RAIO-0818-61492, LLC Response to NRC Request for Additional Information No. 343 (Erai No. 9298) on the NuScale Design Certification Application
| ML18234A445 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 08/22/2018 |
| From: | Rad Z NuScale |
| To: | Document Control Desk, Office of New Reactors |
| References | |
| RAIO-0818-61492 | |
| Download: ML18234A445 (15) | |
Text
RAIO-0818-61492 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com Docket No.52-048 August 22, 2018 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.
343 (eRAI No. 9298) on the NuScale Design Certification Application
REFERENCE:
U.S. Nuclear Regulatory Commission, "Request for Additional Information No.
343 (eRAI No. 9298)," dated January 26, 2018 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 Questions from NRC eRAI No. 9298:
12.03-17 12.03-18 12.03-19 12.03-20 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 Carrie Fosaaen at 541-452-7126 or at cfosaaen@nuscalepower.com.
Sincerely, Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution:
Gregory Cranston, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Getachew Tesfaye, NRC, OWFN-8H12 : NuScale Response to NRC Request for Additional Information eRAI No. 9298 Zackary W. Rad Director, Regulatory Affairs
RAIO-0818-61492 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. 9298
Response to Request for Additional Information Docket No.52-048 eRAI No.: 9298 Date of RAI Issue: 01/26/2018 NRC Question No.: 12.03-17 Regulatory Basis Appendix A to Part 50General Design Criteria (GDC) for Nuclear Power Plants, Criterion 4 requires applicants to ensure that structures, systems, and components important to safety are designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation and postulated accidents.
10 CFR 52.47(a)(5) requires applicants to identify the kinds and quantities of radioactive materials expected to be produced in the operation and the means for controlling and limiting radiation exposures within the limits set forth in 10 CFR Part 20.
Appendix A to Part 50General Design Criteria for Nuclear Power Plants, Criterion 61Fuel storage and handling and radioactivity control, requires systems which may contain radioactivity to be designed with suitable shielding for radiation protection and with appropriate containment, confinement, and filtering systems.
10 CFR 20.1101(b) and 10 CFR 20.1003 require the use of engineering controls to maintain exposures to radiation as far below the dose limits in 10 CFR Part 20, as is practical. The Acceptance Criteria of DSRS Section 12.3-12.4, Radiation Protection Design Features, notes that where the applicants shielding design incorporates material subject to degradation, such as through the effects of radiation (e.g., depletion of boron neutron absorbers,) temperature extremes (e.g., degradation of polymer based materials because of high temperature,) density changes (e.g., sagging or settling of shielding material with age,) the reviewer should ensure that methods are in place to ensure that ORE remains ALARA. The staff should review how the application identifies the allowable constraints (e.g., minimum cooling air flow, maximum shielding material temperature, and maximum allowable neutron flux), and how those parameters are measured and assessed over the design life of the facility. The acceptance criteria of NuScale DSRS section 12.3-12.4 states that the applicants methods for performing shielding design calculations are acceptable if assumptions regarding source terms, cross sections, shield and source geometries, and transport methods are realistic; and if specified NuScale Nonproprietary
radiation zones are consistent with the assumed source term and shielding specified in the design.
Background
DCD Tier 2 Revision 0 Section 12.3.2.2, Design Considerations, states that in addition to concrete, other types of materials such as steel, water, tungsten, and polymer composites are considered for both permanent and temporary shielding. The only location where the use of polyethylene is identified is in DCD Table 12.3-6: Reactor Building Shield Wall Geometry.
DCD Table 12.3-6: Reactor Building Shield Wall Geometry, provides the nominal thickness of concrete for some of the walls in the RXB. DCD Table 12.3-8: Reactor Building Radiation Shield Doors, list the shielded doors located in the RXB. DCD Table 12.3-9: Radioactive Waste Building Radiation Shield Doors, list the shielded doors located in the RWB. DCD Section 12.3 does not contain any information about the assumption for concrete density, other than the references to ANSI/ANS 6.4-2006 and PNNL-25870.
Using information made available to the staff during the RPAC Chapter 12 Audit, the staff reviewed some of the shielding calculation information for the RXB and the RWB. The staff noticed that the polyethylene shielding specified for the bioshield cover is high density polyethylene and includes 5% natural boron.
