ML20190A145
| ML20190A145 | |
| Person / Time | |
|---|---|
| Site: | 07201042 |
| Issue date: | 06/30/2020 |
| From: | TN Americas LLC |
| To: | Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML20190A135 | List: |
| References | |
| E-56684 | |
| Download: ML20190A145 (2) | |
Text
Enclosure 12 to E-56684 Additional Changes Not Associated with the RAIs TN Americas LLC is requesting multiple changes to the proposed Amendment 2 Technical Specifications (TS) and Updated Final Safety Analysis Report (UFSAR) that are not related to the RAI questions. The requested changes are discussed in the following sections of this enclosure and include a description of the change, the impact on the design, and a summary of the impact on the TS and UFSAR.
- 1. Technical Specification Table 3 for Control Components
Description:
Technical Specifications (TS) Table 3 relating to control component (CC) Co-60 equivalent activity limits has been moved from the TS to the UFSAR as part of continued application of the graded approach. In Amendments 0 and 1, different CC limits are imposed in the inner and peripheral regions, and TS Table 3 reflected this distinction.
However, when in the storage configuration, CCs do not contribute appreciably to the dose rate due to the large Cs-137 contribution at the vents, which is unrelated to CCs. In Amendment 2, the same CC source is modeled in all basket locations, and the source magnitude has been increased significantly compared to Amendments 0 and 1. Even with large Amendment 2 CC sources, the average dose rate at the front of an HSM is approximately 4% due to CCs, which is within the uncertainty of the methodology. The dose rate due to CCs is more appropriately addressed per the dose rate limits in TS Section 5.1.2, Radiation Protection Program.
TS Impact: TS Table 3 has been moved from the TS to the UFSAR. TS Table 3, footnote 2 related to neutron source assemblies has been moved to TS Section 2.1. TS Section 5.1.2 has been modified to more clearly indicate that CCs are considered as part of the 72.212 evaluation.
UFSAR Impact: References to TS Table 3 are deleted in Chapters 2 and 6. TS Table 3 has been added to the UFSAR as Table 6-37a.
- 2. Co-60 Equivalent Methodology for Control Components
Description:
CC source term limits in new UFSAR Table 6-37a are expressed as Co-60 equivalent (see also item 1 above). This terminology is consistent with TS Table 3 in Amendment 0 and 1. The intent has always been to estimate Co-60 equivalence for CCs containing hafnium or silver using the same response function methodology used to rank fuel assembly source terms, although this has not been stated explicitly in the UFSAR.
TS Impact: None UFSAR Impact: A discussion on Co-60 equivalence is added to UFSAR Section 6.2.4, Control Components, to provide clarification.
- 3. Integrated Inner Top Cover Plate and Shield Plug
Description:
This change clarifies the terminology related to inner top cover plate and shield plug if both of these components are integrated.
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Enclosure 12 to E-56684 Additional Changes Not Associated with the RAIs TS Impact: None UFSAR Impact: A clarification is added to Section 1.2.1.1 for EOS-37PTH and Section 1.2.1.2 for EOS-89BTH to clarify the option of using a shield plug integrated with the inner top cover plate.
- 4. Reduction in Maximum Allowable Heat Load
Description:
TS Section 2.1 and 2.2 (Thermal Parameters) allows the flexibility to reduce he maximum allowable heat loads based on the thermal analysis methodology in the UFSAR.
This change to Chapter 2 clarifies that the reduction if necessary may be based on the specific fuel assembly type.
TS Impact: None UFSAR Impact: Section 2.4.3 of UFSAR is updated to clarify the methodology to reduce the maximum allowable heat load based on the fuel assembly type.
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