Document: 10 CFR Part 20
Document ID: f9fa227e-b871-4624-b491-d8e41103d10e
Document Type: cfr
Title: Definitions.
Source: 10 CFR Part 20
Source URL: https://www.ecfr.gov/current/title-10/part-20/section-20.1003
Revision Date: 
Chapter: 
Section ID: 20.1003
CFR Part: 20
CFR Title: 10

Content:
y, the Secretary of Energy, the Secretary of Homeland Security, and the head of any other appropriate Federal agency, determines would pose a threat similar to the threat posed by a discrete source of radium-226 to the public health and safety or the common defense and security; and ( ii ) Before, on, or after August 8, 2005, is extracted or converted after extraction for use in a commercial, medical, or research activity. Class (or lung class or inhalation class ) means a classification scheme for inhaled material according to its rate of clearance from the pulmonary region of the lung. Materials are classified as D, W, or Y, which applies to a range of clearance half-times: for Class D (Days) of less than 10 days, for Class W (Weeks) from 10 to 100 days, and for Class Y (Years) of greater than 100 days. Collective dose is the sum of the individual doses received in a given period of time by a specified population from exposure to a specified source of radiation. Commission means the Nuclear Regulatory Commission or its duly authorized representatives. Committed dose equivalent (H T,50 ) means the dose equivalent to organs or tissues of reference (T) that will be received from an intake of radioactive material by an individual during the 50-year period following the intake. Committed effective dose equivalent (H E,50 ) is the sum of the products of the weighting factors applicable to each of the body organs or tissues that are irradiated and the committed dose equivalent to these organs or tissues (H E,50 = Σ w T H T,50 ). Constraint (dose constraint) means a value above which specified licensee actions are required. Controlled area means an area, outside of a restricted area but inside the site boundary, access to which can be limited by the licensee for any reason. Critical Group means the group of individuals reasonably expected to receive the greatest exposure to residual radioactivity for any applicable set of circumstances. Declared pregnant woman means a