ML18037A732

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LLC Response to NRC Request for Additional Information No. 301 (Erai No. 9236) on the NuScale Design Certification Application
ML18037A732
Person / Time
Site: NuScale
Issue date: 02/06/2018
From: Rad Z
NuScale
To:
Document Control Desk, Office of New Reactors
References
RAIO-0218-58544
Download: ML18037A732 (11)
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Text

RAIO-0218-58544 February 06, 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.

301 (eRAI No. 9236) on the NuScale Design Certification Application

REFERENCE:

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

301 (eRAI No. 9236)," dated December 15, 2017 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. 9236:

11.05-1 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 Steven Mirsky at 240-833-3001 or at smirsky@nuscalepower.com.

Sincerely, Za Zackary W Rad W.

Director Regulatory Affairs

Director, NuScale Power, LLC Distribution: Gregory Cranston, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Anthony Markley, NRC, OWFN-8G9A : NuScale Response to NRC Request for Additional Information eRAI No. 9236 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0218-58544 :

NuScale Response to NRC Request for Additional Information eRAI No. 9236 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.: 9236 Date of RAI Issue: 12/15/2017 NRC Question No.: 11.05-1 11.5 RAI - Determination of RCS coolant leakage of 1.0 gpm within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> Regulatory Basis: GDC 13, 30, and 64 In review of DCD sections 11.5.2.1.2, 11.5.2.2.7, and 11.5.2.2.8, the staff determined that there is not enough information presented in the DCD to verify the low end nominal ranges provided in DCD Table 11.5-1. 10 CFR Part 50, Appendix A, GDC 13 requires instrumentation to monitor variables and systems over their anticipated ranges for normal operation, for anticipated operational occurrences, and for accident conditions as appropriate to assure adequate safety.

GDC 30 requires an applicant to identify sources of leakages. GDC 64, requires monitoring for the reactor containment atmosphere, spaces containing components for recirculation of loss-of-coolant accident fluids, effluent discharge paths, and the plant environs for radioactivity that may be released from normal operations, including anticipated operational occurrences, and from postulated accidents. Regulatory Guide 1.45 describes that all monitoring to detect leakages should be able to respond to a leakage increase of 1.0 gpm in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

Key Issue:

The staff is unable to confirm the applicants ability to detect RCS coolant leakage based on the assumed RCS activities presented in DCD section 11.1.

As discussed in the audit, the staff requests the applicant provide the equations and data used to determine the RCS coolant leakage rates for the Condenser Air Removal System monitors (11.5.2.1.2), the Containment Evacuation System monitors (11.5.2.2.7) and the Main Steam System monitors (11.5.2.2.8). Information such as volumes, leakage rates, and assumed RCS activity concentrations should be clearly stated in the response. The staff also requests the applicant provide a discussion on the applicability of a plate out factor given the containment vessel design.

In addition the staff notes discussions in DCD sections 11.1.1.2 and 11.5.2 that mentions the injection of natural argon gas to maintain a constant level in the RCS coolant for leakage detection purposes. It is not clear to staff what the assumed level of Ar-41 will be in the RCS coolant. Is this value based on the primary coolant realistic source terms presented in DCD Table 11.1-6? Or is some higher level of Argon anticipated? If some level of Argon needs to be NuScale Nonproprietary

maintained where is the requirement specified?

The staff requests that the necessary methodology and parameters to perform this calculation be contained in DCD section 11.5. The necessary pointers, parameters, and applicable guidance needs to be clearly stated for the staff to make a determination of compliance with 10 CFR Part 50, Appendix A, GDCs 13, 30,and 64.

NuScale Response:

As described in FSAR Section 5.2.5 and Section 9.3.6.3, the primary means to detect and quantify reactor coolant system (RCS) pressure boundary leakage are changes in containment vessel (CNV) pressure and containment evacuation (CES) sample tank level. Radiation monitors in the CES gaseous discharge line and the CES sample tank provide indication of an RCS leak and the source of the leak, but are not primarily used to quantify the leak rate.

Primary to secondary tube leaks are monitored and quantified using main steam system (MSS) line monitors, condenser air removal system (CARS) monitors and secondary water sampling.

