ML24326A123
| ML24326A123 | |
| Person / Time | |
|---|---|
| Site: | 05200050 |
| Issue date: | 11/21/2024 |
| From: | NuScale |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML24326A092 | List: |
| References | |
| LO-175900 | |
| Download: ML24326A123 (1) | |
Text
Response to SDAA Audit Question Question Number: A-16.3.5.1-4 Receipt Date: 04/29/2024 Question:
SDAA Part 2, Section 6.3, ECCS, first paragraph, the second sentence states:
The ECCS is an important NuScale Power Plant safety system in its safety-related response to LOCAs and as a component of both the reactor coolant and containment vessel (CNV) pressure boundaries.
In what way are the two RVVs and two RRVs components of the CNV pressure boundary?
Response
The reactor vent valve and reactor recirculation valve main valve assemblies are attached to the reactor pressure vessel. Each reactor vent valve and reactor recirculation valve is actuated (opened) and reset (closed) by an actuator assembly. An actuator assembly has two trip valves and a reset valve. The trip and reset valve actuator assemblies are connected to the main valve by hard tubing as shown in US460 Standard Design Approval Application Figures 6.3-1, 6.3-3, and 6.3-4. As shown in Standard Design Approval Application Figures 6.3-3 and 6.3-4, the body of the trip and reset valve actuator assemblies attach to the exterior of the containment pressure vessel shell with a nozzle and safe end configuration and is a part of the containment pressure boundary. The trip and reset valve actuator assembly bodies and bonnets also form part of the reactor coolant pressure boundary. The trip and reset tubing between the main valve and the actuator assembly are part of the reactor coolant pressure boundary.
No changes to the SDAA are necessary.
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