ML19088A331
| ML19088A331 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 03/29/2019 |
| From: | Rad Z NuScale |
| To: | Document Control Desk, Office of New Reactors |
| References | |
| LO-0319-64750 | |
| Download: ML19088A331 (23) | |
Text
LO-0319-64750 March 29, 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 Submittal of Changes to Final Safety Analysis Report, Section 3.7.2, Seismic Design and Appendix 3B, Design Report and Critical Section Details and Response to Related NRC Information Requests
REFERENCES:
- 1. Letter from NuScale Power, LLC to Nuclear Regulatory Commission, NuScale Power, LLC Submittal of the NuScale Standard Plant Design Certification Application, Revision 2, dated October 30, 2018 (ML18311A006)
- 2. Letter from NuScale Power LLC, to Nuclear Regulatory Commission, Response to NRC Request for Additional Information No. 202 (eRAI No. 8911) on the NuScale Design Certification Application, dated January 31, 2019 (ML19031C984)
During public teleconferences with NRC Staff on February 26 and 27, 2019, NuScale Power, LLC (NuScale) discussed several topics related to the Final Safety Analysis Report (FSAR) Section 3.7.2, Seismic Design. Specifically NRC staff requested:
- 1) provide comparison plots between hydrodynamic pressures from the original reactor building (RXB) models and the current RXB models,
- 2) provide an explanation for the NuScale Power Module (NPM) support load reductions obtained with the enhanced RXB SASSI models,
- 3) provide updated FSAR markups for the information contained in the response to RAI 8911 Question 03.09.02-43 (Reference 2), including markups to FSAR Table 3B-28,
- 4) correct an inconsistency in FSAR Section 3.7.2.5.6 regarding description of the modeling approach, and
- 5) provide comparison plots for the In-Structure Response Spectra (ISRS) from the previous seismic runs to the current seismic analysis runs.
The purpose of this letter is to provide the requested information.
Attachment 1 to this letter provides the requested comparison figures for items 1 and 5 above.
Enclosure 1 provides a mark-up of the FSAR pages incorporating revisions, for items 3 and 4 above, to Section 3.7.2, Seismic Design and Appendix 3B, Design Report and Critical Section Details in redline/strikeout format. NuScale will include these changes as part of a future revision to the NuScale Design Certification Application.
Item 2 above is addressed as follows: the seismic loads at the NPM supports are reduced because the enhanced application of hydrodynamic mass to the RXB SASSI models removes over-conservatism at the bay wall locations. Specifically, the hydrodynamic mass associated with the detailed NPM beam model (Section 6.6.6.3 of the NPM Seismic Analysis, TR-0916-51502) is accounted for only once, and the pool water masses are no longer assigned to the bay walls based on tributary areas. For the building analyses described in the FSAR, the water in the bays was counted more than once - first in the tuned NPM model that was imported, and then again with tributary area assignments of the pool water. This overallocation of mass resulted in higher than expected reaction forces for the NPM. The enhanced methodology is described in Section 3.1.3 of the NPM Seismic Analysis.
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
LO-0319-64750 Page 2 of 2 03/29/19 This letter makes no regulatory commitments or revisions to any existing regulatory commitments.
Please feel free to contact Marty Bryan at (541) 452-7172 or at mbryan@nuscalepower.com if you have any questions.
Sincerely, Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution: Samuel Lee, NRC, OWFN-8H12 Gregory Cranston, NRC, OWFN-8H12 Marieliz Vera, NRC, OWFN-8H12 Attachment 1: Comparison figures for hydrodynamic pressure and ISRS Enclosure 1: Changes to NuScale Final Safety Analysis Report Section 3.7.2, 'Seismic Design' and Appendix 3B, 'Design Report and Critical Section Details' NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 1 of 9 1- Hydrodynamic Pressure The hydrodynamic pressure distribution on the three walls around the NPM 1 are compared before and after the hydrodynamic mass was changed. As indicated in the letter above the difference in results has to do with the application of hydrodyamic mass in these areas. The latest model no longer accounts for overallocation of mass in these areas. In these plots 11 feet is the bottom of the pool.
