ML24136A191
| ML24136A191 | |
| Person / Time | |
|---|---|
| Site: | HI-STORM 100 |
| Issue date: | 04/18/2024 |
| From: | Holtec |
| To: | Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML24136A188 | List: |
| References | |
| 5021076 | |
| Download: ML24136A191 (1) | |
Text
Request for Supplemental I
Docket No. 72-1040 Certificate of Compliance No. 1040 Amendment No. 5 to the HI-STORM UMAX Multipurpose Canister Storage System
A. Operating Procedures and Acceptance Criteria and Maintenance Program
RSI-1 Provide revised final safety analysis report (FSAR) pages from the operating procedures and acceptance criteria and maintenance program chapters that incorporate necessary revisions due to the differences in Version B1 and B2 to Version B of the HI-STORM UMAX.
The applicant should revise the SAR to ensure that all the changes related to this amendment are reflected.
The proposed amendment requests to modify the design of the air inlet vents with cover plates used to block and reduce the size of the vents, which result in Version B1 and B2 of the HI-STORM UMAX. However, the operating procedures and acceptance criteria and maintenance program chapters were not updated consistent with the proposed changes to ensure compliance could be maintained. Examples include, but are not limited to, the following:
- a. Section 9.2.2 provides a general checklist for performing the pre-staging inspection of the vertical ventilated module (VVM) cavities. Number 4 of that checklist states [v]ent openings shall be free from obstructions. However, compliance could not be maintained with cover plates.
- b. The last paragraph of Section 9.3 describes routine maintenance and includes the removal of vent blockages. However, cover plates that block the vent should not be removed so clarification should be provided.
- c. For the thermal acceptance function in Table 10.1.1, under the maintenance and operations column, item b) states [p]eriodic surveillance shall be performed by either (1) or (2) below, at the licensees option. Items (1) or (2) are the surveillance requirements in technical specification (TS) 3.1.2, which are proposed as not applicable for HI-STORM UMAX Version B2. Therefore, compliance with these periodic surveillance requirements in Table 10.1.1 could not be maintained for the proposed HI-STORM UMAX Version B2.
- d. The last paragraph of Section 10.3.iii states that [t]he technical specifications require periodic surveillance of the system air inlet and outlet vents However, as stated in example c above, these TS are not applicable to HI-STORM UMAX Version B2 and compliance could not be maintained.
This information is needed to meet the regulatory requirements in 10 CFR 72.230(a) and 72.236(b).
Holtec Response:
As a general note, which may help answer a number of these RSIs, the cover plates are not considered to be blockages, they are part of the vent design for the HI-STORM UMAX Version B1 and B2 to reduce the design size of the vents. Blockage is an off-normal/accident condition
nformation that may occur, while the reduced or non-existent vent sizes in the B1 and B2 are the normal condition design, and the thermal analysis is performed appropriately.
- a. Chapter 9, Section 9.2.2 is revised to clarify that cover plates are installed to reduce the size of the inlet vent opening partially or fully in Version B1 and B2 in accordance with the drawings.
- b. Chapter 9, Section 9.3 is revised to include a note to clarify that the inlet vent openings for Version B1 and B2 use cover plates in accordance with the applicable vent design of the lid and that these cover plates can be installed on an existing Version B inlet vent to convert to the other versions.
- c. Table 10.1.1 and other sections of this chapter are revised to align with the requirements in the technical specification. Specifically, periodic surveillance such as inspection of air vents or temperature monitoring is not required for Version B2.
- d. Section 10.3.iii is revised to clarify that the periodic surveillance of air vents is not required for Version B2.
RSI-2 Provide revised FSAR pages related to the technical specifications bases for the HI-STORM UMAX canister storage system in Appendix 13.A that incorporate revisions based on the proposed revision of TS 3.1.2 and 5.3.3.c
The proposed amendment includes an addition of a note regarding HI-STORM UMAX Version B2 in TS 3.1.2 and an added parenthetical phrase in TS 5.3.3.c. However, the corresponding TS bases in appendix 13.A were not updated to explain the basis of the added note or parenthetical phrase.
This information is needed to determine compliance with 10 CFR 72.230(a) and 72.236(b).
Holtec Response:
Appendix 13.A of the FSAR has been updated to maintain consistency with the proposed revision of TS 3.1.2. Specifically, the LCO section of the SFSC Heat Removal System has been updated to add a statement regarding HI-STORM UMAX VERSION B2 similar to TS 3.1.2.
Holtec recognizes the NRCs observation in that there is no proposed change to the air outlet vent of the VVM that would require a change to the Radiation Protection Program. Therefore, Holtec has deleted this parenthetical phrase from the CoC.
RSI-3 As proposed in TS 5.3.3.c, provide documentation to support why the total(neutron plus gamma) dose rate limit established at the outlet vents on the VVM is only applicable to the VENTILATED VVM, or remove the proposed applicability statement. Also, the staff needs the definitions of the term VENTILATED VVM, if the term is proposed to be retained in the TS.
Currently, VVM is defined in the TS, but VENTILATED VVM is not.
For the proposed HI-STORM UMAX Version B1 and B2, the staff notes that there is no proposed change to the air outlet vent of the VVM that would appear to necessitate a change in the radiation protection program requirements related to that component. In addition, no applicable revisions of the shielding evaluation of the HI-STORM UMAX system chapter or technical specification bases for the Holtec HI-STORM UMAX canister storage system in appendix 13.A were provided as part of the application to provide a basis for the change for the staff to review.
This information is needed to determine compliance with 10 CFR 72.230 and 72.236(d).
Holtec Response:
Holtec recognizes the NRCs observation in that there is no proposed change to the air outlet vent of the VVM that would require a change to the Radiation Protection Program. Therefore, Holtec has deleted this parenthetical phrase from the CoC.
RSI-4 Provide specific operability requirements for HI-STORM UMAX Version B1 in TS limiting conditions for operation (LCO) 3.1.2, as applicable.
In the proposed TS LCO 3.1.2, no specific operability requirements are described for HI-STORM UMAX Version B1. Therefore, the proposed operability requirements applicable to Version B1 is either the air inlet vents blocked less than 50% or compliance with the air temperature monitoring requirements in surveillance requirement (SR) 3.1.2. Since the cover plates installed in Version B1 block the air inlet vents by greater than 50%, only the air temperature monitoring requirements could satisfy operability.
The air temperature monitoring system is an active system and is subject to periodic failure of equipment. This could potentially cause unnecessary entries into TS LCO 3.1.2 when the spent fuel continues to be adequately cooled.
This information is needed to determine compliance with 10 CFR 72.236(l).
Holtec Response:
[
PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390
]
OBS-1 Clarify (provide) the description of the HI-STORM UMAX VVM in the Certificate of Compliance to include the unique air circulation characteristics of the proposed HI-STORM UMAX Version B2.
In the proposed CoC description of the HI-STORM UMAX VVM, it states [a]ir inlets and an air outlet allow air to circulate naturally through the cavity to cool the MPC inside. However, this statement is not entirely accurate for the proposed HI-STORM UMAX Version B2 as the air inlets are completely blocked by cover plates.
This information is needed to determine compliance with 10 CFR 72.236(f).
Holtec Response:
Holtec recognizes the NRCs observation in that this statement is not applicable to the UMAX Version B2. Therefore, Holtec has updated the CoC description to clarify that the above statement is applicable to all UMAX designs, except for the UMAX Version B2 which has no air inlets.