The MSS line monitors are designed to detect Ar-41, and the CARS monitors are capable of detecting various isotopes, including Ar-41, Cs-137, I-131 and other noble gases.

For the purposes of establishing radiation monitor ranges low end, the primary coolant activity concentration of Ar-41 is provided in FSAR Table 11.1-6, and is reported as 1.3314E-01 Ci/gram. The corresponding secondary coolant activity concentration of Ar-41 is provided in FSAR Table 11.1-7, and is reported as 7.1917E-07 Ci/gram. The activity concentrations in the secondary coolant was developed using the applicable parameters listed in FSAR Table 11.1-2 (Primary-to-secondary leak rate = 3.53 lb/day/unit; Argon injection concentration = 0.10 Ci/cc; Secondary coolant mass = 7.158E+04 lb; Secondary steam leak rate = 80 lb/hr/unit).

For the CARS Ar-41 radiation monitors, the nominal range for the Ar-41 detector has been revised to range from 1.0E-07 Ci/cc to 1.0E-01 Ci/cc. This revised low end of the range is more appropriate for detecting the realistic concentration of Ar-41 in the secondary coolant (FSAR Table 11.1-7), and conforms to ANSI N42.18-2004. Similarly, for the MSS line monitors, the nominal range has been revised to range from 1.0E-07 Ci/cc to 1.0E-01 Ci/cc. The range for the CES Ar-41 radiation monitors are also revised to range from 1.0E-07 Ci/cc to 1.0E-01 Ci/cc, however these monitors are not relied upon for quantifying primary coolant leakage into containment.

The injection of argon is an operational option in the event the primary coolant does not contain sufficient radionuclides to detect primary to secondary tube leaks. As discussed in FSAR Section 11.5.2, natural argon can be injected into the reactor coolant system using the guidance of EPRI 1022832, Steam Generator Management Program: PWR Primary to Secondary Leak Guidelines, Rev. 4. This guideline contains the methodology and equations for argon injection, and recommends an Ar-41 target concentration of 0.10 Ci/cc, with a high limit of 0.15 Ci/cc. If NuScale Nonproprietary

there are sufficient radionuclides in the primary coolant (e.g., due to failed fuel or activated corrosion products), injection of argon may not be required. The operating procedure to implement this methodology will be developed as part of COL item 5.4-1.

Because argon is a noble gas, there is no plate out effect within the containment vessel.

Impact on DCA:

Table 11.5-1 and Table 11.5-4 have been revised as described in the response above and as shown in the markup provided in this response.

NuScale Nonproprietary

Tier 2 NuScale Final Safety Analysis Report RAI 11.05-1, RAI 15.00.03-8 Table 11.5-1: Process and Effluent Radiation Monitoring Instrumentation Characteristics System Quantity Type Service Isotopes Nominal Range Location/Function PAM Safety- Media Instrument type related ABS 2 ABS return flow from Cs-137 1.0E-7 to 1.0E-2 Ci/ml ABS return flow from MHS No No Liquid Adjacent-to-line MHS heat exchangers 6A and 6B ABS 2 ABS return flow from Ar-41 3E-3 to 1E-11.0E-7 to ABS return flow from MHS No No Gas Adjacent-to-line MHS 1.0E-1 Ci/cc heat exchangers 6A and 6B ABS 1 ABS high pressure Ar-41 3E-3 to 1E-11.0E-7 to ABS 1100 psi condensate No No Gas Adjacent-to-line condensate tank vent 1.0E-1 Ci/cc tank vent ABS 1 ABS high pressure boiler Ar-41 3E-3 to 1E-11.0E-7 to High pressure boiler to No No Gas Adjacent-to-line to low pressure boiler 1.0E-1 Ci/cc low pressure boiler cross cross feed feed ABVS 1 Radioactive waste Cs-137 3.0E-10 to 1.0E-6 Ci/cc Hot machine shop RWBVS No No Gas Off-line building ventilation exhaust air system (particulate) 11.5-27 BPDS 4 BOP drains Cs-137 1.0E-7 to 1.0E-2 Ci/ml Monitors condensate No No Liquid In-Line Process and Effluent Radiation Monitoring Instrumentation and regeneration skid effluent and TGB drains.

