptable level of quality and safety. The proposed alternative would provide an acceptable level of quality and safety; or (2) Hardship without a compensating increase in quality and safety. Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
3.0 TECHNICAL EVALUATION
3.1 Alternative Request PR-02 Applicable OM Code Edition The applicable Code of record for the Sixth Interval IST Program at Turkey Point, Unit Nos. 3 and 4, is the 2020 Edition of ASME OM Code as incorporated by reference in 10 CFR 50.55a.
Applicable ASME OM Code Components Table 1 below lists the Residual Heat Removal (RHR) pumps at Turkey Point for which alternative testing is being requested:
Table 1 Pump Number Description ASME Code Class OM Code Category (Note 1) 3P210A 3A RHR Pump 2
Group A 3P210B 3B RHR Pump 2
Group A 4P210A 4A RHR Pump 2
Group A 4P210B 4B RHR Pump 2
Group A Note 1: Category A pumps - Pumps that are operated continuously or routinely during normal operation, cold shutdown, or refueling operations (
Reference:
ISTB-2000, Supplement Definitions).
Applicable OM Code Requirements The IST requirements in the ASME OM Code, 2020 Edition, as incorporated by reference in 10 CFR 50.55a, related to this alternative request are as follows:
ASME OM Code, Subsection ISTB, Inservice Testing of Pumps in Water-Cooled Reactor Nuclear Power Plants - Pre-2000 Plants, paragraph ISTB-3500, Data Collection, paragraph ISTB-3510, General, subparagraph (b), Range, subsubparagraph (1) states that the full-scale range of each analog instrument shall be not greater than three times the reference value.
ASME OM Code, Subsection ISTB, paragraph ISTB-3510, subparagraph (a), Accuracy, states, in part, that Instrument accuracy shall be within the limits of Table ISTB-3510-1.
Subparagraph ISTB-3510(a) also states that If a parameter is determined by analytical methods instead of measurement, then the determination shall meet the parameter accuracy requirements of Table ISTB 3510-1 (e.g., flow rate determination shall be accurate to within +/- 2% of actual).
Licensees Proposed Alternative The licensee proposes to use the existing permanently installed Turkey Point RHR pump instrumentation. This currently installed instrumentation, while not meeting the range requirements of ISTB-3510(b)(1), exceeds the ASME OM Code required accuracy of 2 percent required for the Group A quarterly tests of the RHR pumps. This request does not apply to the RHR comprehensive pump testing.
Licensees Reason for Request In its letter dated April 17, 2024, the licensee states in part:
At Turkey Point the RHR pumps are considered Group A pumps. The installed suction and discharge pressure gauges are sized to accommodate pressures up to 600 psig [pounds per square inch gage] expected under standby, cold shutdown, and emergency operation modes. The instrument range is 0 to 600 psig. During the quarterly testing the typical RHR pump differential pressure (delta-P) is approximately 142 psig (discharge pressure approximately 160 psig and suction pressure approximately 18 psig) and as a result the installed suction and discharge pressure instrument ranges exceed the maximum Code allowed range of three times the reference value for the quarterly surveillances.
Licensees Basis for Use of Proposed Alternative Table 2, Comparison of Pressure Instrument Ranges and Accuracies, presents a comparison between the permanently installed pressure gauges on the suction and discharge piping of the RHR pumps along with the ASME OM Code required ranges and accuracies for the Group A quarterly tests.
The existing RHR suction and discharge pressure instruments are calibrated to an accuracy of
+/- 0.25 percent and are of the twice around type such that they may accurately indicate pressure over all modes of RHR operations (Shutdown Cooling and Emergency Core Cooling).
The instrument range on the first revolution is 0 to 300 psig and 300 to 600 psig on the second revolution.
Suction Pressure Suction pressure measurements are recorded and used to derive the pump differential pressure through calculation. The accuracy of the suction pressure measurement normally has little effect on the results of this calculation since, generally, the pump discharge pressure exceeds the suction pressure by 6 to 7 times the reference value. When determining pump differential pressure (DP), the RHR pump DP is approximately 142 psi (discharge pressure approximately 160 psig, while suction pressure is approximately 18 psig). The maximum effect of suction pressure inaccuracies is 0.25 percent x 600 psig, or 1.5 psig. The Code required gauge range for this suction pressure reference value (18 psig) would be 0 to 54 psig. The Code accuracy requirement of 2 percent would cause a maximum inaccuracy of 2 percent x 54 psig, or 1.1 psig, as presented in Table 2.
Discharge Pressure Discharge pressure measurements are also recorded and used to derive the pump differential pressure through calculation. The maximum effect of the discharge pressure inaccuracies is 0.25 percent x 600 psig, or 1.5 psig. The Code required gauge range for the nominal discharge pressure reference value (160 psig) would be to 480 psig. The Code accuracy requirement of 2 percent would cause a maximum inaccuracy of 2 percent x 480 psig, or 9.6 psig, as presented in Table 2.
