ML22088A021

Independent Spent Fuel Storage Installation, 10 CFR 72.48 Biennial Report

ML22088A021
Person / Time
Site:	Maine Yankee
Issue date:	04/01/2022
From:	Laing D Maine Yankee Atomic Power Co
To:	Document Control Desk, Office of Nuclear Material Safety and Safeguards, Division of Fuel Management
References
OMY-22-007
Download: ML22088A021 (2)

Text

MAINE YANKEE 321 Old Ferry Road, Wiscasset, Maine 04578 April 1, 2022 OMY-22-007 Re: 10 CFR 72.48(d)(2) 10 CFR 72.4 ATTN: Document Control Desk Director, Division of Fuel Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Maine Yankee Atomic Power Company Maine Yankee Independent Spent Fuel Storage Installation 2 D NRC License No. DPR-36 (NRC Docket No. 50-309) -- 7 2-- --C> ...>

Subject:

10 CFR 72.48 Biennial Report In accordance with 10 CFR 72.48(d)(2), Maine Yankee Atomic Power Company (Maine Yankee) is required to submit to the NRC a brief description of any changes, tests or experiments made pursuant to 10 CFR 72.48(c), including a summary of the evaluation of each. This report covers the period from April 1, 2020 to March 31, 2022. During this time frame, a 10 CFR 72.48 Evaluation was conducted pursuant to 10 CFR 72.48(c). The following is a summary of that evaluation:

72.48 Evaluation# 20-01 The impact of concrete spalling damage in unreinforced concrete in a triangular area below the lower chamfer of the NAC-UMS Vertical Concrete Casks (VCCs) at Maine Yankee was assessed. The loss of the unreinforced triangular cross-sectional area of concrete below the lower VCC chamfer due to spalling was deemed acceptable. This material serves no role in ensuring that the V CC provides structural support to the transportable storage canister. Its installation is simply a good construction practice to leave no sharp comers.

In addition, the concrete cask average surface dose rates are not an assumption in any accident analysis. They were used to ensure compliance with regulatory limits on occupational dose and dose to the public. Maine Yankee met the requirement ofNAC-UMS TS A 3.2.2 regarding the concrete cask average surface dose rates for each VCC prior to storage operations. As stated in the Bases for NAC-UMS TS A 3.2.2, this was established ONCE for each VCC by ensuring that the limits were met prior to STORAGE OPERATION in accordance with SR 3.2.2.1.

Subsequently, the radiation doses during storage operations are monitored in accordance with the Maine Yankee radiation protection program to ensure compliance with the applicable occupational and public dose limits.

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Maine Yank:ee Atomic Power Company OMY-22-007/April X, 2022/Page 2 The NAC-UMS Final Safety Analysis Report (FSAR) includes analysis of blockage evenls. In addition, NAC-UMS Technical Specification A 3.1.6 ensures that each Concrete Cask Heat Removal System is operable on a periodic basis.

Based on the above, the proposed activity did not:

• Result in more than a minimal increase in the frequency of occurrence of an accident previously evaluated in the NAC-UMS FSAR

• Result in more than a minimal increase in the likelihood of occurrence of a malfunction of an SSC important to safety previously evaluated in the NAC-UMS FSAR

• Result in more than a minimal increase in the consequences of an accident previously evaluated in the NAC-UMS FSAR

• Result in more than a minimal increase in the consequences of a malfunction of an SSC important to safety previously evaluated in the NAC-UMS FSAR

• Create a possibility for an accident of a different type than any previously evaluated in the NAC-UMS FSAR

• Create a possibility for a malfunction of an SSC important to safety with a different result than any previously evaluated in the NAC-UMS FSAR

• Result in a design basis limit for a fission product barrier as described in the NAC-UMS FSAR being exceeded or altered

• Result in a departure from a method of evaluation described in the NAC-UMS FSAR used in establishing the design bases or in the safety analyses This letter contains no commitments.

If you have any questions regarding this submittal, please do not hesitate to contact me at (207) 882-1303.

D. Laing ISFSI Manager cc: D. Lew, NRC Region I Administrator A. Dimitriadis, Chief: Decommissioning Branch, NRC, Region 1 Y. Diaz-Sanabria, Chief, Division of Fuel Management, Storage and Transportation Licensing Branch J. Hyland, State of Maine, Manager Radiation Control Program