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Category:Letter
MONTHYEARML23234A1232024-03-28028 March 2024 US600 DC and SDA 50.46 Exemption - Letter ML23180A1512023-06-29029 June 2023 LLC, Request for Exemption to the Reporting Requirements of 10 CFR 50.46(a)(3) ML21102A3072021-04-15015 April 2021 OEDO-21-00155 - Lessons-Learned from the Design Certification Review of the NuScale Power, LLC, Small Modular Reactor ML21050A4312021-02-19019 February 2021 LLC - Lessons-Learned from the Design Certification Review of the NuScale Power, LLC Small Modular Reactor ML20247J5642020-09-11011 September 2020 Standard Design Approval for the NuScale Power Plant Based on the NuScale 600 Standard Plant Design Certification Application ML20231A8042020-08-28028 August 2020 Final Safety Evaluation Report for the NuScale Standard Plant Design ML20224A4602020-08-25025 August 2020 OEDO-20-00292-Response to the Advisory Committee on Reactor Safeguards Letter on NuScale Power, LLC, Report on the Safety Aspects of the NuScale Small Modular Reactor ML20231A5982020-08-25025 August 2020 OEDO-20-00285_NuScale Area of Focus - Boron Redistribution ML20210M8902020-07-29029 July 2020 Area of Focus - Boron Redistribution ML20195A5872020-07-13013 July 2020 LLC - Submittal of Draft Operator Licensing and Examination Standard for NuScale Small Modular Reactors ML20195C7662020-07-13013 July 2020 LLC Request for Standard Design Approval Based on the NuScale Standard Plant Design Certification Application ML20192A3262020-07-10010 July 2020 LLC, Submittal of Environmental Report: Revision Status ML20198M3932020-07-0202 July 2020 LLC Submittal of Revised Packing Slip for Submittal of the NuScale Standard Plant Design Certification Application, Revision 4.1, Dated June 19, 2020 ML20174A3472020-07-0101 July 2020 OEDO-20-00220 - Area of Focus - Probabilistic Risk Assessment and Emergency Core Cooling System Valve Performance ML20184A2872020-07-0101 July 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Boron Redistribution and General Design Criterion 33, PM-0720-70785, Revision 0 ML20181A2702020-06-22022 June 2020 Final SER for NuScale TR-0516-49422 Loss-of-Coolant Analysis Model, Rev 2 (Letter) ML20181A4322020-06-22022 June 2020 Final SER for NuScale TR-0516-49416 NON-Loss-of-Coolant Analysis Model, Rev 3 (Letter) ML20198M3922020-06-19019 June 2020 LLC - Submittal of the NuScale Standard Plant Design Certification Application, Revision 4.1 ML20171A7312020-06-19019 June 2020 LLC, Submittal of Riser Flow Hole Methodology and Associated Changes to Final Safety Analysis Report Incorporating Its Use ML20157A2232020-06-0303 June 2020 Letter to NuScale Requesting -A for TR-0716-50350 ML20150C5172020-05-29029 May 2020 LLC Submittal of Presentation Materials Entitled NRC Public Meeting Presentation: Boron Redistribution and Associated Design and DCA Changes, PM-0620-70336, Revision 0 ML20150E1772020-05-29029 May 2020 LLC - Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Extended Dhrs Operation and RCS Boron Redistribution (Closed Session), PM-0620-70243, Revision 0 ML20150C8812020-05-29029 May 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Boron Redistribution and Associated Design and DCA Changes, PM-0620-70244, Revision 0 ML20149M1192020-05-28028 May 2020 LLC Summary of Impacts to Erai 8930 Response and Discussion on the Exemption from General Design Criterion 33 ML20141L8082020-05-20020 May 2020 LLC Submittal of Containment Response Analysis Methodology Technical Report, TR-0516-49084, Revision 3 ML20141N0122020-05-20020 May 2020 LLC Submittal of Changes to Final Safety Analysis Report, Section 6.2, Containment Systems, Section 6.3, Emergency Core Cooling System, and Technical Report TR-0516-49084, Containment Response Analysis Methodology Technical Report ML20141L8162020-05-20020 May 2020 LLC, Submittal of Long-Term Cooling Methodology, TR-0916-51299, Revision 3 ML20141M7642020-05-20020 May 2020 LLC Submittal of Nuclear Steam Supply System Advanced Sensor Technical Report, TR-0316-22048, Revision 3 ML20141L7872020-05-20020 May 2020 LLC, Submittal of Second Updates to Standard Plant Design Certification Application, Revision 4 ML20141M1142020-05-20020 May 2020 LLC Submittal of NuScale Instrument Setpoint