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joule per kilogram (100 rads);

(31) “half-value layer” means the thickness of an absorbing material required in order to reduce a beam of radiation to one-half of the beam’s incident exposure rate;

(32) “high ionizing radiation area” means an area that is accessible to an individual in which there exists ionizing radiation at a level that a major portion of the individual’s body may receive a dose in excess of 100 millirems in a one hour period of time;

(33) “imaging” means the use of radiation of sufficient intensity to enable a photographic-like rendition of internal structures to be seen;

(34) “individual” means a natural person;

(35) “individual monitoring” means the assessment of

(A) dose equivalent by the use of devices designed to be worn by an individual;

(B) committed effective dose equivalent by bioassay or by determination of the time-weighted air concentrations to which an individual has been exposed; and

(C) dose equivalent by the use of survey data;

(36) “individual monitoring device” means a device designed to be worn by an individual for the assessment of dose equivalent, such as a film badge, thermoluminescence dosimeter, pocket ionization chamber, and personal air sampling device;

(37) “industrial radiography” means the examination of the internal structure of materials by nondestructive methods utilizing ionizing radiation sources;

(38) “internal dose” means that portion of the dose equivalent received from radioactive material taken into the body;

(39) “interlocked” means the use of a device to preclude exposure to a radiation hazard either by preventing entry to an area or by automatically removing the hazard;

(40) “ionizing radiation”

(A) means an electromagnetic or particulate radiation capable of producing ions, directly or indirectly, in the radiation’s passage through matter;

(B) includes