Washington State University

Revised 9-14
Radiation Safety Office

Acronyms and Definitions

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The following definitions apply to this chapter, SPPM Chapter 9:


ALARA (acronym for "as low as is reasonably achievable") means making every reasonable effort to maintain exposures to radiation as far below the dose limits as possible. See 9.06.

Agreement State

By agreement, the Nuclear Regulatory Commission (NRC) delegates regulatory authority to states to license and regulate:

The mechanism for the transfer of NRC's authority to a state is an agreement signed by the governor of the state and the Chairman of the NRC. See 9.40.

Approved Use

Approved use means a use of a source of ionizing radiation that has been reviewed and preapproved by the Radiation Safety Committee and for which the authorized user has a current and active authorization. See 9.10.

Authorized User

An authorized user is an individual who has been authorized (sublicensed) by the Radiation Safety Committee to possess and use one or more sources of ionizing radiation in her or his research, teaching, and/or service work at the University. (See 9.10.) This includes any individual authorized to possess:

Broad Scope License

A "Type A specific license of broad scope" is a license authorizing receipt, acquisition, ownership, possession, use, and transfer of any chemical or physical form of the byproduct material in the quantities specified in the license, for the specific purposes authorized. See 9.10 and 9.40.


Dosimeter means a device designed to be worn by an individual for the assessment of dose equivalent exposure (e.g., a thermoluminescent dosimeter or an electronic personal monitoring device). See 9.50.


Emergency in this SPPM chapter (Chapter 9) refers to situations that threaten University personnel and/or property. See also 9.80.

Radiological Emergency

A radiological emergency, as applicable at the University, is an incident or situation which involves:

Emergency Response Plan

An emergency response plan defines emergency situations and the specific preventive and response procedures to cope with unsafe situations in an orderly and efficient manner to protect personnel and facilities.

Ionizing Radiation

Ionizing radiation is defined as radiation sufficiently energetic to dislodge electrons from an atom. Ionizing radiation is capable of producing ionization in substances through which it passes. (See 9.10, 9.40, and 9.60.) It includes:

Radiation, as used in this SPPM chapter, does not include nonionizing radiation, such as radio- or microwaves, or visible, infrared, or ultraviolet light.


A radionuclide is an atom with an unstable nucleus characterized by excess energy which is available to be imparted either to a newly-created radiation particle within the nucleus or to an atomic electron (internal conversion). During the decay process, the radionuclide emits an x- or gamma-ray(s) and/or subatomic particles. Such rays or particles constitute ionizing radiation. See 9.50.

Radionuclides may occur naturally, but can also be artificially produced. Radionuclides are often referred to as radioactive isotopes or radioisotopes.


X-rays are penetrating, short-wavelength electromagnetic radiation. X-rays are similar to gamma rays, but are usually less energetic, and originate from the orbital electron cloud surrounding the nucleus of an atom. See 9.10, 9.30, 9.40, and 9.60.

Member of the General Public

A member of the general public is defined as any individual, except when that individual is approved and aware of his or her potential to receive an occupational dose as a radiation worker. In this context, nonradiation workers who frequent approved radiation use areas, e.g., custodians and repair and maintenance personnel, are considered to be members of the general public, as are University guests and visitors. See 9.10, 9.30, and 9.40.

Occupational Dose

Occupational dose means the dose an individual receives when his or her assigned employment duties involve exposure to radiation or to radioactive material. Such material includes licensed and unlicensed sources of radiation, whether in the possession of the licensee or another person. See 9.30.

Occupational dose does not include doses received:

Open-Beam Configuration

Open-beam configuration is defined as a mode of operation of an X-ray system in which an individual could accidentally place some part of his or her body into the primary beam during normal operation if no further safety devices are incorporated. (WAC 246-228-010) A shielding assessment is required for all facilities where open beam systems are installed. See 9.60.

Periodic Intervals

Completion of various tasks, including audits, inspections, calibrations, and testing, at regularly-occurring periodic intervals (e.g., weekly, monthly, quarterly) is required to maintain a successful Radiation Protection Program. See 9.20.

The intervals listed below are intended to provide operational flexibility and not to reduce frequency of the required task. The listed intervals were chosen to be consistent with those authorized in licenses issued by licensing entities (e.g., NRC). Established frequencies are to be maintained over the long term. Allowable intervals may not exceed the following:

Radiation Protection

Radiation protection is the protection of people and the environment from the harmful effects of ionizing radiation. See also 9.06.

Radiation Protection Program

The Radiation Protection Program includes the provisions designed and put in place to reduce human exposure to radiation. See 9.06, 9.10, and 9.20.

Radiation Safety Committee

The Radiation Safety Committee is a WSU organization responsible for monitoring and maintaining a safe radiation environment in locations and facilities where radiation is produced and/or used. The WSU Radiation Safety Committee establishes policy and compliance procedures relating to the safe use of ionizing radiation sources. See 9.06.

Radiation Safety Officer

The Radiation Safety Officer is a suitably trained and experienced individual involved in planning, implementing, and conducting a radiation protection program. This individual must maintain general surveillance of all controlled radiation activity at all use locations listed on the license. The University's broad scope radioactive materials use license also requires that the University delegates this individual with the authority to immediately suspend any use of radiation, as required, to maintain safety. See 9.06.

Radiation Worker

Radiation worker means a University staff member, student, volunteer, guest, visitor, or independent contractor who:

See 9.10 and 9.30.

Radioactive Material

For the purposes of the Radiation Protection Program, radioactive material (see 9.50) refers to all forms of materials regulated by the Nuclear Regulatory Commission (NRC), including the following:

Special Nuclear Material

Special nuclear material consists of uranium-233 or uranium-235, enriched uranium, or plutonium.

Source Material

Source material is natural uranium or thorium or depleted uranium that is not suitable for use as reactor fuel.

Byproduct Material

Byproduct material is nuclear material (other than special nuclear material) that is produced or made radioactive in a nuclear reactor.

Radioactive Materials Spill

Radioactive materials spills may be classified as either minor or major. See 9.80.

Minor Spill

A minor spill involves a readily contained, relatively small amount of material that:

Major Spill

Major spills require the immediate notification and assistance of the Radiation Safety Office so that:

Radioactive Waste

Radioactive waste is defined as:

See 9.70.


Radioactive waste includes, but is not limited to:

Restricted Area

Restricted area means any area to which access is limited for purposes of protecting individuals against undue risks from exposure to radiation and radioactive material. See 9.30.


Shielding is defined as material placed between the source of radiation and the body to reduce external exposure. When considering the possible exposure to the general public, shielding may include the walls, floors, and ceilings of the facility. See 9.60.