RAIO-1018-62345, LLC Response to NRC Request for Additional Information No. 500 (Erai No. 9563) on the NuScale Design Certification Application

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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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October 29, 2018 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 RAIO-1018-62345 Docket No.52-048

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:

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 : 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 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. 9563

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 Tier 1 3.6-1 Draft Revision 3 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 decay heat removal system by accepting the heat from the decay heat removal heat exchanger.

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.

NuScale Tier 1 Reactor Building Tier 1 3.11-7 Draft Revision 3 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 confinement so that the impact from internal fires, smoke, hot gases,or fire suppressants is contained within the RXB fire area of origin.

An inspection will be performed of the RXB as-built fire and smoke barriers.

The following RXB fire and smoke barriers exist in accordance with the fire hazards analysis, and have been qualified for the fire rating specified in the fire hazards analysis:

  • fire-rated doors
  • fire-rated walls, floors, and ceilings
  • smoke barriers 2

Internal flooding barriers provide confinement so that the impact from internal flooding is contained within the RXB flooding area of origin.

An inspection will be performed of the RXB as-built internal flooding barriers.

The following RXB internal flooding barriers exist in accordance with the internal flooding analysis report and have been qualified as specified in the internal flooding analysis report:

  • flood resistant doors
  • curbs and sills
  • walls
  • National Electrical Manufacturer's Association enclosures 3

The Seismic Category I RXB is protected against external flooding in order to prevent flooding of safety-related SSC within the structure.

An inspection will be performed of the RXB as-built floor elevation at ground entrances.

The RXB floor elevation at ground entrances is higher than the maximum external flood elevation.

4 The RXB includes radiation shielding barriers for normal operation and post-accident radiation shielding.

An inspection will be performed of the as-built RXB radiation shielding barriers.

The thickness of RXB radiation shielding barriers is greater than or equal to the required thickness specified in Table 3.11-1.

5 The RXB includes radiation attenuating doors for normal operation and for post-accident radiation shielding. These doors have a radiation attenuation capability that meets or exceeds that of the wall within which they are installed.

An inspection will be performed of the as-built RXB radiation attenuating doors.

The RXB radiation attenuating doors are installed in their design location and have a radiation attenuation capability that meets or exceeds that of the wall within which they are installed in accordance with the approved door schedule design.

6 The RXB is Seismic Category I and maintains its structural integrity under the design basis loads.

i.

An inspection and analysis will be performed of the as-built RXB.

ii.

An inspection will be performed of the as-built RXB.

i.

A design report exists and concludes that the deviations between the drawings used for 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.

NuScale Tier 1 Control Building Tier 1 3.13-3 Draft Revision 3 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 confinement so that the impact from internal fires, smoke, hot gases, or fire suppressants is contained within the CRB fire area of origin.

An inspection will be performed of the CRB as-built fire and smoke barriers.

The following CRB fire and smoke barriers exist in accordance with the fire hazards analysis, and have been qualified for the fire rating specified in the fire hazards analysis:

  • fire-rated doors
  • fire-rated walls, floors, and ceilings
  • smoke barriers 2

Internal flooding barriers provide confinement so that the impact from internal flooding is contained within the CRB flooding area of origin.

An inspection will be performed of the CRB as-built internal flooding barriers.

The following CRB internal flooding barriers exist in accordance with the internal flooding analysis report and have been qualified as specified in the internal flooding analysis report:

  • flood resistant doors
  • walls
  • National Electrical Manufacturer's Association (NEMA) enclosures 3

The Seismic Category I CRB is protected against external flooding in order to prevent flooding of safety-related SSC within the structure.

An inspection will be performed of the CRB as-built floor elevation at ground entrances.

The CRB floor elevation at ground entrances is higher than the maximum external flood elevation.

NuScale Tier 1 Control Building Tier 1 3.13-4 Draft Revision 3 4

The CRB at Elevation 120-0(except for the elevator shaft, the stairwells, and the fire protection vestibule which are Seismic Category II) and below is Seismic Category I and maintains its structural integrity under the design basis loads.

i.

An inspection and analysis will be performed of the as-built CRB.

ii.

An inspection will be performed of the as-built CRB at Elevation 120-0 and below.

i.

A design report exists and concludes that the deviations between the drawings used for construction and the as-built CRB have been reconciled, and the CRB at Elevation 120-0 and below (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 where a potential for adverse interaction with a Seismic Category I SSC exists in the CRB will not impair the ability of Seismic Category I SSC to perform their safety functions during or following a safe shutdown earthquake.

An inspection and analysis will be performed of the as-built non-Seismic Category I SSC in the CRB.

A report exists and concludes that the Non-Seismic Category I SSC located where a potential for adverse interaction with a Seismic Category I SSC exists in the CRB will not impair the ability of Seismic Category I SSC to perform their safety functions during 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.

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

No.

Design Commitment Inspections, Tests, Analyses Acceptance Criteria

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