RAIO-0418-59759, LLC - Response to NRC Request for Additional Information No. 132 (Erai No. 8971) on the NuScale Design Certification Application
| ML18120A309 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 04/30/2018 |
| From: | Rad Z NuScale |
| To: | Document Control Desk, Office of New Reactors |
| References | |
| RAIO-0418-59759 | |
| Download: ML18120A309 (20) | |
Text
RAIO-0418-59759 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com April 30, 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 Response to NRC Request for Additional Information No.
132 (eRAI No. 8971) on the NuScale Design Certification Application
REFERENCES:
- 1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 132 (eRAI No. 8971)," dated August 05, 2017 2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 132 (eRAI No. 8971)," dated October 2, 2017 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. 8971:
03.08.04-14 The response to RAI question 03.08.04-12 was provided in reference 2. The response to UHPDLQLQJRAIquestion 03.08.04-11 will be provided by December 20, 2018 and WKHUHVSRQVHWR
RAI question03.08.04-13 will be provided by August 30, 2018.
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, Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution: Omid Tabatabai, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Prosanta Chowdhury NRC, OWFN-8G9A : NuScale Response to NRC Request for Additional Information eRAI No. 8971 Zackary W. Rad
RAIO-0418-59759 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com :
NuScale Response to NRC Request for Additional Information eRAI No. 8971
NuScale Nonproprietary Response to Request for Additional Information Docket No.52-048 eRAI No.: 8971 Date of RAI Issue: 08/05/2017 NRC Question No.: 03.08.04-14 10 CFR 50, Appendix A, GDC 1, 2, and 4 provides requirements to be met by SSC important to safety. In accordance with these requirements, DSRS Section 3.8.4 provides review guidance pertaining to the design of seismic Category I structures, other than the containment. Consistent with 3.8.4.II.4H, the staff reviews the consideration of dynamic lateral soil pressures on embedded walls.
FSAR Section 3.8.4.3.3 describes lateral soil pressures, including dynamic soil pressures corresponding to SSI and SSSI analyses, applicable to the embedded exterior walls of the buildings. The staff request the applicant to clarify whether these pressures are based on the envelope of all SSI and SSSI analysis cases. Also the staff notes that while FSAR Section 3.8.4.3.3 describes the consideration of the aforementioned lateral soil pressures as part of the design loads for the embedded exterior walls, the magnitude of such loads was not provided in the FSAR. The applicant is requested to provide in the FSAR the pressure distributions with depth of the bounding dynamic soil pressures considered in the design of the embedded exterior walls of the buildings.
NuScale Response:
The bounding dynamic soil pressures on the control building (CRB) exterior walls, with depth, from the standalone SSI CRB model and the combined SSSI control building-reactor building-radioactive waste building (CRB-RXB-RWB) model (triple building model) are presented in FSAR Figures 3.8.4-28 and 3.8.4-29, respectively. The seismic soil pressures on the CRB exterior walls enveloping both the standalone and triple building models are shown in FSAR Figure 3.8.4-30. To determine the enveloping loads, the maximum value from all analysis cases for each element is selected. Then, the average pressure of the set of elements across the width of the wall at the selected elevation is obtained.
The bounding dynamic soil pressures on the RXB exterior walls, with depth, from the standalone SSI RXB model and the SSSI triple building model are presented in FSAR Figures 3.8.4-31 and 3.8.4-32, respectively. The seismic soil pressures on the RXB exterior walls
NuScale Nonproprietary enveloping both the standalone and triple building models are shown in FSAR Figure 3.8.4-33.
To determine the enveloping loads, the maximum value from both models, from all analysis
cases, for each element is selected. Then, the average pressure of the set of elements across
the width of the wall at the selected elevation is obtained.
These pressures, along with lateral, static soil pressure, are also tabulated in new FSAR Wables
3.8.4-15 through 3.8.4-20.
