ML19094B870

LLC Response to NRC Request for Additional Information No. 521 (Erai No. 9672) on the NuScale Design Certification Application

ML19094B870
Person / Time
Site:	NuScale
Issue date:	04/04/2019
From:	Rad Z NuScale
To:	Document Control Desk, Office of New Reactors
References
RAIO-0419-65064
Download: ML19094B870 (10)

Text

RAIO-0419-65064 April 04, 2019 Docket No.52-048 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.

521 (eRAI No. 9672) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 521 (eRAI No. 9672)," dated March 22, 2019

2. Letter LO-0817-55236 from NuScale Power, LLC to Nuclear Regulatory Commission, "NuScale Power, LLC Supplemental Information in Support of NRC Audit of Final Safey Analysis Report, Tier 2, Chapter 19

'Probabilistic Risk Assessment and Severe Accident Evaluation,'" dated August 03, 2017

3. Letter LO-0318-59360 from NuScale Power, LLC to Nuclear Regulatory Commission, "NuScale Power, LLC Supplemental Information in Support of the NRC Audit of Final Safety Analysis Report, Section 19.2 'Severe Accident Evaluation,'" dated April 04, 2018 The purpose of this letter is to provide the NuScale Power, LLC (NuScale) response to the referenced NRC Request for Additional Information (RAI). to this letter contains NuScale's response to the following RAI Question from NRC eRAI No. 9672:

• 19-40 provides an affidavit supporting the request that the proprietary information referenced in our request be withheld from public disclosure in accordance with the requirements of 10 CFR § 2.390. Further, the information referenced in our response contains Export Controlled Information and must be protected from disclosure per the requirements of 10 CFR § 810.

This letter and the enclosed response make no new regulatory commitments and no revisions to any existing regulatory commitments.

NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0419-65064 If you have any questions on this response, please contact Rebecca Norris at 541-452-7539 or at rnorris@nuscalepower.com.

Sincerely, Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution: Gregory Cranston, NRC, OWFN-8H12 Samuel Lee, NRC, OWFN-8H12 Rani Franovich, NRC, OWFN-8H12 : NuScale Response to NRC Request for Additional Information eRAI No. 9672 : Affidavit of Zackary W. Rad, AF-0419-65067 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0419-65064 :

NuScale Response to NRC Request for Additional Information eRAI No. 9672 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9672 Date of RAI Issue: 03/22/2019 NRC Question No.: 19-40 Regulatory Basis 10 CFR 52.47(a)(23) states that a DC application for light-water reactor (LWR) designs must contain an FSAR that includes a description and analysis of design features for the prevention and mitigation of severe accidents. Standard Review Plan (SRP) Section 19.0 includes the following guidance for the NRC reviewer to ensure that 10 CFR 52.47(a)(23) is met:

the reviewer carries out an independent assessment of the plant response to selected severe accident scenarios using the latest version of the MELCOR computer code. The assessment should examine accident scenarios from the PRA, which are chosen based on a combination of frequency, consequence, and dominant risk. Some of these scenarios should be similar or identical to sequences analyzed by the applicant and reported in the PRA. The reviewer compares the results of corresponding sequences and release categories in the two studies. If the results of the assessment do not support and confirm the applicant's simulation of the accident progression, analysis methodology, and interpretations of its analyses of the reactor, containment, and system response to severe accidents, the reviewer engages with the applicant to resolve the differences in results.

The additional information requested by this RAI is necessary for the staff to make a reasonable assurance of safety finding related to the accident scenarios analyzed in Chapter 19 of the NuScale design certification application (DCA). Specifically, it will support the staff confirmation that the applicant's PRA and analysis of severe accident mitigation has sufficient technical acceptability to support the staff's finding that the NuScale design meets the Commission safety goals and containment performance objectives for new reactor designs as described in SECY-90-016, SECY-93-087, and the associated Staff Requirements Memoranda.

NuScale Nonproprietary

Request for additional information In accordance with SRP Section 19.0, the staff selected the following three scenarios for detailed analysis using the staff's independently developed MELCOR model:

Reactor vent valve (RVV) loss of coolant accident (LOCA). The initiator is a spurious opening of one RVV. The other 2 RVVs open when called on by the emergency core cooling system (ECCS) and permitted by the inadvertent actuation block. The reactor safety valves (RSVs) are operable. All injection and cooling systems (i.e., chemical and volume control system (CVCS), containment flooding and drain system (CFDS), and decay heat removal system (DHRS) fail. This scenario is summarized in DCA Part 2 Tier 2, Section 19.2.3.2 under the heading LEC-06T-00 and is documented in detail in non-docketed NuScale document ER-P060-4748.

