ML18302A407

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LLC Response to NRC Request for Additional Information No. 500 (Erai No. 9563) on the NuScale Design Certification Application
ML18302A407
Person / Time
Site: NuScale
Issue date: 10/29/2018
From: Rad Z
NuScale
To:
Document Control Desk, Office of New Reactors
References
RAIO-1018-62345
Download: ML18302A407 (11)
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Text

RAIO-1018-62345 October 29, 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.

500 (eRAI No. 9563) on the NuScale Design Certification Application

REFERENCE:

U.S. Nuclear Regulatory Commission, "Request for Additional Information No.

500 (eRAI No. 9563)," dated August 28, 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 Question from NRC eRAI No. 9563:

  • 14.03.02-3 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,

~~

~ackaryW. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution: Gregory Cranston, NRC, OWFN-8G9A Omid Tabatabai, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Enclosure 1: NuScale Response to NRC Request for Additional Information eRAI No. 9563 NuScale Power, LLC 1100 NE Circle Blvd. , Suite 200 Corvalis, Oregon 97330 , Office: 541.360.0500 , Fax: 541.207.3928 www.nuscalepower.com

RAIO-1018-62345 :

NuScale Response to NRC Request for Additional Information eRAI No. 9563 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.: 9563 Date of RAI Issue: 08/28/2018 NRC Question No.: 14.03.02-3 10 CFR Part 52, Section 52.54, "Issuance of standard design certification," paragraph (a) states that the Commission may issue a standard design certification in the form of a rule for the design if the Commission determines that, among other things, "There is reasonable assurance that the standard design conforms with the provisions of the Act, and the Commission's regulations." When certified, the Appendix to Part 52 that constitutes the standard design certification will include or reference information that is approved and certified by the staff. This information, designated as Tier 1, generally includes, but is not limited to, design descriptions for significant aspects of the design. Tier 1 information is derived from the broader set of information contained in Tier 2, the Design Control Document (DCD), but is generally limited to the subset of the most safety significant information needed to support the staff's approval basis. Therefore, the staff's reasonable assurance finding for design certification relies, on the applicant's DCD Tier 1 and DCD Tier 2 information.

10 CFR 52.47(a)(2) requires, in part, that a design certification application include a description and analysis of the structures of the facility, with emphasis upon performance requirements, the bases, with technical justification therefore, upon which these requirements have been established, and the evaluations required to show that safety functions will be accomplished.

When evaluating the acceptability of this information for seismic Category I structures, the staff's review focuses on a subset of structural information that includes seismic analysis methods, key dimensions of seismic Category I structures, and design of "critical sections." The use of critical sections in the design of safety-related structures is a risk- informed graded approach to achieve the reasonable assurance of safety. In lieu of the safety review of a large number of structural component designs, the staff performs a detailed review of a limited number of critical sections described in Section 3.8 of the DCD that contributed to the overall risk significance of the structures. This approach provides the staff with reasonable assurance of the overall safety NuScale Nonproprietary

performance of the structures based on the successful performance of these limited but critical risk significant locations.

10 CFR 52.47(b)(1), requires that a DC application contain the proposed inspections, tests, analyses, and acceptance criteria (ITAAC) that are necessary and sufficient to provide reasonable assurance that, if the inspections, tests, and analyses are performed and the acceptance criteria met, a plant that incorporates the design certification is built and will operate in accordance with the design certification, the provisions of the Atomic Energy Act, and the NRC's regulations. SRP Section 14.3, and in particular, Sections 14.3.2 and Appendix C provide guidance in developing design descriptions, figures, and ITAAC for structural related items. SRP acceptance criterion 14.3.2.II.2 states that the design description, figures (including key dimensions), and ITAAC should be developed and grouped by systems and building structures. The building structures review checklist in Appendix C of SRP Section 14.3 states that design descriptions for building structures should provide enough dimensions for the COL applicant or licensee to develop dynamic models for the seismic analyses. Examples of these dimensions include overall building dimensions, thickness of walls and floor slabs, thickness of foundation mat, etc.

