ML19184A615

LLC Supplemental Response to NRC Request for Additional Information No. 386 (Erai No. 9316) on the NuScale Design Certification Application

ML19184A615
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Site:	NuScale
Issue date:	07/03/2019
From:	Rad Z NuScale
To:	Document Control Desk, Office of New Reactors
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ML19184A614	List: ML19184A615
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RAIO-0719-66178
Download: ML19184A615 (13)

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RAIO-0719-66178 July 03, 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 Supplemental Response to NRC Request for Additional Information No. 386 (eRAI No. 9316) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 386 (eRAI No. 9316)," dated March 13, 2018

2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 386 (eRAI No.9316)," dated May 10, 2018 The purpose of this letter is to provide the NuScale Power, LLC (NuScale) supplemental response to the referenced NRC Request for Additional Information (RAI).

The Enclosures to this letter contain NuScale's supplemental response to the following RAI Question from NRC eRAI No. 9316:

03.09.02-56 is the proprietary version of the NuScale Supplemental Response to NRC RAI No.

386 (eRAI No. 9316). NuScale requests that the proprietary version be withheld from public disclosure in accordance with the requirements of 10 CFR § 2.390. The proprietary enclosures have been deemed to contain Export Controlled Information. This information must be protected from disclosure per the requirements of 10 CFR § 810. The enclosed affidavit (Enclosure 3) supports this request. Enclosure 2 is the nonproprietary version of the NuScale response.

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

If you have any questions on this response, please contact Marty Bryan at 541-452-7172 or at mbryan@nuscalepower.com.

Sincerely, Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0719-66178 Distribution: Gregory Cranston, NRC, OWFN-8H12 Samuel Lee, NRC, OWFN-8H12 Marieliz Vera, NRC, OWFN-8H12 : NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9316, proprietary : NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9316, nonproprietary : Affidavit of Zackary W. Rad, AF-0719-66179 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0719-66178 :

NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9316, proprietary NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0719-66178 :

NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9316, nonproprietary 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.: 9316 Date of RAI Issue: 03/13/2018 NRC Question No.: 03.09.02-56 In the response to RAI 8884, Question 03.09.02-13, NuScale provided quantitative criteria for evaluating structures for fatigue due to turbulence buffeting and markup changes to the CVAP report. The staff requests that the applicant add details on the turbulent buffeting evaluations of components with lowest resonance frequencies less than 200 Hz to the CVAP report. Without the information, the staff cannot reach a reasonable assurance finding on the structural integrity of the reactor internals components to withstand the adverse effects of vibration.

NuScale Response:

The initial response for RAI 9316 Question 03.09.02-56, as submitted by RAIO-0518-59932, May 10, 2018, is supplemented with the following information. This request was discussed with NRC reviewers in a public CVAP monthly meeting on June 27, 2018.

NuScale has evaluated the reactor vessel internal (RVI) components for turbulent buffeting. The RVI assembly consists of the collection of structures that span from the baffle plate to the lower core support blocks, and has a crossing frequency of ((2(b),(c), ECI Hz. The dominant mode occurs at (( }}2(b),(c), ECI Hz. The RVI assembly has subparts that include the core barrel, reflector, lower riser, upper riser, CRD shaft supports, CRAGT support plate, and core plates. These parts move as a single structure. The RVI assembly is evaluated with a random vibration spectral analysis without using correlation lengths, by applying fully correlated PSDs on panels that are larger than the correlation length. Each panel is uncorrelated with the other panels. This method overestimates the correlation of the turbulent buffeting forces, producing bounding vibration estimates. Other reactor module components with natural frequencies below 200 Hz are the helical coil SG tubes, upper and lower ICIGT, CRD shaft, and CRAGT. NuScale Nonproprietary

The helical SG tubes, ICIGT, CRD shaft, and CRAGT have natural frequencies of ((

                                              }}2(b),(c), ECI, respectively. Discussion of the analysis of these components and their natural frequencies is described in the CVAP technical report, TR-0716-50439.

