RAIO-0418-59450, LLC Response to NRC Request for Additional Information No. 362 (Erai No. 9315) on the NuScale Design Certification Application

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LLC Response to NRC Request for Additional Information No. 362 (Erai No. 9315) on the NuScale Design Certification Application
ML18096B560
Person / Time
Site: NuScale
Issue date: 04/06/2018
From: Wike J
NuScale
To:
Document Control Desk, Office of New Reactors
References
RAIO-0418-59450
Download: ML18096B560 (11)
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Text

RAIO-0418-59450 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com April 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.

362 (eRAI No. 9315) on the NuScale Design Certification Application

REFERENCE:

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

362 (eRAI No. 9315)," dated February 05, 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. 9315:

03.08.02-14 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 Marty Bryan at 541-452-7172 or at mbryan@nuscalepower.com.

Sincerely, Jennie Wike Manager, Licensing NuScale Power, LLC Distribution:

Omid Tabatabai, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Prosanta Chowdhury NRC, OWFN-8G9A

NuScale Response to NRC Request for Additional Information eRAI No. 9315 Jennie Wike

RAIO-0418-59450 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. 9315

NuScale Nonproprietary Response to Request for Additional Information Docket No.52-048 eRAI No.: 9315 Date of RAI Issue: 02/05/2018 NRC Question No.: 03.08.02-14 10 CFR 52.47 requires the design certification applicant to include a description and analysis of the structures, systems, and components with sufficient detail to permit understanding of the system designs.

Per NuScale FSAR Tier 2, Section 6.3.2.3, the emergency core cooling system (ECCS) components (including valves, hydraulic lines, and actuator assemblies) are Quality Group A, Seismic Category I components designed to ASME BPV Code,Section III, Subsection NB.

For consistency, Table 3.2-1, Classification of Structures, Systems, and Components, should be revised to clarify the specified ECCS valves are intended to include the valves, hydraulic lines, and actuator assemblies being Quality Group A, Seismic Category I components.

Per FSAR Tier 2, Section 6.3.2.2, the body of the ECCS actuator assembly serves as both a containment vessel (CNV) pressure boundary and reactor coolant pressure boundary (RCPB).

General Design Criteria (GDCs) 14 and 16 require that:

The reactor coolant pressure boundary shall be designed, fabricated, erected, and tested so as to have an extremely low probability of abnormal leakage, of rapidly propagating failure, and of gross rupture.

Reactor containment and associated systems shall be provided to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are not exceeded for as long as postulated accident conditions require.

The ECCS actuator assembly currently protects both the CNV boundary and RCPB; therefore it is crucial that the welds and actuator assembly itself be designed to ensure and extremely low probability of leakage or failure in accordance with GDCs 14 and 16.

The NRC staff requests the applicant to clarify the inservice inspection (ISI) that will be performed to provide assurance of the structural integrity of the containment nozzle to safe end welds and safe end to ECCS actuator assembly welds, i.e. will they be full volumetric? FSAR Tier 2, Table 6.6-1, Examination Categories, should also be revised to include this information.

NuScale Nonproprietary Also, will the material the actuator assembly body is manufactured from be volumetrically examined as part of the valve fabrication requirements? And what are the fabrication NDE requirements for the entire RCPB portion for this valve?

Also, Per FSAR 6.3.2.2, Equipment and Component Descriptions, valve bonnet seals on each pilot valve establish the pressure boundaries internal to the valve assembly body. And in TR-1116-51962-NP NuScale Containment Leakage Integrity Assurance Technical Report, Section 3.2 Containment Penetrations, it describes a portion of the ECCS actuator pressure boundary that is accomplished by a bolted enclosure (body-to-bonnet) with a dual metal o-ring seal.

