Title 18 . Environmental Conservation

Chapter 85 . Administrative Enforcement

Section 770. Definitions

18 AAC 85.770. Definitions

Definitions in this chapter:

( 1) "AAC" means Alaska Administrative Code;

(2) "AS" means Alaska Statutes;

(3) "agreement state" means any state with which the United States Atomic Energy Commission has entered into an agreement under section 274b. of the Atomic Energy Act of 1954, as amended (73. Stat. 689);

(4) "airborne radioactive material" means any radioactive material dispersed in the air in the form of dusts, fumes, mists, vapors, or gases;

(5) "aluminum equivalent" means the thickness of aluminum affording the same attenuation, under specified conditions, as the material in question;

(6) "beam blocking device" means a movable portion of any enclosure around a radiation source which may be opened or closed to permit or prevent the emergence of an exit beam;

(7) "byproduct material" means any radioactive material (except special nuclear material) yielded in or made radioactive by exposure to the radiation incident to the process of producing or utilizing special nuclear material;

(8) "cabinet radiography" means industrial radiography, using ionizing radiation machines, which is conducted in an enclosed, interlocked cabinet, such that the radiation machine will not operate unless all openings are securely closed, and which cabinet is so shielded that every location on the exterior meets conditions for an uncontrolled area as specified in sec. 170 of this chapter;

(9) "calendar quarter" means any period determined according to either of the following subdivisions:

(A) the first period of any year may begin on any date in January; provided that the second, third and fourth periods accordingly begin on the same date in April, July, and October, respectively, and that the fourth period extend into January of the succeeding year if necessary to complete a three-month quarter. During the first year of use of this method of determination by a registrant, the first period for that year shall also include any additional days in January preceding the starting date of the first period;

(B) the first period in a calendar year of 13 complete, consecutive calendar weeks; the second period in a calendar year of 13 complete, consecutive calendar weeks; the third period in a calendar year of 13 complete, consecutive calendar weeks; the fourth period in a calendar year of 13 complete, consecutive calendar weeks. Alternatively, the four periods may consist of the first 14 complete, consecutive calendar weeks; the next 12 complete, consecutive calendar weeks; the next 14 complete, consecutive calendar weeks; and the last 12 complete, consecutive calendar weeks. If at the end of a calendar year there are any days not falling within a complete calendar week of that year, such days shall be included within the last complete calendar week of the previous year. No registrant shall change the method observed by him of determining calendar quarters except at the beginning of a calendar year;

(10) "cavity" means that portion of a microwave oven in which food may be heated, cooked, or dried;

(11) "cold cathode gas discharge tube" means an electronic device in which electron flow is produced and sustained by ionization of contained gas atoms and ion bombardment of the cathode;

(12) "collimator" means a device constructed of attenuating material used to confine a useful beam within a designated solid angle;

(13) "commissioner" means the Commissioner of the Department of Environmental Conservation;

(14) "cones" means a type of collimator;

(15) "continuous wave laser (c.w. laser)" means a laser which emanates a continuous beam as opposed to a pulsed laser;

(16) "controlled area" means any area access to which is controlled by a registrant for purposes of protection of individuals from exposure to radiation and radioactivity; provided, areas used for residential quarters are not included, although a separate room or rooms in a residential building may be set apart as a controlled area;

(17) "curie (Ci)" means that quantity of radioactive material which decays at the rate of 3.7 x 10 10 disintegrations per second;

(18) "dead-man switch" means a switch so constructed that a circuit-closing contact can only be maintained by continuous pressure by the operator;

(19) "department" means the Department of Environmental Conservation;

(20) "diagnostic-type tube housing" means an X-ray tube housing so constructed that the leakage X- radiation at a distance of one meter from the target cannot exceed 100 milliroentgens in one hour when the tube is operated at any of its specified ratings;

(21) "diaphragms" means a type of collimator;

(22) "dose" means the quantity of radiation absorbed, per unit of mass, by the whole body or by any portion of the body. When these regulations specify a dose during a period of time, the dose means the total quantity of radiation absorbed, per unit of mass during such period of time. Several different units of dose are in current use. Definitions of units used in these regulations are provided in paragraphs (41) and (51) of this section;

