ML18295A791
| ML18295A791 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 10/22/2018 |
| From: | Wike J NuScale |
| To: | Document Control Desk, Office of New Reactors |
| References | |
| RAIO-1018-62208 | |
| Download: ML18295A791 (8) | |
Text
RAIO-1018-62208 October 22, 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. 110 (eRAI No. 8932) on the NuScale Design Certification Application
REFERENCES:
- 1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 110 (eRAI No. 8932)," dated July 30, 2017
- 2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 11 O (eRAI No.8932)," dated May 22, 2018
- 3. NuScale Power, LLC Supplemental Response to "NRC Request for Additional Information No. 110 (eRAI No. 8932)" dated August 24, 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. 8932:
- 03.07.02-6 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, Jefl(;J~
Manager, Licensing NuScale Power, LLC Distribution: Gregory Cranston, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Marieliz Vera, NRC, OWFN-8G9A Enclosure 1: NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 8932 NuScale Power, LLC 1100 NE Circle Blvd. , Suite 200 Corvalis, Oregon 97330 , Office: 541.360.0500 , Fax: 541.207.3928 www.nuscalepower.com
NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 8932 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.: 8932 Date of RAI Issue: 07/31/2017 NRC Question No.: 03.07.02-6 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. DSRS 3.7.2 provides guidance that effects of potential separation or loss of contact between the structure and the soil during the earthquake should be considered in SSI analysis. On Page 3.7-23 of the FSAR, in the second paragraph from the bottom, the applicant states, To model the soil separation, the Young's modulus of the backfill elements down to a depth of 25 (the top four layers of backfill elements) was decreased by a factor of 100. The applicant is requested to provide a basis for 25 ft of separation depth.
Also, please clarify if the modulus reduction by a factor of 100 applies only to the backfill elements interfacing with the exterior walls or to all the backfill elements outside the exterior walls.
- b. On Page 3.7-23 of the FSAR, in the bottom paragraph, the applicant states, Soil separation has negligible effect on the response of the structure. The primary point of comparison is at the NPM. The study showed that the maximum reaction force at the base of the NPMs decreased by approximately 5 percent, and the maximum reaction force at the NPM lug restraints decreased by more than 15 percent. The applicant is requested to provide information on soil separation effect on computed transfer functions and seismic demands (forces, ISRS) at critical section locations and external walls. Please provide comparison plots for results between the intact and soil-separated cases. When soil-separation results in increased seismic demands, such increased demands should be taken into account in establishing the design basis seismic demands.
NuScale Nonproprietary
- c. The staff notes that a soil-separation study was conducted for the RXB but not for the CRB. The applicant is requested to provide a technical justification for not conducting a similar study for the CRB.
NuScale Response:
During a public meeting on October 2, 2018, the NRC requested NuScale submit a supplemental response to RAI 8932 Question 03.07.02-6. Further, the NRC provided the following details concerning past submittals for this question and clarification needed in the new supplemental response:
- 1. NRC Feedback: NuScale proposed to add a new COL Item to the FSAR to require the COL applicant to perform a site-specific evaluation of the effects of soil separation.
However, the staff believes that a statement located immediately above the proposed COL Item 3.7-11 (see FSAR markup, Page 3.7-116, Draft Revision 2) which reads Based on the results of these studies, it is concluded that modeling the structures as fully embedded is an acceptable design approach should be augmented with a qualifying statement that such a conclusion should be confirmed or established through a site-specific evaluation of the effects of soil separation on site-specific seismic demands, or to that effect.
NuScale Response: A qualifying statement has been added to FSAR Section 3.7.2.1.1.3 to note that the soil separation analysis will be confirmed with a site-specific evaluation.
- 2. NRC Feedback: In the proposed COL Item 3.7-11 statement, the staff notes that a qualifying phrase if applicable is included. Please explain why this phrase is needed and what it implies.
NuScale Response: This phrase was added because there may be some sites for which soil separation won't be a concern, for example, sites with cohensionless soil. However, "if applicable" has been stricken from COL Item 3.7-11 since COL applicants always have the option to provide a technical justification for not completing COL items as they are written.
