RMS - General definitions concerning health physics and radiation protection Q-S


Radioactive Materials Branch


General Definitions used in Health Physics & Radiation Protection

Qualitative fit test (QLFT)
A pass/fail fit test to assess the adequacy of respirator fit that relies on the individual's response to the test agent.

Quality factor (Q)
The modifying factor that is used to derive dose equivalent from absorbed dose. Quality factors are provided in the definition of rem below.

Quantitative fit test (QNFT)
An assessment of the adequacy of respirator fit by numerically measuring the amount of leakage into the respirator.

Quarter
A period of time equal to one-fourth of the year observed by the licensee or registrant (approximately 13 consecutive weeks), providing that the beginning of the first quarter in a year coincides with the starting date of the year and that no day is omitted or duplicated in consecutive quarters.

Rad
The special unit of absorbed dose. One rad is equal to an absorbed dose of 100 ergs/gram or 0.01 joule/kilogram (0.01 gray).

Radiation (ionizing radiation)
Except as otherwise defined in 15A NCAC 11 .1400 of the North Carolina Regulations for Protection Against Radiation, means alpha particles, beta particles, gamma rays, x-rays, neutrons, high-speed electrons, high-speed protons, and other particles capable of producing ions.

Radiation area
An area, accessible to individuals, in which radiation levels could result in an individual receiving a dose equivalent in excess of 0.005 rem (0.05 mSv) in one hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates.

Radiation machine
Any device capable of producing radiation except devices which produce radiation only from radioactive material.

Radiation safety officer
One who has the knowledge and responsibility to apply appropriate radiation protection rules.

Radiation Safety Officer (for Radiography)
An individual named by the licensee or registrant who has knowledge of, responsibility for, and authority to ensure compliance with appropriate radiation protection rules, standards, and practices on behalf of the licensee or registrant and who meets the requirements of 15A NCAC 11 .0510(g) of this the North Carolina Regulations for Protection Against Radiation.

Radiation Sickness(syndrome)
The complex of symptoms characterizing the disease known as radiation injury, resulting from excessive exposure of the whole body (or large part) to ionizing radiation. The earliest of these symptoms are nausea, fatigue, vomiting, and diarrhea, which may be followed by loss of hair (epilation), hemorrhage, inflammation of the mouth and throat, and general loss of energy. In severe cases, where the radiation exposure has been relatively large, death may occur within two to four weeks. Those who survive six weeks after the receipt of a single large dose of radiation may generally be expected to recover.

Radioactive marker
Means radioactive material placed subsurface or on a structure intended for subsurface use for the purpose of depth determination or direction orientation.

Radioactive material
Any material, solid, liquid, or gas, which emits radiation spontaneously

Radioactive waste disposal facility
Any low-level radioactive waste disposal facility, as defined in G.S. 104E-5(9c), established for the purpose of receiving low-level radioactive waste, as defined in 15A NCAC .1202, generated by another licensee for the purpose of disposal.

Radioactive waste processing facility
Any low-level radioactive waste facility, as defined in G.S. 104E-5(9b), established for the purpose of receiving waste generated by another licensee to be stored, compacted, incinerated or treated.

Radioactivity
The disintegration of unstable atomic nuclei by emission of radiation.

Radiographer
Any individual who performs or who, in attendance at the site where sources of radiation are being used, personally supervises industrial radiographic operations and who is responsible to the licensee or registrant for assuring compliance with the requirements of the North Carolina Regulations for Protection Against Radiation and all license or registration conditions.

Radiographer's assistant
Any individual who, under the personal supervision of a radiographer, uses sources of radiation, related handling tools, or survey instruments in industrial radiography.

Radiographic exposure device
Any instrument containing a sealed source fastened or contained therein, in which the sealed source or shielding thereof may be moved, or otherwise changed, from a shielded to unshielded position for purposes of making a radiographic exposure. Commonly called a camera or projector.

Radium (Ra)
A radioactive metallic element with atomic number 88. As found in nature, the most common isotope has a mass number of 226. It occurs in minute quantities associated with uranium in pitchblende, carnotite, and other minerals.

Radon
An invisible, radioactive gas that occurs naturally in soil. Radon is a daughter of radium and one of the heaviest gases known

Reference man
A hypothetical aggregation of human physical and physiological characteristics arrived at by international consensus as published by the International Commission on Radiological Protection. These characteristics may be used by researchers and public health workers to standardize results of experiments and to relate biological insult to a common base.

Registrant
Any person who is registered with the agency as required by provisions of these Rules or the Act.

Registration
Registration with the agency in accordance with the North Carolina Regulations for Protection Against Radiation..

Regulations of the U.S. Dept. of Transportation
The regulations in 49 CFR Parts 100-189.

