The definitions, abbreviations, and acronyms in this section apply throughout chapters 246-220 through 246-254 WAC unless the context clearly indicates otherwise. Additional definitions used only in a certain chapter are included in that chapter.
TABLE I
QUALITY FACTORS AND ABSORBED DOSE EQUIVALENCIES
TYPE OF RADIATION | Quality Factor (Q) | Absorbed Dose Equal to A Unit Dose Equivalenta |
X, gamma, or beta radiation and high-speed electrons | 1 | 1 |
Alpha particles, multiple-charged particles, fission fragments and heavy particles of unknown charge | 20 | 0.05 |
Neutrons of unknown energy | 10 | 0.1 |
High-energy protons | 10 | 0.1 |
a Absorbed dose in rad equal to 1 rem or the absorbed dose in gray equal to 1 Sv.
If it is more convenient to measure the neutron fluence rate rather than to determine the neutron dose equivalent rate in sievert per hour or rem per hour as required for Table I, then 0.01 Sv (1 rem) of neutron radiation of unknown energies may, for purposes of these rules, 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 Table II to convert a measured tissue dose in gray or rad to dose equivalent in sievert or rem.
TABLE II
MEAN QUALITY FACTORS, Q, AND FLUENCE PER UNIT DOSE EQUIVALENT FOR MONOENERGETIC NEUTRONS
Neutron Energy (MeV) | Quality Factora (Q) | Fluence per Unit Dose Equivalentb (neutrons cm-2 rem-1) | Fluence per Unit Dose Equivalentb (neutrons cm-2 Sv-1) |
(thermal) 2.5 x 10-8 | 2 | 980 x 106 | 980 x 108 |
1 x 10-7 | 2 | 980 x 106 | 980 x 108 |
1 x 10-6 | 2 | 810 x 106 | 810 x 108 |
1 x 10-5 | 2 | 810 x 106 | 810 x 108 |
1 x 10-4 | 2 | 840 x 106 | 840 x 108 |
1 x 10-3 | 2 | 980 x 106 | 980 x 108 |
1 x 10-2 | 2.5 | 1010 x 106 | 1010 x 108 |
1 x 10-1 | 7.5 | 170 x 106 | 170 x 108 |
5 x 10-1 | 11 | 39 x 106 | 39 x 108 |
1 | 11 | 27 x 106 | 27 x 108 |
2.5 | 9 | 29 x 106 | 29 x 108 |
5 | 8 | 23 x 106 | 23 x 108 |
7 | 7 | 24 x 106 | 24 x 108 |
10 | 6.5 | 24 x 106 | 24 x 108 |
14 | 7.5 | 17 x 106 | 17 x 108 |
20 | 8 | 16 x 106 | 16 x 108 |
40 | 7 | 14 x 106 | 14 x 108 |
60 | 5.5 | 16 x 106 | 16 x 108 |
1 x 102 | 4 | 20 x 106 | 20 x 108 |
2 x 102 | 3.5 | 19 x 106 | 19 x 108 |
3 x 102 | 3.5 | 16 x 106 | 16 x 108 |
4 x 102 | 3.5 | 14 x 106 | 14 x 108 |
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.
ORGAN DOSE WEIGHTING FACTORS
Organ or Tissue | wT |
Gonads | 0.25 |
Breast | 0.15 |
Red bone marrow | 0.12 |
Lung | 0.12 |
Thyroid | 0.03 |
Bone surfaces | 0.03 |
Remainder | 0.30a |
Whole Body | 1.00b |
a 0.30 results form 0.06 for each of 5 "remainder" organs, excluding the skin and the lens of the eye, that receive the highest doses.
b For the purpose of weighting the external whole body dose, for adding it to the internal dose, a single weighting factor, wT =1.0, has been specified. The use of other weighting factors for external exposure will be approved on a case-by-case basis until such time as specific guidance is issued.
Wash. Admin. Code § 246-220-010
Statutory Authority: RCW 70.98.050 and 70.98.080. 11-03-020, § 246-220-010, filed 1/7/11, effective 2/7/11; 09-06-003, § 246-220-010, filed 2/18/09, effective 3/21/09. Statutory Authority: RCW 70.98.050. 06-05-019, § 246-220-010, filed 2/6/06, effective 3/9/06; 04-23-093, § 246-220-010, filed 11/17/04, effective 12/18/04; 01-05-110, § 246-220-010, filed 2/21/01, effective 3/24/01; 00-08-013, § 246-220-010, filed 3/24/00, effective 4/24/00; 99-15-105, § 246-220-010, filed 7/21/99, effective 8/21/99; 98-13-037, § 246-220-010, filed 6/8/98, effective 7/9/98; 95-01-108, § 246-220-010, filed 12/21/94, effective 1/21/95; 94-01-073, § 246-220-010, filed 12/9/93, effective 1/9/94. Statutory Authority: RCW 70.98.050 and 70.98.080. 91-15-112 (Order 184), § 246-220-010, filed 7/24/91, effective 8/24/91. Statutory Authority: RCW 43.70.040. 91-02-049 (Order 121), recodified as § 246-220-010, filed 12/27/90, effective 1/31/91. Statutory Authority: RCW 70.98.080. 87-01-031 (Order 2450), § 402-12-050, filed 12/11/86; 83-19-050 (Order 2026), § 402-12-050, filed 9/16/83. Statutory Authority: Chapter 70.121 RCW. 81-16-031 (Order 1683), § 402-12-050, filed 7/28/81. Statutory Authority: RCW 70.98.050. 81-01-011 (Order 1570), § 402-12-050, filed 12/8/80; Order 1095, § 402-12-050, filed 2/6/76; Order 708, § 402-12-050, filed 8/24/72; Order 1, § 402-12-050, filed 7/2/71; Order 1, § 402-12-050, filed 1/8/69; Rules (part), filed 10/26/66.