In generic technical specifications (TS) Subsection 3.4.5, "RCS Operational LEAKAGE," LCO 3.4.5 states that RCS operational LEAKAGE shall be limited to: a) no pressure boundary LEAKAGE, b) 0.5 gpm unidentified LEAKAGE, c) 2 gpm identified LEAKAGE from the RCS, and d) 150 gallons per day primary to secondary LEAKAGE.

The NRC staff requests that the applicant clarify the periodic testing and inspection provisions it will implement to ensure no leakage past the O-ring seals of the ECCS actuator pressure boundary during normal operating conditions. Also, explain how LCO 3.4.5 limits a), b), and c) would apply to leakage past the ECCS actuator O-ring seals or through the valve body. Explain how such RCS leakage outside of containment would be detected, identified, and quantified during operation." Were such leakage to occur without being identified but within the limit of LCO 3.4.5, what would the possible consequences be at the onset of an event?

NuScale Response:

The emergency core cooling system (ECCS) main valves (Reactor Vent Valve (RVV) and Reactor Recirculation Valve (RRV)) and pilot valve assemblies (identified as the RVV Trip, RRV Trip and Reset Valves in FSAR Tier 2 Table 3.2-1) are identified and specified in FSAR Tier 2 Table 3.2-1 as Quality Group A, Seismic Category I. However, the hydraulic lines are not specified. FSAR Table 3.2-1 has been modified to add the hydraulic lines and to clarify the valve names.

Inservice inspection of the ECCS trip/reset pilot valve assembly nozzle to safe end, and the safe end to valve welds is discussed in FSAR Tier 2 Table 6.2-3 (RVV and RRV trip/reset pilot assembly nozzle to safe end weld) and FSAR Tier 2 Table 5.2-8 (RVV and RRV trip/reset pilot assembly safe end to valve weld) respectively. The nozzle to safe end weld falls under ASME Section XI Table IWB-2500-1 (B-F) inspection requirements. The weld at this connection location is on a nominal pipe size (NPS) of 4 or greater. Therefore the weld should have a volumetric and surface examination. FSAR Tier 2 Table 6.2-3 indicates only a surface examination is required. FSAR Tier 2 Table 6.2-3 has been modified for this weld to identify that both a volumetric and surface examinations are required. The safe end to valve weld falls under ASME Section XI Table IWB-2500-1 (B-J) inspection requirements. The weld at this location is

NuScale Nonproprietary less than an NPS 4. Therefore, the weld should have a surface examination. FSAR Tier 2 Table 5.2-8 indicates no examination is required. Therefore, FSAR Tier 2 Table 5.2-8 has been modified for this weld to identify a surface examination is required.

FSAR Tier 2 Table 6.6-1 defines the inspection requirements for Class 2 and Class 3 components. The RVV and RRV trip/reset pilot valve assemblies are Class 1 components and their inservice inspection requirements are defined in FSAR Tier 2 Table 6.2-3 and FSAR Tier 2 Table 5.2-8. Therefore, FSAR Table 6.6-1 does not need to be modified to identify the RVV and RRV trip/reset pilot valves.

The ECCS pilot valve assembly Reactor Coolant Pressure Boundary (RCPB) components will have a fabrication volumetric examination performed. The RVV and RRV trip/reset pilot valves are ASME BPVC Class 1 valves and follow the requirements of ASME BPVC Article NB-2000.

Per the requirement of ASME BPVC Subarticle NB-2540 the materials listed in FSAR Tier 2 Table 6.1-3 for RCPB valve body and bonnets are to have a volumetric examination.

The RVV and RRV trip/reset pilot valves have bolted bonnets and no welding on the RCPB is performed. Therefore no fabrication NDE, other than the material examination requirements of ASME BPVC Subarticle NB-2500, is required.

