ML25051A088
| ML25051A088 | |
| Person / Time | |
|---|---|
| Site: | 05200050 |
| Issue date: | 02/20/2025 |
| From: | Shaver M NuScale |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| Shared Package | |
| ML25051A087 | List: |
| References | |
| RAIO-179683 | |
| Download: ML25051A088 (1) | |
Text
RAIO-179683 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360.0500 Fax 541.207.3928 www.nuscalepower.com February 20, 2025 Docket No.52-050 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738
SUBJECT:
NuScale Power, LLC Response to NRC Request for Additional Information No. 037 (RAI-10357 R1) on the NuScale Standard Design Approval Application
REFERENCE:
NRC Letter to NuScale, Request for Additional Information No. 037 (RAI-10357 R1), dated October 17, 2024 The purpose of this letter is to provide the NuScale Power, LLC (NuScale) response to the referenced NRC Request for Additional Information (RAI).
The enclosure to this letter contains the NuScale response to the following RAI question from NRC RAI-10357 R1:
15.0.5-4 is the proprietary version of the NuScale Response to NRC RAI No. 037 (RAI-10357 R1, Question 15.0.5-4). NuScale requests that the proprietary version be withheld from public disclosure in accordance with the requirements of 10 CFR § 2.390.
The enclosed affidavit (Enclosure 3) supports this request. Enclosure 2 is the nonproprietary version of the NuScale response.
This letter makes no regulatory commitments and no revisions to any existing regulatory commitments.
If you have any questions, please contact Amanda Bode at 541-452-7971 or at abode@nuscalepower.com.
I declare under penalty of perjury that the foregoing is true and correct. Executed on February 20, 2025.
Sincerely, Mark W. Shaver Director, Regulatory Affairs NuScale Power, LLC
RAIO-179683 Page 2 of 2 02/20/2025 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360.0500 Fax 541.207.3928 www.nuscalepower.com Distribution:
Mahmoud Jardaneh, Chief New Reactor Licensing Branch, NRC Getachew Tesfaye, Senior Project Manager, NRC Stacy Joseph, Senior Project Manager, NRC
- NuScale Response to NRC Request for Additional Information RAI-10357 R1, Question 15.0.5-4, Proprietary Version : NuScale Response to NRC Request for Additional Information RAI-10357 R1, Question 15.0.5-4, Nonproprietary Version : Affidavit of Mark W. Shaver, AF-179684
RAIO-179683 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360.0500 Fax 541.207.3928 www.nuscalepower.com NuScale Response to NRC Request for Additional Information RAI-10357 R1, Question 15.0.5-4, Proprietary Version
RAIO-179683 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360.0500 Fax 541.207.3928 www.nuscalepower.com NuScale Response to NRC Request for Additional Information RAI-10357 R1, Question 15.0.5-4, Nonproprietary Version
Response to Request for Additional Information Docket: 052000050 RAI No.: 10357 Date of RAI Issue: 10/17/2024 NRC Question No.: 15.0.5-4 Issue Section 15.0.5.3.2 describes the long-term cooling minimum collapsed liquid level analyses. The Steam Generator Tube Failure (SGTF) event is identified as the most limiting event for minimum collapsed liquid level above the top of active fuel. The collapsed liquid level for the SGTF case is 0.23 ft (2.76 inches) above the top of active fuel. This is lower than the other limiting events, breaks outside of containment, which have a calculated collapsed liquid level of at least 1.57 ft (18.8 inches) above the top of active fuel.
During its audit, the staff observed that the SGTF event appears to be modeled differently with NRELAP5 than how it is modeled for the SGTF event presented in SDA Section 15.6.3 using the methodology from the non-LOCA LTR. Given the minimal margin in the collapsed liquid level for the SGTF event presented in SDA Section 15.0.5, the apparent difference in modeling from the SGTF event presented in 15.6.3 and the notable difference between the results from the other limiting long term cooling cases the staff is seeking information on the modeling of the event and clarification of the modeling in the SDA. Additionally, the staff is seeking information and clarification of assumptions, including conservatisms, used.
Information Requested In addition to the expected general plant response that is already provided in the FSAR, revise the FSAR to describe how the SGTF case is modeled, relative to the break outside containment cases, and an explanation of why the SGTF case has a lower collapsed liquid level. Revise the FSAR to describe assumptions and conservatism in the modeling of the SGTF case.