Based on information made available to the staff during the RPAC Chapter 12 a, the staff was able to review some of the assumptions used for the RXB shielding analysis. However, the RXB MCNP6 analysis package for the RXB was not available for staff review, so the staff was unable to assess what values were used in the actual RXB shielding calculations.
The acceptance criteria of NuScale DSRS section 12.3-12.4 states that the applicants methods for performing shielding design calculations are acceptable if assumptions regarding source terms, cross sections, shield and source geometries, and transport methods are realistic; and if specified radiation zones are consistent with the assumed source term and shielding specified in the design.
Key Issue 1 DCD Tier 2 Section 12.3.2, Shielding, DCD Section 12.3.2.3, Calculation Methods, and DCD Section 12.3.2.4.3, Reactor Building, do not specify the values of key assumptions, such as minimum polyethylene density, or that the polyethylene is supposed to contain boron; nor the minimum weight percent of boron in the polyethylene documented.
Question 1 To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions with respect to the neutron shielding materials incorporated into the NuScale Nonproprietary
design, the staff requests that the applicant:
Justify/explain the assumptions used to perform the neutron shielding analysis for the bioshield polyethylene shielding, including the associated methods, models and assumptions used to establish the identified values, As necessary, revise DCD Section 12.3.2, and Table 12.3-6 to describe the these assumptions OR Provide the specific alternative approaches used and the associated justification.
NuScale Response:
NuScale has revised the design of the bioshield and has removed the borated polyethylene layer and replaced it with concrete. The shielding analysis results, documented in FSAR Tier 2 Table 12.3-6, and Tier 1 Table 3.11-1 have been revised to reflect this change. For the shielding design, as described in the FSAR, the materials used include steel and concrete. FSAR Tier 2 Tables 12.3-6 and 12.3-7 (and Tier 1 Tables 3.11-1 and 3.12-1) identify the locations and materials that are provided as part of the shielding design. Other shielding materials may be employed by the licensee for temporary or compensatory shielding.
Impact on DCA:
FSAR Tier 1 Table 3.11-1 and Tier 2 Table 12.3-6 have been revised as described in the response above and as shown in the markup provided in this response.
NuScale Nonproprietary
NuScale Tier 1 Reactor Building Tier 1 3.11-3 Draft Revision 2 RAI 12.03-17, RAI 12.03-27 Table 3.11-1: Reactor Building Shield Wall Geometry Elev.
Room Name North Wall (Note 1)
East Wall (Note 1)
South Wall (Note 1)
West Wall (Note 1)
Floor (Note 2)
Ceiling (Note 2) 24 Module 1 CVCS ion exchanger sluice room 20 structural steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 2 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 3 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 4 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 5 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 6 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 7 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 8 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 9 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 10 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 11 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Module 12 CVCS ion exchanger sluice room 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 20" concrete/steel composite slab 24 Degasifier room A 5 concrete, RXB exterior wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 3 concrete (floor of 50 elevation) 24 Degasifier room B 5 concrete, RXB exterior wall 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 10 concrete (ground floor) 3 concrete (floor of 50 elevation) 24 Pool cleanup filter room A 5 concrete, RXB wall 20 concrete/steel partition wall 20 concrete/steel partition wall 5 concrete, RXB exterior wall 10 concrete (ground floor) 3 concrete (floor of 50 elevation) 24 Pool cleanup filter room B 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall 5 concrete, RXB exterior wall 10 concrete (ground floor) 3 concrete (floor of 50 elevation)
NuScale Tier 1 Reactor Building Tier 1 3.11-6 Draft Revision 2 100 Modules 1-6 CVCS vertical pipe chases 20 concrete/steel partition wall 20 concrete/steel partition wall 5 concrete (reactor pool wall) 20 concrete/steel partition wall N/A N/A 100 Modules 7-12 CVCS vertical pipe chases 5 concrete (reactor pool wall) 20 concrete/steel partition wall 20 concrete/steel partition wall 20 concrete/steel partition wall N/A N/A 126 Reactor pool area 5 concrete wall 5 concrete wall 5 concrete wall 5 concrete wall 21.523.5 concrete, 2 high-density polyethylene, 0.250.5 steel (Bioshield) 4 concrete roof Note 1: A 20 concrete/steel partition wall consists of two one-half inch steel plates with 19 of concrete in between.
Note 2: A 20 concrete/steel composite slab consists of two one-half inch steel plates with 19 of concrete in between.