NuScale Nonproprietary
Impact on DCA:
FSAR Tier 2, Section 3.7.2 and FSAR Tier 2, Table 1.8-2 have 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 Interfaces with Certified Design RAI 01-61, RAI 02.04.13-1, RAI 03.04.01-4, RAI 03.04.02-1, RAI 03.04.02-2, RAI 03.04.02-3, RAI 03.05.01.04-1, RAI 03.05.02-2, RAI 03.06.02-6, RAI 03.06.02-15, RAI 03.06.03-11, RAI 03.07.01-2, RAI 03.07.01-3, RAI 03.07.02-6S1, RAI 03.07.02-6S2, RAI 03.07.02-8, RAI 03.07.02-12, RAI 03.08.04-3S2, RAI 03.08.04-23S1, RAI 03.08.04-23S2, RAI 03.08.05-14S1, RAI 03.09.02-15, RAI 03.09.02-48, RAI 03.09.02-67, RAI 03.09.02-69, RAI 03.09.03-12, RAI 03.09.06-5, RAI 03.09.06-6, RAI 03.09.06-16, RAI 03.09.06-16S1, RAI 03.09.06-27, RAI 03.11-8, RAI 03.11-14, RAI 03.11-14S1, RAI 03.11-18, RAI 03.13-3, RAI 04.02-1S2, RAI 05.02.03-19, RAI 05.02.05-8, RAI 05.04.02.01-13, RAI 05.04.02.01-14, RAI 06.02.06-22, RAI 06.02.06-23, RAI 06.04-1, RAI 09.01.01-20, RAI 09.01.02-4, RAI 09.01.05-3, RAI 09.01.05-6, RAI 09.03.02-3, RAI 09.03.02-4, RAI 09.03.02-5, RAI 09.03.02-6, RAI 09.03.02-8, RAI 10.02-1, RAI 10.02-2, RAI 10.02-3, RAI 10.02.03-1, RAI 10.02.03-2, RAI 10.03.06-1, RAI 10.03.06-5, RAI 10.04.06-1, RAI 10.04.06-2, RAI 10.04.06-3, RAI 10.04.10-2, RAI 11.01-2, RAI 12.03-55S1, RAI 13.01.01-1, RAI 13.01.01-1S1, RAI 13.02.02-1, RAI 13.03-4, RAI 13.05.02.01-2, RAI 13.05.02.01-2S1, RAI 13.05.02.01-3, RAI 13.05.02.01-3S1, RAI 13.05.02.01-4, RAI 13.05.02.01-4S1, RAI 14.02-7, RAI 19-31, RAI 19-31S1, RAI 19-38, RAI 20.01-13 Table 1.8-2: Combined License Information Items Item No. Description of COL Information Item Section COL Item 1.1-1: A COL applicant that references the NuScale Power Plant design certification will identify the 1.1 site-specific plant location.
COL Item 1.1-2: A COL applicant that references the NuScale Power Plant design certification will provide the 1.1 schedules for completion of construction and commercial operation of each power module.
COL Item 1.4-1: A COL applicant that references the NuScale Power Plant design certification will identify the 1.4 prime agents or contractors for the construction and operation of the nuclear power plant.
COL Item 1.7-1: A COL applicant that references the NuScale Power Plant design certification will provide site- 1.7 specific diagrams and legends, as applicable.
COL Item 1.7-2: A COL applicant that references the NuScale Power Plant design certification will list additional 1.7 site-specific piping and instrumentation diagrams and legends as applicable.
COL Item 1.8-1: A COL applicant that references the NuScale Power Plant design certification will provide a list of 1.8 departures from the certified design.
COL Item 1.9-1: A COL applicant that references the NuScale Power Plant design certification will review and 1.9 address the conformance with regulatory criteria in effect six months before the docket date of the COL application for the site-specific portions and operational aspects of the facility design.
COL Item 1.10-1: A COL applicant that references the NuScale Power Plant design certification will evaluate the 1.10 potential hazards resulting from construction activities of the new NuScale facility to the safety-related and risk significant structures, systems, and components of existing operating unit(s) and newly constructed operating unit(s) at the co-located site per 10 CFR 52.79(a)(31).