It should be noted that the dynamic soil pressures shown in FSAR Figures 3.8.4-28 through
3.8.4-33 are not directly used as an externally applied load case in the design of the CRB and
RXB. Instead, the thick-shell element formulation from SASSI2010 was used, which provides all
of the in-plane forces and moments and out-of-plane shear forces. This formulation eliminates
the need to determine the dynamic soil pressures on the walls from the backfill soil and apply
them as equivalent static wall pressures in SAP2000. The soil pressures presented in the table
in FSAR, Tier 2, Section 3.8.4.3.3 include the envelope of the seismic soil pressures from the
SSI and SSSI analyses.
The results used for design are the envelope of all SSI and SSSI cases, as described in FSAR,
Tier 2, Section 3.7.2.4.1.
Determination of Finite Element Forces and Moments in the RXB and CRB The static and dynamic demand forces and moments are obtained from the following models.
A standalone model, which includes only the RXB and backfill soil:
1.
SAP2000 analyses - static forces and moments, static loads include deadweight, live load, equipment weight, wind pressure, tornado pressure, surcharge loading, snow load, pipe support loads, and hydrostatic pressure.
SASSI2010 - SSI forces and moments: envelope of maximum demand forces and moments from all standalone SSI analyses cases.
Missing hydrodynamic pool wall pressures due to 3D FSI effects are obtained from the ANSYS fluid-structure interaction analysis.
A combined triple building model, which includes the RXB, CRB, radwaste building 2.
(RWB), and backfill soil.
Differential displacement effect: a large-scale SAP2000 finite element model was developed to include the effect of foundation differential movements. This model includes the three NuScale buildings, backfill soil, and a significant portion of the free-field soil.
SASSI2010 - SSI forces and moments: envelope of maximum demand forces and moments from all triple building SSI analysis cases.
NuScale Nonproprietary For all SSI analyses, the demand forces and moments generated from the horizontal 3.
seismic loads are increased by 5% and are combined by means of the square root of the sum of the squares (SRSS).
Final demand forces are obtained as follows:
4.
Total element demand loads = maximum demand static demand forces/moments from SAP2000 analyses for cracked, uncracked, single, and triple building models + maximum seismic demand forces/moments from SASSI2010 analyses from cracked, uncracked, single, and triple building models.
This process is the same for the CRB, except that there are no hydrodynamic forces.
Impact on DCA:
FSAR Tier 2, Section 3.8.4 has been revised as described in the response above and as shown in the markup provided in this response.
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-55 Draft Revision 2 For the static soil pressure, the lateral soil pressure is calculated assuming that the soil is completely confined and cannot move. The soil is also considered to be submerged for the total embedment depth because the water table is close to grade level. Therefore, the total horizontal pressure from the submerged soil is calculated as the sum of the hydrostatic pressure and the lateral soil pressure considering the buoyant effect. Because the water provides a buoyant effect, the effective pressure is calculated using the difference between the soil density and water density. For the RXB, the embedment depth used in the mathematical model is 85'.
RAI 02.05.04-3, RAI 02.05.04-3S1 Maximum Hydrostatic Pressure
= 62.4 pcf Unit weight of water, H = 85 ft Embedment depth, u = H = 5304 psf RAI 02.05.04-3, RAI 02.05.04-3S1 Effective Lateral Pressure sat = 130 pcf Unit weight of saturated soil, b = sat - = 67.6 pcf Buoyant unit weight RAI 02.05.04-3, RAI 02.05.04-3S1 H = 85 ft Embedment Depth, Ko = 0.5 Coefficient of pressure at rest, phe = Kob H = 2873 psf RAI 02.05.04-3, RAI 02.05.04-3S1 Surcharge Loads pq= 250 psf Surcharge Load, phq = Ko pq = 125 psf RAI 02.05.04-3, RAI 02.05.04-3S1 Total Maximum Lateral Soil Pressure The total maximum lateral soil pressure at a depth H is the sum of the hydrostatic pressure, the effective lateral pressure, and the surcharge lateral pressures calculated above.