Table 3.11-1: Reactor Building Shield Wall Geometry (Continued)
Elev.
Room Name North Wall (Note 1)
East Wall (Note 1)
South Wall (Note 1)
West Wall (Note 1)
Floor (Note 2)
Ceiling (Note 2)
NuScale Final Safety Analysis Report Radiation Protection Design Features Tier 2 12.3-35 Draft Revision 2 RAI 12.03-17, RAI 12.03-23 Table 12.3-6: Reactor Building Shield Wall Geometry Elev.
Room #
(see Note 1)
Room Name North Wall (Note 2)
East Wall (Note 2)
South Wall (Note 2)
West Wall (Note 2)
Floor (Note 3)
Ceiling (Note 3)
Source Term 24 010-040 Module 1 CVCS ion exchanger sluice room 20 Structural steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-041 Module 2 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-042 Module 3 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-043 Module 4 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-044 Module 5 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-045 Module 6 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-051 Module 7 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-050 Module 8 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-049 Module 9 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-048 Module 10 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed 24 010-047 Module 11 CVCS ion exchanger sluice room 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall 10 Concrete (ground floor) 20 Concrete/steel composite slab CVCS mixed bed and CVCS cation bed
NuScale Final Safety Analysis Report Radiation Protection Design Features Tier 2 12.3-41 Draft Revision 2 75 N/A Modules 1-6 CVCS vertical pipe chases 20 Concrete/steel partition wall 20 Concrete/steel partition wall 5 Concrete (reactor pool wall) 20 Concrete/steel partition wall N/A N/A CVCS pipe 75 N/A Modules 7-12 CVCS vertical pipe chases 5 Concrete (reactor pool wall) 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall N/A N/A CVCS pipe 86 N/A Modules 1-6 CVCS vertical pipe chases 20 Concrete/steel partition wall 20 Concrete/steel partition wall 5 Concrete (reactor pool wall) 20 Concrete/steel partition wall N/A N/A CVCS pipe 86 N/A Modules 7-12 CVCS vertical pipe chases 5 Concrete (reactor pool wall) 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20 Concrete/steel partition wall N/A N/A CVCS pipe 100 N/A Modules 1-6 CVCS vertical pipe chases 20 Concrete/steel partition wall 20 Concrete/steel partition wall 5 Concrete (reactor pool wall) 20Concrete/steel partition wall N/A N/A CVCS pipe 100 N/A Modules 7-12 CVCS vertical pipe chases 5 Concrete (reactor pool wall) 20 Concrete/steel partition wall 20 Concrete/steel partition wall 20Concrete/steel partition wall N/A N/A CVCS pipe 126 010-022 Reactor pool area 5' Concrete wall 5' Concrete wall 5' Concrete wall 5' Concrete wall 21.5"23.5" Concrete 2" High-density polyethylene 0.250.5" Steel (Bioshield) 4' Concrete roof NPM Note 1: Refer to Figure 1.2-10 through Figure 1.2-18 for room locations.
Note 2: A 20" concrete/steel partition wall consists of two one-half inch steel plates with 19" of concrete in between.
Note 3: A 20" concrete/steel composite slab consists of two one-half inch steel plates with 19" of concrete in between.
Table 12.3-6: Reactor Building Shield Wall Geometry (Continued)
Elev.
Room #
(see Note 1)
Room Name North Wall (Note 2)
East Wall (Note 2)
South Wall (Note 2)
West Wall (Note 2)
Floor (Note 3)
Ceiling (Note 3)
Source Term
Response to Request for Additional Information Docket No.52-048 eRAI No.: 9298 Date of RAI Issue: 01/26/2018 NRC Question No.: 12.03-18 The Regulatory Basis and Background are in RAI-9298 Q-31062 Key Issue 2 DCD Tier 1 Section 3.11, Reactor Building, states that the RXB includes radiation shielding barriers for normal operation and post-accident radiation shielding. It further states that DCD Tier 1 Table 3.11-2, Reactor Building Inspections, Tests, Analyses, and Acceptance Criteria, contains the inspections, tests, and analyses for the RXB. DCD Tier 1 Table 3.11-1 item 4 Acceptance Criteria states that the thickness of RXB radiation shielding barriers is greater than or equal to the required thickness specified in DCD Tier 1 Table 3.11-1. However, there is no specification for the boron content of the polyethylene listed in DCD Tier1 Table 3.11, and there is no description of the minimum polyethylene density.