The evaluation will include identification of management and administrative controls necessary to eliminate or mitigate the consequences of potential hazards and demonstration that the limiting conditions for operation of an operating unit would not be exceeded. This COL item is not applicable for construction activities (build-out of the facility) at an individual NuScale Power Plant with operating NuScale Power Modules.
COL Item 2.0-1: A COL applicant that references the NuScale Power Plant design certification will demonstrate 2.0 that site-specific characteristics are bounded by the design parameters specified in Table 2.0-1.
If site-specific values are not bounded by the values in Table 2.0-1, the COL applicant will demonstrate the acceptability of the site-specific values in the appropriate sections of its combined license application.
COL Item 2.1-1: A COL applicant that references the NuScale Power Plant design certification will describe the 2.1 site geographic and demographic characteristics.
COL Item 2.2-1: A COL applicant that references the NuScale Power Plant design certification will describe 2.2 nearby industrial, transportation, and military facilities. The COL applicant will demonstrate that the design is acceptable for each potential accident, or provide site-specific design alternatives.
COL Item 2.3-1: A COL applicant that references the NuScale Power Plant design certification will describe the 2.3 site-specific meteorological characteristics for Section 2.3.1 through Section 2.3.5, as applicable.
COL Item 2.4-1: A COL applicant that references the NuScale Power Plant design certification will investigate 2.4 and describe the site-specific hydrologic characteristics for Section 2.4.1 through Section 2.4.14, except Section 2.4.8 and Section 2.4.10.
COL Item 2.5-1: A COL applicant that references the NuScale Power Plant design certification will describe the 2.5 site-specific geology, seismology, and geotechnical characteristics for Section 2.5.1 through Section 2.5.5, below.
Tier 2 1.8-3 Draft Revision 3
NuScale Final Safety Analysis Report Interfaces with Certified Design Table 1.8-2: Combined License Information Items (Continued)
Item No. Description of COL Information Item Section COL Item 3.7-11: A COL applicant that references the NuScale Power Plant design certification will perform a 3.7 site-specific analysis that, if applicable, assesses the effects of soil separation. The COL applicant will confirm that the in-structure response spectra in the soil separation cases are bounded by the in-structure response spectra shown in FSAR Figure 3.7.2-107 through Figure 3.7.2-122.
COL Item 3.8-1: A COL applicant that references the NuScale Power Plant design certification will describe the 3.8 site-specific program for monitoring and maintenance of the Seismic Category I structures in accordance with the requirements of 10 CFR 50.65 as discussed in Regulatory Guide 1.160.
Monitoring is to include below grade walls, groundwater chemistry if needed, base settlements and differential displacements.
COL Item 3.8-2: A COL applicant that references the NuScale Power Plant design certification will confirm that 3.8 the site independent Reactor Building and Control Building are acceptable for use at the designated site.
COL Item 3.8-3: A COL applicant that references the NuScale Power Plant design certification will identify local 3.8 stiff and soft spots in the foundation soil and address these in the design, as necessary.
COL Item 3.8-4: A COL applicant that references the NuScale Power Plant design certification will evaluate and 3.8 document construction aid elements such as steel beams, Q-decking, formwork, lugs, and other items that are left in place after construction but that were not part of the certified design to verify the construction aid elements do not have an appreciable adverse effect on overall mass, stiffness, and seismic demands of the certified building structure. The COL applicant will confirm that these left in place construction aid elements will not have adverse effects on safety-related structures, systems, and components per Section 3.7.2.
COL Item 3.9-1: A COL applicant that references the NuScale Power Plant design certification will provide the 3.9 applicable test procedures before the start of testing and will submit the test and inspection results from the comprehensive vibration assessment program for the NuScale Power Module, in accordance with Regulatory Guide 1.20.