Methodology Technical Report, TR-0616-49121, Revision 3 ML20141L8042020-05-20020 May 2020 LLC Submittal of Technical Specifications Regulatory Conformance and Development, TR-1116-52011, Revision 4 ML20128J3162020-05-18018 May 2020 OEDO-20-00167 - Response to the ACRS Letter on Combustible Gas Monitoring ML20133K0882020-05-12012 May 2020 LLC, Submittal of Presentation Materials Entitled Public Meeting Presentation: Topic - Emergency Core Cooling System (ECCS) Boron Distribution (Closed Session), PM-0420-69512, Revision 0 ML20133J9142020-05-11011 May 2020 LLC Submittal of Presentation Materials Entitled Public Meeting Presentation: Topic - Emergency Core Cooling System (ECCS) Boron Distribution, PM-0420-69511, Revision 0 ML20112F4552020-05-0101 May 2020 LLC, Design Certification Application Phases 5 and 6 Review Status ML20107F8492020-05-0101 May 2020 OEDO-2000140 - NuScale Area of Focus - Helical Tube Steam Generator Design ML20104A0792020-04-27027 April 2020 OEDO-20-00115 - Safety Evaluation Report for Topical Report TR-0516-49416, Revision 2, Non-Loss-of-Coolant Accident Analysis Methodology ML20099H0802020-04-0808 April 2020 LLC - Submittal of Presentation Materials Entitled NRC Public Meeting: Revisions to Nuscale'S EPZ Sizing Methodology Topical Report, PM-0420-69598, Revision 0 ML20098G2372020-04-0707 April 2020 Nuscale Power, LLC Submittal of Remaining Closure Items for the Emergency Core Cooling System Valve Failure Mode Effects Analysis Audit Items ML20097F1922020-04-0606 April 2020 Nuscale Power, LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: Nuscale Topic - Hydrogen/Oxygen Monitoring, PM-0420-69518, Revision 0 ML20094H6742020-04-0303 April 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation NuScale Topic-Probabilistic Risk Assessment with a Focus on Emergency Core Cooling System Analysis PM-0420-69559, Revision 0 ML20092L8992020-04-0101 April 2020 LLC - Submittal of Updates to Standard Plant Design Certification Application, Revision 4 ML20072M6682020-03-30030 March 2020 Response to NuScale Letter Dated February 24, 2020, on Planned SDA Application Content ML20072H3332020-03-0909 March 2020 LLC - Submittal of Presentation Materials Entitled Public Meeting Presentation: Topic - Emergency Core Cooling System (ECCS) Boron Distribution, PM-0320-69218, Revision 0 ML20057D9002020-03-0606 March 2020 Submittal of Errata to Final SE for NuScale Power, LLC TR-1010-859-NP-A, Quality Assurance Program Description for the NuScale Power Plant ML20062F7262020-03-0505 March 2020 Request for Withholding Information from Public Disclosure for Nuscale Power, LLC Letter Public ML20069A9632020-03-0404 March 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topical Report, Loss-of-Coolant Accident Evaluation Model, PM-0320-69138, Revision 0 ML20069A1772020-03-0404 March 2020 LLC - Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topical Report-Non-Loss-of-Coolant Accident, PM-0320-69141, Revision 0 ML20069A1572020-03-0404 March 2020 LLC - Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topical Report-Rod Ejection Accident Methodology, PM-0320-69146, Revision 0 ML20066G2802020-03-0303 March 2020 LLC, Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale Topic - Hydrogen Monitoring, PM-0220-69071, Revision 0 2024-03-28
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April 27, 2020 Matthew W. Sunseri, Chairman Advisory Committee on Reactor Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
SAFETY EVALUATION REPORT FOR TOPICAL REPORT TR-0516-49416, REVISION 2, NON-LOSS-OF-COOLANT ACCIDENT ANALYSIS METHODOLOGY
Dear Mr. Sunseri:
In your letter dated March 25, 2020 (Agencywide Documents Access and Management System Accession No. ML20085K048), the Advisory Committee on Reactor Safeguards (ACRS or the Committee) reported on the Committees review of the U.S. Nuclear Regulatory Commission (NRC) staffs safety evaluation (SE) of the NuScale Power, LLC (NuScale), Topical Report TR-0516-49416, Revision 2, Non-Loss-Of-Coolant Accident Analysis Methodology, issued November 30, 2019. I appreciate the time and effort that the ACRS has devoted to this review, as reflected in meetings with the ACRS Subcommittee on February 19-20, 2020, and the ACRS Full Committee on March 5, 2020.