(23) "enclosure" means a cabinet, box, or other container, provided by the manufacturer or user of a radiation machine, from which the source of the radiation cannot be removed without destroying the function of the source;

(24) "energy density" means the intensity of electromagnetic radiation energy per unit area; usually expressed in joules per square centimeter (j/cm 2 );

(25) "field radiography" means all industrial radiography using ionizing radiation machines other than cabinet radiography and shielded room radiography;

(26) "filter" means any material placed in a useful beam to preferentially absorb less penetrating radiations;

(27) "gas laser" means a type of laser in which the laser action takes place in a gas medium, usually a c.w. laser;

(28) "half-value layer (hvl)" means the thickness of an absorbing material to reduce a beam of radiation to one-half of its incident exposure rate;

(29) "high ionizing radiation area" means any area, accessible to individuals, in which there exists ionizing radiation at such levels that a major portion of the body could receive in any one hour a dose in excess of 100 millirems;

(30) "individual" means any human being;

(31) "industrial radiography" means the examination of the microscopic structure of materials by nondestructive methods utilizing ionizing radiation sources;

(32) "inherent filtration" means any filtration in a useful beam due to a beam window or any other permanent part of a radiation source enclosure;

(33) "interlock" means a device for precluding exposure to a radiation hazard either by preventing entry to an area or by automatically removing the hazard;

(34) "ionizing radiation" means any electromagnetic or particulate radiation capable of producing ions, directly or indirectly, in its passage through matter. Ionizing radiation includes, but is not limited to, gamma rays, X-rays, alpha and beta particles, and high speed electrons, neutrons, and protons;

(35) "ionizing radiation area" means any area, accessible to individuals, in which there exists ionizing radiation at such levels that a major portion of a body could receive in any one hour a dose in excess of five millirems or in any five consecutive days a dose in excess of 100 millirems;

(36) "kilovolts peak (kVp)" means the crest value of kilovolts of the potential of a pulsating potential generator. When only one-half of the wave is used, the value refers to the useful half of the wave;

(37) "laser" means light amplification by stimulated emission of radiation and is a device which emits a monochromatic, coherent beam of light, i.e., light possessing a single wave length and all waves in phase;

(38) "laser control area" means any area which contains one or more lasers in which the activity of employees and transient individuals is subject to control and supervision;

(39) "lead equivalent" means the thickness of lead affording the same attenuation, under specified conditions, as the material in question;

(40) "leakage radiation" means all radiation emitted from an enclosure except the useful beam;

(41) "microwave oven" means a device designed to heat, cook or dry food through the application of electromagnetic radiation with frequencies in the microwave region. The Federal Communications Commission has designed the frequencies of 915 MHz and 2450 MHz for microwave oven use;

(42) "microwave radiation" means electromagnetic waves in the frequency range of about 300 - 300,000 MHz;

(43) "non-ionizing radiation" means any electromagnetic or particulate radiation not capable of producing ions, directly or indirectly, in its passage through matter. Non-ionizing radiation includes, but is not limited to, microwaves, infrared light, ultra-violet light, and coherent, monochromatic light;

(44) "person" means any municipal corporation, political subdivision, public or private corporation, individual, partnership, or other entity;

(45) "personnel monitoring equipment" means devices designed to be worn or carried by an individual for the purpose of measuring doses (e.g., film badges, pocket chambers, pocket dosimeters, film rings, etc.);

(46) "power density" means the intensity of electromagnetic radiation power per unit area; usually expressed in watts per square centimeter (W/cm 2 );

(47) "primary protection barrier" means a barrier sufficient to attenuate a useful beam to a required degree;

(48) "protective apron" means an apron made of attenuating materials used to reduce radiation exposure;

(49) "protective barrier" means a barrier of attenuating materials used to reduce radiation exposure;

(50) "protective glove" means a glove made of attenuating materials used to reduce radiation exposure;

(51) "pulsed laser" means a laser that delivers energy in short pulses, not in a continuous beam as does a continuous wave laser;

(52) "q-switched laser" means a laser capable of extremely high peak powers for very short durations (pulse length of several nanoseconds);

