ML24348A033

Response to NuScale Topical Report Audit Question Number A-NonLOCA.LTR-26

ML24348A033
Person / Time
Site:	05200050
Issue date:	12/13/2024
From:	NuScale
To:	Office of Nuclear Reactor Regulation
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Download: ML24348A033 (1)

Text

Response to NuScale Topical Report Audit Question Question Number: A-NonLOCA.LTR-26 Receipt Date: 04/15/2024 Question:

Please review and update Table 7-3.

Table 7-3, which lists analytical limits and actuation delays (reactor trip system and engineered safety features actuation system), does not reflect the NPM-20 design for reactor trips and ESF actuations. For example, Nine reactor trip functions have different setpoints (Analytical Limits)

There is one new reactor trip function for the NPM-20, i.e., Hi RCS Avg Temp There are numerous changes in various ESF actuation functions and setpoints, e.g., in the ECCS, DHRS, and Demin Water Isolation System The Hi CNV (containment vessel) Water Level ECCS actuation function appears to be deleted for the NPM-20, apparently replaced with RPV Riser Level actuation functions.

Please provide markups to the TR accordingly.

Response

As stated in Section 7.1.6.3 of the topical report (TR-0516-49416-P, Revision 4):

Examples of the analytical limits and actuation delays are summarized in Table 7-3. The values in Table 7-3 are example values used to aid the subsequent methodology discussion. Application of the methodology to a specific [NuScale Power Module (NPM)]

design requires the use of analytical limits and actuation delays associated with that NPM design.

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For the US460 design (i.e., NPM-20), the specific analytical limits and actuation delays are provided in Final Safety Analysis Report (FSAR) Table 15.0-7.

Because the topical report explicitly identifies Table 7-3 as an example only to aid understanding the methodology, it is not necessary for Table 7-3 to be consistent with any specific NPM design. Therefore, no changes are required.

No changes to the SDAA are necessary.

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