Impact on DCA: The CVAP Technical Report TR-0716-50439 Section 3.2.3 has been revised as described in the response above and as shown in the markup provided with this response. NuScale Nonproprietary

NuScale Comprehensive Vibration Assessment Program Technical Report TR-0716-50439-NP Draft Rev. 12 PSD is specified in Table 3-9 for certain components identified as susceptible to TB in Table 3-1. Table 3-9 Turbulent buffeting power spectral density inputs used in analysis Flow Type and Component Shape Applicable Components Literature PSD Used (( Parallel flow over isolated cylinder Equation 3-2 Tube bundle cross-flow Equation 3-3 Bounding annular flow Equation 3-1

                                                                             }}2(a),(c),ECI Note(s) for Table 3-9:

1. Testing is performed to verify that the pressure PSD due to internal two-phase flow is sufficiently bounded by the pressure PSD for single-phase flow to justify use of the single-phase pressure PSD used in the analysis.

2. The RVI assembly is a collection of structures that responds to turbulent buffeting forces as a group. It includes the lower and upper riser, reflector, core barrel, core support blocks, CRAGT supports, lower and upper core plates, and the CRD shaft supports.

Equation 3-1 is from Reference 8.1.3. It provides a PSD for components with annular and axial flow velocities. It is applied to some components that experience crossflow, and this simplification is bounding based on the frequencies and characteristic lengths of the analyzed components. Due to the relatively low flow velocities, the reduced frequency for some components is larger than five. For those cases, the PSD is evaluated with a reduced frequency of five to provide bounding results. © Copyright 20198 by NuScale Power, LLC 63

NuScale Comprehensive Vibration Assessment Program Technical Report TR-0716-50439-NP Draft Rev. 12 Gp ( f ) = 5.3x104 F 3.5 , F > 0.4 where: GP ( f ) PSD of the turbulent pressure as a function of modal

                                      =

frequency (psi2/Hz) and F = Reduced frequency (-). The structural response due to the turbulence is calculated using the inputs that have been discussed. Equations to determine the root mean square (RMS) response are assigned based on the direction of the flow and the dimension of the structure, using the appropriate PSDs, damping ratios, modal analysis results, and flow characteristics for the analyzed components. The mean square response of the SG tubes, CRD shafts, ICIGTs, and CRAGTs are derived using Equations 9.4 and 9.40 of Reference 8.1.3. Equations 8.45, 8.46, and 8.47 of Reference 8.1.3 are the basis for the RVI mean square response calculation. The RVI assembly is evaluated with a random vibration spectral analysis without using correlation lengths, by applying fully correlated PSDs on panels that are larger than the correlation length. Each panel is uncorrelated with the other panels. This method overestimates the correlation of the turbulent buffeting forces, producing bounding vibration estimates. Using the RMS response, degradation mechanisms associated with impact and vibration fatigue are evaluated. For the structures where the support (RVI assembly) and the structure may move independently, the relative motion is calculated by adding the two vibrations together with a square root of the sum of the squares method. Components with less than five times the RMS vibrationone inch of separation are evaluated for impact. Components with fundamental frequencies less than 200 Hz and those whose response cannot be bounded by nearby components exposed to similar turbulent conditions are evaluated for fatigue. Table 3-9 lists the components analyzed for turbulent buffeting. Each has a fundamental frequency below 200 Hz. After the RMS response is calculated as discussed above, components undergo further separation screening: Tthe acceptance criterion for a component remaining separated from an adjacent component is that the clearance is greater than 5 RMS deflection. For components that do not meet the criterion, the surface stress is calculated and an impact fatigue assessment is performed. Surface stress is calculated using a semi-empirical approximation from Reference 8.1.3 for a vibrating tube in a loose hole (Equation 3-4). The impact frequency for the steam generator tubes is the average of the first ten modal frequencies, because these modes contribute the majority of the RMS response. For RVI evaluations, the crossing frequency is used. 15 E 4 M e f i 2 ymax 2 S rms = c 3 Equation 3-4 D © Copyright 20198 by NuScale Power, LLC 65

NuScale Comprehensive Vibration Assessment Program Technical Report TR-0716-50439-NP Draft Rev. 12 where: Srms = Surface stress due to impact (psi) c = Contact stress parameter, page 357 of Reference 8.1.3 (-) E = Elastic modulus (psi) Me Effective mass, for a tube usually taken as 2/3 of the mass of the

