ML17346B303

LLC Supplemental Response to NRC Request for Additional No. 229 (Erai No. 9101) on the NuScale Design Certification Application

ML17346B303
Person / Time
Site:	NuScale
Issue date:	12/12/2017
From:	Rad Z NuScale
To:	Document Control Desk, Office of New Reactors
References
RAIO-1217-57637
Download: ML17346B303 (6)

Text

RAIO-1217-57637 December 12, 2017 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 Supplemental Response to NRC Request for Additional Information No. 229 (eRAI No. 9101) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 229 (eRAI No. 9101)," dated September 14, 2017

2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 229 (eRAI No.9101)," dated November 10, 2017 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

Question from NRC eRAI No. 9101:

09.02.02-4 This supplemental response supersedes the response provided by Reference 2.

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 Anthony Markley, NRC, OWFN-8G9A : NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9101 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-1217-57637 :

NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9101 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.: 9101 Date of RAI Issue: 09/14/2017 NRC Question No.: 09.02.02-4 10 CFR 52.47(a)(2) requires that a standard design certification applicant provide a description

and analysis of the structures, systems, and components (SSCs) of the facility, with emphasis

upon performance requirements, the bases, with technical justification therefor, upon which

these requirements have been established, and the evaluations required to show that safety

functions will be accomplished.

10 CFR 52.47(c)(2) requires that a standard design certification of a nuclear power reactor

design that uses simplified, inherent, passive, or other innovative means to accomplish its

safety functions must provide an essentially complete nuclear power reactor design except for

site-specific elements such as the service water intake structure and the ultimate heat sink, and

must meet the requirements of 10 CFR 50.43(e).

FSAR Tier 2, Table 9.2.2-1 specifies the design heat load for the reactor component cooling

water system (RCCWS) to be 21 MBtu/hr and the design flow rate for the RCCWS pumps to be

660 gpm.

FSAR Tier 2, Figure 9.2.2-1, identifies that the RCCWs provides cooling to the following heat

loads:

Control rod drive mechanism (CRDM) Cooling Coils Chemical and volume control system (CVCS) non-regenerative heat exchangers (NRHX)

Containment Evacuation System (CES) condensers and vacuum pumps Process sampling system (PSS) coolers and analyzer cooler temperature control units (TCUs)

To clarify that the RCCWS flow and heat load specified in Table 9.2.2-1 is sufficient to provide the necessary cooling for the RCCW heat loads identified in Figure 9.2.2-1, the applicant is requested to:

Provide the heat loads of all the above systems Provide the flow rate required to each of the specified heat loads Discuss how the operators could know that there is insufficient heat removal capability in the RCCWS and what procedures would be required for the operators to take.

NuScale Nonproprietary

NuScale Response:

First and second bullet response regarding heat loads and flow rates:

As noted in FSAR Section 9.2.2.1, the RCCWS provides no safety-related function, is not credited for mitigation of design basis accidents, and has no safe shutdown functions. Also, as noted in FSAR Section 9.2.2.3, RCCWS cooling is not required for any safety-related or risk-significant components to perform their functions. While the CRDMs are safety-related due to their function of safe shutdown of the reactor, the electromagnetic drive coils and rod position indication that are cooled by RCCWS are part of the control rod drive system and do not impact the ability to safely shut down the reactor. The RCCWS heat removal information (heat loads and flow rates) was not provided originally in the FSAR because it does not affect the safety functions.

The two tables below contain preliminary expected heat loads and flow rates for components of the RCCWS. Table 1 contains heat loads and flow rates expected for normal operating condition while Table 2 contains heat loads and flow rates used for the purpose of sizing the equipment. Table 2 contains expected heat loads that could be experienced during operation evolutions that need to be included in the system sizing so that plant operation would not be limited by the RCCWS capacity. If the heat loads and flow rates in Tables 1 and 2 were to change, the revised heat loads and flow rates are not required to be provided in a revised RAI response as this information does not serve any safety or important to safety function.

NuScale Nonproprietary

Table 1. Normal Operation RCCWS Flow Rates and Heat Loads Flow Rate Heat Load Temp. Temp Component Qty Operating Condition (gpm) (BTU/hr) ea. In (°F) Out (°F) ea.

CRDM 96 Normal 2 40,200 80 120.5 CVCS 22 gpm CVCS NRHX 6 (purification, no 20 551,000 80 135.5 makeup or letdown)

One continuous PSS Coolers 6 12 116,000 80 99.5 analyzer per module One continuous TCU PSS TCU 1 17 60,000 80 87.2 for 6 modules CE Condenser 6 Normal 8 90,000 80 102.7 CE Vacuum 6 Normal 2 35,830 80 116.1 Pump TOTAL 461 8,676,180 Table 2. Sizing Basis RCCWS Flow Rates and Heat Loads Flow Operating Rate Heat Load Temp. Temp Component Qty Condition (gpm) (BTU/hr) ea. In (°F) Out (°F) ea.

CRDM 96 Normal 2 40,200 100 140.5 CVCS 42 gpm (22 CVCS NRHX 2 gpm purif. + 20 gpm 240 3,575,000 100 130 (fouled) letdown, no makeup)

CVCS NRHX CVCS 22 gpm 4 90 1,877,000 100 142 (fouled) (300°F RHX outlet)

One continuous PSS Coolers 6 12 116,000 100 119.5 analyzer per module One continuous TCU PSS TCU 1 17 60,000 100 107.2 for 6 modules CE Condenser 6 Normal 8 90,000 100 122.7 CE Vacuum 12 Normal 2 35,830 100 136.1 Pump TOTAL 1,193 20,243,160 Third bullet response regarding what procedures would be required for the operators to take:

NuScale Nonproprietary

The RCCWS contains temperature and flow indication for every component heat load.

Operating procedures will provide the operator with the ability to diagnose and respond to malfunctions.

The Plant Control System continuously monitors the components cooled by the RCCWS and sends that information to the Control Room Human-System Interface (HSI). If the RCCWS fails to cool any or multiple components, automatic actions (automated procedure) will occur to mitigate the abnormal occurrence and restore sufficient heat removal capability. If automatic actions fail to mitigate the abnormal event the operator will follow prescribed steps in alarm response procedures and abnormal system operating procedures until the event is mitigated and sufficient heat removal capability is restored.

With regards to operations procedure development, COL Item 13.5-2 requires that the applicant describe the site-specific procedures that operators use in the main control room and locally in the plant, including normal operating procedures, abnormal operating procedures, and emergency operating procedures.

Impact on DCA:

There are no impacts to the DCA as a result of this response.

NuScale Nonproprietary