Connecticut Administrative Code › Title 19 - Public Health and Safety › 24 - Radiation Sources and Radioactive Materials › Section 19-24-4 - Definitions

Current through July 10, 2024
(a)
(1)
			 "Dose," as used in sections
			 19-24-1 to
			 19-24-14,
			 inclusive, means the quantity of radiation absorbed, per unit of mass, by the
			 body or by any portion of the body. When a dose during a period of time is
			 specified, the dose means the total quantity of radiation absorbed, per unit of
			 mass, by the body or by any portion of the body during such period of time.
			 Several different units of dose are in current use. The definitions are set
			 forth in subdivisions (2) and (3) below.
(2) The "rad," as used in sections
			 19-24-1 to
			 19-24-14,
			 inclusive, is a measure of the dose of any ionizing radiation to body tissues
			 in terms of the energy absorbed per unit mass of the tissue. One rad is the
			 dose corresponding to the absorption of one hundred ergs per gram of tissue.
			 (One millirad (m rad) = 0.001 rad.)
(3) The "rem," as used in said sections, is a
			 measure of the dose of any ionizing radiation to body tissue in terms of its
			 estimated biological effect relative to a dose of one roentgen (r) of x-rays.
			 (One millirem (mrem) = 0.001 rem.) The relation of the rem to other dose units
			 depends upon the biological effect under consideration and upon the conditions
			 of irradiation. For the purpose of this regulation, any of the following is
			 considered to be equivalent to a dose of one rem:
(A) A dose of one roentgen due to x- or gamma
			 radiation;
(B) A dose of one rad
			 due to x-, gamma, or beta radiation;
(C) A dose of one-tenth rad due to neutrons
			 or high energy protons;
(D) A dose
			 of five-hundredths rad due to particles heavier than protons and with
			 sufficient energy to reach the lens of the eye. If it is more convenient to
			 measure the neutron flux, or equivalent, than to determine the neutron dose in
			 rads, as provided in subparagraph (C) above, one rem of neutron radiation may
			 for purposes of sections
			 19-24-1 to
			 19-24-14,
			 inclusive, be assumed to be equivalent to fourteen million neutrons per square
			 centimeter incident upon the body; or, if there exists sufficient information
			 to estimate with reasonable accuracy the approximate distribution in energy of
			 the neutrons, the incident number of neutrons per square centimeter equivalent
			 to one rem may be estimated from the following table:
Neutron Flux Dose Equivalents
Neutron energy (Mev)
Number of neutrons per square centimeter
						  equivalent to a dose of 1 rem
						  (neutrons/cm2)
Average Flux to deliver 100 millirem in 40
						  hours (neutrons/cm2per sec.)
Thermal
. . . . . . . .
970 x 106
670
0.0001
. . . . . . . .
720 x 106
500
0.005
. . . . . . . .
820 x 106
570
0.02
. . . . . . . .
400 x 106
280
0.1
. . . . . . . .
120 x 106
80
0.5
. . . . . . . .
43 x 106
30
1.0
. . . . . . . .
26 x 106
18
2.5
. . . . . . . .
29 x 106
20
5.0
. . . . . . . .
26 x 106
18
7.5
. . . . . . . .
24 x 106
17
10
. . . . . . . .
24 x 106
17
10 to 30
. . . . . . . .
14 x 106
10
(4) For determining exposure to x- or gamma
			 rays with energies up to three Mev, the dose limits specified may be assumed to
			 be equivalent to the "air dose." "Air dose" means the dose as measured by a
			 properly calibrated appropriate instrument in air at or near the body surface
			 in the region of highest dosage rate.