O-ring seals are used for the body-to-bonnet seals for each ECCS trip and reset pilot valve assembly that is located on the exterior of the CNV. These seals provide containment and reactor coolant pressure boundary functions. These seals are as-found tested per 10 CFR 50 Appendix J Type B each refueling outage. A separate as-left test is performed (1) if the as found leak rate is unsatisfactory and rework is performed, or (2) if any other activity was performed during the outage that could have affected seal leakage integrity. In addition to Appendix J requirements, technical specifications 3.4.5, RCS Operational LEAKAGE, 3.6.1, Containment, and 5.5.9, Containment Leakage Rate Testing Program, requirements apply.

The O-ring seals are subject to the leakage limits of technical specification 3.4.5 and are part of the RCS leakage testing performed in accordance with surveillance requirement (SR) 3.4.5.1.

The O-ring seals are also subject to the Appendix J limits which must be met to comply with the OPERABILITY requirements of technical specification 3.6.1.

Leakage outside of containment would be detected and quantified by combining the indications from the instrumentation required by specification 3.4.7, RCS Leakage Detection Instrumentation, with the results of SR 3.4.5.1, and any other available information. The Containment Evacuation System condensate channels measure RCS leakage into the containment volume. SR 3.4.5.1 performs an overall RCS water inventory balance. An otherwise unexplained difference in results from these two measurements would be a possible indication of leakage outside the containment volume. Plant procedures would direct further investigation to determine if leakage was via leaks from the CVCS or other attached system flow paths, or an indication of O-ring leakage. Detailed discussion of RCS leakage detection is provided in FSAR section 5.2.5, Reactor Coolant Pressure Boundary Leakage Detection.

NuScale Nonproprietary Leakage less than the limit of LCO 3.4.5 would require evaluation to determine if it is within the limits established by 10 CFR 50, Appendix J. If the Appendix J criteria are not met, then immediate corrective action or a reactor shutdown would be required in accordance with the Conditions and Required Actions of technical specification 3.6.1. If the leakage did not exceed the Appendix J criteria then the unit would continue to operate as it would with any other containment leakage within the limits of the regulations.

Impact on DCA:

FSAR Tier 2, Table 3.2-1, Table 5.2-8, and Table 6.2-3 have been revised as described in the response above and as shown in the markup provided in this response.

NuScale Final Safety Analysis Report Classification of Structures, Systems, and Components Tier 2 3.2-12 Draft Revision 2 RAI 03.02.01-2, RAI 03.02.01-3, RAI 03.02.02-2, RAI 03.02.02-6, RAI 03.08.02-14, RAI 05.04.02.01-6, RAI 06.02.04-2, RAI 09.02.02-1, RAI 09.02.04-1, RAI 09.02.05-1, RAI 09.02.06-1, RAI 09.02.07-4, RAI 09.02.07-5, RAI 09.02.09-2, RAI 09.03.04-5, RAI 09.04.02-1, RAI 10.04.07-2, RAI 11.02-1, RAI 19-14 Table 3.2-1: Classification of Structures, Systems, and Components SSC (Note 1)

Location SSC Classification (A1, A2, B1, B2)

RTNSS Category (A,B,C,D,E)

QA Program Applicability (Note 2)

Augmented Design Requirements (Note 3)

Quality Group / Safety Classification (Ref RG 1.26 or RG 1.143)

(Note 4)

Seismic Classification (Ref.

RG 1.29 or RG 1.143)

(Note 5)

CNTS, Containment System All components (except as listed below)

RXB A1 N/A Q

None B

I

  • CVC Injection & Discharge Nozzles
  • CVC PZR Spray Nozzle
  • CVC PZR Spray CIV
  • CVC RPV High Point Degasification Nozzle
  • CVC RPV High Point Degasification CIV
  • RVV & RRV Trip/Reset # 1 & 2 Nozzles
  • RVV Trip 1 & 2/Reset #3 Nozzles
  • CVC Injection & Discharge CIVs RXB A1 N/A Q