RAI 02.05.04-3, RAI 02.05.04-3S1 ph= u + phe + phq = 8302 psf RAI 02.05.04-3, RAI 02.05.04-3S1, RAI 03.08.04-14 Figure 3.8.4-27 shows a diagram of the total lateral, static soil pressure distribution.
The bounding dynamic soil pressures on the control building (CRB) exterior walls, with depth, from the standalone SSI CRB model and the combined SSSI control building-reactor building-radioactive waste building (CRB-RXB-RWB) model (triple building model) are presented in Figure 3.8.4-28 and Figure 3.8.4-29, respectively.
The seismic soil pressures on the CRB exterior walls enveloping both the
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-56 Draft Revision 2 standalone and triple building models are shown in Figure 3.8.4-30. To determine the enveloping loads, the maximum value from all analysis cases for each element is selected. Then, the average pressure of the set of elements across the width of the wall at the selected elevation is obtained. The bounding dynamic soil pressures on the RXB exterior walls, with depth, from the standalone SSI RXB model and the SSSI triple building model are presented in Figure 3.8.4-31 and Figure 3.8.4-32, respectively. The seismic soil pressures on the RXB exterior walls enveloping both the standalone and triple building models are shown in Figure 3.8.4-33. To determine the enveloping loads, the maximum value from all analysis cases for each element is selected. Then, the average pressure of the set of elements across the width of the wall at the selected elevation is obtained.
RAI 03.08.04-14 These pressures, along with lateral, static soil pressure, are also tabulated in Table 3.8.4-15 through Table 3.8.4-20. It should be noted that the dynamic soil pressures shown in these figures are not directly used in the design of the CRB and RXB. Instead, the thick-shell element formulation from SASSI2010 was used, which provides all of the in-plane forces and moments and out-of-plane shear forces. This formulation eliminates the need to determine the dynamic soil pressures on the walls from the backfill soil and apply them as equivalent static wall pressures in SAP2000.
RAI 03.08.04-14 Seismic soil pressure is computed from the SASSI2010 Soil-Structure Interaction analysis. The normal stresses in the backfill soil solid elements, adjacent to the embedded portion of the RXB exterior walls, represent the soil pressure. For example, for the RXB, the following table provides the summary of total soil pressures on the four walls and total overturning moments induced by the soil pressures. These pressures are the enveloping values of all SSI and SSSI analysis cases.
RAI 02.05.04-3, RAI 02.05.04-3S1 RAI 03.08.04-14 Determination of Finite Element Forces and Moments in the RXB and CRB RAI 03.08.04-14 The static and dynamic demand forces and moments are obtained from the following models.
RAI 03.08.04-14
- 1) A standalone model, which includes only the RXB and backfill soil -
Wall ID Total Soil Pressure on Walls (kips)
Total Overturning Moment (Kip-ft)
North wall 570,991 8,911,955 South wall 425,678 7,925,347 West wall 188,731 2,614,131 East wall 178,541 3,096,417
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-57 Draft Revision 2 SAP2000 analyses - static forces and moments, static loads include deadweight, live load, equipment weight, wind pressure, tornado pressure, surcharge loading, snow load, pipe support loads, and hydrostatic pressure.
SASSI2010 - SSI forces and moments: envelope of maximum demand forces and moments from all standalone SSI analyses cases.
Missing hydrodynamic pool wall pressures due to 3D FSI effects are obtained from the ANSYS fluid-structure interaction analysis.
RAI 03.08.04-14
- 2) A combined triple building model, which includes the RXB, CRB, radwaste building (RWB), and backfill soil.
Differential displacement effect: a large-scale SAP2000 finite element model was developed to include the effect of foundation differential movements. This model includes the three buildings, backfill soil, and a significant portion of the free-field soil.
SASSI2010 - SSI forces and moments: envelope of maximum demand forces and moments from all triple building SSI analysis cases.
RAI 03.08.04-14
- 3) For all SSI analyses, the demand forces and moments generated from the horizontal seismic loads are increased by 5% and are combined by means of the square root of the sum of the squares (SRSS).
