ML25069A648
| ML25069A648 | |
| Person / Time | |
|---|---|
| Site: | 05200050 |
| Issue date: | 03/10/2025 |
| From: | NuScale |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML25069A609 | List: |
| References | |
| LO-180139 | |
| Download: ML25069A648 (1) | |
Text
Response to NuScale Topical Report Audit Question Question Number: A-FSR.LTR-50 Receipt Date: 10/14/2024 Question:
Section 6.5.12 Fuel Storage System Seismic Event (1) Why werent Eccentric position Scenarios 2 and 5 modeled? (2) If FSRs move in unison, could this result in the FA essentially being in the same relative location within their storage cells? This eccentric position was not investigated in section 6.5.4, why not? (3) [
] If some FSRs were loaded with different amounts of FA would the difference in inertia cause them to not move in unison? Would that change the reactivity conclusions of the analysis? (4) During a potential seismic event could/would the FSRs be deformed in a manner that could affect the reactivity conclusions of the analysis? Any such deformation would become the new normal for the FSR and must be considered.
Response
(1) Scenario 3 is bounding for the fuel storage loading configurations evaluated, as shown in Table 6-25.
[
]
(2) If all the fuel assemblies are in the same relative position within their cells, they will interact with each other as if they are all centered, because they are separated by the same distance.
(3) The rack motion cases are conservative for the following reasons. [
]
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(4) The racks are placed in the spent fuel pool with a minimum separation of [
] These impact forces result in stress ratios for the outer rack elements and elements adjacent to the fuel assemblies [
, ] as shown in Table 4-26. Significantly higher stresses would need to occur for a permanent deformation of the storage rack to reduce the minimum distance between fuel assemblies. [
] Therefore, the structural model shows no deformation that affects reactivity.
No changes to the LTR are necessary.
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