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Annex special quantities and units
RADIATION
PROTECTION
OF WORKERS
19
IN MINES
careful and should include, either as regular examinations or as special investigations, chest radiography, respiratory function tests and sputum cytology.
ANNEX SPECIAL QUANTITIES
AND UNITS
In Annex B of ICRP Publication 32, detailed explanations are given concerning those special quantities and units which are used in the case of radon, thoron and their decay products. The main definitions are presented below. Potential cI energy
The potential u energy, sp, of an atom is the total a energy emitted during the decay of this atom along the decay chain down to *“Pb(RaD) or *“Pb respectively. The total potential a energy per Bq of activity of a radionuclide becomes EJ&, where the decay constant II, is expressed in S - ‘. Values of E, and cp/A are listed in Table A. 1. Table A.l. Potential
a energy per atom and per Bq Potential
Radionuclide
per atom (Q (lo-l2 (MeV)
J)
t( energy per Bq &/A,) (lo-” (MeV)
J)
ZZZRn(Rn) “*Po(RaA) ‘14Pb(RaB) 2’4Bi(RaC) Z’4Po(RaC’)
19.2 13.7 7.69 7.69 7.69
3.07 2.19 1.23 1.23 1.23
9.15 lo6 3 620 17 800 13 100 2.0 lo’-3
14 700 5.79 28.6 21.0 3.0 10-e
“‘Rn(Tn) ‘16Po(ThA) ‘l’Pb(ThB) 212Bi(ThC) “‘Po(ThC’)
20.9 14.6 7.80 7.80 8.78
3.34 2.34 1.25 1.25 1.41
1660 3.32 4.31 105 4.09 lo4 3.85 1O-6
2.65 5.32 1O-3 691 65.6 6.2 1O-9
Potential a-energy concentration in air
The potential a-energy concentration of any mixture of short-lived ***Rn or **‘Rn decay products is the sum of the potential alpha energy of all decay product atoms present per unit volume of air. If C,,i is the activity concentration of a decay product nuclide i in air, the potential alpha-energy concentration, C,, of the decay product mixture becomes:
summed over all short-lived decay products down to 210Pb or *“Pb respectively. In Table A.2 the conversion factors between activity concentration (in Bq m-“) and potential cc-energy concentration are listed for the short-lived decay product nuclides of ***Rn and 220Rn with three different units. Equilibrium-equivalent radon concentration (EC,,,) and equilibrium factor (F)
The E& of a non-equilibrium mixture of short-lived radon decay products in air is that activity concentration of radon in radioactive equilibrium with its short-lived decay products
20
REPORT
Table A.2. Potential Radionuclide
*16Po(ThA) =*Pb(ThB) *12Bi(ThC) * 1*Po(ThC’)
OF COMMITTEE
a-energy
4
concentration
per Bq
mm3
MeV I-’
1O-1o J mm3
10-e WL
3.62 11.8 13.1 2.0 1o-6
5.19 28.6 21.0 3.0 10-6
21.8 137 101 1.6 lo-’
3.32 1O-3 431 40.9 3.85 1O-9
5.52 lo-” 691 65.6 6.2 1O-9
0.0256 3 320 315 3.0 lo-*
that has the same potential a-energy concentration, CP9as the non-equilibrium mixture to which the EC&, refers. The “equilibrium factor”, F, with respect to potential a energy is defined as the ratio of the EC& to the actual activity concentration G,, of radon in air:
Activity and potential a-energy exposure (E) The “activity exposure” of an individual to ***Rn or **ORn is the time integral over the activity concentration of ***Rn or **‘Rn, respectively, to which the individual is exposed during a definite period of time. Its unit is, for example, Bq h m - 3. The “potential a-energy exposure” of an individual to short-lived 222Rn or **‘Rn decay products is the time-integral over the potential alpha-energy concentration of the decay product mixture to which the individual is exposed during a definite period of time. This quantity can be expressed in J h mV3. Activity and potential a-energy intake by inhalation The “potential a-energy intake” of an individual by inhalation of radon decay products is the inhaled potential alpha energy of the decay product mixture during a definite period of time. If u is the mean breathing rate during this period, the potential alpha-energy intake, Z,, is related to the potential alpha-energy exposure, Z$ by the equation:
Table A.3. Conversion factors between activity (&) and potential a-energy intake (I& of “‘Rn **‘Rn decay products I#ORadionuclide *‘sPo(RaA) 214Pb(RaB) *‘&Bi(RaC) ‘16Po(ThA) “‘Pb(ThB) 2’2Bi(ThC)
lo J)
I,(Bq) 5.8 28.6 21.0 0.0053 691 65.6
intake and
IdlO’ Bq)
Z,,(J) 17.2 3.50 4.16 18900 0.145 1.52
RADIATION PROTECTION OF WORKERS IN MINES
21
“Activity intake” by inhalation is the inhaled activity of a radionuclide during a definite period of time. The activity intake, I,, and the potential E-energy intake, Z,, of a decay product of “‘Rn or 220Rn are related by: Z, = (~#4~ 1, The conversion factor, EJ&, is the potential ctenergy per unit of activity of the decay product being considered, which is given in Table A. 1. The rounded values for the ratios (Z,,/Z.)and (Z,/Z,) given in Table A.3 are recommended for practical purposes.
REFERENCES 1. ICRP Publication 24. Radiation protection in uranium and other mines. A report of Committee 4 of the International Commission on Radiological Protection. Annals ofthe ICRP 1, No. 1, Pergamon Press (1977). 2. ICRP Publication 26. Recommendations of the International Commission on Radiological Protection. Annals of the ICRP 1, No. 3, Pergamon Press (1977). 3. ICRP Publication 30. Limits for intakes of radionuclides by workers. Annuls ofthe ICRP 2, No. 3/4,3, Nos l-4,4, No. 3/4, 5, Nos 14, 6, No. 2/3, 7, Nos l-3, 8, Nos l-3, 8, No. 4, Pergamon Press (1979-1982). 4. ICRP Publication 32. Limits for inhalation of radon daughters by workers. Annals ofthe ICRP 6, No. 1, Pergamon Press (1982). 5. ICRP Publication 35. General principles of monitoring for radiation protection of workers. Annals of the ICRP9, No. 4, Pergamon Press (1982). 6. United Nations Scientific Committee on the Effects of Atomic Radiation. Ionising radiation: sources and biological effects. 1982 Report to the General Assembly, New York, United Nations (1982). 7. Infernational Conference on Radiation Hazards in Mining: Control, Measurements and Medical Aspects, Golden (USA), October 4-9, 1981. (M. Gomez, ed.), New York, Society of Mining Engineering (1981). 8. Internarional Conference on Occupational Radiation safety in Mining. Toronto, October 14-18, 1984. (H. Stocker, ed.), Toronto, Canadian Nuclear Association (1985). 9. ICRP Publication 37. Cost-benefit analysis in the optimization of radiation protection. Annals ofthe ICRP 10,No. 2/3, Pergamon Press (1983). IO. OECD-NEA. Dosimetry aspects of exposure to radon and thoron daughter products. Report by a Group of Experts of the OECD Nuclear Energy Agency, OECD, Paris (1983). 11. Johnson, J. R. A review of the dosimetry from inhalation of long-lived alpha activity in ore dust. In: Occupational Radiation &fery in Mining, Vol. 1,495-502, Toronto, October 1418, 1984. (H. Stocker, ed.), Toronto, Canadian Nuclear Association (1985). 12. OECD-NEA. Metrology and monitoring of radon, thoron and their daughters. Report by a Group of Experts of the OECD Nuclear Energy Agency, SAN/DOC (84) 6, Paris (1984). 13. IAEA, WHO and ILO. Radiation and occupational health: A training manual for occupational physicians. Joint report in press (IAEA).
