ML17355A678

LLC Response to NRC Request for Additional Information No. 134 (Erai No. 8934) on the NuScale Design Certification Application

ML17355A678
Person / Time
Site:	NuScale
Issue date:	12/21/2017
From:	Rad Z NuScale
To:	Document Control Desk, Office of New Reactors
References
eRAI 8934, RAIO-1217-57899
Download: ML17355A678 (27)

Text

RAIO-1217-57899 December 21, 2017 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.

134 (eRAI No. 8934) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 134 (eRAI No. 8934)," dated August 05, 2017

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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 NuScale's response to the following RAI Question from

NRC eRAI No. 8934:

03.07.02-15 The response to RAI Questions 03.0702-13 and 03.07.02-14 were previously provided in

Reference 2. This completes all responses to RAI No. 134 (eRAI No. 8934).

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, Z ckary W. Rad Za Zackary Director, Regulatory Affairs NuScale Power, LLC Distribution: Gregory Cranston, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Marieliz Vera, NRC, OWFN-8G9A : NuScale Response to NRC Request for Additional Information eRAI No. 8934 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-1217-57899 :

NuScale Response to NRC Request for Additional Information eRAI No. 8934 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.: 8934 Date of RAI Issue: 08/05/2017 NRC Question No.: 03.07.02-15 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.

a. On Page 3.7-30 of the FSAR, Eq. 3.7-14 represents the conversion of ANSYS FSI-based hydrodynamic pressure to SASSI2010 equivalent static pressure. In this process, ANSYS used the CSDRS-compatible Capitola time history input on a fixed-base model and SASSI2010 used the CSDRS-compatible Capitola time history input for Soil Types 7, 8, and 11, respectively. The applicant is requested to explain why FSI correction factors for the case of CSDRS-HF-compatible time history input for Soil Type 9 (hard rock) are not considered. Since the boundary conditions for an ANSYS fixed-base model and a SASSI model with Soil Type 9 (hard rock) are similar, it appears that FSI- correction factors developed for Soil Type 9 may be more representative.

b. On Page 3.7-31 of the FSAR, the fourth paragraph, The pressure at the bottom of the pool due to , describes an approach the applicant took in taking into account the FSI effects on vertical water pressure estimation. The applicant is requested to provide a technical basis for the approach taken.

NuScale Response:

The following response provides an explanation as to why the fluid structure interaction (FSI) correction factors for the case of high frequency certified seismic design response spectra (CSDRS-HF) compatible time history input for Soil Type 9 are not considered and a technical basis for the approach taken to account for the FSI effects on vertical water pressure estimation.

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a)

Both the FSI and the NPM analyses used synthetic ground motions based on Capitola seed time histories. Based on the overall building base shear comparison in Table 1 below, these runs using soil types 7, 8, and 11, and CSDRS spectrum are more controlling than the soil type 9 with synthetic time history based on Lucerne seed time history and CSDRS-HF spectrum.

Therefore, the factors used to convert ANSYS FSI hydrodynamic pressures to equivalent static pressures for Soil Types 7, 8, and 11 adequately envelope Soil Type 9.

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Table 1: Seismic Base Reactions* (Extracted from FSAR Table 3.8.5-3)

Concrete Seismic Load Global FX Global Fy Global Fz Model Soil Type Case Case (kips) (kips) (kips)

S7 CSDRS Capitola 326528 177221 222932 S8 CSDRS Capitola 306274 206799 205032 S11 CSDRS Capitola 151960 135837 185963 Cracked 7% S7 CSDRS- HF Lucerne 119790 77946 147529 Damping S9 CSDRS- HF Lucerne 126622 82652 162443

% Reaction Ratio =

S9 CSDRS- HF/ - 39 40 73 Reactor Maximum Building S7 CSDRS Capitola 331587 203856 225014 S8 CSDRS Capitola 311880 212752 208268 S11 CSDRS Capitola 152056 138287 186456 Uncracked S7 CSDRS- HF Lucerne 114361 82076 156119 7% Damping S9 CSDRS- HF Lucerne 155572 99573 167031

% Reaction Ratio =

S9 CSDRS- HF/ S7 - 47 47 74 CSDRS

• These loads are the maximums of the total base reaction time histories obtained by the step-by-step combination of the reactions in all springs below the foundation NuScale Nonproprietary

The ANSYS FSI analysis determined that an average equivalent static pressure can be applied as a load to the RXB to account for the effects of 3-D FSI that are underestimated in SSI results that use fluid mass lumping methodology. Figure 1 shows the equivalent static pool water pressure to be added is 4.20 psi, and it can be produced by applying a hydrostatic pressure due to 0.28g.

Table 2 shows a summary of average equivalent static pressure for Soil Types 7, 8, and 11 that were based on the SSI analyses results for the pool floor and wall accelerations using the CSDRS compatible Capitola time histories. The highest 4.20 psi equivalent static pressure value is based on Soil Type 7. The equivalent static pressures for Soil Type 11 (the soil type that more closely matches the SSI base reactions of Soil Type 9) are twenty to sixty percent lower than Soil Type 7. This indicates that the average equivalent static pressure for soil Type 9 will be lower than the maximum from Soil Type 7.