Therefore, the applicant is requested to incorporate DCD Tier 1 Design Descriptions, including characteristics of the seismic analysis and design of "critical sections" for seismic Category I structures. This information needs to be designated as Tier 1 information to support the staff's reasonable assurance finding. The information to be included in NuScale DCD Tier 1, based on DCD Tier 2, Rev. 1, is given below. This list provides examples and does not constitute a complete set of items to be included in DCD Tier 1. The information to be included in DCD Tier 1 may be in the form of text, tables, and/or figures, which are based on the design presented in DCD Tier 2.

1. Provide plans, elevations and cross-sections with dimensions for the Reactor Building (RXB), including the ultimate heat sink pool, and Control Building (CRB) which will remain invariant for each applicant of the NuScale design and will support the structural ITAAC
2. Provide descriptions of the structural design for the ultimate heat sink pool, the reactor pool, refueling area pool and spent fuel pool, including the confinement provided by the liner and leak detection system components such as leak chase channels.
3. Identification of the Concrete Code, and Structural Steel Code with editions used in the design of safety related structures (e.g., ACI-349, and ANSI/AISC-N690; with the NuScale Nonproprietary

applicable editions/dates identified).

4. List of critical sections corresponding to reinforced concrete members and structural steel members for the RXB and CRB, locations of the critical section, key dimensions and other design attributes [e.g. demand over capacity ratios or, concrete compressive strength and area of steel per unit length, thickness/size and material specification (for steel members)].
5. A summary description of the seismic analysis methods that are used for the seismic Category I structures. Additionally, a summary description of the seismic response (e.g.,

ISRS, forces and moments, and deformation) and respective locations that are needed by a COL applicant for comparing against the responses from the site-specific dynamic evaluation.

6. Clarify that ITAAC for the CRB underground tunnel are included in ITAAC for CRB.

NuScale Response:

Question 1 response Plans, elevations and cross-sections with dimensions for the Reactor Building (RXB), and Control Building (CRB) are provided in Tier 2, Section 1.2, Figures 1.2-10 through 1.2-27.

As stated in 10 CFR 52.47(b)(1), the purpose of ITAAC is to provide reasonable assurance that a constructed facility conforms to NRC regulations and its license. ITAAC are not meant to be a one-for-one check of detailed design and construction features and do not verify every design and construction feature included in the FSAR. ITAAC are just one element of the licensees construction, testing, and quality programs, which include: the quality assurance program, quality control inspections, vendor surveillances and inspections, engineering design verifications, operational readiness reviews, and the construction inspection program (CIP).

The NRCs CIP provides oversight of aforementioned programs. Thus, not all construction related activities need to be verified by ITAAC. Inspections, tests, and analyses would be conducted under the licensees quality programs, and in accordance with applicable codes and standards, even if no ITAAC existed; therefore, it is unnecessary to include in ITAAC inspections, tests, and analyses that do not meet first principles, as defined and described in NuScale Nonproprietary

FSAR Section 14.3.2, and for which implementation is effectively assured via licensee quality programs and NRC oversight thereof.

Question 2 response A description of the ultimate heat sink, which includes the reactor pool, spent fuel pool, and refueling pool, is provided in Tier 2, Section 1.2.2.4.2. Additional detail is provided in Tier 2, Section 9.2.5 which states, among other things, that the ultimate heat sink is a set of safety-related pools of borated water. Tier 1 Section 3.6.1 already states that the structural components of the UHS are a component of the RXB. A pointer has been added in Tier 1 Section 3.6.1 that directs the reader to Tier 1 Section 3.11 for requirements of the reactor building.

Question 3 response Tier 2 Section 3.8.4.2.1 contains a list of industry design codes and standards to design the reactor building and the control building. Tier 1 Design Descriptions are intended to be self-contained and do not make direct reference to Tier 2 or industrial codes and standards.

This approach is necessary because referencing industry design codes and standards in Tier 1 would elevate the other documents to certified design material status. This is unacceptable because it would impose on the referenced document all of the more rigorous certified design material control and thus be incompatible with the intent of the two-tiered approach. Such references in ITAAC could make any nonconformance with any provision of such a code or standard a basis to withhold authorization to load fuel or to request a hearing prior to fuel load.