RAI 03.08.04-14
- 4) Final demand forces are obtained as follows: Total element demand loads =
maximum static forces/moments from SAP2000 analyses for cracked, and uncracked, single and triple building models + maximum seismic demand forces/moments from SASSI2010 analyses from cracked, and uncracked, single and triple building models.
RAI 03.08.04-14 This process is the same for the CRB, except that there are no hydrodynamic forces.
RAI 02.05.04-3, RAI 02.05.04-3S1 COL Items 2.5-1, 3.7-3, 3.7-5, 3.7-6, and 3.8-2 specify the site-specific geology and soil-structure interaction analysis requirements of the NuScale Power Plants.
3.8.4.3.4 Live Loads (L)
Live loads are a non-permanent weight based upon the maximum loads expected by the use and occupancy of the structure. RXB live loads include floor area loads, lay down loads, fuel transfer casks and equipment handling loads, and similar items.
The RXB uses a base live load of 100 psf, and a live load of 250 psf for the Nuclear Fuel Storage & Refueling Areas and for the portions of the EL. 50'-0" floor
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-95 Draft Revision 2 RAI 03.08.04-14 Table 3.8.4-15: Seismic and Static Soil Pressures on CRB Walls for Standalone Model Elev.
No.
Elev.
(ft)
Seismic Static (psi)
North (psi)
South (psi)
East (psi)
West (psi) 1 95.9 14.3 14.4 13.1 12.3 3.0 2
89.6 7.1 7.0 6.9 7.3 7.1 3
83.4 8.5 8.1 7.6 7.1 11.3 4
77.1 14.5 14.0 11.2 10.0 15.5 5
70.9 12.8 12.1 11.0 10.7 19.7 6
64.6 12.0 12.1 10.7 9.2 23.8 7
58.1 15.1 14.9 15.2 12.6 28.2 8
51.5 17.8 17.9 18.2 16.7 32.6
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-96 Draft Revision 2 RAI 03.08.04-14 Table 3.8.4-16: Seismic and Static Soil Pressures on CRB Walls for Triple Building Model Elev.
No.
Elev.
(ft)
Seismic Static (psi)
North (psi)
South (psi)
East (psi)
West (psi) 1 95.9 16.3 16.6 23.4 15.6 3.0 2
89.6 7.8 7.8 10.1 11.0 7.1 3
83.4 8.0 7.9 10.0 9.7 11.3 4
77.1 15.8 16.1 21.1 16.5 15.5 5
70.9 12.9 12.9 18.9 20.7 19.7 6
64.6 12.3 12.0 17.5 17.0 23.8 7
58.1 21.4 19.9 19.8 27.5 28.2 8
51.5 41.7 38.4 41.5 55.9 32.6
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-97 Draft Revision 2 RAI 03.08.04-14 Table 3.8.4-17: Enveloping Seismic Soil Pressures on CRB Walls Elev.
No.
Elev.
(ft)
Seismic Static (psi)
North (psi)
South (psi)
East (psi)
West (psi) 1 95.9 16.3 16.6 23.4 15.6 3.0 2
89.6 7.8 7.8 10.1 11.0 7.1 3
83.4 8.0 7.9 10.0 9.7 11.3 4
77.1 15.8 16.1 21.1 16.5 15.5 5
70.9 12.9 12.9 18.9 20.7 19.7 6
64.6 12.3 12.0 17.5 17.0 23.8 7
58.1 21.4 19.9 19.8 27.5 28.2 8
51.5 41.7 38.4 41.5 55.9 32.6
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-98 Draft Revision 2 RAI 03.08.04-14 Table 3.8.4-18: Seismic and Static Soil Pressures on RXB Walls for Standalone Model Elev.
No.
Elev.
