Part 4731.0315 - CRITICAL MASSSubpart 1.Calculation.A. For purposes of this chapter, special nuclear material in quantities not sufficient to form a critical mass means: (1) uranium enriched with the isotope U-235 in quantities not exceeding 350 grams of contained U-235;(2) uranium-233 in quantities not exceeding 200 grams;(3) plutonium in quantities not exceeding 200 grams; or(4) any combination of special nuclear material under subitems (1) to (3) according to the formula in item B.B. For each kind of special nuclear material, determine the ratio between the quantity of that special nuclear material and the quantity under item A for the same kind of special nuclear material. The sum of the ratios for all kinds of special nuclear materials in combination must not exceed unity. For example, the following quantities in combination would not exceed the limitation and are within the formula, as follows: (175 grams U-235/350) + (50 grams U-233/200) + (50 grams Pu/200) = 1
Subp. 2.Exemption.To determine whether the exemption granted in Code of Federal Regulations, title 10, part 150.10, applies to the receipt, possession, or use of special nuclear material at any particular plant or other authorized location of use, a person must include in the quantity computed according to subpart 1 the total quantity of special nuclear material that the person is authorized to receive, possess, or use at the plant or other location of use at any one time.
Minn. R. agency 144, ch. 4731, GENERAL PROVISIONS, pt. 4731.0315
Statutory Authority: MS s 144.1202; 144.1203