ML24348A061
| ML24348A061 | |
| Person / Time | |
|---|---|
| Site: | 05200050 |
| Issue date: | 12/13/2024 |
| From: | NuScale |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML24348A006 | List:
|
| References | |
| LO-176318 | |
| Download: ML24348A061 (1) | |
Text
Response to NuScale Topical Report Audit Question Question Number: A-NonLOCA.LTR-41 Receipt Date: 06/10/2024 Question:
Tables 7-58, 7-62, and 7-66 discuss loss of AC power scenarios for the uncontrolled control rod assembly (CRA) bank withdrawal from subcritical or low power startup conditions, uncontrolled CRA bank withdrawal at power, and control rod misoperation events. However, no discussion of loss of normal DC power is provided. Provide topical report markups discussing the loss of normal DC power scenarios considered for these transients.
Response
TR-0516-49416-P, Non-Loss-of-Coolant Accident Analysis Methodology, Revision 4, Tables 7-58, 7-62, and 7-66 discuss loss of alternating current (AC) power but do not discuss direct current (DC) power. The discussion of AC power and not DC power in these tables is the same as in Tables 7-58, 7-62, and 7-66 of TR-0516-49416-P-A, Revision 3, that was previously reviewed and approved by the NRC.
In the NRCs Safety Evaluation Report (SER) for TR-0516-49416-P-A, Revision 3, a limitation and condition was included that stated that [a]n applicant or licensee seeking to apply this methodology to a design must receive a separate approval through that design review for the event-specific electrical power assumptions (AC/DC), single failures, and the need for operator actions necessary to mitigate non-LOCA design basis events, with emphasis added.
The process being used for TR-0516-49416-P, Revision 4 is the same as previously used for TR-0516-49416-P-A, Revision 3. The event-specific information is provided in the Final Safety Analysis Report (FSAR). The NRC has already requested additional information on loss of power scenarios for the events associated with Tables 7-58, 7-62, and 7-66 in audit question NuScale Nonproprietary NuScale Nonproprietary
A-15.4.1-2. The NuScale response and supplemental response to audit question A-15.4.1-2 provides the necessary information supporting the FSAR.
Therefore, there is no need to revise Tables 7-58, 7-62, and 7-66 of TR-0516-49416-P, Revision 4, because the information is provided in the FSAR rather than the topical report.
No changes to the SDAA are necessary.
NuScale Nonproprietary NuScale Nonproprietary