None A

I

  • NPM Lifting Lugs
  • Top Support Structure
  • Top Support Structure Diagonal Lifting Braces RXB B1 None AQ-S
  • CNV Fasteners
  • CNV Seismic Shear Lug
  • CNV CRDM Support Frame
  • Containment Pressure Transducer (Narrow Range)
  • Containment Water Level Sensors (Radar Transceiver)
  • SG 1 & 2 Steam Temperature Sensors (RTD)

RXB A1 N/A Q

None N/A I

CNTS CFDS Piping in containment RXB B2 None AQ-S None B

II Piping from (CES, CFDS, FWS, MSS, and RCCWS) CIVs to disconnect flange (outside containment)

RXB B2 None AQ-S None D

I CVCS Piping from CIVs to disconnect flange (outside containment)

RXB B2 None AQ-S None C

I CIV Close and Open Position Sensors:

  • CES, Inboard and Outboard
  • CFDS, Inboard and Outboard
  • CVCS, Inboard and Outboard PZR Spray Line
  • CVCS, Inboard and Outboard RCS Discharge
  • CVCS, Inboard and Outboard RCS Injection
  • CVCS, Inboard and Outboard RPV High-Point Degasification
  • RCCWS, Inboard and Outboard Return and Supply
  • SGS, Steam Supply CIV/MSIVs and CIV/MSIV Bypasses RXB B2 None AQ-S IEEE 497-2002 with CORR 1 N/A I

Containment Pressure Transducer (Wide Range)

RXB B2 None AQ-S IEEE 497-2002 with CORR 1 N/A I

  • Containment Air Temperature (RTDs)
  • Steam plenums RXB A1 N/A Q

None A

I

  • SG tube supports
  • Upper and lower SG supports RXB A1 N/A Q

None N/A I

  • Steam piping inside containment
  • Thermal relief valves RXB A2 N/A Q

None B

I Flow restrictors RXB A2 N/A Q

None N/A I

NuScale Final Safety Analysis Report Classification of Structures, Systems, and Components Tier 2 3.2-14 Draft Revision 2

  • Discharge Spoolpiece Drain Valve
  • Discharge Spoolpiece Isolation Valve
  • Injection Spoolpiece Drain Valve
  • Pressurizer Spoolpiece Drain Valve
  • NuScale Power Module Removable Spoolpieces
  • RPV High Point Degasification Isolation Valve
  • RPV High Point Degasification Spoolpiece Drain Valve

I Hydrogen bottle and distribution assembly including excess flow valve RXB B2 None AQ-S None D

II Pressure Indicating Transmitter for Hydrogen Injection Bottle RXB B2 None AQ-S None N/A II

  • Mass Flow Instruments for CVC Injection Line
  • CVC Discharge Line,
  • CVC Makeup Line,
  • LRW Letdown Line (Pressure, Temperature, Flow)

RXB B2 None AQ None N/A III

  • Other Instrumentation (Pressure, Temperature, Flow, Radioactivity, Boron)

RXB B2 None None None N/A III All other components RXB B2 None None None D

III BAS, Boron Addition System All components (except as listed below)

RXB B2 None None None D

III

  • Instrumentation (Pressure, Temperature, Flow, Level, Position)
  • Hopper Scale
  • Batch Tank Mixer RXB B2 None None None N/A III MHS, Module Heatup System All components (except as listed below)

RXB B2 None None None D

III

  • Instrumentation (Pressure, Temperature, Level)

RXB B2 None None None N/A III ECCS, Emergency Core Cooling System

  • Reactor Vent Valve (RVV)
  • RVV Trip Valve
  • Reactor Recirculation Valve (RRV)
  • RRV Trip Valve
  • Reset Valve
  • Hydraulic lines RXB A1 N/A Q

None A

I

  • RRV Position Indication
  • RVV Position Indication
  • Trip Valve Position Indication RXB B2 None AQ-S IEEE 497-2002 with CORR 1 N/A I

Reset Valve Position Indication RXB B2 None AQ-S None N/A II DHRS, Decay Heat Removal System SG Steam Pressure Instrumentation (4 per side)