Question 4 response Critical sections are listed and described (including geometry and material information) in Tier 2 Appendix 3B. A portion the ITAAC listed in Section 3.11 and 3.13 of Tier 1 have been expanded to note that the design report which concludes that the as built RXB and CRB will maintain its structural integrity under design basis loads will also show that demand to capacity ratios are less than 1.0.

Question 5 response The seismic analysis methods are described in Tier 2, Section 3.7.2.1. In addition, COL items already exist that require the COL applicant to compare the generic design to the site specific design; these are COL Items 3.7-5, 3.7-6, and 3.7-10.

NuScale Nonproprietary

Question 6 response The CRB tunnel is a part of the CRB structure as described in Tier 2, Section 1.2.2.2. In addition, the tunnel is described in the CRB modeling in Tier, 2 Sections 3.7.2.1.2.5 and Section 3.8.4.1.2. Thus any ITAAC associated with the CRB is also applicable to the CRB tunnel.

Impact on DCA:

FSAR Tier 1, Section 3.6.1 and FSAR Tier 1, Table 3.11-2 and Table 3.1.3-1 have been revised as described in the response above and as shown in the markup provided in this response.

NuScale Nonproprietary

NuScale Tier 1 Ultimate Heat Sink 3.6 Ultimate Heat Sink 3.6.1 Design Description

System Description

The scope of this section is the ultimate heat sink (UHS). The UHS is the system of structures and components credited for functioning as a heat sink for decay heat removal from the NuScale Power Modules during normal reactor operations or shutdown following an accident or transient, including a loss-of-coolant accident. The UHS is a safety-related system and supports up to 12 NuScale Power Modules. The Reactor Building (RXB) houses all UHS equipment.

The configuration of the UHS includes the combined volume of water in the reactor pool, refueling pool (RFP), and spent fuel pool (SFP). The pool areas are open to each other with a weir wall partially separating the SFP from the RFP. The dry dock area is not considered part of the UHS volume.

RAI 14.03.02-3 The structural components of the reactor pool, RFP, and SFP (i.e., structural walls, weir wall, and floor) and associated pool liners are a component of the RXB structure. The design commitments for the Reactor Building are provided in Tier 1 Section 3.11.

The UHS performs the following safety-related system functions that are verified by Inspections, Tests, Analyses, and Acceptance Criteria:

  • The UHS supports the containment system by providing the removal of heat via direct water contact with the containment vessel.
  • The UHS supports the spent fuel system by providing the removal of decay heat from the spent fuel via direct water contact with the spent fuel assemblies.

The UHS performs the following nonsafety-related system functions that are verified by Inspections, Tests, Analyses, and Acceptance Criteria:

  • The UHS supports the containment system by providing the radiation shielding for the NPMs via the water surrounding the components.
  • The UHS supports the spent fuel system by providing radiation shielding for spent fuel via the water surrounding the components.
  • The UHS supports the RXB by having an assured water make-up line that can provide emergency make-up water to the UHS during off-normal events.

Design Commitments

  • The UHS American Society of Mechanical Engineers (ASME) Code Class 3 piping system listed in Table 3.6-1 complies with ASME Code Section III requirements.

Tier 1 3.6-1 Draft Revision 3

NuScale Tier 1 Reactor Building RAI 14.03.02-3, RAI 14.03.03-1, RAI 14.03.03-11S1 Table 3.11-2: Reactor Building Inspections, Tests, Analyses, and Acceptance Criteria No. Design Commitment Inspections, Tests, Analyses Acceptance Criteria 1 Fire and smoke barriers provide An inspection will be performed of the The following RXB fire and smoke confinement so that the impact from RXB as-built fire and smoke barriers. barriers exist in accordance with the internal fires, smoke, hot gases,or fire fire hazards analysis, and have been suppressants is contained within the qualified for the fire rating specified in RXB fire area of origin. the fire hazards analysis:

  • fire-rated doors
  • fire-rated walls, floors, and ceilings
  • flood resistant doors
  • curbs and sills
  • walls
  • National Electrical Manufacturer's Association enclosures 3 The Seismic Category I RXB is An inspection will be performed of the The RXB floor elevation at ground protected against external flooding in RXB as-built floor elevation at ground entrances is higher than the maximum order to prevent flooding of safety- entrances. external flood elevation.

related SSC within the structure.

