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:
rt 20 . Respiratory protective device means an apparatus, such as a respirator, used to reduce the individual's intake of airborne radioactive materials. Restricted area means an area, access to which is limited by the licensee for the purpose of protecting individuals against undue risks from exposure to radiation and radioactive materials. Restricted area does not include areas used as residential quarters, but separate rooms in a residential building may be set apart as a restricted area. Sanitary sewerage means a system of public sewers for carrying off waste water and refuse, but excluding sewage treatment facilities, septic tanks, and leach fields owned or operated by the licensee. Self-contained breathing apparatus (SCBA) means an atmosphere-supplying respirator for which the breathing air source is designed to be carried by the user. Shallow-dose equivalent (H s ), which applies to the external exposure of the skin of the whole body or the skin of an extremity, is taken as the dose equivalent at a tissue depth of 0.007 centimeter (7 mg/cm 2 ). Site boundary means that line beyond which the land or property is not owned, leased, or otherwise controlled by the licensee. Source material means— ( 1 ) Uranium or thorium or any combination of uranium and thorium in any physical or chemical form; or ( 2 ) Ores that contain, by weight, one-twentieth of 1 percent (0.05 percent), or more, of uranium, thorium, or any combination of uranium and thorium. Source material does not include special nuclear material. Special nuclear material means— ( 1 ) Plutonium, uranium-233, uranium enriched in the isotope 233 or in the isotope 235, and any other material that the Commission, pursuant to the provisions of section 51 of the Act, determines to be special nuclear material, but does not include source material; or ( 2 ) Any material artificially enriched by any of the foregoing but does not include source material. Stochastic effects means health effects that occur