BPDS 1 BOP drains Cs-137 1.0E-7 to1.0E-2 Ci/ml Inlet to 6A-BPD-TNK-0001 No No Liquid Adjacent-to-line from ABS blowdown CARS 12 Condenser air removal Ar-41 3.E-3 to 1E+11.0E-7 to Condenser air removal Yes No Gas Adjacent-to-line Sys 1.0E-1 Ci/cc skid - Ar-41 CARS 12 Condenser air removal Cs-137 3E-10 to 1E-6 Ci / cc Condenser air removal Yes No Gas Off-line (PING) sys (particulate) skid air particulate CARS 12 Condenser air removal I-131 3E-10 to 5E-8 Ci / cc Condenser air removal Yes No Gas Off-line (PING) sys (iodine) skid supply air iodine CARS 12 Condenser air removal Kr-85 3E-7 to 1.0E+5 Ci/cc Condenser air removal Yes No Gas Off-line (PING)

Sampling System sys (noble gas) Xe-133 skid (NG)

CVCS 12 CVCS suction from RCS Cs-137 1E-7 to 1E-2 Ci / ml RCS discharge sample line No No Liquid Adjacent- to-line sample line Draft Revision 1 CES 12 Containment evacuation Ar-41 3.E-3 to 1E+11.0E-7 to CES vacuum pump No No Gas Adjacent- to-line atmosphere gas 1.0E-1 Ci/cc discharge line CES 12 Containment evacuation Cs-137 3.E-10 to 1E-6 Ci/cc CES vacuum pump No No Gas Off-line (PING) atmosphere gas discharge line particulate (particulate)

Table 11.5-1: Process and Effluent Radiation Monitoring Instrumentation Characteristics (Continued)

Tier 2 NuScale Final Safety Analysis Report System Quantity Type Service Isotopes Nominal Range Location/Function PAM Safety- Media Instrument type related GRW 2 GRW decay beds Kr-85 3E-7 to 1E-2 Ci/cc Downstream of decay No No Gas Off-line discharge lines Xe-133 beds discharge line to HVAC exhaust LRW 2 LRW discharge to Cs-137 1E-7 to 1E-2 Ci/ml LRW effluent discharge No No Liquid Adjacent-to-line environment line to environment MSS 24 MSS main steam line A Ar-41 3.E-3 to 1E+11.0E-7 to Main steam line A No No Gas Adjacent to-line 1.0E-1 Ci/cc MSS 24 MSS main steam line B Ar-41 3.E-3 to 1E+11.0E-7 to Main steam line B No No Gas Adjacent to-line 1.0E-1 Ci/cc PSCS 1 Pool surge control Kr-85 3E-7 to 1E-2 Ci / cc Pool surge control storage No No Gas Off-line system Xe-133 tank vent line RBVS 3 Spent fuel pool Cs-137 3E-10 to 1E-6 Ci / cc RBVS spent fuel pool and No No Gas Off-line (PING) ventilation exhaust refuel dock exhaust air (particulate)

RBVS 3 Spent fuel pool I-131 3E-10 to 5E-8 Ci / cc RBVS spent fuel pool and No No Gas Off-line (PING) 11.5-29 ventilation exhaust refuel dock exhaust air Process and Effluent Radiation Monitoring Instrumentation and (iodine)

RBVS 3 Spent fuel pool Kr-85 3E-7 to 1.0E-2 Ci/cc RBVS spent fuel pool and No No Gas Off-line (PING) ventilation exhaust Xe-133 refuel dock exhaust air (noble gas)

RBVS 1 Reactor Building Cs-137 3E-10 to 1E-6 Ci/cc RBVS general area exhaust No No Gas Off-line ventilation system air (particulate)

RBVS 1 Reactor Building I-131 3E-10 to 5E-8 Ci / cc RBVS general area exhaust No No Gas Off-line ventilation system air (iodine)

RBVS 1 Plant vent particulate Cs-137 1E-7 to 1E-2 Ci/cc Plant exhaust stack Yes No Gas Off-line (PING)

RBVS 1 Plant vent iodine I-131 3E-10 to 1E-6 Ci/cc Plant exhaust stack Yes No Gas Off-line (PING)

Sampling System RBVS 1 Plant vent noble gas Kr-85 3E-7 to 1E-2 Ci/cc Plant exhaust stack Yes No Gas Off-line (PING)

