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:
s a period of time equal to one-fourth of the year observed by the licensee (approximately 13 consective weeks), providing that the beginning of the first quarter in a year coincides with the starting date of the year and that no day is omitted or duplicated in consecutive quarters. Rad (See § 20.1004 ). Radiation (ionizing radiation) means alpha particles, beta particles, gamma rays, x-rays, neutrons, high-speed electrons, high-speed protons, and other particles capable of producing ions. Radiation, as used in this part, does not include non-ionizing radiation, such as radio- or microwaves, or visible, infrared, or ultraviolet light. Radiation area means an area, accessible to individuals, in which radiation levels could result in an individual receiving a dose equivalent in excess of 0.005 rem (0.05 mSv) in 1 hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates. Reference man means a hypothetical aggregation of human physical and physiological characteristics arrived at by international consensus. These characteristics may be used by researchers and public health workers to standardize results of experiments and to relate biological insult to a common base. Rem (See § 20.1004 ). Residual radioactivity means radioactivity in structures, materials, soils, groundwater, and other media at a site resulting from activities under the licensee's control. This includes radioactivity from all licensed and unlicensed sources used by the licensee, but excludes background radiation. It also includes radioactive materials remaining at the site as a result of routine or accidental releases of radioactive material at the site and previous burials at the site, even if those burials were made in accordance with the provisions of 10 CFR part 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