(53) "rad" means a measure of the dose of any ionizing radiation to a material in terms of the energy absorbed per unit mass of material. One rad is the dose corresponding to the absorption of 100 ergs per gram of material;

(54) "radiation" means all ionizing and non-ionizing radiation and sonic, infrasonic, and ultrasonic waves;

(55) "radiation machine" means any device capable of producing radiation except devices which produce ionizing radiation only from radioactive material;

(56) "radiation source" means a radiation machine or radioactive material;

(57) "radioactive material" means any material, solid, liquid, or gas, which emits ionizing radiation spontaneously;

(58) "radiographer" means an individual who performs, or who, in attendance at a site where ionizing radiation sources are being used, personally supervises industrial radiographic operations;

(59) "radiographer's assistant" means any individual who, under the personal supervision of a radiographer, used ionizing radiation sources, related handling tools, or survey instruments in industrial radiography;

(60) "radiographic exposure device" means any instrument containing a sealed source of ionizing radiation, in which the source of shielding thereof may be moved, or otherwise changed, from shielded to unshielded position for purposes of making a radiographic exposure;

(61) "radionuclide" means a radioactive element;

(62) "registrant" means a person required by this chapter to register with the department;

(63) "rem" means a measure of dose of any ionizing radiation to body tissue in terms of the estimated biological effect relative to a dose of one roentgen of X-ray. The relation of the rem to other dose units depends upon the biological effect under consideration and upon the condition of irradiation. Any of the following is considered to be equivalent to a dose of one rem:

(A) an exposure to one roentgen of X- or gamma radiation;

(B) a dose of one rad due to X-, gamma, or beta radiation;

(C) a dose of 0.1 rad due to neutrons or high energy protons;

(D) a dose of 0.5 rad due to particles heavier than protons and with sufficient energy to reach the lens of the eye;

(64) "roentgen (R)" means an amount of X- or gamma radiation such that the associated corpuscular emission per 0.001293 grams of air produces in air ions carrying one electrostatic unit of quantity of electricity of either sign;

(65) "scattered radiation" means radiation that, during passage through matter, has been deviated in direction;

(66) "sealed source" means radioactive material that is permanently bonded or fixed in a capsule or matrix designed to prevent release and dispersal of the radioactive material under the most severe conditions which are likely to be encountered in normal use and handling;

(67) "secondary protective barrier" means a barrier sufficient to attenuate stray radiation to a required degree;

(68) "shielded room radiography" means industrial radiography, using ionizing radiation machines, which is conducted in an enclosed room, the interior of which is not occupied during radiographic operations, which is so shielded that every location on the exterior meets conditions for an uncontrolled area as specified in sec. 170 of this chapter, and the only access to which is through openings which are interlocked so that the ionizing radiation machine will not operate unless all openings are securely closed;

(69) "shutter" means a device, generally of lead, fixed to an X-ray tube housing to intercept the useful beam;

(70) "source material" means uranium or thorium, or any combination thereof, in any physical or chemical form or ores which contain 0.05 percent or more of uranium, thorium, or any combination thereof. Source material does not include special nuclear material;

(71) "special nuclear material" means uranium -235, -233, and plutonium;

(72) "specular reflection" means the reflection from a polished or mirrorlike surface;

(73) "storage container" means a device in which sealed sources are transported or stored;

(74) "stray radiation" means radiation not serving any useful purpose and includes leakage and scattered radiation;

(75) "survey" means an evaluation of radiation protection practices. When appropriate, such evaluation includes a physical survey of the location of material and equipment, and measurements of levels of radiation or concentration of radioactive materials present;

(76) "therapeutic-type tube housing" means an X-ray tube housing so constructed that the leakage X- radiation at a distance of one meter from the target cannot exceed one roentgen in one hour; and at a distance of five centimeters from any point on the surface of the housing accessible to the patient cannot exceed 30 roentgens in one hour when the tube is operated at any of its specified ratings;

(77) "uncontrolled area" means any area access to which is not controlled by the registrant for purposes of protection of individuals from exposure to radiation and radioactive materials, and any area used for residential quarters;

(78) "useful beam" means that part of an ionizing radiation which passes through a window, aperture, cone or other collimating device of a tube housing.

History: Eff. 9/16/71, Register 39

Authority: AS 46.03.020