Figure 1: Development of Average Static Pressure of 4.20 psi at Mid Height of Pool Water for SAP2000 Model to Account for 3D FSI Effects NuScale Nonproprietary

Table 2: Equivalent Wall Pressure to Be Adjusted in SAP2000 Model Due to FSI Effects Soil Type 7 Soil Type 8 Soil Type 11 Envelope Difference Difference Difference Pressure to Maximum between between between be Added Difference Section ANSYS and ANSYS and ANSYS and to per Section SASSI2010 SASSI2010 SASSI2010 SAP2000 Wall Pressures Wall Pressures Wall Pressures Model (psi) (psi) (psi) (psi) (psi)

All X Wall 3.090 2.428 1.286 3.090 All Y Wall 4.129 3.637 1.960 4.129 4.20 Z

4.203 3.921 3.373 4.203 Foundation Soil Type 7 Governs the Pressure Estimation In addition, reactor building ANSYS analyses in the X, Y, and Z directions were performed using the CSDRS-HF Lucerne time histories. Table 3 summarizes the results. Figure 2 through Figure 19 provide the pressure contours on the RXB outer walls and foundation resisting the X, Y, Z fluid motions. The pressures on the walls and foundations for CSDRS-HF cases are within four percent of respective CSDRS pressure values. This demonstrates that results from the high frequency soil types are similar to results from the non-high frequency soil types.

The average equivalent static pressure scaling factor based on the SSI analyses results for the pool floor and wall accelerations results obtained for Soil Types 7, 8, and 11 using the CSDRS adequately envelope the Soil Type 9 CSDRS-HF demand forces used for the RXB design.

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Table 3: ANSYS Wall Pressure Contours Comparison between CSDRS and CSDRS-HF PRESSURE Pressure Range Remarks from CSDRS CSDRS-HF DIRECTION (PSI) Pressure Contours 0.35 to 10.7 (CSD) The pressure X-Wall due to X Figure 2 Figure 3 0.44 to 10.9 contours are close (CSD-HF) 0.55 to 10.5 (CSD) The pressure Y-Wall due to X Figure 4 Figure 5 0.58 to 10.9 contours are close (CSD-HF) 1.92 to 11.5 Z-Foundation due to (CSD) The pressure Figure 6 Figure 7 X 1.35 to 10.9 contours are close (CSD-HF) 0.39 to 7.6 (CSD)

The pressure X-Wall due to Y Figure 8 Figure 9 0.19 to 7.7 (CSD-contours are close HF) 1.11 to 8.2 (CSD)

The pressure Y-Wall due to Y Figure 10 Figure 11 1.01 to 8.1 (CSD-contours are close HF) 0.73 to 7.9 (CSD)

Z-Foundation due to The pressure Figure 12 Figure 13 0.52 to 7.4 (CSD-Y contours are close HF) 0.75 to 16.8 The pressure (CSD)

X-Wall due to Z Figure 14 Figure 15 contours for CSD are 0.61 to 15.0 slightly higher (CSD-HF) 0.75 to 16.8 The pressure (CSD)

Y-Wall due to Z Figure 16 Figure 17 contours for CSD are 0.77 to 15.0 slightly higher (CSD-HF) 10.2 to 18.8 The pressure Z-Foundation due to (CSD)

Figure 18 Figure 19 contours for CSD are Z 8.44 to 15.0 slightly higher (CSD-HF)

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Figure 2: Hydrodynamic Pressure at X Nodes due to X Input Time History using CSDRS NuScale Nonproprietary

Figure 3: Hydrodynamic Pressure at X Nodes due to X Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 4: Hydrodynamic Pressure at Y Nodes due to X Input Time History using CSDRS NuScale Nonproprietary

Figure 5: Hydrodynamic Pressure at Y Nodes due to X Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 6: Hydrodynamic Pressure at Z Nodes due to X Input Time History using CSDRS NuScale Nonproprietary

Figure 7: Hydrodynamic Pressure at Z Nodes due to X Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 8: Hydrodynamic Pressure at X Nodes due to Y Input Time History using CSDRS NuScale Nonproprietary

Figure 9: Hydrodynamic Pressure at X Nodes due to Y Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 10: Hydrodynamic Pressure at Y Nodes due to Y Input Time History using CSDRS NuScale Nonproprietary

Figure 11: Hydrodynamic Pressure at Y Nodes due to Y Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 12: Hydrodynamic Pressure at Z Nodes due to Y Input Time History using CSDRS NuScale Nonproprietary

Figure 13: Hydrodynamic Pressure at Z Nodes due to Y Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 14: Hydrodynamic Pressure at X Nodes due to Z Input Time History using CSDRS NuScale Nonproprietary

Figure 15: Hydrodynamic Pressure at X Nodes due to Z Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 16: Hydrodynamic Pressure at Y Nodes due to Z Input Time History using CSDRS NuScale Nonproprietary

Figure 17: Hydrodynamic Pressure at Y Nodes due to Z Input Time History using CSDRS-HF NuScale Nonproprietary

Figure 18: Hydrodynamic Pressure at Z Nodes due to Z Input Time History using CSDRS NuScale Nonproprietary

Figure 19: Hydrodynamic Pressure at Z Nodes due to Z Input Time History using CSDRS-HF NuScale Nonproprietary

b)

The FSI effects are accounted for by adding a pressure of 4.2 psi, obtained from ANSYS FSI analysis, to the SAP2000 model. The SAP2000 program is capable of incorporating only the lumped fluid masses and does not have the FSI analysis capability. Consequently, hydrodynamic pressures were computed separately using ANSYS FSI analysis and were added to the SAP2000 model as equivalent static load.

Total fluid pressure on wall = Hydrostatic pressure (15 psi) + Hydrodynamic pressure (4.2 psi, obtained from ANSYS FSI analysis) = 19.2 psi =1.28* 15 psi = 1.28* Hydrostatic pressure Therefore, a 1.28g vertical static loading was added to the SAP2000 model to ensure the additional hydrodynamic pressure is accounted for in the design.

Impact on DCA:

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

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