CVCS LOCA inside containment. The initiator is a charging line break inside containment. All three RVVs open when called on by the ECCS and permitted by the inadvertent actuation block. The RSV is operable. All injection and cooling systems (i.e.,

CVCS, DHRS, and CFDS) fail. This scenario is summarized in DCA Part 2 Tier 2, Section 19.2.3.2 under the heading LCC-05T-01 and is documented in detail in non-docketed NuScale document ER-P060-4749.

CVCS LOCA outside containment. The initiator is a charging line break outside containment. No ECCS valves open. The RSV is operable. All injection and cooling systems (i.e., CVCS, DHRS, and CFDS) fail. This scenario is summarized in DCA Part 2 Tier 2, Section 19.2.3.2 under the heading LCU-03T-01 and is documented in detail in non-docketed NuScale document ER-P060-4750.

The staff ran simulations of the above three scenarios with its independently developed MELCOR model and will compare the results to those of the applicant. For each scenario, the staff will produce a timing- of-events table comparing the staff's and the applicant's results side by side. In addition, the staff will produce plots comparing the staff's and the applicant's results on the same chart. To enable the staff to make detailed comparisons per the above SRP Section 19.0 review guidance to help identify any potential issues with the applicant's safety analysis, the staff requests that the applicant provide the following information for each of the above three scenarios. The staff requests this information in electronic format to facilitate creating comparison plots.

Total decay power Total oxidation power Pressure and temperature for the following locations:

NuScale Nonproprietary

o Pressurizer o Reactor pressure vessel (RPV) riser o Core region o RPV lower plenum o Steam generators o Containment vessel (CNV) upper plenum o CNV lower plenum Instantaneous and integrated flow rates for the following locations:

o RSVs o ECCS valves (reactor recirculation valves (RRVs) and RVVs) o CVCS break paths o CNV design leakage o Steam generator relief valves RPV, steam generator, and CNV water level and water mass For RPV, provide swollen and collapsed liquid level For steam generators, include water mass in all secondary lines that is in communication with the steam generators after the steam generators are assumed to isolate from the power conversion system at the beginning of the accident (NuScale's MELCOR variables FWIC, MSIC, DHRS)

Cladding and corium temperature for each node RPV lower plenum and CNV lower plenum corium debris masses RPV lower head and CNV lower head heat structure temperature RPV lower head and CNV lower head heat loss Mole fraction of gasses (steam, oxygen, carbon dioxide, nitrogen, hydrogen, carbon monoxide) in the lower and upper head of the RPV and CNV Integrated hydrogen and carbon monoxide generation Released mass fraction of fission products from the fuel for each MELCOR class (as a fraction of core inventory)

Fission product release (as a fraction of core inventory) in the following locations for each MELCOR class (both airborne and deposited) o Reactor coolant system o CNV o Reactor building NuScale Nonproprietary

NuScale Response:

The requested information was provided to the staff on Digital Versatile Discs (DVDs) transmitted by NuScale letters LO-0817-55236 dated August 03, 2017 and LO-0318-59360 dated April 04, 2018. The information was initially provided in support of NRC audits (ML17143A139 and ML18053A216) and, per this response, is submitted on the NuScale docket. As indicated in letters LO-0817-55236 and LO-0318-59360 and their associated affidavits, the information on the DVDs is proprietary and NuScale requests that the transmitted files be withheld, in their entirety, from public disclosure in accordance with the requirements of 10 CFR § 2.390. The DVDs also contain Export Controlled Information. This information must be protected from disclosure per the requirements of 10 CFR § 810.

Impact on DCA:

There are no impacts to the DCA as a result of this response.

NuScale Nonproprietary

RAIO-0419-65064 :

Affidavit of Zackary W. Rad, AF-0419-65067 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

NuScale Power, LLC AFFIDAVIT of Zackary W. Rad I, Zackary W. Rad, 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 Excel files provided by NuScale letters LO-0318-59360 and LO-0817-55236 reveal distinguishing aspects about the processes and methods by which NuScale performs severe accident modeling.

NuScale has performed significant research and evaluation to develop these data 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, NuScale's 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 NuScale's 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 provided in NuScale letters LO-0318-59360 and LO-0817-55236.

(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 § AF-0419-65067 Page 1 of 2

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 NuScale's 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 April 4, 2019.

Zackary W. Rad AF-0419-65067 Page 2 of 2