Hydrodynamic Pressure Comparison for the East Wall of the NPM 1 DCA Latest 90 80 70 60 Elevation (ft) 50 40 30 20 10 0
500 0 500 1000 1500 2000 2500 3000 Hydrodynamic Pressure (psf per g)
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 2 of 9 Hydrodynamic Pressure Comparison for the West Wall of the NPM 1 DCA Latest 90 80 70 60 Elevation (ft) 50 40 30 20 10 0
1000 0 1000 2000 3000 4000 5000 6000 7000 8000 Hydrodynamic Pressure (psf per g)
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 3 of 9 Hydrodynamic Pressure Comparison for the Pool Wall of the NPM 1 DCA Latest 90 80 70 60 Elevation (ft) 50 40 30 20 10 0
0 500 1000 1500 2000 2500 3000 3500 4000 4500 Hydrodynamic Pressure (psf per g) 2- NPM Lug Support ISRS Comparison The ISRS presented below are based on each model being run with soil 7, the capitola time history, and cracked concrete.
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 4 of 9 NPM 1 East Lug Support ISRS Comparison in the NS Direction DCA Latest 4
3.5 3
2.5 ISRS (g) 2 1.5 1
0.5 0
0.1 1 10 100 Frequency (Hz)
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 5 of 9 NPM 1 North Lug Support ISRS Comparison in the EW Direction DCA Latest 3
2.5 2
ISRS (g) 1.5 1
0.5 0
0.1 1 10 100 Frequency (Hz)
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 6 of 9 NPM 1 West Lug Support ISRS Comparison in the NS Direction DCA Latest 4
3.5 3
2.5 ISRS (g) 2 1.5 1
0.5 0
0.1 1 10 100 0.5 Frequency (Hz) 3- NPM Skirt Support ISRS Comparison Similar to above, the ISRS presented below are based on each model being run with soil 7, the capitola time history, and cracked concrete.
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 7 of 9 NPM1 Skirt Support ISRS Comparion in the EW Direction DCA Latest 1.6 1.4 1.2 1
ISRS (g) 0.8 0.6 0.4 0.2 0
0.1 1 10 100 Frequency (Hz)
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 8 of 9 NPM1 Skirt Support ISRS Comparisonin the NS Direction DCA Latest 1.4 1.2 1
ISRS (g) 0.8 0.6 0.4 0.2 0
0.1 1 10 100 Frequency (Hz)
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
Comparison Figures for Hydrodynamic LO-0319-64750 Attachment 1 Pressure and ISRS Page 9 of 9 NPM1 Skirt Support ISRS Comparisonin the Vertical Direction DCA Latest 1.8 1.6 1.4 1.2 ISRS (g) 1 0.8 0.6 0.4 0.2 0
0.1 1 10 100 Frequency (Hz)
NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
LO-0319-64750 :
Changes to NuScale Final Safety Analysis Report Section 3.7.2, 'Seismic Design' and Appendix 3B,
'Design Report and Critical Section Details' NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com
NuScale Final Safety Analysis Report Seismic Design show which models are used, what results are extracted, and how these results are used to design the basemat.
3.7.2.1.3.2 NuScale Power Modules Up to twelve NPMs will be inside the RXB. The modules are partially immersed in the reactor pool. The NPMs are not permanently bolted or welded to the pool floor or walls. Instead they are geometrically supported and constrained at four locations. The geometrical constraints are designed to keep each NPM in its location before, during, and after a seismic event.
The base support is a steel skirt that rests outside a permanently installed ring plate attached at the bottom of the reactor pool. The other three geometrical supports are steel lug restraints located on the walls of each bay at approximately the midpoint of the module (~EL. 75). The NPM has lugs that align with a slot in the restraint. Each restraint prevents movement in the direction parallel to the wall and allows the NPM to move freely in the upward direction. In other words, the lug and restraint provides only horizontal restraint in the in-plane direction for the supporting wall.
The lug and lug restraint combination is shown in Figure 3.7.2-22. Figure 3.7.2-23 shows the top view of a restrained NPM. The placement of the twelve NPMs in the model of the RXB is shown in Figure 3.7.2-24. An enlarged view of the NPM pool region is shown in Figure 3.7.2-25.
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 dry 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 Tier 2 3.7-120 Draft Revision 3
NuScale Final Safety Analysis Report Seismic Design 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. This more detailed beam model, described in Section 6.4 of TR-0916-51502, is generated by adding mass and spring elements to create a fluid structure interaction response that is equivalent to a 3D model of an NPM and pool bay. The development and validation of the detailed beam model are described in Section 6.5 of TR-0916-51502. The reactor building model that uses the detailed NPM beam models is structurally similar to the SASSI2010 model previously described.
