ML22224A240

Hermes CP Application General Audit Question on Load Combinations

ML22224A240
Person / Time
Site:	Hermes
Issue date:	07/29/2022
From:	Benjamin Beasley NRC/NRR/DANU/UAL1
To:	Peebles D Kairos Power
Beasley B
References
Download: ML22224A240 (1)

Text

From: Beasley, Benjamin To: peebles@kairospower.com Cc: Cuadrado de Jesus, Samuel; Helvenston, Edward; gardner@kairospower.com; Martin Bryan; Le, Tuan; Schmidt, Jeffrey

Subject:

General Audit Question on Load Combinations Date: Friday, July 29, 2022 10:38:00 AM

Drew, Below is a follow-up question on structural load combinations. We are glad to schedule an audit discussion if needed when you are ready.

Regards, Ben

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Benjamin Beasley Senior Project Manager Advanced Reactor Licensing Branch 1 Office of Nuclear Reactor Regulation 301-415-2062 Benjamin.Beasley@nrc.gov Question 4.7-1 Principal Design Criterion (PDC) 1 from the Kairos topical report states:

Structures, systems, and components which are safety significant shall be designed, fabricated, erected, and tested to quality standards commensurate with the safety significance of the functions to be performed. Where generally recognized codes and standards are used, they shall be identified and evaluated to determine their applicability, adequacy, and sufficiency and shall be supplemented or modified as necessary to assure a quality product in keeping with the required safety function.

Neither Section 4.3 Reactor Vessel System nor Section 4.7 Reactor Vessel Support System of the Hermes PSAR include design information for load combination methodology. The load combination information is needed to provide reasonable assurance that structures and components will remain intact such that the reactor can be shut down and maintained in a safe condition and that PDC 1 will be satisfied. Additionally, the load combination information will also support PDC 2, Design Bases for Protection Against Natural Phenomena, and PDC 4, Environmental and Dynamic Effects Design Bases. The NRC staff requests that Kairos include the methodologies of load combination in either Section 4.3 or Section 4.7 of the Hermes PSAR. The methodologies of load combination can be tabulated in a manner similar to Table 3 of RG 1.143 Design Guidance for Radioactive Waste Management Systems, Structures, and Components Installed in Light-Water-Cooled Nuclear Power Plants ". Another example may be found in Section 3.4.2.5 (page 3-28) of the SHINE facility PSAR (ML15258A371).