4 The RXB includes radiation shielding An inspection will be performed of the The thickness of RXB radiation barriers for normal operation and as-built RXB radiation shielding shielding barriers is greater than or post-accident radiation shielding. barriers. equal to the required thickness specified in Table 3.11-1.

5 The RXB includes radiation An inspection will be performed of the The RXB radiation attenuating doors attenuating doors for normal as-built RXB radiation attenuating are installed in their design location operation and for post-accident doors. and have a radiation attenuation radiation shielding. These doors have a capability that meets or exceeds that radiation attenuation capability that of the wall within which they are meets or exceeds that of the wall installed in accordance with the within which they are installed. approved door schedule design.

6 The RXB is Seismic Category I and i. An inspection and analysis will be i. A design report exists and maintains its structural integrity under performed of the as-built RXB. concludes that the deviations the design basis loads. ii. An inspection will be performed of between the drawings used for the as- built RXB. construction and the as-built RXB have been reconciled, and the RXB maintains its structural integrity under the design basis loads and that all demand to capacity ratios are less than 1.0 (i.e. D/C < 1.0).

ii. The dimensions of the RXB critical sections conform to the approved design.

Tier 1 3.11-7 Draft Revision 3

NuScale Tier 1 Control Building RAI 14.03.02-3 Table 3.13-1: Control Building Inspections, Tests, Analyses, and Acceptance Criteria No. Design Commitment Inspections, Tests, Analyses Acceptance Criteria 1 Fire and smoke barriers provide An inspection will be performed of the The following CRB fire and smoke confinement so that the impact from CRB as-built fire and smoke barriers. barriers exist in accordance with the internal fires, smoke, hot gases, or fire fire hazards analysis, and have been suppressants is contained within the qualified for the fire rating specified in CRB fire area of origin. the fire hazards analysis:

  • fire-rated doors
  • fire-rated walls, floors, and ceilings
  • flood resistant doors
  • walls
  • National Electrical Manufacturer's Association (NEMA) enclosures 3 The Seismic Category I CRB is An inspection will be performed of the The CRB floor elevation at ground protected against external flooding in CRB as-built floor elevation at ground entrances is higher than the maximum order to prevent flooding of safety- entrances. external flood elevation.

related SSC within the structure.

Tier 1 3.13-3 Draft Revision 3

NuScale Tier 1 Control Building Table 3.13-1: Control Building Inspections, Tests, Analyses, and Acceptance Criteria (Continued)

No. Design Commitment Inspections, Tests, Analyses Acceptance Criteria 4 The CRB at Elevation 120-0(except for i. An inspection and analysis will be i. A design report exists and the elevator shaft, the stairwells, and performed of the as-built CRB. concludes that the deviations the fire protection vestibule which are ii. An inspection will be performed of between the drawings used for Seismic Category II) and below is the as-built CRB at Elevation 120- construction and the as-built CRB Seismic Category I and maintains its 0 and below. have been reconciled, and the CRB structural integrity under the design at Elevation 120-0 and below basis loads. (except for the elevator shaft, the stairwells, and the fire protection vestibule) maintains its structural integrity under the design basis loads and that all demand to capacity ratios are less than 1.0 (i.e.

D/C < 1.0).

ii. The dimensions of the CRB critical sections conform to the approved design.

5 Non-Seismic Category I SSC located An inspection and analysis will be A report exists and concludes that the where a potential for adverse performed of the as-built non-Seismic Non-Seismic Category I SSC located interaction with a Seismic Category I Category I SSC in the CRB. where a potential for adverse SSC exists in the CRB will not impair interaction with a Seismic Category I the ability of Seismic Category I SSC to SSC exists in the CRB will not impair perform their safety functions during the ability of Seismic Category I SSC to or following a safe shutdown perform their safety functions during earthquake. or following a safe-shutdown earthquake as demonstrated by one or more of the following criteria:

  • The collapse of the non-seismic Category I structure to strike a seismic Category I SSC.
  • The collapse of the non-Category I structure will not impair the integrity of Seismic Category I SSCs, nor result in incapacitating injury to control room occupants,
  • The non-Category I structure will be analyzed and designed to prevent its failure under SSE conditions.

Tier 1 3.13-4 Draft Revision 3

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