Because fluid mass has been added to the detailed NPM beam model, a more enhanced methodology for modeling hydrodynamic mass in the pool area was used. This is described in Section 3.1.3 of TR-0916-51502. 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 as described in Section 8.0 of TR-0916-51502. 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 3-D model discussed in Appendix 3A and Appendix 3B.2.7. The lug supports are designed for a generic capacity in a detailed submodel and checked against the design loadsreaction forces from the SASSI2010 building model and 3-D model. This is described in more detail in Appendix 3B.2.7.
3.7.2.1.3.3 Reactor Building Crane The RBC is a bridge crane used to transport modules between the operating locations and the refueling and disassembly area and the drydock. The RBC travels on rails on the top of the reactor pool walls at EL. 145'-6". When not in use, the RBC is parked over the refueling pool with the trolley at the north end near the dry dock gate. In this position, the RBC is not above either the SFP or the NPMs. The RBC is described in Section 9.1.5.
Reactor Building Crane Model Included in the Reactor Building SASSI2010 Model Tier 2 3.7-121 Draft Revision 3
NuScale Final Safety Analysis Report Seismic Design Figure 3.7.2-97 provides node locations that were used to develop the ISRS for the NPM bay walls at the lug restraints. The enveloping ISRS for these locations are provided in Figure 3.7.2-116.
RAI 03.08.04-23S2, RAI 03.08.04-23S3 3.7.2.5.6 NuScale Power Module Skirt, and Lug Supports, and Reactor Flange Tool Base ISRSIn-Structure Response Spectra RAI 03.08.04-23S2, RAI 03.08.04-23S3 At the CNV skirts of NPM1 and NPM6, response spectra are generated for the time histories at the eight spider nodes, directly beneath each corresponding NPMto the eight spider elements. The SASSI node numberscoordinates of these ISRS locations are listed in Table 3.7.2-54.
RAI 03.08.04-23S2, RAI 03.08.04-23S3 The resulting spider node spectra are then averaged for each module. This results in nine averaged skirt response spectra for each module, based on the threesix seismic cases provided (Soil Type 7, Capitola time history, cracked and uncracked concrete nominal stiffness, cracked concrete reduced stiffness, uncracked concrete nominal stiffness), and three NPM stiffness cases) each with three components (X,Y, and Z). The ISRS of the nine averaged skirt response spectra is then enveloped for NPM1 and NPM6 in the X, Y, and Z directions. The sSix resulting enveloping ISRS (two modules x one skirt support x three directions) for the nominal stiffness cases for NPM1 and NPM6 CNV skirts are shown in Figure 3.7.2-156 and Figure 3.7.2-157.
RAI 03.08.04-23S2 At the CNV lugs of NPM1 and NPM6, response spectra are generated for the time histories at the nodes listed in Table 3.7.2-55. The spectra for the nominal stiffness cases are then enveloped at each of the lugs on NPM1 and NPM6, resulting in 18 total enveloping spectra (two modules x three lugs x three directions). These spectra are shown in Figure 3.7.2-158 through Figure 3.7.2-163.
RAI 03.08.04-23S3 Response spectra are generated for time histories at four reactor flange tool (RFT) base locations. The coordinates of these ISRS locations are listed in Table 3.7.2-58.
For each case, there are 12 (3 directions x 4 locations) ISRS generated. For the two analysis cases (cracked and uncracked concrete), the total number of ISRS is 24 (12 x 2 cases). The plots of the ISRS for the nominal stiffness cases are presented in Figure 3.7.2-164 through Figure 3.7.2-171.
