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Nuscale Power, LLC Supplemental Response to NRC Request for Additional Information No. 366 (Erai No. 9292) on the Nuscale Design Certification Application
	ML18319A292
Person / Time
Site:	NuScale
Issue date:	11/15/2018
From:	Rad Z; NuScale
To:	; Document Control Desk, Office of New Reactors
References
	RAIO-1118-62949
	Download: ML18319A292 (22)
	v • d • e

November 15, 2018 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 RAIO-1118-62949 Docket No.52-048

SUBJECT:

NuScale Power, LLC Supplemental Response to NRC Request for Additional Information No. 366 (eRAI No. 9292) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 366 (eRAI No. 9292)," dated February 08, 2018

2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 366 (eRAI No.9292)," dated April 09, 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 Questions from NRC eRAI No. 9292:

12.03-43

12.03-44

12.03-45

12.03-46

12.03-47 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 Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-1118-62949 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. 9292

RAIO-1118-62949 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. 9292

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9292 Date of RAI Issue: 02/08/2018 NRC Question No.: 12.03-43 Regulatory Basis Appendix A to 10 CFR Part 50 General Design Criteria for Nuclear Power Plants, Criterion (GDC) 61 Fuel Storage and Handling and Radioactivity Control, requires that new and spent fuel storage facilities include provisions for inspection and the provision for testing are important to verify that there is no corrosion of the spent fuel pool liner.

10 CFR 52.47(a)(6) requires compliance with the requirements of 10 CFR 20.1406 Minimization of contamination, which requires a description in the DCD how facility design and procedures for operation will minimize, to the extent practicable, contamination of the facility and the environment, facilitate eventual decommissioning, and minimize, to the extent practicable, the generation of radioactive waste.

10 CFR 20.1406 requires applicants to describe in the application how facility design and procedures for operation will minimize, to the extent practicable, contamination of the facility and the environment, facilitate eventual decommissioning, and minimize, to the extent practicable, the generation of radioactive waste. The acceptance criteria of NuScale DSRS Section 12.3-12.4, Radiation Protection Design Features, state that the applicant is to describe how facility design addresses the requirements of 10 CFR 20.1406.

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 guidance provided in NuScale DSRS Section 12.3-12.4 Radiation Protection Design Features, and Standard Review Plan (SRP) Section 9.1.2 New and Spent Fuel Storage, are consistent with and support the review of the design features provided for satisfy these regulatory requirements.

NuScale Nonproprietary

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Background===

Information contained in DCD Tier 2 Revision 0, and in the response to RAI 8963 Question 03.08.05 Question 23, dated October 17 2017, (RAI-8963-03.08.05-23) indicates that portions of the pool liner may not be covered by the pool leakage detection system (PLDS). Based on the information contained within the RAI response and the DCD, it is not clear to the staff how the applicant intends to meet the regulatory requirements for providing at an early stage of the design, sufficient information that demonstrates the capability of the PLDS to detect low leakage rates from structures containing pool water.

The Liquid Radioactive Release Task Force Final Report (ADAMS Accession No. ML062650312,) documents that radioisotopes have been released from spent fuel pools, including fission products. The report further noted that the potential exists for unplanned and unmonitored releases of radioactive liquids to migrate offsite undetected, including those portions of spent fuel pools not visible to operators. Leakage (and the resultant contamination) that enters the ground below the plant may be undetected. Radioactive contamination in groundwater onsite may migrate offsite undetected. One of the main components resulting in ground water contamination identified by the Task Force was leakage from spent fuel pools.

Key Issue 1 The NuScale response states that FSAR Tier 2, Section 9.1.3.2.5 describes the pool leakage detection system (PLDS). Per this section, the PLDS consists of floor leakage channels, perimeter leakage channels, channel drainage lines, leak collection headers, leakage rate measuring lines, and valves. The floor leakage channels are embedded in the concrete beneath the field welded seams of the pool floor liner plates in the UHS pools and the dry dock. A perimeter channel is embedded in concrete at the wall and floor liner joint area. Based on the staff interpretation of this response and information contained in the DCD, it appears that the NuScale design only monitors for leakage from welds located on the base mat and at the juncture of the walls and the base mat.

However, the guidance in SRP Section 9.1.2 does not make a distinction between those sections of the pool liner located on the wall, and those sections of the liner located on the base mat.

The acceptance criteria of DSRS Section 12.3-12.4 states that the acceptability of the design features described in the application will be based on the guidance contained in RG 4.21 and Appendix 12.3-12.4-A Evaluation and Scoping information for Structures, Systems, and Components 10 CFR 20.1406 Design Review. Attachment A of DSRS 12.3-12.4 Appendix NuScale Nonproprietary

12.3-12.4-A, specifically identifies structures, systems and components, such as spent fuel pools, separated from the environment by a single barrier, or with below grade concrete-to-concrete joints (such as the Ultimate Heat Sink pool in the NuScale Reactor Building). Appendix 12.3-12.4-A Attachment B Examples of Structures, Systems, and Components for 20.1406 Review, specifically identifies the spent fuel pool as an area for the staff to review.

