ML24215A044
| ML24215A044 | |
| Person / Time | |
|---|---|
| Site: | 05200050 |
| Issue date: | 08/02/2024 |
| From: | NuScale |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML24215A000 | List:
|
| References | |
| LO-169995 | |
| Download: ML24215A044 (1) | |
Text
Response to SDAA Audit Question Question Number: A-3.8.5-12 Receipt Date: 11/06/2023 Question:
Please include in SDAA Table 2.0-1 the coefficient of friction (CoF) of 0.5 between the concrete foundation and soil for the CRB nonlinear analysis. Note that this coefficient was included previously in DCA Table 2.0-1 and should be included in the SDAA.
Response
NuScale revises US460 Standard Design Approval Application (SDAA) Table 2.0-1 to reflect the coefficient of friction (CoF) of 0.5 between the concrete foundation and soil for the Control Building (CRB) nonlinear analysis.
Markups of the affected changes, as described in the response, are provided below:
NuScale Nonproprietary NuScale Nonproprietary
NuScale Final Safety Analysis Report Site Characteristics and Site Parameters NuScale US460 SDAA 2.0-2 Draft Revision 2 Audit Question A-2.5.4-1S, A-2.8.3-7, A-3.8.5-12 Table 2.0-1: Site Parameters Parameter Description Site Parameter References to Parameter Geography and Demography (Section 2.1)
Minimum exclusion area boundary 369 feet from the closest release point Section 2.1 and Section 2.3.4 Minimum outer boundary of low population zone 369 feet from the closest release point Section 2.1 and Section 2.3.4 Nearby Industrial, Transportation, and Military Facilities (Section 2.2)
External hazards (e.g., explosions, fires, release of toxic chemicals and flammable clouds, pressure effects) on plant structures, systems, and components (SSC)
No external hazards Section 2.2 Aircraft hazards on plant SSC No design basis aircraft hazards Section 2.2 and Section 3.5.1 Meteorology (Section 2.3)
Maximum precipitation rate 19.4 inches per hour 6.3 inches for a 5 minute period Section 3.4.2 Normal roof snow load 50 psf Section 3.4.2 and Section 3.8.4 Extreme roof snow load 75 psf Section 3.4.2 and Section 3.8.4 100-year return period 3-second wind gust speed 190 mph (Exposure Category C) with an importance factor of 1.15 for Reactor Building (RXB), Control Building (CRB), and Radioactive Waste Building (RWB)
Section 3.3.1 and Section 3.8.4 Design basis tornado maximum wind speed translational speed maximum rotational speed radius of maximum rotational speed pressure drop rate of pressure drop 270 mph 55 mph 215 mph 150 ft 1.6 psi 0.9 psi/sec Section 3.3 and Section 3.8.4 Tornado missile spectra Table 2 of Regulatory Guide 1.76, Revision 1, Region I Section 3.3, Section 3.5.1, Section 3.5.2, and Section 3.5.3 Maximum wind speed design basis hurricane 290 mph Section 3.3 and Section 3.8.4 Hurricane missile spectra Tables 1 and 2 of Regulatory Guide 1.221, Revision 0 Section 3.5.1, Section 3.3, Section 3.5.2, and Section 3.5.3 Accident release /Q values at exclusion area boundary and outer boundary of low population zone(1) 0-2 hr 8.96E-04 s/m3 Section 15.0.3 and Section 11.3.3 2-8 hr 7.41E-04 s/m3 8-24 hr 3.32E-04 s/m3 24-96 hr 3.63E-04 s/m3 96-720 hr 3.51E-04 s/m3
NuScale Final Safety Analysis Report Site Characteristics and Site Parameters NuScale US460 SDAA 2.0-4 Draft Revision 2 Lateral soil variability Uniform site (less than 20 degree dip of soil layers)
Section 2.5.4 Minimum allowable soil bearing capacities(2)(3)
- RXB static bearing capacity
- RXB dynamic bearing capacity
- CRB static bearing capacity
- CRB dynamic bearing capacity 16 ksf 34 ksf 6 ksf 25 ksf Section 2.5.4 and Section 3.8.5 Minimum soil angle of internal friction 30 degrees Section 2.5.4 and Section 3.8.5 Minimum shear wave velocity 1000 fps at bottom of foundation Section 2.5.4 Liquefaction potential No liquefaction potential Section 2.5.4 Static Coefficient of friction (CoF) 0.58 where CoF = tan ()
Section 2.5.4 and Section 3.8.5 Kinetic Coefficient of friction (CoF) between the concrete foundation and soil for the CRB nonlinear analysis 0.50 Section 2.5.4 and Section 3.8.5 Maximum settlement for the RXB, CRB, and RWB
- Maximum tilt
- Maximum total settlement
- Maximum differential settlement RXB CRB RWB 0.1 inches 0.2 inches 0.3 inches per 50 feet per 50 feet(4) per 50 feet 1.5 inches 1.0 inches 1.3 inches(5) 0.2 inches 0.3 inches 0.7 inches Section 2.5.4 and Section 3.8.5 Slope failure potential No slope failure potential Section 2.5.5 Note 1: The /Q values provided are conservatively calculated based on approximately 90 percent of the exclusion area boundary distance.
Note 2: Minimum allowable soil bearing capacity is equivalent to the maximum soil bearing demand.
Note 3: Maximum static and dynamic bearing demands are obtained at the building base edges.
Note 4: For the Seismic Category I portion of the building.
Note 5: At the edge of the tunnels that extend towards the RXB.
Table 2.0-1: Site Parameters (Continued)
Parameter Description Site Parameter References to Parameter
NuScale Final Safety Analysis Report Geology, Seismology, and Geotechnical Engineering NuScale US460 SDAA 2.5-2 Draft Revision 2 There is no potential for soil liquefaction. This analysis can be performed with the site-specific safe shutdown earthquake.
Audit Question A-2.8.3-7, A-3.8.5-12 The minimum coefficient of static friction at the interfaces between the basemat and the soil is 0.58. In addition, the minimum coefficient of friction between the concrete foundation and soil is 0.50 for the CRB nonlinear analysis. The friction is defined between concrete and clean gravel, gravel-sand mixture, or coarse sand with a friction angle of 30 degrees (Reference 2.5-1).
The minimum soil angle of internal friction is 30 degrees.
There are no rigid safety-related connections between the structures and no safety-related connections to other site structures. The maximum allowable total settlement, maximum total settlement, maximum tilt, and maximum differential settlement values are provided in Table 2.0-1. For sites not meeting these parameters, site-specific analyses demonstrate the adequacy of the standard plant design.
The following are key design parameters:
minimum shear wave velocity Audit Question A-2.5.4-7 minimum allowable soil bearing capacity and associated factors of safety uniformity of soil layers potential for soil liquefaction minimum coefficient of static friction minimum soil angle of internal friction tilt 2.5.5 Stability of Slopes The standard plant layout assumes a uniform, graded site. Therefore, no slope failure potential is a key design parameter.
2.5.6 References 2.5-1 Department of the Navy, Design Manual 7.2 - Foundation and Earth Structures, NAVFAC DM-7.2, Alexandria, VA, May 1982.