(normal range) Xe-133 RBVS 1 / Plant vent extended Kr-85 3E-7 to 1E+4 Ci/cc Plant exhaust stack Yes No Gas Off-line (PING)

Draft Revision 1 range gas (accident mid- Xe-133 range)

RBVS 1 / Plant vent extended Kr-85 3E-7 to 1E+4 Ci/cc Plant exhaust stack Yes No Gas Off-line (PING) range gas (accident high Xe-133 range)

Table 11.5-1: Process and Effluent Radiation Monitoring Instrumentation Characteristics (Continued)

Tier 2 NuScale Final Safety Analysis Report System Quantity Type Service Isotopes Nominal Range Location/Function PAM Safety- Media Instrument type related RWBVS 1 Radioactive Waste Cs-137 3E-10 to 1E-6 Ci/cc RWBVS exhaust air No No Gas Off-line Building ventilation particulate system (particulate)

RWBVS 1 Radioactive Waste I-131 3E-10 to 5E-8 Ci / cc RWBVS exhaust air iodine No No Gas Off-line Building ventilation system (iodine)

RCCW 12 RCCW return lines from Cs-137 1E-7 to 1E-2 Ci/ml RCCW return lines from No No Liquid Adjacent-to-line CES condensers CES condensers RCCW 24 RCCW return lines from Cs-137 1E-7 to 1E-2 Ci/ml RCCW return lines from No No Liquid Adjacent-to-line CVC NRHX and PSS CVC NRHX and PSS coolers coolers RWDS 1 RCCWS water drained Cs-137 1E-7 to 1E-2 Ci/ml RWDS tank-0020 No No Liquid Adjacent-to-line from the CVCS non-regenerative and RCCW HX 11.5-30 SCWS 1 Site cooling water Cs-137 1E-7 to 1E-2 Ci/ml From cooling tower to No No Liquid Off-line with UWS discharge basin sampling Process and Effluent Radiation Monitoring Instrumentation and blowdown line capability SCWS 1 Site cooling water Cs-137 1E-7 to 1E-2 Ci/ml From cooling tower to No No Liquid Adjacent-to-line UWS discharge basin overflow line SCWS 3 SCW reactor pool cooling Cs-137 1E-7 to 1E-2 Ci/ml SCW reactor pool cooling No No Liquid Off-line HXs return lines HXs return lines prior to entering the main header SCWS 2 SCW spent fuel pool Cs-137 1E-7 to 1E-2 Ci/ml SCW spent fuel pool No No Liquid Off-line cooling HX return lines cooling HX return lines SCWS 4 SCW RCCW return lines Cs-137 1E-7 to 1E-2 Ci/ml SCW RCCW return lines No No Liquid Off-line TGSS 2 Turbine gland sealing Ar-41 3.E-3 to 1E-11.0E-7 to Turbine generator skid No No Gas Adjacent-to-line Sampling System system skid exhaust 1.0E-1 Ci/cc common exhaust vent common vent, Turbine point Ar-41 Building Draft Revision 1 TGSS 2 Turbine gland sealing I-131 3E-10 to 5E-8 Ci / cc Turbine generator skid No No Gas Off-line (PING) system skid exhaust common exhaust vent common vent, Turbine point Iodine Building

Tier 2 NuScale Final Safety Analysis Report RAI 11.05-1, RAI 15.00.03-8 Table 11.5-4: Effluent and Process Radiation Monitoring System Dynamic Ranges Radiation Monitor Dynamic Detection Range Principal Radionuclides Basis for Dynamic Range Measured A. Effluent Radiation Monitors RBVS 3E-7 to 1E+4 Ci /cc Noble gas (Kr-85, Xe-133):