3.7.2.5.7 Control Building In-Structure Response Spectra RAI 03.08.04-23, RAI 03.08.04-23S3 The ISRS corresponding to each main floor of the CRB identified below are provided oin the listed figures. The governing ISRS envelop the ISRS taken from node locations on the corners of the buildings to capture the torsional and rocking Tier 2 3.7-141 Draft Revision 3
Table 3.7.2-35: Analysis Model Summary (Continued)
Tier 2 NuScale Final Safety Analysis Report No. Analysis Model Concrete Computer SSI and SSSI Soil SSI and SSSI Time Purpose Building FSAR Explanation FSAR Results Condition Program Types Considered History Inputs Response and Figures Used 18 Envelope of ISRS Envelope of SASSI2010 See above See above Seismic ISRS generation ISRS Sections:3.7.2.5.6, Figures: 3.7.2-117a for CRB cracked & using 4% material 3.7.2.9 through -122b uncracked damping 19 RXB linear Cracked & N/A N/A N/A Evaluate flotation, sliding, Factor of Sections: 3.8.4.3, Table 3.8.5-5 stability - stand- uncracked and overturning safety 3.8.5, 3.8.5.4.1.2, alone building 3.8.5.5, 3.8.5.6.1 20 RXB nonlinear Cracked & ANSYS 7, 8 & 11 (with CSDRS Averaged Evaluate flotation, sliding, Displace- Sections: 3.8.4.3, Figures: 3.8.5-53 stability - stand- uncracked CSDRS Input); 9 Reactions from: and overturning ment 3.8.5, 3.8.5.4.1.2, through -76; Table alone model (with CSDRS-HF Capitola, Chi-Chi, 3.8.5.6.1; Table 3.8.5- 3.8.5-12 (however, input Input) El Centro, Izmit, 6 seismic base Yermo. CSDRS-HF:
reactions Lucerne envelope both the RXB Stand-Alone and Triple 3.7-236 Bldg SASSI Models) 21 CRB linear Cracked & N/A N/A N/A Evaluate flotation, sliding, Factor of Sections: 3.8.4.3, Not presented stability - stand- uncracked and overturning safety 3.8.5, 3.8.5.4.1.3, alone building 3.8.5.5 22 CRB nonlinear Cracked & ANSYS 7 & 11 (with CSDRS CSDRS: Capitola Evaluate flotation, sliding, Displace- Sections: 3.8.4.3, Table 3.8.5-13; stability - stand- uncracked Input) and overturning ment 3.8.5, 3.8.5.4.1.4, Figures: 3.8.5-49 & -
alone model 3.8.5.6.2; Figures: 50; Sections:
3.8.5-26 & -27, 3.8.5- 3.8.5.6.2.2 &
48 3.8.5.6.2.3 23 RXB-CRB-RWB Cracked & SAP2000 N/A N/A Evaluate settlement for Settlement Sections: 3.8.4.3; Table 3.8.5-8 multiple bldg - uncracked RXB and CRB Figures: 3.8.5-41 settlement 24 NuScale Power Cracked & ANSYS 7 (with CSDRS CSDRS: Capitola Determine reaction forces Reactions, Sections: 3.7.2.1.2.2, TR-0916-51502 Module (NPMs 1 uncracked Input) for NPM, ISRS and forces, 3.7.3; Appendix 3A; Tables 8-1 through and 6) ISRStime histories for NPM moments, Table 3.9-8; TR-0916- 8-97 and Table C-2; components. ISRS, time 51502 Sections 3.1.5 Figures B-1 through Draft Revision 3 Seismic Design histories & 5.0 B-3327; Figures C-22
& C-23 25 RXB fuel storage N/A ANSYS Analysis based on Analysis based on Structural analysis of the Member Sections: 3.7.3, See COL Item 9.1-8 racks RXB ISRS RXB ISRS RXB fuel storage racks stresses 3.8.4.3.1.7, 9.1; TR-0816-49833
Table 3.7.2-35: Analysis Model Summary (Continued)
Tier 2 NuScale Final Safety Analysis Report No. Analysis Model Concrete Computer SSI and SSSI Soil SSI and SSSI Time Purpose Building FSAR Explanation FSAR Results Condition Program Types Considered History Inputs Response and Figures Used 26 Reactor Building N/A ANSYS Analysis based on Analysis based on Structural analysis of RBC Member Section 9.1.5 Not presented crane (RBC) RXB ISRS RXB ISRS forces 27 RXB bioshield - Cracked & SAP2000 Analysis based on Analysis based on Structural analysis of Member Sections: 3.7.3, Table 3.7.3-14 partial model uncracked RXB ISRS RXB ISRS bioshield forces 3.7.3.3.12; Figures:
3.7.3-1 & -2; Tables 3.7.3-8 through -132 28 Reactor Flange Cracked & ANSYS Soil Type 7 (with CSDRS: Capitola Determine core plate time Reaction Sections: 3.8.4.1.15, Tables: 3.8.4-21, Tool Refueling uncracked CSDRS Input) histories and ISRS, as well forces, 3.8.4.3.1.12, 3.8.4.4.2, 3.8.4-22, 3.8.4-23; Configuration as reactions for structural moments, 3.8.4.5 TR-0916-51502 components ISRS, time Figures: 3.8.4.34, Tables 8-8 and 8-9; histories 3.8.4.35, 3.8.4.36 Figures B-34 through B-39 3.7-237 Draft Revision 3 Seismic Design
NuScale Final Safety Analysis Report Design Reports and Critical Section Details the NPM impacts the passive support ringplates, the resulting upward vertical and horizontal loads will be resisted by the concrete anchors in tension and shear and concrete in edge bearing. Figure 3B-48 and Figure 3B-49 show the details of the passive support platering.
