Gilson and Voss - Voss Associates

6CEN
The 6CEN equation can be used to calculate the exposure rate
in R/hr at one foot for x-ray and gamma radiation point sources
with energies between 70 KeV and 2 MeV.
R/hr at 1 foot = 6CEN
where; C = curies of radioactive material
E = photon energy in MeV
N = abundance of that photon expressed as a decimal
2.22TBqEN
The same formula in Sv/h is given by 2.22 TBqEN,
where TBq is the number of terabecquels.
Sv/hr at 30 cm = 2.22TBqEN
where; TBq = quantity of radioactive material
Airborne Activity General Dispersion Model
239
Assume a 1 ìCi (37 kBq) release of respirable Pu inside a
large room measuring 12 x 12 x 3 meters with a ventilation
turnover rate of 7 volumes per hour. The General Dispersion
Model uses this 2ð formula for volume. V = 2/3 x ð x R 3
3
Volume in cm 30 cm 1 M 10 M
@ distance R 5.65E4 2.09E6 2.09E9
Concentration @ distance R
in ìCi / cc 1.77E-5 4.78E-7 4.78E-10
3
in Bq / M 6.55E5 1.77E4 17.7
in DAC 8.85E6 2.39E5 239
Time for airborne wave front to reach distance R
13 sec 43 sec 7.15 min
1 CFM sample for 1 week equals 10,080 CF ( 285.4 M 3 )
3
2 CFM sample for 1 week equals 20,160 CF ( 571 M )
Page 67
6CEN
The 6CEN equation can be used to calculate the exposure rate
in R/hr at one foot for x-ray and gamma radiation point sources
with energies between 70 KeV and 2 MeV.
R/hr at 1 foot = 6CEN
where; C = curies of radioactive material
E = photon energy in MeV
N = abundance of that photon expressed as a decimal
2.22TBqEN
The same formula in Sv/h is given by 2.22 TBqEN,
where TBq is the number of terabecquels.
Sv/hr at 30 cm = 2.22TBqEN
where; TBq = quantity of radioactive material
Airborne Activity General Dispersion Model
239
Assume a 1 ìCi (37 kBq) release of respirable Pu inside a
large room measuring 12 x 12 x 3 meters with a ventilation
turnover rate of 7 volumes per hour. The General Dispersion
Model uses this 2ð formula for volume. V = 2/3 x ð x R 3
3
Volume in cm 30 cm 1 M 10 M
@ distance R 5.65E4 2.09E6 2.09E9
Concentration @ distance R
in ìCi / cc 1.77E-5 4.78E-7 4.78E-10
3
in Bq / M 6.55E5 1.77E4 17.7
in DAC 8.85E6 2.39E5 239
Time for airborne wave front to reach distance R
13 sec 43 sec 7.15 min
1 CFM sample for 1 week equals 10,080 CF ( 285.4 M 3 )
3
2 CFM sample for 1 week equals 20,160 CF ( 571 M )
Page 67
6CEN
The 6CEN equation can be used to calculate the exposure rate
in R/hr at one foot for x-ray and gamma radiation point sources
with energies between 70 KeV and 2 MeV.
R/hr at 1 foot = 6CEN
where; C = curies of radioactive material
E = photon energy in MeV
N = abundance of that photon expressed as a decimal
2.22TBqEN
The same formula in Sv/h is given by 2.22 TBqEN,
where TBq is the number of terabecquels.
Sv/hr at 30 cm = 2.22TBqEN
where; TBq = quantity of radioactive material
Airborne Activity General Dispersion Model
239
Assume a 1 ìCi (37 kBq) release of respirable Pu inside a
large room measuring 12 x 12 x 3 meters with a ventilation
turnover rate of 7 volumes per hour. The General Dispersion
Model uses this 2ð formula for volume. V = 2/3 x ð x R 3
3
Volume in cm 30 cm 1 M 10 M
@ distance R 5.65E4 2.09E6 2.09E9
Concentration @ distance R
in ìCi / cc 1.77E-5 4.78E-7 4.78E-10
3
in Bq / M 6.55E5 1.77E4 17.7
in DAC 8.85E6 2.39E5 239
Time for airborne wave front to reach distance R
13 sec 43 sec 7.15 min
1 CFM sample for 1 week equals 10,080 CF ( 285.4 M 3 )
3
2 CFM sample for 1 week equals 20,160 CF ( 571 M )
Page 67
6CEN
The 6CEN equation can be used to calculate the exposure rate
in R/hr at one foot for x-ray and gamma radiation point sources
with energies between 70 KeV and 2 MeV.
R/hr at 1 foot = 6CEN
where; C = curies of radioactive material
E = photon energy in MeV
N = abundance of that photon expressed as a decimal
2.22TBqEN
The same formula in Sv/h is given by 2.22 TBqEN,
where TBq is the number of terabecquels.
Sv/hr at 30 cm = 2.22TBqEN
where; TBq = quantity of radioactive material
Airborne Activity General Dispersion Model
239
Assume a 1 ìCi (37 kBq) release of respirable Pu inside a
large room measuring 12 x 12 x 3 meters with a ventilation
turnover rate of 7 volumes per hour. The General Dispersion
Model uses this 2ð formula for volume. V = 2/3 x ð x R 3
3
Volume in cm 30 cm 1 M 10 M
@ distance R 5.65E4 2.09E6 2.09E9
Concentration @ distance R
in ìCi / cc 1.77E-5 4.78E-7 4.78E-10
3
in Bq / M 6.55E5 1.77E4 17.7
in DAC 8.85E6 2.39E5 239
Time for airborne wave front to reach distance R
13 sec 43 sec 7.15 min
1 CFM sample for 1 week equals 10,080 CF ( 285.4 M 3 )
3
2 CFM sample for 1 week equals 20,160 CF ( 571 M )
Page 67