DCD Tier 2 Section 12.3.2.2, Design Considerations, states that DCD Tier 2 Table 12.3-6 shows the nominal shielding thicknesses for rooms in plant buildings. DCD Tier 2 Table 12.3-6:
Reactor Building Shield Wall Geometry, provides the nominal thickness of concrete for some of the walls in the RXB. However, there is no specification for the boron content of the polyethylene listed in DCD Tier 2 Table 12.3-6.
Question 2 To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions with respect to the neutron shielding materials incorporated into the design, the staff requests that the applicant:
As necessary, revise DCD Tier 1 Section 3.11 and DCD Tier 1 Table 3.11-1, to include the description of boron in the polyethylene shielding material and the density of the polyethylene material, As necessary, revise DCD Tier 2 Section 12.3.2.2 and DCD Table 12.3-6, to include the description of boron in the polyethylene shielding material and the density of the polyethylene material, NuScale Nonproprietary
OR Provide the specific alternative approaches used and the associated justification.
NuScale Response:
See the NuScale response to RAI 12.03-17 (9298).
Impact on DCA:
There are no impacts to the DCA as a result of this response.
NuScale Nonproprietary
Response to Request for Additional Information Docket No.52-048 eRAI No.: 9298 Date of RAI Issue: 01/26/2018 NRC Question No.: 12.03-19 The Regulatory Basis and Background are in RAI-9298 Q-31062 Key Issue 3 The Acceptance Criteria of DSRS Section 12.3-12.4, Radiation Protection Design Features, notes that where the applicants shielding design incorporates material subject to degradation, such as through the effects of radiation (e.g., depletion of boron neutron absorbers,) temperature extremes (e.g., degradation of polymer based materials because of high temperature,) methods are in place to ensure the integrity of the shielding, and how the application identifies the constraints (e.g., minimum cooling air flow, maximum shielding material temperature, and maximum allowable neutron flux,) and how those parameters are measured, assessed over the design life of the facility.
Question 3 To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions with respect to the neutron shielding materials incorporated into the design, the staff requests that the applicant:
Justify/explain the design features and required constraints needed to ensure the integrity of the shielding over the design life of the plant, Explain/Justify the control mechanisms proposed to ensure that the constraints needed to ensure the integrity of the radiation shielding over the design life of the plant, As necessary, revise DCD Section 12.3.2, to describe these parameters, and the associated controls (e.g., COL Item,)
OR Provide the specific alternative approaches used and the associated justification.
NuScale Nonproprietary
NuScale Response:
See the NuScale response to RAI 12.03-17 (9298).
Impact on DCA:
There are no impacts to the DCA as a result of this response.
NuScale Nonproprietary
Response to Request for Additional Information Docket No.52-048 eRAI No.: 9298 Date of RAI Issue: 01/26/2018 NRC Question No.: 12.03-20 The Regulatory Basis and Background are in RAI-9298 Q-31062 Key Issue 4 DCD Tier 2 Revision 0 Section 12.3.2.2 Design Considerations, states that in addition to concrete, other types of materials such as steel, water, tungsten, and polymer composites are considered for both permanent and temporary shielding. However, the only location where the use of shielding material other than concrete is identified, is the polyethylene identified in DCD Table 12.3-6: Reactor Building Shield Wall Geometry. Based on information made available to the staff during the RPAC Chapter 12 Audit, it appears that the shielding design also credits a number of steel/iron plates that are provided for other than structural support.
Question 4 To facilitate staff understanding of the application information sufficient to make appropriate regulatory conclusions with respect to the neutron shielding materials incorporated into the design, the staff requests that the applicant:
Identity those areas, outside of the Containment Vessel, where steel/iron material is specifically credited for shielding, Identify other areas of the plant where shielding material other than concrete, steel/iron are
- used, As necessary, revise DCD Section 12.3.2, and to describe this shielding material, Justify/explain the design features and required operational constraints to ensure the integrity of the shielding over the design life of the plant, As necessary, revised section DCD Section 12.3.2, and to describe these parameters, OR Provide the specific alternative approaches used and the associated justification.
NuScale Nonproprietary
NuScale Response:
See the NuScale response to RAI 12.03-17 (9298).
Impact on DCA:
There are no impacts to the DCA as a result of this response.
NuScale Nonproprietary