RAI 03.07.02-10, RAI 03.08.04-31 NuScale Power Module Model:
RAI 03.07.02-10S1 A SASSI building model with a detailed NPM beam model, described in Section 3.7.2, is used to perform dynamic analyses on the RXB and extract results at the NPM to RXB interface locations. The RXB analysis produces local acceleration time histories that are used as input to the NPM seismic analysis discussed in Appendix 3A.
RAI 03.07.02-10S1, RAI 03.08.04-10S1 A separate ANSYS model is used to perform a non-linear dynamic analysis of the NPM. This model only includes the pool water and one NPM (1 or 6). The analysis results are based on the envelope of the sixtwelve runs shown in Table 3B-53. The static reaction force, including the dead weight and the static buoyancy, is 1,090.41,250 kips in the vertical direction. The maximum uplift displacement, due to seismic, of the module from the floor is less than 0.125 inch. The enveloping reaction forces between the ANSYS and SASSI models are provided in Table 3B-28 and used for the design basis in the following subsections.
Envelope Loads:
RAI 03.07.02-10, RAI 03.07.02-20, RAI 03.08.04-10S1, RAI 03.08.04-31
- Vertical downward load, P = 3,8593,144 kips. This load includes dead load, fluid pressure load, and seismic load. Dead load is the static buoyancy load described above and is equal to 1,090.41,250 kips. The fluid pressure load is determined by the product of the baseplateNPM skirt ring area (14.5' x 14.5'4,310 in2), the fluid density (62.4 pcf), and the normal operating reactor pool depth (69') and is equal to 905.3129 kips. The enveloping downward seismic load is 1,8631,765.2 kips.
RAI 03.07.02-20, RAI 03.08.04-10S1
- The vertical displacement is less than 0.125 inch. The passive support ringplate is 4.5 inches thick below the bevel, therefore, there will always be lateral support from the passive support platering.
RAI 03.07.02-10, RAI 03.07.02-20
- Lateral load:
East-West seismic load = 1,144875.1 kips North-South seismic load = 1,103995.3 kips Square Root Sum of Squares horizontal seismic load =
2 2
( 875.1 + 995.3 ) = 1,325.3 kips RAI 03.08.04-10S1 Tier 2 3B-28 Draft Revision 3
NuScale Final Safety Analysis Report Design Reports and Critical Section Details Considering a 5 percent load increase to account for accidental torsion, the SRSS horizontal seismic load is 1,391.4 kips.
RAI 03.07.02-20, RAI 03.08.04-10S1 It is possible for the support ringplates and anchors to experience an upward vertical force if the NPM were to strike thea support ringplate during a seismic event. Because this force is of extremely short duration and the contact surface small, only a limited amount of force is transferred to the support platering. A coefficient of friction value between wet steel and steel of 0.2 is multiplied by the square root sum of squares of east-west and north-south seismic loads to determine this force.
RAI 03.07.02-10, RAI 03.07.02-20, RAI 03.08.04-10S1 Vuplift = 0.2 x 1,391.4 kips = 278.3 kips Materials and Material Strength:
- Stainless Steel: The stainless steel used for the liner plate conforms to ASTM A-167 or ASTM A-240 Type 304L and has a 0.2 percent offset yield strength of 25 ksi, and ultimate tensile strength 70 ksi.
