10 CFR 150.11 - Critical mass.

prev | next
§ 150.11 Critical mass.
(a) For the purposes of this part, special nuclear material in quantities not sufficient to form a critical mass means uranium enriched in the isotope U-235 in quantities not exceeding 350 grams of contained U-235; uranium-233 in quantities not exceeding 200 grams; plutonium in quantities not exceeding 200 grams; or any combination of them in accordance with the following formula: For each kind of special nuclear material, determine the ratio between the quantity of that special nuclear material and the quantity specified above for the same kind of special nuclear material. The sum of such ratios for all kinds of special nuclear materials in combination shall not exceed unity. For example, the following quantities in combination would not exceed the limitation and are within the formula, as follows:
(175 (grams contained U-235/350) (50 grams U-233)/200) (50 grams Pu/200)=1
(b) To determine whether the exemption granted in § 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 shall include in the quantity computed according to paragraph (a) of this section the total quantity of special nuclear material which he is authorized to receive, possess or use at the plant or other location of use at any one time.
[27 FR 1352, Feb. 14, 1962, as amended at 30 FR 12069, Sept. 22, 1965]

Title 10 published on 2014-01-01

no entries appear in the Federal Register after this date.

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

This list is taken from the Parallel Table of Authorities and Rules provided by GPO [Government Printing Office].

It is not guaranteed to be accurate or up-to-date, though we do refresh the database weekly. More limitations on accuracy are described at the GPO site.


United States Code
Statutes at Large

Title 10 published on 2014-01-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 10 CFR 150 after this date.

  • 2014-02-11; vol. 79 # 28 - Tuesday, February 11, 2014
    1. 79 FR 8097 - Deliberate Misconduct Rule and Hearings on Challenges to the Immediate Effectiveness of Orders
      GPO FDSys XML | Text
      NUCLEAR REGULATORY COMMISSION
      Proposed rule.
      Submit comments by May 12, 2014. Comments received after this date will be considered if it is practical to do so. However, the NRC is able to ensure consideration only of comments received on or before this date.
      10 CFR Parts 2, 30, 40, 50, 52, 60, 61, 63, 70, 71, 72, 76, 110, and 150