NuScale Nonproprietary NuScale Nonproprietary
NuScale Response:
The long-term cooling analysis is revised such that the steam generator tube failure (SGTF) event is modeled similar to the modeling for the SGTF presented in final safety analysis report Section 15.6.3. As a result of this revision, the minimum collapsed liquid level during the limiting SGTF event is ((2(a),(c) The SGTF remains the most limiting event for minimum level, but the revised SGTF modeling results in increased margin for minimum collapsed liquid level above the top of active fuel as shown in Table 1. Changes in the limiting results of other events in Table 1 are the result of model changes unrelated to SGTF modeling. (( }}2(a),(c) in accordance with the updated extended passive cooling evaluation model requirement, previously provided in response to audit item A-XPC.LTR-1(b). Table 1: Limiting Collapsed Liquid Level above Top of Active Fuel during Emergency Core Cooling System Cooldown Event Minimum Collapsed Liquid Level above Top of Fuel (ft) Time of Minimum Level (seconds) Discharge line break inside containment 3.07 84,520 Discharge line break outside containment 2.12 64,990 Injection line break inside containment 2.99 85,951 Injection line break outside containment 2.20 66,469 SGTF 2.03 80,443 The revised calculation, EC-120490, Revision 2, NPM-20 Long-Term Cooling Analysis, is provided for NRC audit with this response. Given the revised modeling of the SGTF event, this request for additional information question is no longer applicable. Updates to Section 15.0.5 of the final safety analysis report, incorporating the revised long-term cooling analysis, will be provided with Revision 2 of the Standard Design Approval Application. NuScale Nonproprietary NuScale Nonproprietary
Impact on US460 SDAA: There are no impacts to US460 SDAA as a result of this response. NuScale Nonproprietary NuScale Nonproprietary
RAIO-179683 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360.0500 Fax 541.207.3928 www.nuscalepower.com Affidavit of Mark W. Shaver, AF-179684
AF-179684 Page 1 of 2
NuScale Power, LLC AFFIDAVIT of Mark W. Shaver I, Mark W. Shaver, state as follows: (1) I am the Director of Regulatory Affairs of NuScale Power, LLC (NuScale), and as such, I have been specifically delegated the function of reviewing the information described in this Affidavit that NuScale seeks to have withheld from public disclosure, and am authorized to apply for its withholding on behalf of NuScale. (2) I am knowledgeable of the criteria and procedures used by NuScale in designating information as a trade secret, privileged, or as confidential commercial or financial information. This request to withhold information from public disclosure is driven by one or more of the following: (a) The information requested to be withheld reveals distinguishing aspects of a process (or component, structure, tool, method, etc.) whose use by NuScale competitors, without a license from NuScale, would constitute a competitive economic disadvantage to NuScale. (b) The information requested to be withheld consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), and the application of the data secures a competitive economic advantage, as described more fully in paragraph 3 of this Affidavit. (c) Use by a competitor of the information requested to be withheld would reduce the competitors expenditure of resources, or improve its competitive position, in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product. (d) The information requested to be withheld reveals cost or price information, production capabilities, budget levels, or commercial strategies of NuScale. (e) The information requested to be withheld consists of patentable ideas. (3) Public disclosure of the information sought to be withheld is likely to cause substantial harm to NuScales competitive position and foreclose or reduce the availability of profit-making opportunities. The accompanying Request for Additional Information response reveals distinguishing aspects about the response by which NuScale develops its NuScale Power, LLC Response to NRC Request for Additional Information (RAI No. 10357 R1, Question 15.0.5-4) on the NuScale Standard Design Approval Application. NuScale has performed significant research and evaluation to develop a basis for this response and has invested significant resources, including the expenditure of a considerable sum of money. The precise financial value of the information is difficult to quantify, but it is a key element of the design basis for a NuScale plant and, therefore, has substantial value to NuScale. If the information were disclosed to the public, NuScales competitors would have access to the information without purchasing the right to use it or having been required to undertake a similar expenditure of resources. Such disclosure would constitute a misappropriation of NuScales intellectual property, and would deprive NuScale of the opportunity to exercise its competitive advantage to seek an adequate return on its investment. (4) The information sought to be withheld is in the enclosed response to NRC Request for Additional Information RAI 10357 R1, Question 15.0.5-4. The enclosure contains the designation Proprietary at the top of each page containing proprietary information. The information considered by NuScale to be proprietary is identified within double braces, (( }} in the document.
AF-179684 Page 2 of 2 (5) The basis for proposing that the information be withheld is that NuScale treats the information as a trade secret, privileged, or as confidential commercial or financial information. NuScale relies upon the exemption from disclosure set forth in the Freedom of Information Act (FOIA), 5 USC § 552(b)(4), as well as exemptions applicable to the NRC under 10 CFR §§ 2.390(a)(4) and 9.17(a)(4). (6) Pursuant to the provisions set forth in 10 CFR § 2.390(b)(4), the following is provided for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld: (a) The information sought to be withheld is owned and has been held in confidence by NuScale. (b) The information is of a sort customarily held in confidence by NuScale and, to the best of my knowledge and belief, consistently has been held in confidence by NuScale. The procedure for approval of external release of such information typically requires review by the staff manager, project manager, chief technology officer or other equivalent authority, or the manager of the cognizant marketing function (or his delegate), for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside NuScale are limited to regulatory bodies, customers and potential customers and their agents, suppliers, licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or contractual agreements to maintain confidentiality. (c) The information is being transmitted to and received by the NRC in confidence. (d) No public disclosure of the information has been made, and it is not available in public sources. All disclosures to third parties, including any required transmittals to NRC, have been made, or must be made, pursuant to regulatory provisions or contractual agreements that provide for maintenance of the information in confidence. (e) Public disclosure of the information is likely to cause substantial harm to the competitive position of NuScale, taking into account the value of the information to NuScale, the amount of effort and money expended by NuScale in developing the information, and the difficulty others would have in acquiring or duplicating the information. The information sought to be withheld is part of NuScales technology that provides NuScale with a competitive advantage over other firms in the industry. NuScale has invested significant human and financial capital in developing this technology and NuScale believes it would be difficult for others to duplicate the technology without access to the information sought to be withheld. I declare under penalty of perjury that the foregoing is true and correct. Executed on February 20, 2025. Mark W. Shaver}}