ML18333A211

LLC Supplemental Response to NRC Request for Additional Information No. 221 (Erai No. 9114) on the NuScale Design Certification Application

ML18333A211
Person / Time
Site:	NuScale
Issue date:	11/29/2018
From:	Rad Z NuScale
To:	Document Control Desk, Office of New Reactors
References
RAIO-1118-63602
Download: ML18333A211 (7)

Text

RAIO-1118-63602 November 29, 2018 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. 221 (eRAI No. 9114) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 221 (eRAI No. 9114)," dated September 12, 2017

2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 221 (eRAI No.9114)," dated November 13, 2017

3. NuScale Power, LLC Supplemental Response to "NRC Request for Additional Information No. 221 (eRAI No. 9114 )" dated February 21, 2018

4. NuScale Power, LLC Supplemental Response to "NRC Request for Additional Information No. 221 (eRAI No. 9114)" dated May 14, 2018

5. NuScale Power, LLC Supplemental Response to "NRC Request for Additional Information No. 221 (eRAI No. 9114 )" dated October 31, 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 Enclosure to this letter contains NuScale's supplemental response to the following RAI Question from NRC eRAI No. 9114:

• 03.07.02-31 This letter and the enclosed response 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,

/

~~

~ackary 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-1118-63602 Distribution: Gregory Cranston, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Marieliz Vera, NRC, OWFN-8G9A : NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9114 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-1118-63602 :

NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9114 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.: 9114 Date of RAI Issue: 09/12/2017 NRC Question No.: 03.07.02-31 10 CFR 52.47(a)(20) requires that an application for Design Certification must include the information necessary to demonstrate that the standard plant complies with the earthquake engineering criteria in 10 CFR 50, Appendix S. 10 CFR 50 Appendix S requires that the safety functions of structures, systems, and components (SSCs) must be assured during and after the vibratory ground motion associated with the Safe Shutdown Earthquake (SSE) through design, testing, or qualification methods.

FSAR Tier 2, Section 3A.1 states the seismic analysis of the NuScale Power Module (NPM) is provided in technical report, TR-0916-51502, NuScale Power Module Seismic Analysis. In TR-0916-51502, Section 3.1, the applicant indicates that NPM simplified beam models developed in ANSYS are incorporated into the RXB system model used in SAP2000 and SASSI2010 analyses. In TR-0916-51502, Section 6.0, the applicant discusses how NPM simplified beam models were derived from the corresponding NPM detailed 3D models in ANSYS. However, the staff notes that the NPM beam models depicted in Figure 6- 1 (dry) and Figure 6-13 (wet) in TR-0916-51502 appear to be different than the model shown in FSAR Figure 3.7.2-28, which FSAR Section 3.7.2.1.2.2 states represents the SASSI2010 NPM beam model.

Therefore, the applicant is requested to explain how the NPM beam models included in the SAP2000/SASSI2010 RXB models were developed and validated (e.g., comparison of dynamic characteristics between the detailed and simplified models).

NuScale Nonproprietary

NuScale Response:

The following responses have been provided as a supplement to RAI 9114 Question 03.07.02-31, as discussed during a public meeting on November 13, 2018.

Question:

For the purpose of record, please provide written responses to Subquestions 1 and 2 in staffs 06/26/2018 feedback.

Response

1. The staff notes that there are some differences between the tables included in RAI responses dated 02/21/2018 and 05/15/2018, particularly in the values of 3D model modal frequencies.

Please explain why these differences exist between the two responses?

As previously clarified during a phone call on 06/26/2018, the RAI response dated 02/21/2018 provided modal results from the updated 3D detailed ANSYS model referenced from TR-0916-51502, NuScale Power Module Seismic Analysis. However, the NPM beam model used in the SASSI building analyses was tuned to a previous configuration of the 3D detailed model. In response to this RAI, it was requested to provide the original modal comparisons between the NPM beam model and the 3D model that was used to develop it. These results were provided in the 05/15/2018 response.

2. In Table 1, values for X-Frequency and X-Effective Mass for the 3D model corresponding to the 3rd mode of the beam model (17.14 Hz and 284 slinch) are missing. Explain or clarify this omission.