  • Realistic Primary Coolant and Secondary Coolant Activity 1E-9 to 1E+2 Ci /cc Iodine (I-131):
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 CARS 3E-3 to 1E+11.0E-7 to 1.0E-1 Ci /cc Ar-41:
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 CARS 3E-7 to 1E+5 Ci / cc Noble gas (Kr-85, Xe-133):
  • Realistic Primary Coolant and Secondary Coolant Activity Process and Effluent Radiation Monitoring Instrumentation and 1E-9 to 1E+2 Ci / cc Iodine (I-131):
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 TGSS 3E-3 to 1E+11.0E-7 to 1.0E-1 Ci /cc Ar-41:
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004
  • Best Estimate Fuel Isotopic Inventory Calculation 3E-10 to 1E-6 Ci / cc Particulate (Cs-137):
  • Best Estimate Fuel Isotopic Inventory Calculation Draft Revision 1
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 LRWS 1E-7 to 1E-2 Ci / ml Cs-137:
  • Realistic Primary Coolant and Secondary Coolant Activity
  • Best Estimate Fuel Isotopic Inventory Calculation

Table 11.5-4: Effluent and Process Radiation Monitoring System Dynamic Ranges (Continued)

Tier 2 NuScale Final Safety Analysis Report Radiation Monitor Dynamic Detection Range Principal Radionuclides Basis for Dynamic Range Measured ABVS 3E-10 to 1E-6 Ci / cc Particulate (Cs-137):

  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 GRWS Common Discharge to 3E-7 to 1E-2 Ci / cc Noble gas
  • Normal Effluent Release Source Term Calculation HVAC (Kr-85, Xe-133)

GRWS Decay Bed Discharge 3E-7 to 1E-2 Ci / cc Noble gas

  • Normal Effluent Release Source Term Calculation Lines (Kr-85, Xe-133)

CES Vacuum Pump Discharge 3E-7 to 1E-2 Ci / cc Noble gas

  • Best Estimate Fuel Isotopic Inventory Calculation (Kr-85, Xe-133)
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-3E-10 to 1E-6 Ci / cc Particulate 2004.

(Cs-137) 3E-10 to 1E-8 Ci / cc Iodine (I-131)

CES Vacuum Pump Discharge 3E-3 to 1E+11.0E-7 to 1.0E-1 Ci / Ar-41:

  • EPRI 1022832 Steam Generator Management Program: PWR 11.5-36 cc Primary-to-Secondary Leak Guidelines, Revision 4 Process and Effluent Radiation Monitoring Instrumentation and
  • Realistic Primary Coolant and Secondary Coolant Activity
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 MSS 3E-3 to 1E+11.0E-7 to 1.0E-1 Ci / Ar-41:
  • Realistic Primary Coolant and Secondary Coolant Activity
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Specification and Performance of On-Site Instrumentation for Sampling System Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 CVCS* 1E-7 to 1E-2 Ci / ml Cs-137:
  • Realistic Primary Coolant and Secondary Coolant Activity Draft Revision 1
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Also area radiation monitors
  • Specification and Performance of On-Site Instrumentation for described in Section 12.3.4 Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004

Table 11.5-4: Effluent and Process Radiation Monitoring System Dynamic Ranges (Continued)

Tier 2 NuScale Final Safety Analysis Report Radiation Monitor Dynamic Detection Range Principal Radionuclides Basis for Dynamic Range Measured RCCWS 1E-7 to 1E-2 Ci / ml Cs-137:

  • Realistic Primary Coolant and Secondary Coolant Activity
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 SCWS Heat Exchanger Outlets 1E-7 to 1E-2 Ci / ml Cs-137:
  • Realistic Primary Coolant and Secondary Coolant Activity
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Realistic Primary Coolant and Secondary Coolant Activity Blowdown
  • Best Estimate Fuel Isotopic Inventory Calculation
  • Realistic Primary Coolant and Secondary Coolant Activity 11.5-37 Overflow
  • Best Estimate Fuel Isotopic Inventory Calculation Process and Effluent Radiation Monitoring Instrumentation and
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 ABS Flash Tank Vent 3E-3 to 1E+11.0E-7 to 1.0E-1 Ci /cc Ar-41
  • Realistic Primary Coolant and Secondary Coolant Activity
  • Release of Radioactive Materials in Gaseous and Liquid Effluent
  • Best Estimate Fuel Isotopic Inventory Calculation Sampling System
  • Specification and Performance of On-Site Instrumentation for Continuously Monitoring Radioactivity in Effluents, ANSI N42.18-2004 Draft Revision 1 ABS MHS Return 3E-3 to 1E+11.0E-7 to 1.0E-1 Ci /cc Ar-41
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