RAI 03.07.02-10, RAI 03.07.02-20, RAI 03.08.04-10S1
- AusteniticDuplex Stainless: The steel used for the 5 3/4-in.-thick bearing plate that supports the NPMs vertically is ASTM A240965 Type S32205Grade F304 with a yield strength of 22.465 ksi and ultimate tensile strength of 61.891.7 ksi at a design temperature of 300 degrees Fahrenheit. Passive plates and guide plates are made of the same material type.
- Concrete for Basemat: The concrete strength, f'c is 5000 psi RAI 03.07.02-20, RAI 03.08.04-10S1 A total of 36, 3/4 in. diameter, ASTM F1554, Grade 55 concrete anchors are used to anchor the passive support ring and embedded plate assembly. These anchors have a yield strength of 55 ksi and designations of S1 (weldable) and S4 (Charpy test).A total of 88 #18 ASTM A706 Grade 60 steel reinforcing bars are used to anchor the embed plate in the four quadrants. The number of anchors in each quadrant (22) is designed for NPM loads.
RAI 03.07.02-20, RAI 03.08.04-10S1 A total of 30, 1.5 in. thread diameter, ASTM A479, Type UNS S21800 bolts fasten the passive support ring to the embedded plate.A total of 16 threaded bolts and 32 pins made of material ASTM A564, Type 17400 with heat treatment condition of H1150, with yield strength of 105 ksi and tensile strength at 300 degrees Fahrenheit of 135 ksi, are used to attach the four passive plates to the embed plate.
Load Path:
RAI 03.07.02-20, RAI 03.08.04-10S1 Tier 2 3B-29 Draft Revision 3
NuScale Final Safety Analysis Report Design Reports and Critical Section Details
- The vertical load is resisted by the 5 3/4 in. thick donut-shape embed plate supporting the 4 1/2 in. thick NPM skirt ring.14.5 ft square, 4 in. thick bearing ring plate.
RAI 03.07.02-20, RAI 03.08.04-10S1
- The lateral load is resisted by bolts/pins that connect the passive support ringplate to the embedded bearing plate. The bolts/pins transfer the lateral load to the bearingembed plate, which, in turn, transfers the load, via bearing, to the concrete basemat.
Evaluation:
Vertical Load Bearing Capacity RAI 03.07.02-10, RAI 03.07.02-20, RAI 03.08.04-10S1, RAI 03.08.04-31
- Area of concrete in bearing, Abrg, is 4310 in2, therefore the bearing pressure (PV/ Abrg) is 0.7390 ksi
- Allowable bearing pressure = ()(0.85f'c) = 2.76 ksi [ = 0.65]
RAI 03.07.02-10, RAI 03.07.02-20, RAI 03.08.04-10S1, RAI 03.08.04-31
- The maximum D/C ratio of the anchor bar shear strength is equal to 0.55bolts is due to concrete breakout in tension and is equal to 0.74.
Lateral Load Resistance RAI 03.07.02-10, RAI 03.07.02-20, RAI 03.08.04-10S1
- The D/C ratio of the bolts/pins in shear and tension is 0.6092.
RAI 03.07.02-10, RAI 03.07.02-20, RAI 03.08.04-10S1, RAI 03.08.04-31
- The maximum D/C ratio for concrete edge bearing due to lateral load transferred from the bearing plate is 0.5883.
RAI 03.08.04-10S1
- The true capacity of the NPM support plate assembly, where D/C would reach a value of 1.0, occurs for a load of 1,391.4 kips/0.60=2,319 kips.
3B.2.7.4 Nuscale Power Module Lug Restraint The NPM lug restraint design consists of a stainless steel bumper comprised of 2 thick plates with 2 thick stiffener plates. The bumpers are welded to 2 thick stainless steel liner plates. On the inside of the liner plate there are 3 thick, 5 wide (48 depth) steel shear lugs to transfer the lateral shear loads into the wall. Finally, the two bumpers on either side of the lug on the pool walls are bolted together with through-bolts to withstand tensile loads due to moments from the eccentric lateral shear loads. The design layout for the support system for the NPM lug restraints is shown in Figure 3B-51.
Tier 2 3B-30 Draft Revision 3
NuScale Final Safety Analysis Report Design Reports and Critical Section Details The bending stress in the 2" thick liner plate can be bounded by considering the moment at the base of highest loaded shear lug as an upper bound moment in the liner plate.