COL Item 3.9-2: A COL applicant that references the NuScale Power Plant design certification will develop 3.9 design specifications and design reports in accordance with the requirements outlined under American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section III (Reference 3.9-1). A COL applicant will address any known issues through the reactor vessel internals reliability programs (i.e. Comprehensive Vibration Assessment Program, steam generator programs, etc.) in regards to known aging degradation mechanisms such as those addressed in Section 4.5.2.1.
COL Item 3.9-3: A COL applicant that references the NuScale Power Plant design certification will provide a 3.9 summary of reactor core support structure ASME service level stresses, deformation, and cumulative usage factor values for each component and each operating condition in conformance with ASME Boiler and Pressure Vessel Code Section III Subsection NG.
COL Item 3.9-4: A COL applicant that references the NuScale Power Plant design certification will submit a 3.9 Preservice Testing program for valves as required by 10 CFR 50.55a.
COL Item 3.9-5: A COL applicant that references the NuScale Power Plant design certification will establish an 3.9 Inservice Testing program in accordance with ASME OM Code and 10 CFR 50.55a.
COL Item 3.9-6: A COL applicant that references the NuScale Power Plant design certification will identify any 3.9 site-specific valves, implementation milestones, and the applicable ASME OM Code (and ASME OM Code Cases) for the preservice and inservice testing programs. These programs are to be consistent with the requirements in the latest edition and addenda of the OM Code incorporated by reference in 10 CFR 50.55a in accordance with the time period specified in 10 CFR 50.55a before the scheduled initial fuel load (or the optional ASME Code Cases listed in Regulatory Guide 1.192 incorporated by reference in 10 CFR 50.55a).
COL Item 3.9-7: Not Used.
COL Item 3.9-8: A COL applicant that references the NuScale Power Plant design certification will develop 3.9 specific test procedures to allow detection and monitoring of power-operated valve assembly performance sufficient to satisfy periodic verification design basis capability requirements.
Tier 2 1.8-7 Draft Revision 3
NuScale Final Safety Analysis Report Seismic Design RAI 03.07.02-6, RAI 03.07.02-6S2 Based on the results of these studies, it is concluded that modeling the structures as fully embedded is an acceptable design approach. This will be confirmed through a site-specific evaluation as described in COL Item 3.7-11.
RAI 03.07.02-6S1, RAI 03.07.02-6S2 COL Item 3.7-11: A COL applicant that references the NuScale Power Plant design certification will perform a site-specific analysis that, if applicable, assesses the effects of soil separation. The COL applicant will confirm that the in-structure response spectra in the soil separation cases are bounded by the in-structure response spectra shown in FSAR Figure 3.7.2-107 through Figure 3.7.2-122.
RAI 03.07.02-23 Effect of Non-Vertically Propagating Seismic Waves RAI 03.07.02-23 A sensitivity study was performed to determine the effect of non-vertically propagating shear waves. This study, first, establishes a procedure for evaluating a structure that experiences non-vertically propagating seismic waves, and second, analyzes the RXB DCA model with non-vertically propagating seismic waves.
RAI 03.07.02-23 The intent of the SSI analysis study with non-vertically propagating (that is, inclined) waves is to compare the SSI results with those of the design-basis case, which uses conventional, vertically propagating shear (SV and SH) and P-waves for the seismic input. A body wave (either SV- or P-wave) propagating at an inclined angle will include both horizontal and vertical motions in the free field, whereas an inclined SH-wave generates only horizontal motion in the free field.
RAI 03.07.02-23 For the sensitivity study, Soil Type 7 was selected for the free-field soil properties because it is a nearly uniform soil profile with a high shear wave velocity, Vs, of 5,000 ft/sec. Using a uniform and stiff soil for this study will give conservative results because, for non-uniform and soft soil profiles, the angle of incidence decreases as the wave propagates toward the surface, due to Snell's law and, thus, the effect of non-vertically propagating waves will be much less.
RAI 03.07.02-23 Analyses were performed and results compared for the following angles of incidence, , where is measured from the vertical axis (see Figure 3.7.2-149):
RAI 03.07.02-23
= 0° or apparent wave velocity = , that is, the vertically propagating wave case Tier 2 3.7-113 Draft Revision 3