(ft)
Seismic Static (psi)
North (psi)
South (psi)
East (psi)
West (psi) 1 95.9 60.7 61.2 33.0 28.8 3.0 2
89.6 15.2 15.3 12.9 16.3 7.1 3
83.4 24.2 24.5 16.7 13.3 11.3 4
77.1 50.4 51.3 30.8 28.9 15.5 5
70.9 42.5 43.4 25.4 23.0 19.7 6
64.6 34.3 34.6 24.2 22.5 23.8 7
58.4 35.4 35.3 24.4 24.2 28.0 8
52.1 30.3 29.8 26.0 25.6 32.2 9
45.9 31.4 31.0 23.7 22.9 36.4 10 39.6 30.6 30.1 25.1 23.7 40.5 11 33.4 37.0 36.9 29.0 27.0 44.7 12 27.1 63.2 62.6 45.2 41.6 48.9
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-99 Draft Revision 2 RAI 03.08.04-14 Table 3.8.4-19: Seismic and Static Soil Pressures on RXB Walls for Triple Building Model Elev.
No.
Elev.
(ft)
Seismic Static (psi)
North (psi)
South (psi)
East (psi)
West (psi) 1 95.9 59.6 57.2 26.1 22.4 3.0 2
89.6 19.0 18.2 19.8 16.0 7.1 3
83.4 23.4 21.3 16.8 11.4 11.3 4
77.1 54.6 51.0 28.5 23.2 15.5 5
70.9 44.9 36.2 26.9 22.0 19.7 6
64.6 36.9 32.0 23.0 37.8 23.8 7
58.4 31.9 29.5 23.3 39.1 28.0 8
52.1 29.7 26.7 30.6 38.0 32.2 9
45.9 34.3 29.0 53.5 52.3 36.4 10 39.6 42.7 29.5 85.5 53.5 40.5 11 33.4 67.6 49.1 95.9 56.3 44.7 12 27.1 120.3 80.5 117.4 78.7 48.9
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-100 Draft Revision 2 RAI 03.08.04-14 Table 3.8.4-20: Enveloping Seismic Soil Pressures on RXB Walls Elev.
No.
Elev.
(ft)
Seismic Static (psi)
North (psi)
South (psi)
East (psi)
West (psi) 1 95.9 62.3 61.9 41.2 28.8 3.0 2
89.6 19.4 18.6 20.4 17.1 7.1 3
83.4 24.8 24.6 20.6 13.5 11.3 4
77.1 55.4 52.5 39.2 28.9 15.5 5
70.9 46.6 43.8 33.1 24.5 19.7 6
64.6 37.9 35.4 29.2 37.8 23.8 7
58.4 36.3 35.3 29.6 39.1 28.0 8
52.1 32.3 30.5 34.2 38.0 32.2 9
45.9 36.6 33.9 53.5 52.3 36.4 10 39.6 43.2 32.7 85.5 53.5 40.5 11 33.4 67.7 52.3 95.9 56.5 44.7 12 27.1 121.5 86.3 117.4 79.1 48.9
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-128 Draft Revision 2 RAI 03.08.04-14 Figure 3.8.4-28: Seismic Soil Pressures on CRB Walls of Standalone Model
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-129 Draft Revision 2 RAI 03.08.04-14 Figure 3.8.4-29: Seismic Soil Pressures on CRB Walls of Triple Building Model
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-130 Draft Revision 2 RAI 03.08.04-14 Figure 3.8.4-30: Enveloping Seismic Soil Pressures on CRB Walls of Standalone and Triple Building Models
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-131 Draft Revision 2 RAI 03.08.04-14 Figure 3.8.4-31: Seismic Soil Pressure on RXB Walls from Standalone Model
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-132 Draft Revision 2 RAI 03.08.04-14 Figure 3.8.4-32: Seismic Soil Pressure on RXB Walls from Triple Building Model
NuScale Final Safety Analysis Report Design of Category I Structures Tier 2 3.8-133 Draft Revision 2 RAI 03.08.04-14 Figure 3.8.4-33: Enveloping Soil Pressure on RXB Walls by Standalone and Triple Building Models