Question 1

a. Please discuss how the proposed NuScale design is consistent with the requirements of GDC 61 and 10 CFR 20.1406.

b. Alternatively, revise the DCD to include sufficient information to describe any features to address potential-leakage monitoring for all walls in contact with the pool water, including the Ultimate Heat Sink, the fuel storage area, the dry dock area and the refueling area.

OR Provide the specific alternative approaches used and the associated justification.

NuScale Response:

Background:

The NRC conducted a focused regulatory audit on the NuScale Pool Leakage Detection System (PLDS) between June 14th and July 12th. NuScale agreed during the audit exit meeting to submit a supplemental response to eRAI 9292, Question 12.03-43.

The supplemental response should provide a comprehensive documentation/approach of the strategy to identify and minimize the flow of borated water into the UHS reinforced concrete to ensure that the structural integrity of the UHS walls will be maintained throughout of the life of the license.

If different than the strategies implemented in the operating fleet, the documentation/approach should clearly describe and justify how such approach will ensure equivalent or better performance than the operating fleet.

The response should also provide FSAR markups with a summary of the aforementioned documentation/approach. Additionally, the proposed FSAR markups should address, applicable NuScale Nonproprietary

liner plate design codes and standards, quality assurance requirements, a description of the liner plate design analysis and results including design loads (e.g. demands due to elevated temperature, construction activities, etc.) and allowable limits in accordance with 10 CFR Part 50 Appendix A, GDC 1, 2, and 4, and the described guidance in DSRS section 3.8.4 (Appendix D, subsection I.4 and I.6) and DSRS section 9.1.2 (sub section 9.1.2.III.4A). The applicant should provide docketed figures showing liner plate anchorage details and leak chase channel arrangements.

The supplemental response should also provide a comprehensive documentation/approach to ensure that the integrity of the seam-welds between the pool liner plate segments is not adversely affected due to construction activities.

Supplemental Response:

NuScale has elected to change the PLDS design in the pool walls to be similar to strategies implemented by the operating fleet. Leak channels have been added to the walls behind seam welds protecting the UHS by directing leakage to the wall collection channel in the floor. The welds and the leak channels are permanent physical features that will protect the UHS from borated water during the life of the plant.

The modified NuScale liner wall design is described in the revised DCA pages accompanying this response.

Impact on DCA:

FSAR Sections 9.1.3, Table 9.3.2-4: Local Sample Points and Table 12.3-28: Regulatory Guide 4.21 Design Features for Pool Leak Detection System 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 Fuel Storage and Handling Tier 2 9.1-34 Draft Revision 3 The elevation of the bottom of each PSCS piping penetration through a wall of the dry dock, RFP, or SFP; and the open ends of equalization line, are above the 55 ft pool water level. The piping deeper in the dry dock and RFP is equipped with anti-siphoning devices. These devices are also above the 55 ft pool water level.

The vent line on the pool surge control storage tank has a continuous air monitor with grab sample capabilities to monitor effluent releases from the tank. The radiation monitoring and sampling equipment for the tank vent are described in Section 11.5.2.

The supply and discharge lines to and from the pool surge control storage tank are embedded underground or in a yard area pipe chase. Each line is within a guard pipe from the catch basin to the RXB. The sump drain line is also embedded underground or in a yard area pipe chase and within a guard pipe from the catch basin to the RWB. Each guard pipe provides collection and permits periodic surveillance for PSCS piping leaks.

The PSCS storage tank is equipped with a water level instrument that provides overflow protection. In addition to initiating an alarm locally and in the main control room, the instrumentation provides an automatic isolation of the water transfer line to the tank when the water level reaches the high level setpoint.

9.1.3.2.5 Pool Leakage Detection System The PLDS performs the following nonsafety-related functions:

1) provides for collection of water leaking from the pool liner

2) directs the flow to sumps for detection of collected leakage for operator evaluation RAI 12.03-43, RAI 12.03-43S1 The PLDS consists of floor and wall leakage channels, perimeter leakage channels, channel drainage lines, leak collection headers, leakage rate measuring lines, and valves. The valves are used to isolate each channel drainage line and leakage rate measuring line. System components with the potential for contact with borated water are stainless steel. The floor leakage channels are embedded in the concrete beneath field welded seams of the pool floor liner plates in the UHS pools and dry dock that cannot be fully inspected on both sides. Additional leakage channels are attached behind the wall liner plate seal welds. The wall liner plates are erected prior to concrete placement. Wall liner welds are inspected on both sides of the plate before pouring concrete that covers the welds. A perimeter channel is embedded in concrete at the wall and floor liner joint area. The channels collect leakage from the pool wall and floor liner plates and direct it to a sump or to collection header piping leading to a sump in the radioactive waste drain system (RWDS). The leakage collected in the RWDS sumps is routed to the LRWS for further processing. The PLDS will be accompanied by monitoring and surveillance by plant personnel (see COL Item 12.3-7). Section 3.2 provides the safety and seismic classifications for the system and identifies the applicable QA requirements.