RXB A1 N/A Q

None N/A I

  • Actuation Valve (2 per side)
  • Condenser (1 per side)

RXB A2 N/A Q

None B

I

  • Condenser Outlet Pressure Instrumentation (3 per side)
  • Condenser Outlet Temperature Instrumentation (2 per side)
  • Valve Position Indicator (2 for open, 2 for close per side)

RXB B2 None AQ-S IEEE 497-2002 with CORR 1 N/A I

Level Instrument (2 per side)

RXB B2 None AQ-S None N/A II CRHS, Control Room Habitability System All components (except as listed below)

CRB B2 None AQ-S None N/A I

  • CRE Pressure Relief Isolation Valve Position Indicators CRB B2 None AQ-S IEEE 497-2002 with CORR 1 N/A I

Table 3.2-1: Classification of Structures, Systems, and Components (Continued)

SSC (Note 1)

Location SSC Classification (A1, A2, B1, B2)

RTNSS Category (A,B,C,D,E)

QA Program Applicability (Note 2)

Augmented Design Requirements (Note 3)

Quality Group / Safety Classification (Ref RG 1.26 or RG 1.143)

(Note 4)

Seismic Classification (Ref.

RG 1.29 or RG 1.143)

(Note 5)

NuScale Final Safety Analysis Report Integrity of Reactor Coolant Boundary Tier 2 5.2-42 Draft Revision 2 RAI 03.06.02-17, RAI 03.08.02-14 Table 5.2-8: American Society of Mechanical Engineers Class 1 Piping Inspection Elements Description Examination Category Examination Method Notes Dual valve, single body isolation valve to safe-end B-J Surface and Volumetric Refer to Section 5.2.4.1 for discussion on welds between the containment and the dual valve, single body CIVs.

CRDM nozzles B-J Surface or Volumetric RCS discharge piping and RPV nozzle safe end to piping RCS discharge piping to excess flow check valve and containment safe end (inside containment)

RCS injection piping and RPV nozzle safe end to piping RCS injection piping to excess flow check valve and containment safe end (inside containment)

PZR spray piping and RPV nozzle safe end to piping PZR spray piping to excess flow check valve and containment safe end (inside containment)

RPV high point degasification piping and RPV nozzle safe end to piping RPV high point degasification to excess flow check valve and containment safe end (inside containment)

B-J Surface RRV and RVV trip-reset actuators to safe ends RRV and RVV trip-reset actuators piping and fitting welds B-J NoneSurface Exempted by ASME BPVC Section XI, Paragraph IWB-1220 due to small size of piping and fittings.

RRV and RVV bolts B-G-2 VT-1 Inspection is only required when disassembled.

RRV and RVV trip-reset actuators piping and fitting welds B-J None Exempted by ASME BPVC Section XI, Paragraph IWB-1220 due to small size of piping and fittings.

NuScale Final Safety Analysis Report Containment Systems Tier 2 6.2-60 Draft Revision 2 RAI 03.08.02-14, RAI 05.02.04-3, RAI 06.02.01-3, RAI 06.02.02-2, RAI 06.02.06-17, RAI 06.02.06-18, RAI 06.06-3 Table 6.2-3: Containment Vessel Inspection Elements Component Description Examination Category Examination Method Notes CNV Shell and Head Welds Bottom head to core region shell B-A Volumetric Core region shell to lower transition shell B-A Volumetric Lower transition shell to lower flange B-A Volumetric Upper flange to RPV support lug shell B-A Volumetric RPV support lug shell to steam plenum access shell B-A Volumetric Steam plenum access shell to upper shell B-A Volumetric Upper shell to top head B-A Volumetric Support Welds Support skirt ring to support skirt F-A Visual Support skirt to bottom head B-K Surface or volumetric CNV shipping/storage support lug B-K Surface CNV support lug B-A Volumetric Alignment pin to threaded insert B-K Surface Instrument enclosure base to CNV None None Exempted by IWF-1230 CNV Nozzle to Shell and Head Welds Feedwater lines B-D Volumetric Examination requirement IWB-2500-7(b)

