Glossary cont'd - doe-hdbk-1106-97

DOE-HDBK-1106-97

GLOSSARY (continued)

Radionuclide: A radioactive (unstable) nuclide.

Radioisotope: An unstable isotope of an element that decays or disintegrates spontaneously,

emitting radiation. Approximately 5,000 natural and artificial radioisotopes have been identified.

Reference Man: A hypothetical individual whose characteristics are often used to estimate

radiation dose. Reference Man is to be 20-30 years of age, 170 cm (5 ft 10 in) in height, weighing

70 kg (160 lb); and living in a climate with an average temperature of from 10○ to 20○ C.

Reference Man is a Caucasian and is Western European or North American in habitat and

custom.

Rem: A unit of dose equivalent. The word comes from the acronym Roentgen Equivalent Man

and takes into account the biological effect from an absorbed dose of radiation.

Retrospective Monitoring: Retrospective monitoring is a series of measurements made after an

intake is suspected to confirm the intake and assess any doses that may result from the intake.

Roentgen: The unit for exposure. It is that amount of gamma or X-rays required to produce ions

carrying 1 electrostatic unit of electrical charge in 1 cubic centimeter (2.58 X 10-4coulomb/kg) of

dry air under standard conditions.

Scintillation Detector: The combination of phosphor, photomultiplier tube, and associated

electronic circuits for counting light emissions produced in the phosphor by ionizing radiation.

Sealed radioactive source means a radioactive source manufactured, obtained, or retained for the

purpose of utilizing the emitted radiation. The sealed radioactive source consists of a known or

estimated quantity of radioactive material contained within a sealed capsule, sealed between

layer(s) of non-radioactive material, or firmly fixed to a non-radioactive surface by electroplating

or other means intended to prevent leakage or escape of the radioactive material. Sealed

radioactive sources do not include reactor fuel elements, nuclear explosive devices, and

radioisotope thermoelectric generators.