Relative Biological Effectiveness (RBE)
Is a factor expressing the relative effectiveness of radiations with differing linear-energy-transfer (LET) values, in producing a given biological effect. This unit is now limited to use in radiobiology.

Rem
The special unit of any of the quantities expressed as dose equivalent. The dose equivalent in rems is equal to the absorbed dose in rads multiplied by the quality factor (1 rem = 0.01 sievert). As used in the North Carolina Regulations for Protection Against Radiation, the quality factors for converting absorbed dose to dose equivalent are as follows:

QUALITY FACTORS AND ABSORBED DOSE EQUIVALENCIES
TYPE OF RADIATION	Quality Factor Q	Absorbed Dose Equal to a Unit Dose Equivalent^a
X-, gamma, or beta radiation	1	1
Alpha particles, multiple-charged particles, fission fragments and heavy particles of unknown energy	20	0.05
Neutrons of unknown energy	10	0.1
High-energy protons	10	0.1

^aAbsorbed dose in rad equal to one rem or the absorbed dose in gray equal to one sievert.
If it is more convenient to measure the neutron fluence rate than to determine the neutron dose equivalent rate in rems per hour or sieverts per hour, one rem (0.01 Sv) of neutron radiation of unknown energies may, for purposes of the rules in 15A NCAC 11, be assumed to result from a total fluence of 25 million neutrons per square centimeter incident upon the body.
If sufficient information exists to estimate the approximate energy distribution of the neutrons, the licensee or registrant may use the fluence rate per unit dose equivalent or the appropriate Q value from the following table to convert a measured tissue dose in rads to dose equivalent in rems:

MEAN QUALITY FACTORS, Q, AND FLUENCE PER UNIT DOSE EQUIVALENT FOR MONOENERGETIC NEUTRONS
	Neutron Energy (MeV)	Quality Factor^a (Q)	Fluence per Unit Dose Equivalent^b (neutrons cm^-2 rem^-1)
thermal	2.5 x 10^-8	2	980 x 10⁶
	1 x 10^-7	2	980 x 10⁶
	1 x 10^-6	2	810 x 10⁶
	1 x 10^-5	2	810 x 10⁶
	1 x 10^-4	2	840 x 10⁶
	1 x 10^-3	2	980 x 10⁶
	1 x 10^-2	2.5	1010 x 10⁶
	1 x 10^-1	7.5	170 x 10⁶
	5 x 10^-1	11	39 x 10⁶
	1	11	27 x 10⁶
	2.5	9	29 x 10⁶
	5	8	23 x 10⁶
	7	7	24 x 10⁶
	10	6.5	24 x 10⁶
	14	7.5	17 x 10⁶
	20	8	16 x 10⁶
	40	7	14 x 10⁶
	60	5.5	16 x 10⁶
	1 x 10²	4	20 x 10⁶
	2 x 10²	3.5	19 x 10⁶
	3 x 10²	3.5	16 x 10⁶
	4 x 10²	3.5	14 x 10⁶
^{^a} Value of quality factor (Q) at the point where the dose equivalent is maximum in a 30-cm diameter cylinder tissue-equivalent phantom.
^b Monoenergetic neutrons incident normally on a 30-cm diameter cylinder tissue-equivalent phantom.

Respiratory protective device
An apparatus, such as a respirator, used to reduce the individual's intake of airborne radioactive materials.

Restricted area
An area, access to which is controlled by the licensee or registrant for purposes of protecting individuals against undue risks from exposure to radiation and radioactive materials. Restricted area does not include areas used as residential quarters, but separate rooms in a residential building may be set apart as a restricted area.

Roentgen (R)
The special unit of exposure. One roentgen equals 2.58 x 10^-4 coulombs/kilogram of air.

Sanitary sewerage
A system of public sewers for carrying off waste water and refuse, but excluding sewage treatment facilities, septic tanks, and leach fields owned or operated by the licensee.

Scintillation Detector
The combination of phosphor, photomultiplier tube and associated electronic circuits used to count light emissions produced in the phosphor by ionizing radiation.

Sealed source
Radioactive material that is permanently bonded, fixed or encapsulated so as 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.

Self-contained breathing apparatus (SCBA)
An atmosphere-supplying respirator for which the breathing air source is designed to be carried by the user.

Shallow-dose equivalent (H_s)
As applies to the external exposure of the skin or an extremity, is taken as the dose equivalent at a tissue depth of 0.007 centimeter (7 mg/cm²) averaged over an area of one square centimeter.

SI unit
A unit of measure from the International System of Units as established by the General Conference of Weights and Measures.

Sievert
The SI unit of any of the quantities expressed as dose equivalent. The dose equivalent in sieverts is equal to the absorbed dose in grays multiplied by the quality factor (1 Sv = 100 rems).

