ML20302A487

Enclosure 2 - NRC Feedback on Terrestrials Exemptions White Paper (Public-Redacted)

ML20302A487
Person / Time
Site:	99902076
Issue date:	01/27/2021
From:	Benjamin Beasley NRC/NRR/DANU/UARL
To:	Irish S Terrestrial Energy USA
Muniz G
Shared Package
ML20302A488	List: ML20302A481 ML20302A487
References
EPID: L-2020-LRO-0052
Download: ML20302A487 (3)

Text

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION U.S Nuclear Regulatory Commission Staff Observations on Examination of Regulatory Requirements to Determine Exemption Needs for the IMSR Core-unit White Paper Note: (( )) denotes proprietary information.

1. General

a. The NRC staff notes that the review of this document was limited to the items identified in the white paper, based on the scope of the request and the nature of the white paper. No observations regarding the regulatory applicability of items that were not listed are provided as part of this evaluation.

b. Terrestrial Energy USA (TEUSA) notes that an applicants ability to seek approval of major portions of a design in developing an application for a Standard Design Approval (SDA) provides substantial flexibility in standardization. TEUSA also states that [d]epending on the maturity of the design and engineering, an SDA could be developed for selected SSCs

[systems, structures and components] or larger integrated portions of the design at a level of detail analogous to that of a design certification application. The NRC staff agrees with this characterization, but notes that a subsequent submittal referencing a major portions SDA (such as a combined license (COL) application) would be required to address items not covered in the scope of the SDA.

c.

TEUSA addresses regulations at the subpart level (e.g. Section 50.34) in its white paper. The NRC staff evaluated the statements provided at this level, however certain complex regulations have different applicability statements among their provisions (e.g., Title 10 of the Code of Federal Regulations (10 CFR) Sections 50.34 or 52.137) and, therefore, not all portions of a given regulatory subpart may apply to the IMSR Core-unit SDA application. In certain cases, regulations include applicability differences between Part 50 and Part 52 applications. Examples include 10 CFR Sections 50.60 and 50.61, which are not applicable if applying under Part 50, but are cited as requirements in 52.137(a)(14) without specifying applicability to only water-cooled nuclear reactors. The NRC staff believes an exemption to these requirements would be needed; however, the NRC staffs review of an exemption request for relief from an applicable requirement that has no technical justification would likely be straightforward and efficient and would minimize unnecessary burden.

2. Regulatory Analysis Methodology

a. The white paper classifies regulations into three categories: applicable, not applicable, and exemption. The NRC staff takes no issue with the categorization, but disagrees with the characterization associated with not applicable. TEUSA states that regulations are not applicable if they are not technically relevant, which staff considers to be an overly broad characterization. While some regulations refer to technical relevance, the technical relevance of a regulation does not necessarily determine its applicability. Depending on the specific regulation, a regulation that is not technically relevant may or may not require an exemption if an applicant seeks to not meet that regulation. As noted above, the NRC staffs evaluation of an exemption from a regulation that is truly not technically relevant to the review of the design would likely be straightforward and efficient. Based on its review of the white paper, the NRC staff does not

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believe this characterization led to any misclassification of regulations, but provides this discussion for context regarding any future characterizations.

b. The white paper states that the scope of the evaluations was limited to the IMSR Core-unit. This review was performed with that understanding and does not include an evaluation of any regulations beyond that stated scope.

3. Regulatory Analysis Results

a. For regulations discussed in this section, the NRC staff provides no additional feedback if it agrees with the characterization provided in the white paper-that is, if no comment below exists, the NRC staff agrees with the initial characterization of applicability. The positions expressed in the staffs feedback are not final and could change based on new or additional information and potential design or operation changes as the design evolves.

b. TEUSA states that certain regulations are applicable to CPs/OLs/COLs, but not SDAs (or vice versa). In some cases, this may not be accurate. Specifically, TEUSA states that ((

)) is not applicable to SDAs, but subsection

((

)) requires SDAs to include analysis in accordance with the requirements of ((

)). Other examples include: ((

)).

c.

TEUSA states that ((

)). The NRC staff disagrees;((

)) The information provided in the TEUSA white paper (coupled with additional design details) could partially address this requirement.

d. For 10 CFR 50.48, the white paper ((

.))

e. For 10 CFR 50.55a, the white paper states that ((

)). In cases where the standards are not required for a non-LWR, no exemption would be needed. However, the use of codes and standards that are not required in order to justify the capability and pedigree of certain SSCs would likely need to be the subject of a future engagement to ensure there is an adequate basis to apply the codes and standards for a given purpose.

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f. For 10 CFR 50.68, [

))

((

))

g. For 10 CFR 50.70 and 50.71 the white paper states ((

))

h. In reference to 10 CFR 50.72 and 50.73, the white paper states that ((

))

i.

For 10 CFR 50.100, the white paper states ((

))

j.

For 10 CFR 50.110 and 50.111, the white paper states ((

))

k. For 10 CFR 50, Appendix B, the white paper states ((

))

l.

In reference to 10 CFR 50 Appendix E, the white paper states that ((

))

m. The white paper states that 10 CFR 50, Appendix I ((

))

n. For 10 CFR 50, Appendix J, the white paper states ((

]