PROTECTION
OF WORKERS
19
IN MINES
careful and should include, either as regular examinations or as special investigations, chest radiography, respiratory function tests and sputum cytology.
ANNEX SPECIAL QUANTITIES
AND UNITS
In Annex B of ICRP Publication 32, detailed explanations are given concerning those special quantities and units which are used in the case of radon, thoron and their decay products. The main definitions are presented below. Potential cI energy
The potential u energy, sp, of an atom is the total a energy emitted during the decay of this atom along the decay chain down to *“Pb(RaD) or *“Pb respectively. The total potential a energy per Bq of activity of a radionuclide becomes EJ&, where the decay constant II, is expressed in S - ‘. Values of E, and cp/A are listed in Table A. 1. Table A.l. Potential
a energy per atom and per Bq Potential
Radionuclide
per atom (Q (lo-l2 (MeV)
J)
t( energy per Bq &/A,) (lo-” (MeV)
J)
ZZZRn(Rn) “*Po(RaA) ‘14Pb(RaB) 2’4Bi(RaC) Z’4Po(RaC’)
19.2 13.7 7.69 7.69 7.69
3.07 2.19 1.23 1.23 1.23
9.15 lo6 3 620 17 800 13 100 2.0 lo’-3
14 700 5.79 28.6 21.0 3.0 10-e
“‘Rn(Tn) ‘16Po(ThA) ‘l’Pb(ThB) 212Bi(ThC) “‘Po(ThC’)
20.9 14.6 7.80 7.80 8.78
3.34 2.34 1.25 1.25 1.41
1660 3.32 4.31 105 4.09 lo4 3.85 1O-6
2.65 5.32 1O-3 691 65.6 6.2 1O-9
Potential a-energy concentration in air
The potential a-energy concentration of any mixture of short-lived ***Rn or **‘Rn decay products is the sum of the potential alpha energy of all decay product atoms present per unit volume of air. If C,,i is the activity concentration of a decay product nuclide i in air, the potential alpha-energy concentration, C,, of the decay product mixture becomes:
summed over all short-lived decay products down to 210Pb or *“Pb respectively. In Table A.2 the conversion factors between activity concentration (in Bq m-“) and potential cc-energy concentration are listed for the short-lived decay product nuclides of ***Rn and 220Rn with three different units. Equilibrium-equivalent radon concentration (EC,,,) and equilibrium factor (F)
The E& of a non-equilibrium mixture of short-lived radon decay products in air is that activity concentration of radon in radioactive equilibrium with its short-lived decay products
20
REPORT
Table A.2. Potential Radionuclide
*16Po(ThA) =*Pb(ThB) *12Bi(ThC) * 1*Po(ThC’)
OF COMMITTEE
a-energy
4
concentration
per Bq
mm3
MeV I-’
1O-1o J mm3
10-e WL
3.62 11.8 13.1 2.0 1o-6
5.19 28.6 21.0 3.0 10-6
21.8 137 101 1.6 lo-’
3.32 1O-3 431 40.9 3.85 1O-9
5.52 lo-” 691 65.6 6.2 1O-9
0.0256 3 320 315 3.0 lo-*
that has the same potential a-energy concentration, CP9as the non-equilibrium mixture to which the EC&, refers. The “equilibrium factor”, F, with respect to potential a energy is defined as the ratio of the EC& to the actual activity concentration G,, of radon in air:
Activity and potential a-energy exposure (E) The “activity exposure” of an individual to ***Rn or **ORn is the time integral over the activity concentration of ***Rn or **‘Rn, respectively, to which the individual is exposed during a definite period of time. Its unit is, for example, Bq h m - 3. The “potential a-energy exposure” of an individual to short-lived 222Rn or **‘Rn decay products is the time-integral over the potential alpha-energy concentration of the decay product mixture to which the individual is exposed during a definite period of time. This quantity can be expressed in J h mV3. Activity and potential a-energy intake by inhalation The “potential a-energy intake” of an individual by inhalation of radon decay products is the inhaled potential alpha energy of the decay product mixture during a definite period of time. If u is the mean breathing rate during this period, the potential alpha-energy intake, Z,, is related to the potential alpha-energy exposure, Z$ by the equation:
Table A.3. Conversion factors between activity (&) and potential a-energy intake (I& of “‘Rn **‘Rn decay products I#ORadionuclide *‘sPo(RaA) 214Pb(RaB) *‘&Bi(RaC) ‘16Po(ThA) “‘Pb(ThB) 2’2Bi(ThC)
lo J)
I,(Bq) 5.8 28.6 21.0 0.0053 691 65.6
intake and
IdlO’ Bq)
Z,,(J) 17.2 3.50 4.16 18900 0.145 1.52
RADIATION PROTECTION OF WORKERS IN MINES
21
“Activity intake” by inhalation is the inhaled activity of a radionuclide during a definite period of time. The activity intake, I,, and the potential E-energy intake, Z,, of a decay product of “‘Rn or 220Rn are related by: Z, = (~#4~ 1, The conversion factor, EJ&, is the potential ctenergy per unit of activity of the decay product being considered, which is given in Table A. 1. The rounded values for the ratios (Z,,/Z.)and (Z,/Z,) given in Table A.3 are recommended for practical purposes.
REFERENCES 1. ICRP Publication 24. Radiation protection in uranium and other mines. A report of Committee 4 of the International Commission on Radiological Protection. Annals ofthe ICRP 1, No. 1, Pergamon Press (1977). 2. ICRP Publication 26. Recommendations of the International Commission on Radiological Protection. Annals of the ICRP 1, No. 3, Pergamon Press (1977). 3. ICRP Publication 30. Limits for intakes of radionuclides by workers. Annuls ofthe ICRP 2, No. 3/4,3, Nos l-4,4, No. 3/4, 5, Nos 14, 6, No. 2/3, 7, Nos l-3, 8, Nos l-3, 8, No. 4, Pergamon Press (1979-1982). 4. ICRP Publication 32. Limits for inhalation of radon daughters by workers. Annals ofthe ICRP 6, No. 1, Pergamon Press (1982). 5. ICRP Publication 35. General principles of monitoring for radiation protection of workers. Annals of the ICRP9, No. 4, Pergamon Press (1982). 6. United Nations Scientific Committee on the Effects of Atomic Radiation. Ionising radiation: sources and biological effects. 1982 Report to the General Assembly, New York, United Nations (1982). 7. Infernational Conference on Radiation Hazards in Mining: Control, Measurements and Medical Aspects, Golden (USA), October 4-9, 1981. (M. Gomez, ed.), New York, Society of Mining Engineering (1981). 8. Internarional Conference on Occupational Radiation safety in Mining. Toronto, October 14-18, 1984. (H. Stocker, ed.), Toronto, Canadian Nuclear Association (1985). 9. ICRP Publication 37. Cost-benefit analysis in the optimization of radiation protection. Annals ofthe ICRP 10,No. 2/3, Pergamon Press (1983). IO. OECD-NEA. Dosimetry aspects of exposure to radon and thoron daughter products. Report by a Group of Experts of the OECD Nuclear Energy Agency, OECD, Paris (1983). 11. Johnson, J. R. A review of the dosimetry from inhalation of long-lived alpha activity in ore dust. In: Occupational Radiation &fery in Mining, Vol. 1,495-502, Toronto, October 1418, 1984. (H. Stocker, ed.), Toronto, Canadian Nuclear Association (1985). 12. OECD-NEA. Metrology and monitoring of radon, thoron and their daughters. Report by a Group of Experts of the OECD Nuclear Energy Agency, SAN/DOC (84) 6, Paris (1984). 13. IAEA, WHO and ILO. Radiation and occupational health: A training manual for occupational physicians. Joint report in press (IAEA).