Your letter offered the following conclusions and recommendations:
- 1. The Non-Loss-Of-Coolant Accident (non-LOCA) Analysis Methodology topical report, with the limitations and conditions imposed by the staff SE report, provides an acceptable methodology to analyze anticipated occurrences, infrequent events, and postulated accidents for the NuScale Power Module (NPM).
- 2. The staff should include an additional condition that allows application of this topical report with any critical heat flux (CHF) correlation approved for use in NPM applications.
- 3. The staffs SE report should be issued with this additional condition.
With regard to these conclusions and recommendations, the NRC staffs review of the prescreening CHF correlation employed in the non-LOCA methodology includes an examination of various references1,2,3. The NRC staff has concluded that the behavior of the prescreening CHF correlation noted by the ACRS is expected, and the references support, the validity of the 1 Todreas, Neil E., and Mujid Kazimi, Nuclear Systems, Volume 1, 2nd Edition, Boca Raton, FL: CRC Press (2011).
2 RELAP5-3D© Code Manual, Volume IV: Models and Correlations, Revision 4.3, The RELAP5-3D© Code Development Team, Idaho National Laboratory (October 2015).
3 Hejzlar, Pavel, and Neil E. Todreas, Consideration of critical heat flux margin prediction by subcooled or low quality critical heat flux correlations, Nuclear Engineering and Design, Volume 163, Issues 1-2, pp. 215-223 (June 1996).
M. Sunseri correlation for comparing relative minimum CHF ratio values (e.g., for identifying limiting CHF cases) but not for calculating absolute values (e.g., for quantifying thermal margins).
The prescreening CHF correlation described in the non-LOCA topical report and the NSP correlations, implemented in the VIPRE-01 subchannel code, produce similar trends given variations in the input parameters as shown in the non-LOCA topical report. This information was confirmed by the NRC staffs audit (ADAMS Accession No. ML19039A090). The NRC staff, therefore, finds the prescreening CHF correlation to be acceptable because it can be reasonably expected to identify the limiting CHF cases to be further analyzed using VIPRE-01.
The NRC staff emphasizes that the non-LOCA prescreening CHF correlation is used for relative comparisons only and is not used to determine thermal margins.
While the NRC staff understands the ACRSs desire for flexibility in the prescreening CHF correlation, reflected in Conclusions and Recommendations 2 and 3, the NRC staff notes that the applicant has not requested NRC approval of other CHF correlations for prescreening. As such, the NRC staff has not reviewed other CHF correlations for this purpose. The condition and limitation proposed by ACRS would necessitate additional justification from the applicant, and review findings by the NRC staff, that other CHF correlations approved for NPM applications can reliably identify the limiting CHF cases relative to the NSP correlations in VIPRE-01. The NRC staff does not believe that that the proposed condition and limitation is needed given that a methodology acceptable to the NRC staff already exists. Should an applicant or licensee wish to use a different approach as part of its non-LOCA CHF prescreening process in the future, it should submit a change to the topical report for the NRC staffs review and approval.
The NRC staff appreciates the ACRSs review and will issue the SE with no additional conditions and limitations by June 2020.
Sincerely, Robert Digitally signed by Robert M. Taylor M. Taylor Date: 2020.04.27 08:40:46 -04'00' Ho Nieh, Director Office of Nuclear Reactor Regulation Docket No.: 52-048 cc: Chairman Svinicki Commissioner Baran Commissioner Caputo Commissioner Wright SECY
Pkg: ML20091K561 Ltr: ML20104A079 *via e-mail NRR-106 OFFICE DNRL/NRLB: PM DNRL/NRLB: LA QTE DSS/SNRB: BC NAME MJohnson* CSmith* QTE* RPatton*
DATE 04/09/2020 04/13/2020 04/15/2020 04/15/2020 OFFICE DNRL/NRLB: BC DSS:D DNRL: D NRR: D*
NAME MDudek* JDonoghue* ABradford* HNieh (RTaylor for)
DATE 04/15/2020 04/17/2020 04/17/2020 4/27/2020