RAI 03.08.04-21S3, RAI 03.08.04-36 From Table 3B-26, the maximum moment on the plate occurs at the shear lug at Y = 88.2" for lug load in the +Y direction. Please see Table 3B-57, which provides D/C ratios for the various lug component stress checks. The D/C ratios listed in Table 3B-57 are for the individual modes of failure for components of the lug assembly. In this table, the demand is the load that is resisted by each component, due to an applied total load of 3500 kips in the SAP2000 model.
RAI 03.08.04-21S3 The highest D/C ratio is for concrete bearing against the shear lugs at 0.777.
Since this maximum ratio is due to the 3500 kips load, the maximum capacity of the lug assembly is 3500 kips/0.777=4500 kips.
3B.2.7.4.2 Overall Lug Restraint Reaction RAI 03.07.02-10, RAI 03.07.02-10S1, RAI 03.08.04-36 Table 3B-28 presents the envelope lug reactions, for all twelve bays, using the threetwelve analysis cases with Soil Type 7 for Capitola input motion with 4 percent structural damping of the SASSI RXB model and the equivalent analysis performed on the NPM detailed seismic model (Reference TR-0916-51502).
Since the maximum lug reactions are below the lug support design capacity of 4,500 kips, the design is acceptable.
RAI 03.08.04-13 3B.2.8 Evaluation of RXB for Load Combinations Involving Thermal and Accident Pressure Loads RAI 03.08.04-13 T0, Ta, and Pa strains in the reinforcing steel and liner steel of the RXB are given in Table 3B-58. Concrete strains under combined static load cases are given in Table 3B-59. Reinforcing steel and liner steel strains for Load Combinations 10 and 13 are given in Table 3B-60 and Table 3B-61 respectively along with demand from combined static demand and individual maximum T0 and Ta+ Pa strains.
RAI 03.08.04-13 Strain averaging is employed at some localized regions as described in Section 3B.1.3. It should be noted that, for regions where averaging is employed, linear addition of T0 and Ta+ Pa strains with static load cases do not necessarily give load combination 10 and 13 resultants as these strains do not necessarily occur at the same location, therefore, the maximum combined strain is not the sum of both maximum strains.
RAI 03.08.04-13 Tier 2 3B-33 Draft Revision 3
NuScale Final Safety Analysis Report Design Reports and Critical Section Details RAI 03.07.02-10S1, RAI 03.08.04-23S3 Table 3B-28: Enveloped NPM Lug Support and Skirt Support Reaction Forces Using Soil Type 7 (CSDRS) and Design Capacities (x103 kips)
Enveloped Input Case SRSS Vertical East Wing Pool Wall West Wing Skirt Lug Horizontal Skirt Wall E-W Lug Wall Support Assembly Skirt Reaction* N-S Lug Reaction N-S Lug Plate Capacity Reaction Reaction (x103 kips) Reaction Capacity (x103 kips)
(x103 kips) (x103 kips) (x103 kips)
NPM Seismic Analysis 1.201.33 1.621.77 3.151.93 3.681.98 2.241.68 SASSI Building Seismic 1.590.72 1.861.625 2.181.38 2.821.54 2.301.33 2.32 4.50 Analysis
- Vertical skirt reactions are not resisted by the support plates, the NPM is free to move vertically Tier 2 3B-109 Draft Revision 3
NuScale Final Safety Analysis Report Design Reports and Critical Section Details RAI 03.08.04-31 Table 3B-53: Analysis Cases for NuScale Power Modules Run Case ID Ground Motion Seed Soil Type NPM Module Concrete Section NPM Module Stiffness 1 Capitola 7 1 Cracked Nominal 2 Capitola 7 1 UncCracked NominalReduced (Scaled to 77%)
3 Capitola 7 61 Cracked NominalIncreased (Scaled to 130%)
4 Capitola 7 61 Uncracked Nominal 5 Capitola 7 1 CUncracked Reduced (Scaled to 77%)
6 Capitola 7 61 CUncracked Reduced (Scaled to 77%)Increased (Scaled to 130%)
7 Capitola 7 6 Cracked Nominal 8 Capitola 7 6 Cracked Reduced (Scaled to 77%)
9 Capitola 7 6 Cracked Increased (Scaled to 130%)
10 Capitola 7 6 Uncracked Nominal 11 Capitola 7 6 Uncracked Reduced (Scaled to 77%)
12 Capitola 7 6 Uncracked Increased (Scaled to 130%)
Tier 2 3B-151 Draft Revision 3