Combination Based on the inaccuracies of the suction and discharge pressure gauges (+/- 1.5 psig), the largest possible error in the differential pressure calculation is +/- 3 psig. Use of gauges with ASME OM Code required ranges, and applying the Code accuracy requirements, the largest possible inaccuracies would be 1.1 psig + 9.6 psig, or 10.7 psig, as presented in Table 2.
Therefore, the use of permanently installed pressure instruments would reduce the overall instrument inaccuracies with respect to the differential pressure for the quarterly test from 10.7 psig to 3.0 psig.
Using the provisions of this request (to use the permanently installed pressure instrumentation) as an alternative to the specific requirements of ISTB-3510(b)(1) identified above for the RHR Group A quarterly tests will provide adequate indication of pump performance and continue to provide an acceptable level of quality and safety.
Table 2. Comparison of Pressure Instrument Ranges and Accuracies Suction Pressure Gauge Range Accuracy Suction Pressure Accuracy Turkey Point 0-600 psig 0.25%
1.5 psig Group A 0-54 psig (Note 1) 2.0%
1.1 psig Note 1: Suction Pressure Reference = 18 psig, ISTB-3510(b)(1) Maximum Range = 3 x Reference = 54 psig Discharge Pressure Gauge Range Accuracy Discharge Pressure Accuracy Turkey Point 0-600 psig 0.25%
1.5 psig Group A 0-480 psig (Note 2) 2.0%
9.6 psig Note 2: Suction Pressure Reference = 160 psig, ISTB-3510(b)(1) Maximum Range = 3 x Reference = 480 psig Combination - Differential Pressure Suction Gauge Range Suction Pressure Accuracy Discharge Gauge Range Discharge Pressure accuracy Total Inaccuracy (psig)
Turkey Point 0-600 psig 0.25%
(1.5 psig) 0-600 psig 0.25%
(1.5 psig) 3.0 Group A 0-54 psig 2.0%
(1.1 psig) 0-480 psig 2.0%
(9.6 psig) 10.7 3.2
NRC Staff Evaluation
In Alternative Request PR-02, the licensee requests an alternative to the ASME OM Code instrument accuracy requirements of ASME OM Code, Subsection ISTB, paragraph ISTB-3510(b)(1), for the RHR pumps 3P210A, 3P210B and 4P210A and 4P210B suction and discharge pressure instruments during quarterly Group A tests. Paragraph ISTB-3510(b)(1) requires that the full-scale range of each instrument be no greater than three times the reference value. The licensee proposes to use the installed suction and discharge pressure gauges that do not meet this requirement.
For Group A tests, the ASME OM Code requires instrument accuracy to be within 2 percent of full-scale and the full-scale range of each instrument be no greater than three times the reference value. The combination of these two requirements results in an effective accuracy requirement of +/- 6 percent of the reference value suction and discharge pressure measurements and a higher maximum inaccuracy for the calculated delta pressure value. The licensee has demonstrated in Table 2 that by using gauges with higher accuracy than required by ASME OM Code with ranges that would otherwise exceed what the Code allows, the overall accuracy required by the Code for the combined DP value can be met or exceeded.
Based on its review, the NRC staff has determined that the licensees proposal in Alternative Request PR-02 to use the existing permanently installed Turkey Point RHR pump instrumentation for quarterly Group A tests of the RHR pumps within the scope of this request provides an acceptable level of quality and safety because the installed instrumentation provides a measurement accuracy that exceeds the resulting measurement accuracy of
+/-6 percent for Group A tests if ASME OM Code requirements are met. Therefore, the staff finds that the licensee has met the requirements in 10 CFR 50.55a(z)(1) in Alternative Request PR-02 for Turkey Point, Unit Nos. 3 and 4.
4.0 CONCLUSION
As set forth above, the NRC staff has determined that Alternative Request PR-02 as described in the licensee letter dated April 17, 2024, provides an acceptable level of quality and safety for the proposed testing for the specified pumps at Turkey Point, Unit Nos. 3 and 4, during the Sixth Interval IST Program. Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(1). Therefore, the NRC staff authorizes the use of Alternative Request PR-02, at Turkey Point, Unit No. 3, during the Sixth Interval IST Program, which is scheduled to begin on February 22, 2025, and to end on February 21, 2035, and at Turkey Point, Unit No. 4, Sixth Interval IST Program, which is scheduled to begin on April 15, 2025, and to end on April 14, 2035.
All other ASME OM Code requirements as incorporated by reference in 10 CFR 50.55a for which relief or an alternative was not specifically requested, and granted or authorized (as appropriate), in the subject request remain applicable.
Principal Contributors: Bedi, NRR T. Scarbrough, NRR Date: December 12, 2024
ML24344A077 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DEX/EMIB/BC NRR/DORL/LPL2-2/BC NAME PBuckberg ABaxter SBailey DWrona DATE 12/5/2024 12/10/2024 12/4/2024 12/12/2024