Main steam lines B-D Volumetric Examination requirement IWB-2500-7(b)

CRDS return line B-D Volumetric Examination requirement IWB-2500-7(b)

CVCS makeup line B-D Volumetric Examination requirement IWB-2500-7(b)

CVCS pressurizer spray line B-D Volumetric Examination requirement IWB-2500-7(b)

I&C Divisions B-D Not required See Table IWB-2500-1 (B-D) Note 1 Containment evacuation system line B-D Volumetric Examination requirement IWB-2500-7(b)

Containment flood and drain system line B-D Volumetric Examination requirement IWB-2500-7(b)

CRDS supply line B-D Volumetric Examination requirement IWB-2500-7(b)

CVCS letdown line B-D Volumetric Examination requirement IWB-2500-7(b)

RPV high point degasification line B-D Volumetric Examination requirement IWB-2500-7(b)

Pressurizer heater power (Elect-1 and 2)

B-D Not required See Table IWB-2500-1 (B-D) Note 1 I&C channels A-D B-D Not required See Table IWB-2500-1 (B-D) Note 1 Decay heat removal system lines B-D Volumetric Single sided, shell side. Examination requirement IWB-2500-7(b)

NuScale Final Safety Analysis Report Containment Systems Tier 2 6.2-61 Draft Revision 2 Head manway B-D Not required See Table IWB-2500-1 (B-D) Note 1 CRDM access opening B-D Not required See Table IWB-2500-1 (B-D) Note 1 CNV manway B-D Not required See Table IWB-2500-1 (B-D) Note 1 SG inspection ports B-D Not required See Table IWB-2500-1 (B-D) Note 1 Pressurizer heater access ports B-D Not required See Table IWB-2500-1 (B-D) Note 1 RRV and RVV trip/reset B-D Not required See Table IWB-2500-1 (B-D) Note 1 CRDM power B-D Not required See Table IWB-2500-1 (B-D) Note 1 RPI groups B-D Not required See Table IWB-2500-1 (B-D) Note 1 Nozzle-to-Safe-end Dissimilar Metal Welds (SE)

Feedwater lines SE (inner and outer)

B-F Surface and Volumetric Main steam lines SE (inner and outer)

B-F Surface and Volumetric CRDS return line SE (outer)

B-F Surface and Volumetric CRDS return lines SE (inner)

B-F Surface CVCS makeup line SE (outer)

B-F Surface and Volumetric CVCS makeup line SE (inner)

B-F Surface CVCS pressurizer spray line SE (outer)

B-F Surface and Volumetric CVCS pressurizer spray line SE (inner)

B-F Surface Containment evacuation system line SE B-F Surface Containment flood and drain system line SE (inner and outer)

B-F Surface CRDS supply line SE (inner and outer)

B-F Surface CVCS letdown line SE (inner and outer)

B-F Surface RPV high point degasification line SE (inner and outer)

B-F Surface Decay heat removal system lines SE (inner and outer)

B-F Surface RRV and RVV trip/reset SE B-F Surface and Volumetric Threaded Fastener Threaded Insert Welds I&C Divisions None VT-1 No inspection requirement. Augmented to VT-1 when bolts are removed.

Pressurizer heater power (Elect - 1 and 2)

None VT-1 No inspection requirement. Augmented to VT-1 when bolts are removed.

I&C channels A-D None VT-1 No inspection requirement. Augmented to VT-1 when bolts are removed.

Head manway None VT-1 No inspection requirement. Augmented to VT-1 when bolts are removed.

Table 6.2-3: Containment Vessel Inspection Elements (Continued)

Component Description Examination Category Examination Method Notes

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