Site boundary
That line beyond which the land or property is not owned, leased, or otherwise controlled by the licensee or registrant.

Source of radiation
Any radioactive material, or any device or equipment emitting or capable of producing radiation.

Special form radioactive material
Radioactive material which satisfies the following conditions:

a)	It is either a single solid piece or is contained in a sealed capsule that can be opened only by destroying the capsule;
b)	The piece or capsule has at least one dimension not less than five millimeters (0.197 inch); and
c)	It satisfies the test requirements specified by the U.S. Nuclear Regulatory Commission, Subpart F of 10 CFR Part 71, and the tests prescribed in Rule .0114 of this Section. A special form encapsulation designed in accordance with the U.S. Nuclear Regulatory Commission requirements, Subpart F of 10 CFR Part 71, in effect on June 30, 1984, and constructed prior to July 1, 1985, may continue to be used. A special form encapsulation either designed or constructed after June 30, 1985, must meet requirements of this definition applicable at the time of its design or construction.

a)	plutonium, uranium-233, uranium enriched in the isotope 233 or in the isotope 235, and any other material that the United States Nuclear Regulatory Commission, pursuant to the provisions of Section 51 of the Atomic Energy Act of 1954 (42 U.S.C. 2D11 et seq.;), determines to be special nuclear material, but does not include source material; or
b)	any material artificially enriched by any of the foregoing but does not include source material.

Special nuclear material in quantities not sufficient to form a critical mass
Means uranium enriched in the isotope uranium-235 in quantities not exceeding 350 grams of contained uranium-235; uranium-233 in quantities not exceeding 200 grams; plutonium in quantities not exceeding 200 grams; or any combination of uranium-235, uranium enriched in uranium-235 and plutonium in accordance with the following formula: For each kind of special nuclear material, determine the ratio between the quantity of that special nuclear material and the quantity specified in the North Carolina Regulations for Protection Against Radiation for the same kind of special nuclear material. The sum of these ratios for all the kinds of special nuclear material in combination shall not exceed unity. For example, the following quantities in combination would not exceed the limitations and are within the formula, as follows:

Stereotactic Radiosurgery
Means the use of external radiation in conjunction with a stereotactic guidance device to very precisely deliver a therapeutic dose to a tissue volume.

Stochastic effects
Health effects that occur randomly and for which the probability of the effect occurring, rather than its severity, is assumed to be a linear function of dose without threshold. Hereditary effects and cancer incidence are examples of stochastic effects.

Subsurface Tracer Study
The release of a substance tagged with radioactive material for the purpose of tracing the movement or position of the tagged substance in the well-bore or adjacent formation.

Supplied-air respirator (SAR or airline respirator)
An atmosphere-supplying respirator for which the source of breathing air is not designed to be carried by the user.

Survey
An evaluation of the radiological conditions and potential hazards incident to the production, use, transfer, release, disposal, or presence of sources of radiation. When appropriate, such an evaluation includes a physical survey of the location of sources of radiation and measurements or calculations of levels of radiation, or concentrations or quantities of radioactive material present.

	(a)	at intervals not to exceed 13 weeks; or
	(b)	once per 13 weeks at about the same time during each 13 week period (completed during the same month of the quarter (first month, second month or third month) each quarter over a time period of several quarters.

a)	a radiopharmaceutical or radiation from a licensed source without a written directive where a written directive is required by Sub-items 137(a)(i) and 137(b)-(f) of this Rule;
b)	a radiopharmaceutical or radiation from a licensed source where a written directive is required by Sub-items 137(a)(i) and 137(b)-(f) of this Rule without recording each administered radiopharmaceutical dosage or radiation dose in the appropriate record on a daily basis;
c)	a radiopharmaceutical dosage of greater than 30 microcuries of sodium iodide I-125 and I-131 when:
	(i)	the administered dosage differs from the prescribed dosage by more than 10 percent of the prescribed dosage; and
	(ii)	the difference between the administered dosage and prescribed dose exceeds 15 microcuries;
d)	a therapeutic dosage of any radiopharmaceutical dosage other than sodium iodide I-125 or I-131 when the administered dosage differs from the prescribed dosage by more than 10 percent of the prescribed dosage;
e)	a teletherapy or accelerator radiation dose when the calculated weekly administered dose is 15 percent greater than the weekly prescribed dose; or
f)	a brachytherapy radiation dose when the calculated administered dose differs from the prescribed dose by more than 10 percent of the prescribed dose.

	a)	uranium or thorium or any combination of uranium and thorium in any physical or chemical form; or
	b)	ores which contain, by weight, 0.05 percent or more of uranium, thorium, or any combination thereof.
	Source material does not include special nuclear material.

175 (gram contained U-235)	+	50 (grams U-233)	+	50 (grams Pu)	is ≤ 1
350		200		200