NuScale Final Safety Analysis Report Process Auxiliaries Tier 2 9.3-43 Draft Revision 3 RAI 10.04.06-1, RAI 10.04.06-2, RAI 10.04.06-3, RAI 12.03-2, RAI 12.03-3, RAI 12.03-44S1 Table 9.3.2-4: Local Sample Points Sample Point System Process Fluid Type Sampling Method Analysis(1)

ABS steam discharge line (downstream of boilers)

ABS steam continuous pH, cation conductivity ABS feedwater line (at pump discharge)

ABS liquid continuous pH, hydrazine, dissolved oxygen Boron addition system (BAS) boric acid storage tank BAS liquid grab Boric acid batch tanks BAS liquid grab Condenser air removal system (CARS) seal water separator tank vent line CARS gas grab CES sample vessel liquid discharge line CES liquid grab CES particulate, iodine, and noble gas radiation monitoring skid CES gas grab hydrogen, oxygen, radionuclides Circulating water system (CWS) cooling tower basin CWS liquid grab CFWS high pressure feedwater heater discharge line CFWS liquid continuous grab dissolved oxygen total iron(2)

Main condenser hotwell CFWS liquid continuous sodium, cation conductivity grab Combined polisher effluents CFWS liquid grab Feedwater discharge from low pressure feedwater heater CFWS liquid grab Feedwater discharge from intermediate pressure feedwater heater CFWS liquid grab Demineralized water system (DWS) storage tank DWS liquid grab radionuclides Gaseous radioactive waste system (GRWS) moisture separator discharge GRWS gas continuous oxygen, hydrogen grab GRWS effluent release to plant exhaust GRWS gas continuous oxygen grab Liquid radioactive waste system (LRWS) low conductivity waste collection tanks LRWS liquid grab Low conductivity waste sample tanks LRWS liquid grab Treated liquid waste effluent discharge line LRWS liquid grab High conductivity waste collection tanks LRWS liquid grab High conductivity waste sample tanks (2 sample points total; one per tank)

LRWS liquid grab Detergent waste collection tank LRWS liquid grab LRWS low conductivity waste process skid effluent line LRWS liquid grab radionuclides, tritium High conductivity waste processing skid effluent line LRWS liquid grab radionuclides, tritium Upstream of module heatup system (MHS) heat exchangers MHS liquid grab Reactor pool cooling system (RPCS) effluent to pool cleanup system RPCS liquid grab Spent fuel pool cooling system (SFPCS) effluent to pool cleanup system SFPCS liquid grab Pool cleanup system (PCUS) demineralizer influent PCUS liquid grab PCUS effluent PCUS liquid grab

NuScale Final Safety Analysis Report Process Auxiliaries Tier 2 9.3-44 Draft Revision 3 Pool Leakage Detection System (PLDS) at the channel drainage line PLDS liquid grab Pool surge control system (PSCS) tank (at tank discharge line)

PSCS liquid grab Reactor component cooling water system (RCCWS) common return lines RCCWS liquid grab radionuclides, tritium RCCWS drain lines of individual components being cooled RCCWS liquid grab radionuclides Radioactive waste drain system (RWDS) sump tanks; one sample point per each sump tank)

RWDS liquid grab Reactor Building chemical drain tank RWDS liquid grab Reactor Building RCCWS drain tank RWDS liquid grab Site cooling water system (SCWS) discharge line to central utility building SCWS liquid grab SCWS discharge lines to utility water system discharge basin SCWS liquid continuous conductivity, pH, chlorine, and corrosion inhibitors, grab radionuclides, tritium SCWS cooling tower basin SCWS liquid continuous pH, total dissolved solids, chlorine grab radionuclides, tritium SCWS supply lines to reactor pool cooling heat exchangers SCWS liquid grab Upstream of filters on SCWS return lines from reactor pool cooling heat exchangers SCWS liquid grab Downstream of filters on SCWS return lines from reactor pool cooling heat exchangers SCWS liquid grab SCWS supply lines to SFPC heat exchangers SCWS liquid grab Upstream of filters on SCWS return lines from SFPC heat exchangers SCWS liquid grab Downstream of filters on SCWS return lines from SFC heat exchangers SCWS liquid grab SCWS supply lines from RCCW heat exchangers SCWS liquid grab Upstream of filters on SCWS return lines from RCCW heat exchangers SCWS liquid grab Downstream of filters on RCCW return lines from reactor pool cooling heat exchangers SCWS liquid grab Solid radioactive waste system (SRWS) phase separator tank discharge line to dewatering skid SRWS liquid grab Turbine generator system (TGS) gland steam condenser exhaust TGS gas grab Utility water system (UWS) discharge basin UWS liquid grab radionuclides, tritium Utility water system (UWS) between UWS supply pump header and UWS distribution header UWS liquid grab radionuclides, tritium Notes:

