ML18074A342

LLC Supplemental Response to NRC Request for Additional Information No. 207 (Erai No. 9059) on the NuScale Design Certification Application

ML18074A342
Person / Time
Site:	NuScale
Issue date:	03/15/2018
From:	Rad Z NuScale
To:	Document Control Desk, Office of New Reactors
References
RAIO-0318-59155
Download: ML18074A342 (5)

Text

RAIO-0318-59155 March 1, 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 Supplemental Response to NRC Request for Additional Information No. 207 (eRAI No. 9059) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 207 (eRAI No. 9059)," dated September 01, 2017

2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 207 (eRAI No.9059)," dated October 24, 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. 9059:

v 06.02.04-9 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, Zackary W. Rad Di t Regulatory Director, R l t Aff i Affairs NuScale Power, LLC Distribution: Omid Tabatabai, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Prosanta Chowdhury NRC, OWFN-8G9A : NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9059 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0318-59155 :

NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9059 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.: 9059 Date of RAI Issue: 09/01/2017 NRC Question No.: 06.02.04-9 The 10 CFR 50.34(f)(3)(iv) requirement states in part Provide one or more dedicated

containment penetrationsin order not to preclude future installation of systems to prevent

containment failure, such as a filtered vented containment system. (II.B.8) In FSAR Tier 2,

Table 1.9-5, Conformance with TMI Requirements (10 CFR 50.34(f))..., the applicant states

should any future development identify a need for a new penetration, adding such a

penetration to the NuScale vessel is a substantially different process versus the typical

containment. The staff would like the applicant to describe the substantially different process

versus the typical containment and how this process if applied to the NuScale design would not

preclude later installation of containment venting systems, if required.

NuScale Response:

During a January 30, 2018 follow-up call concerning the response to RAI 9059, the staff expressed concern that the departure discussion in Table 1.9-5 for TMI Requirement 10 CFR 50.34(f)(3)(iv) is focused in hydrogen combustion since other severe accident progressions besides hydrogen combustion could challenge hydrogen combustion. Accordingly, Table 1.9-5 is revised to align the departure discussion in the comment column for 10 CFR 50.34(f)(3)(iv) with the language in FSAR Section 6.2.1.1.1, which references Section 19.2.3.

Impact on DCA:

Table 1.9-5 has 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 06.02.04-7S1, RAI 06.02.04-9, RAI 06.02.04-9S1, RAI 08.01-1, RAI 08.02-4, RAI 08.02-6, RAI 08.03.02-1, RAI 09.02.06-1 Table 1.9-5: Conformance with TMI Requirements (10 CFR 50.34(f)) and Generic Issues (NUREG-0933)

Item Regulation Description / Title Conformance Comments Section Status 50.34(f)(1)(i) Perform a plant/site-specific probabilistic Partially Design certification will address reliability of core 19.0 risk assessment, the aim of which is to seek Conforms and containment heat removal systems, with an 19.1 such improvements in the reliability of core update required by COL applicant to reflect site- 19.2 and containment heat removal systems as specific conditions.

are significant and practical and do not impact excessively on the plant (II.B.8) 50.34(f)(1)(ii) Perform an evaluation of the proposed Not Applicable This rule requires an evaluation of proposed Not Applicable auxiliary feedwater system (II.E.1.1) PWR auxiliary feedwater (AFW) systems. The NuScale plant design does have an AFW system like a typical LWR. Neither the literal language nor the intent of this rule applies to the NuScale design.

50.34(f)(1)(iii) Perform an evaluation of the potential for Not Applicable The NuScale reactor design differs from large Not Applicable and impact of reactor coolant pump seal PWRs because the NuScale design does not 1.9-234 damage following small-break LOCA require or include reactor coolant pumps.

(II.K.2.16 and II.K.3.25) Rather, the NuScale design uses passive natural circulation of the primary coolant, eliminating the need for reactor coolant pumps.

50.34(f)(1)(iv) Perform an analysis of the probability of a Not Applicable This guidance is applicable only to PWRs that are Not Applicable small-break LOCA caused by a stuck-open designed with power-operated pressurizer relief power-operated relief valve (PORV) (II.K.3.2) valves. The NuScale design does not use power-operated relief valves.

50.34(f)(1)(v) Perform an evaluation of the safety Not Applicable This requirement applies only to BWRs. Not Applicable effectiveness of providing for separation of Conformance with Regulatory Criteria high pressure coolant injection and reactor core isolation cooling system initiation levels (II.K.3.13) 50.34(f)(1)(vi) Perform a study to identify practicable Not Applicable This requirement applies only to BWRs. Not Applicable system modifications that would reduce Regardless, the issue contemplated by this challenges and failures of relief valves requirement was related to power-operated (II.K.3.16) relief valves. The NuScale design does not use Draft Revision 2 power-operated relief valves.

Table 1.9-5: Conformance with TMI Requirements (10 CFR 50.34(f)) and Generic Issues (NUREG-0933) (Continued)

Tier 2 NuScale Final Safety Analysis Report Item Regulation Description / Title Conformance Comments Section Status 50.34(f)(3)(iv) Provide one or more dedicated Departure This requirement is not technically relevant to 6.2 containment penetrations, equivalent in the NuScale design. This TMI requirement is 19.2 size to a single 3-foot-diameter opening based on traditional large LWR containment (II.B.8) designs and the potential, as of the time of the requirement, need for future containment venting systems to accommodate severe accidents. The NuScale containment vessel design differs from a typical LWR containment structure because of its high-pressure capability.

A 3-foot opening relative to the NuScale containment is unnecessary. Containment structural integrity and availability of equipment necessary for safe shutdown are assured for hydrogen combustion scenarios occurring 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following an event initiation, with have no adverse effect on containment integrity or plant safety functions. The NuScale design includes 1.9-243 provisions to allow venting the containment atmosphere, including connections for portable equipment, if necessary beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.As discussed in Section 6.2.1.1.1, the calculated peak containment for design basis events remains less than the CNV internal design pressure. As discussed in Section 19.2.3, peak containment pressures do not challenge containment integrity for any analyzed severe Conformance with Regulatory Criteria accident progression. (Refer to TR-0716-50424, Section 2.8).

50.34(f)(3)(v) Preliminary Design Information - Not Applicable Pursuant to 10 CFR 52.47(a)(8) and Not Applicable Containment Integrity (II.B.8) 10 CFR 50.34(f), paragraph (f)(3)(v) is excluded from the information required to be included in an application for a design certification.

50.34(f)(3)(vi) For plant designs with external hydrogen Not Applicable The NuScale design does not have external Not Applicable Draft Revision 2 recombiners, provide redundant dedicated hydrogen recombiners.

containment penetrations (II.E.4.1) 50.34(f)(3)(vii) Provide a description of the management Not Applicable This requirement is applicable only to applicants Not Applicable plan for design and construction activities and holders of reactor facility licenses.

(II.J.3.1)