ML19150A317
| ML19150A317 | |
| Person / Time | |
|---|---|
| Site: | NuScale |
| Issue date: | 05/30/2019 |
| From: | NRC |
| To: | NRC/NRO/DLSE/LB1 |
| References | |
| Download: ML19150A317 (56) | |
Text
14.03.01-1 Please see the attachment to this Request for Additional Information.
Title 10, Section 52.47(b)(1) of the Code of Federal Regulations (CFR) requires that a design certification application contain the proposed inspections, tests, analyses, and acceptance criteria (ITAAC) that are necessary and sufficient to provide reasonable assurance that, if the inspections, tests, and analyses are performed and the acceptance criteria met, a facility that incorporates the design certification has been constructed and will operate in accordance with the design certification, the provisions of the Atomic Energy Act of 1954, as amended (AEA), and the NRC's rules and regulations. For the ITAAC to be "sufficient," (1) the inspections, tests, and analyses (ITA) must clearly identify those activities necessary to demonstrate that the acceptance criteria (AC) are met; (2) the AC must state clear design or performance objectives demonstrating that the Tier 1 design commitments (DCs) are satisfied; (3) the ITA and AC must be consistent with each other and the Tier 1 DC; (4) the ITAAC must be capable of being performed and satisfied prior to fuel load; and (5) the ITAAC, as a whole, must provide reasonable assurance that, if the ITAAC are satisfied, the facility has been constructed and will be operated in accordance with the design certification, the AEA, and the NRC's rules and regulations.
The staff has reviewed all DCD Rev 2, Tier 1 ITAAC tables and Chapter 1 of Tier 1 against these objectives, and in light of NRC guidance, Commission policy, and lessons learned from plants that are currently under construction that are in the process of implementing ITAAC. Based on this review, the staff has compiled the attached list of proposed ITAAC wording changes. The applicant is requested to make these changes in the Tier 1 ITAAC tables and in Chapter 1 of Tier 1, or otherwise show that the ITAAC comply with 10 CFR 52.47(b)(1). Additionally, the applicant is requested to address the following items, or otherwise show that the ITAAC comply with 10 CFR 52.47(b)(1):
- 1. ITAAC 29 in Table 2.5-7 verifies that the MCR isolation switches are located in the remote shutdown station but it does not verify the functionality of the switches. Please explain how ITAAC 29 verifies that the MCR isolation switches actually isolate the manual MCR switches from the MPS in case of fire. If ITAAC 29 does not verify the functionality of the MCR isolation switches, please explain what changes to the existing ITAAC in Tier 1 would be necessary to verify the functionality of the MCR isolation switches through ITAAC. If the applicant believes that ITAAC are not necessary to verify the functionality of the MCR isolation switches, please explain this and please explain why an ITAAC is, nonetheless, necessary to verify the location of the MCR isolation switches.
- 2. The design commitments listed in the design descriptions of DCA Part 2, Tier 1 are not consistent with the design commitments in the corresponding ITAAC tables. Although not identified in the attachment, the design commitments in the design descriptions of DCA Part 2, Tier 1 should be revised to be consistent with the design commitment in the ITAAC tables. Additional explanations for the basis of the staff's proposed revisions in the attachment are provided below:
1.Tier 1, Section 1.1: Propose adding a definition of "approved design" to clarify what this term refers to. Without a definition, it is not clear who the approver is or when the design is considered approved (at certification or when the ITAAC is closed?). To provide clarity and flexibility, the staff proposes to define the "approved design" in terms of the updated final safety analysis report.
2.Tier 1, Section 1.2.4: Propose adding explanatory material consistent with past design certifications as applied to the NuScale design.
3.ITAAC 12 in Table 2.1-4: To resolve the use of the ambiguous word, "approximately" in the AC.
4.ITAAC 22 in Table 2.1-4: To clarify the applicability of the ITAAC to the assemblies and to add consideration of overload currents.
5.ITAAC 1 and 2 in Table 2.3-1: To make the scope of the ITA and AC consistent with the DC.
6.ITAAC 3, 4, and 6 in Table 2.5-7: To clarify the applicability of physical separation, electrical isolation, and communications independence in the DC and ITAAC.
7.ITAAC 15 in Table 2.5-7: To clarify the DC and make the DC consistent with the AC.
8.ITAAC 21 in Table 2.5-7: To clarify the DC and resolve an inconsistency between the DC and AC.
9.ITAAC 2, 3, and 4 in Table 2.7-2: The DCs for ITAAC 2 to 4 relate to a single Chemical Volume and Control System (CVCS) high radiation signal, but the AC for each ITAAC cover all 3 CVCS radiation signals. The proposed changes consolidate ITAAC 2 to 4 so that the scope of the DC matches the scope of the AC.
10.ITAAC 1 in Table 3.4-1: To resolve an inconsistency between the DC and AC.
11.ITAAC 4 in Table 3.4-1: The DC is actually an ITA. The staff's proposed revisions correct this.
12.ITAAC 2 in Table 3.5-1: To remove an unnecessary conditional statement in the DC and to clarify what the "approved" analysis is.
13.ITAAC 3 in Table 3.7-1: To clarify in the AC the alternative shutdown capability referred to in the DC.
14.ITAAC 4, 5, and 6 in Table 3.9-2: See explanation for ITAAC 2, 3, and 4 in Table 2.7-2.
15.ITAAC 8 and 9 in Table 3.9-2: See explanation for ITAAC 2, 3, and 4 in Table 2.7-2.
16.ITAAC 1, 2, and 3 in Table 3.10-1: To resolve inconsistencies between the DC and AC.
17.ITAAC 7 in Table 3.10-1: The DC is actually an ITA. The staff's proposed revisions correct this and make it consistent with the AC.
18.ITAAC 8 in Table 3.10-1: This ITAAC could be deleted if the proposed revisions to ITAAC 7 in Table 3.10-1 are incorporated as shown in the attachment since the scope of the revised ITAAC 7 would encompass the scope of ITAAC 8.
19.ITAAC 10 in Table 3.10-1: To resolve inconsistencies between the DC and AC.
20.ITAAC 5 in Table 3.11-2: To remove unnecessary and ambiguous qualifying language in the AC.
21.ITAAC 2 in Table 3.12-2: To remove unnecessary and ambiguous qualifying language in the AC.
22.ITAAC 7 and 8 in Table 3.16-1: To make the scope of the ITAAC consistent among the DC, ITA, and AC.
23.ITAAC 9 in Table 3.16-1: To clarify the scope of the ITA.
24.ITAAC 10 in Table 3.16-1: To make the scope of the ITA and AC consistent with the DC.
25.ITAAC 2, 3, and 4 in Table 3.17-2: See explanation for ITAAC 2, 3, and 4 in Table 2.7-2.
26.ITAAC 2 and 3 in Table 3.18-2: See explanation for ITAAC 2, 3, and 4 in Table 2.7-2.