1. Specific analyses, limits, and monitoring frequencies will be specified in plant procedures.

2. Total iron is collected using integrated sampling.

Table 9.3.2-4: Local Sample Points (Continued)

Sample Point System Process Fluid Type Sampling Method Analysis(1)

NuScale Final Safety Analysis Report Radiation Protection Design Features Tier 2 12.3-73 Draft Revision 3 RAI 12.03-43S1 Table 12.3-28: Regulatory Guide 4.21 Design Features for Pool Leak Detection System Objective Design Features Objective 1: Minimize the potential for leaks or spills and provide containment areas The pool leakage detection system (PLDS) has leak channels behind the pool wall liner and under the pool floor liner to guide pool leaks to a drain header that leads to RWDS sumps. The PLDS uses welded channels and piping to minimize potential for leaks. Pool leaks are designed to flow through the leak channels to the RWDS sumps.

The PLDS uses stainless steel material to prevent corrosion. This feature reduces the potential for leaks. This also applies to Objective 3.

Objective 2: Provide leak detection capability The RWDS sumps, located in the RXB, are equipped with level transmitters to detect leakage from the pool liner.

Objective 3: Reduce contamination to minimize releases, cross-contamination and waste generation The PLDS is designed with corrosion resistant materials for the wetted parts (leak channels, piping, and valves). The selected material is compatible with the operating environment of the pool water.

The PLDS drain lines from the leak channels are gravity drained to the RWDS through enclosed pipes. This design feature prevents spread of contamination.

Objective 4: Facilitate decommissioning The PLDS is designed for full service life of the plant. With the exception of the leak channels embedded into the concrete, the individual drain lines and the main header are above the ground. This design feature facilitates decommissioning.

Objective 5: Operating programs and documentation COL item Objective 6: Site radiological environmental monitoring COL item

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9292 Date of RAI Issue: 02/08/2018 NRC Question No.: 12.03-44 The Regulatory Basis and Background are in RAI-9292 Question 31048 Key Issue 2 DCD Tier 2 Revision 0 Table 9.3.2-4: Local Sample Points, does not list the pool leakage detection system (PLDS), as one of the process sampling points. Furthermore, the response to RAI-8963-03.08.05-23, states that channels collect leakage from the pool liner plates and direct it to a sump or to collection header piping that leads to a sump that is part of the radioactive waste drain system (RWDS). The RWDS sumps are located in the reactor building (RXB) gallery areas at top of concrete elevation 24- 0. However, neither DCD Figure 1.2-10: Reactor Building 24-0 Elevation, nor DCD Figure 12.3-1a: Reactor Building Radiation Zone Map - 24' Elevation show sumps on this elevation of the Reactor Building.

Question 2 Revise DCD Figure 1.2-10 or DCD Figure 12.3-1a to show the location of the sump(s) used as collection points for the pool liner leakage detection system.

OR Provide the specific alternative approaches used and the associated justification.

NuScale Nonproprietary

NuScale Response:

Background:

The NRC conducted a focused regulatory audit on the NuScale Pool Leakage Detection System (PLDS) between June 14th and July 12th. NuScale agreed during the audit exit meeting to submit a supplemental response to eRAI 9292, Question 12.03-44.

The supplemental response should discuss the methods for taking a representative sample of the PLDS. In addition NuScale was requested to update DCD Table 9.3.2-4 to include the local sampling points for the PLDS.

Supplemental Response:

Individual leak channels would be isolated at the channel drainage line, a sample bottle positioned and the leak rate measuring line valve for the channel of interest opened to capture effluent. The sample would then be analyzed to verify the leak source (e.g., a ground water intrusion versus a pool leak) and follow up actions taken based on analysis results. FSAR Table 9.3.2-4 has been updated to include local sampling points as shown in the revised DCA pages accompanying this response.

Impact on DCA:

FSAR Table 9.3.2-4 has been revised as described in the response above and as shown in the markup provided in this response.