                                     =

two adjacent spans (lbf-s2/in) fi = Impact frequency (Hz) y max = Maximum RMS vibration amplitude (in) D = Tube outer diameter (in) An alternating impact stress is calculated as one-half of the surface stress, and used with a fatigue curve based on RMS stress (similar to Figure 11.6 of Reference 8.1.3) to obtain a usage factor. In addition to the impact fatigue, TB can cause fatigue due to vibration stresses. However, due to the very low vibration amplitudes and alternating stresses, the vibration stresses do not result in fatigue usage for any component susceptible to TB. Out of the components analyzed for TB, four (not including the RVI assembly, which acts as the support for the CRD shaft and ICIGT) components are shown to impact their adjacent supports and are discussed below. Impact between the SG tubes and SG tube support is predicted to occur, and the fatigue usage due to vibration and impact is calculated to be (( }}2(b),(c),ECI which provides a margin of safety of (( }}2(b),(c),ECI This result demonstrates adequate SG tube performance for the component design life, subject to verification testing of analytical inputs and safety margin as identified in Table 3-10. Impact between the ICIGT and the CRD shaft supports (which move as part of the RVI assembly), between the CRD shaft and the CRD shaft supports, and between the CRAGT and the guide tube support is predicted to occur.Impact between the ICIGT and the CRD shaft supports, between the CRD shaft and CRD shaft supports, and between the CRAGT and the guide tube support is predicted to occur. For all three impact pairs, the results show that the RMS vibrations do not result in fatigue usage due to the displacements themselves or due to impact. These results are due to the very low alternating stresses generated from the TB, which can be primarily attributed to the low-flow velocities. Table 3-10 provides an overview of the analysis results and required testing. © Copyright 20198 by NuScale Power, LLC 66

NuScale Comprehensive Vibration Assessment Program Technical Report TR-0716-50439-NP Draft Rev. 12 Table 3-10 Turbulent buffeting results summary Verification Contact Fatigue Method and Frequency Component Items to Verify Test Occurs? Margin (%) Note 1 Testing (Hz) Phase Frequencies SG FIV SG helical mode shapes Separate yes (( }}2(b),(c),ECI (Section Various tubing vibration effects 4.1.2) amplitude ICIGT Note 2 Yes (( }}2(b),(c),ECI100 N/A N/A N/A (( CRD shaft Yes 100 N/A N/A N/A RVI Yes 100 N/A N/A N/A assembly CRAGT Yes 100 N/A N/A N/A }}2(b),(c),ECI Note(s) for Table 3-10:

1. Safety margin is reported based on the margin to the allowable fatigue usage based on the predicted fatigue usage due to vibration and/or impact.

2. The lower ICIGT is reported because it has the lowest frequency and the highest response for ICIGT.

3.2.4 Acoustic Resonance Acoustic resonance is evaluated for the steam plenums and nozzles, main steam isolation valves, MSIV bypass lines, SGS piping, CNTS piping, DHRS piping, and at valve and instruments ports. It was determined that AR is not possible at the steam plenums and nozzles. The flow through these nozzles prevents the formation of shear waves and AR in these cavities. The MSIVs are an unlikely source of pressure fluctuations associated with AR because the MSIVs are directly mounted on the steam piping with no standpipe. The only locations that flow excitation due to AR may be possible are at the branch lines and cavities at the following locations:

• the closed side branches from the CNTS MS piping with connections to: steam tee to the DHRS actuation valves DHRS steam line and actuation valves MS drain valves Upstream line to bypass MSIV Downstream line to bypass MSIV
• the closed side branches from the SGS feedwater piping with connections to: tee to the DHRS condenser DHRS condensate line to the DHRS condenser pressure relief valves
• the closed side branches in the CNTS FW piping to the FW drain valves
• the closed side branches in the CNTS CVC piping to the CVC drain valves

© Copyright 20198 by NuScale Power, LLC 67

RAIO-0719-66178 : Affidavit of Zackary W. Rad, AF-0719-66179 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, 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 competitor's 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 NuScale's competitive position and foreclose or reduce the availability of profit-making opportunities. The accompanying Request for Additional Information response reveals distinguishing aspects about the method by which NuScale develops its power module seismic analysis.

NuScale has performed significant research and evaluation to develop a basis for this method 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. AF-0719-66179

4. The information sought to be withheld is in the enclosed response to NRC Request for Additional Information No. 386, eRAI No. 9316. 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.

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 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 July 3, 2019. Zackary W. Rad AF-0719-66179}}