As previously clarified during a phone call on 06/26/2018, the beam model provides an estimated response of the 3D detailed model. As such, it has been tuned to capture only the most major frequencies in the modal analysis within reason. The 3rd mode of the beam model has a low mass participation value and was not matched to the 3D detailed model.

Question:

In the RAI response, the applicant used the terms, detailed 3D model and simplified 3D model, in the following instances:

NuScale Nonproprietary

(a) In FSAR markup Page 3.7-119 (Draft revision 3), right above the newly added sentences in the top paragraph: in order to tune the simplified model to match the detailed 3-D model response.

(b) In TR-0916-51502-P markup Page 147 (Draft revision 2), in the top paragraph: To validate the NPM beam model, a modal analysis was performed in order to tune the simplified model to match the detailed 3D model response. The frequencies for the most significant modes are shown in Table 6-21 which demonstrate dynamic compatibility with the simplified 3D model (c) In TR-0916-51502-P markup Page 148 (Draft revision 2), Table 6-21: Major mode comparisons between simplified NuScale Power Module beam model and simplified 3D model Please explain the differences between the detailed 3D model and simplified 3D model as used in the above context.

Response

Detailed 3D model refers to 3D model of the module with fluid elements (i.e., wet condition) whereas simplified 3D model refers to 3D model of the module without fluid elements (i.e., dry condition).

Revision 3 of the FSAR has been updated to state, "... in order to tune the simplified beam model to match the simplified 3-D model response.

Impact on DCA:

FSAR Tier 2, Section 3.7.2.1.2.2 has been revised as described in the response above and as shown in the markup provided in this response.

NuScale Nonproprietary

NuScale Final Safety Analysis Report Seismic Design Figure 3.7.2-26 shows a view of the RXB model with twelve NPMs within the support walls. The lug restraints can be seen near the mid-height of the NPMs in the figure. Figure 3.7.2-27 shows a single NPM. In this figure, the lug restraint can be seen at the upper part of the NPM and the support skirt can be seen at the base of the NPM.

NuScale Power Module Model Included in the Reactor Building SASSI2010 Model RAI 03.07.02-10S1, RAI 03.07.02-20, RAI 03.07.02-20S1, RAI 03.07.02-31S1, RAI 03.07.02-31S2, RAI 03.07.02-31S3, RAI 03.07.02-31S4 Within the SASSI2010 building model, the NPM is represented by a beam model as shown in Figure 3.7.2-28. The beam model was developed to have similar dynamic characteristics as a 3-D ANSYS model of a single NPM bay. To validate the NPM beam model, a modal analysis in three directions was performed in order to tune the simplified beam model to match the detailedsimplified 3-D model response. The frequencies for the most significant modes are shown in Table 6-21 of TR-0916-51502 and demonstrate dynamic compatibility with the 3-D model by matching mode frequencies with significant mass participation, thereby assuring adequate force transfer through the building dynamic response. The simplified beam model captures the overall dynamic behavior of the 3-D NPM model required for the building response analyses used in the SASSI2010 and SAP2000 models. The skirt support at the base of the containment restricts horizontal and vertical movements. Eight rigid beams arranged like the legs of a spider are modeled to connect the NPM model containment skirt to nodes in the building model located at the interface of the skirt and pool floor. Table 3.7.2-36 and Table 3.7.2-37 outline the NPM beam model to RXB model interface boundary conditions for the SASSI2010 and ANSYS models, respectively.

RAI 03.07.02-10S1 Detailed NuScale Power Module Model Included in the Reactor Building SASSI2010 Model RAI 03.07.02-10S1 The RXB-NPM interface and NPM specific analyses replace the simplified beam model with a more detailed NPM beam model. The reactor building is structurally similar to the SASSI2010 model previously described. The NPM beam models are replaced with the detailed beam models for selected SSI analyses to evaluate the RXB-NPM interactions. The development and validation of the detailed beam model and the SASSI2010 reactor building model with detailed beam model are provided in Appendix 3A. The RXB analysis produces local acceleration time histories that are used as input to the NPM seismic analysis. The seismic analysis of the NPM is discussed in Appendix 3A.

RAI 03.07.02-10, RAI 03.07.02-10S1, RAI 03.07.02-10S2 At the interface between the NPM and the RXB, the design loads for the skirt supports are defined as the envelope of the SASSI2010 building model and the Tier 2 3.7-119 Draft Revision 3