Rad Data Handbook 20.. - Voss Associates
Rad Data Handbook 20.. - Voss Associates
Rad Data Handbook 20.. - Voss Associates
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MISCELLANEOUS RULES OF THUMB<br />
1. One watt of power in a reactor requires 3.1E10 fissions per<br />
second. In a reactor operating for more than 4 days, the<br />
total fission products are about 3 Ci / watt at 1.5 min after<br />
shutdown. At 2 yr after shutdown, the fission products are<br />
approximately 75 Ci / MW-day.<br />
2. The quantity of a short-lived fission product in a reactor<br />
which has been operated about four times as long as the<br />
half-life is given by; Ci (FY)(PL) ,<br />
where FY is the fission yield (%/100) and PL is the power<br />
level in watts.<br />
3. Correction factor for unsealed ion chambers to STP (0 0 C<br />
and 760 mm of Hg) is f = (t + 273)/(273) x (760 / P)<br />
where t is the ambient temperature in degrees C and P is<br />
the ambient barometric pressure in mm of Hg.<br />
4. The activity of an isotope (without radioactive daughter) is<br />
reduced to less than 1% after seven half-lives.<br />
5. NATURALLY OCCURRING RADIONUCLIDES<br />
Primordial<br />
Cosmogonic<br />
40<br />
K<br />
Tritium<br />
87 7<br />
Rb<br />
Be<br />
Natural U and Th C 14<br />
6. Unified Time, Distance, and Shielding formula for reduction<br />
of external dose.<br />
2 n<br />
Rem = Initial Rem/hr x T in hours x (D<br />
2) x 0.5<br />
2<br />
(D)<br />
1<br />
Where: Rem is the dose after applying reduction methods<br />
T is the exposure time in hours<br />
D<br />
1<br />
is the initial distance to the source<br />
D<br />
2<br />
is the new distance to the source<br />
n<br />
0.5 is the Shielding for ‘n’ half-value layers<br />
MISCELLANEOUS RULES OF THUMB<br />
1. One watt of power in a reactor requires 3.1E10 fissions per<br />
second. In a reactor operating for more than 4 days, the<br />
total fission products are about 3 Ci / watt at 1.5 min after<br />
shutdown. At 2 yr after shutdown, the fission products are<br />
approximately 75 Ci / MW-day.<br />
2. The quantity of a short-lived fission product in a reactor<br />
which has been operated about four times as long as the<br />
half-life is given by; Ci (FY)(PL) ,<br />
where FY is the fission yield (%/100) and PL is the power<br />
level in watts.<br />
3. Correction factor for unsealed ion chambers to STP (0 0 C<br />
and 760 mm of Hg) is f = (t + 273)/(273) x (760 / P)<br />
where t is the ambient temperature in degrees C and P is<br />
the ambient barometric pressure in mm of Hg.<br />
4. The activity of an isotope (without radioactive daughter) is<br />
reduced to less than 1% after seven half-lives.<br />
5. NATURALLY OCCURRING RADIONUCLIDES<br />
Primordial<br />
Cosmogonic<br />
40<br />
K<br />
Tritium<br />
87 7<br />
Rb<br />
Be<br />
Natural U and Th C 14<br />
6. Unified Time, Distance, and Shielding formula for reduction<br />
of external dose.<br />
2 n<br />
Rem = Initial Rem/hr x T in hours x (D<br />
2) x 0.5<br />
2<br />
(D)<br />
1<br />
Where: Rem is the dose after applying reduction methods<br />
T is the exposure time in hours<br />
D<br />
1<br />
is the initial distance to the source<br />
D<br />
2<br />
is the new distance to the source<br />
n<br />
0.5 is the Shielding for ‘n’ half-value layers<br />
MISCELLANEOUS RULES OF THUMB<br />
1. One watt of power in a reactor requires 3.1E10 fissions per<br />
second. In a reactor operating for more than 4 days, the<br />
total fission products are about 3 Ci / watt at 1.5 min after<br />
shutdown. At 2 yr after shutdown, the fission products are<br />
approximately 75 Ci / MW-day.<br />
2. The quantity of a short-lived fission product in a reactor<br />
which has been operated about four times as long as the<br />
half-life is given by; Ci (FY)(PL) ,<br />
where FY is the fission yield (%/100) and PL is the power<br />
level in watts.<br />
3. Correction factor for unsealed ion chambers to STP (0 0 C<br />
and 760 mm of Hg) is f = (t + 273)/(273) x (760 / P)<br />
where t is the ambient temperature in degrees C and P is<br />
the ambient barometric pressure in mm of Hg.<br />
4. The activity of an isotope (without radioactive daughter) is<br />
reduced to less than 1% after seven half-lives.<br />
5. NATURALLY OCCURRING RADIONUCLIDES<br />
Primordial<br />
Cosmogonic<br />
40<br />
K<br />
Tritium<br />
87 7<br />
Rb<br />
Be<br />
Natural U and Th C 14<br />
6. Unified Time, Distance, and Shielding formula for reduction<br />
of external dose.<br />
2 n<br />
Rem = Initial Rem/hr x T in hours x (D<br />
2) x 0.5<br />
2<br />
(D)<br />
1<br />
Where: Rem is the dose after applying reduction methods<br />
T is the exposure time in hours<br />
D<br />
1<br />
is the initial distance to the source<br />
D<br />
2<br />
is the new distance to the source<br />
n<br />
0.5 is the Shielding for ‘n’ half-value layers<br />
MISCELLANEOUS RULES OF THUMB<br />
1. One watt of power in a reactor requires 3.1E10 fissions per<br />
second. In a reactor operating for more than 4 days, the<br />
total fission products are about 3 Ci / watt at 1.5 min after<br />
shutdown. At 2 yr after shutdown, the fission products are<br />
approximately 75 Ci / MW-day.<br />
2. The quantity of a short-lived fission product in a reactor<br />
which has been operated about four times as long as the<br />
half-life is given by; Ci (FY)(PL) ,<br />
where FY is the fission yield (%/100) and PL is the power<br />
level in watts.<br />
3. Correction factor for unsealed ion chambers to STP (0 0 C<br />
and 760 mm of Hg) is f = (t + 273)/(273) x (760 / P)<br />
where t is the ambient temperature in degrees C and P is<br />
the ambient barometric pressure in mm of Hg.<br />
4. The activity of an isotope (without radioactive daughter) is<br />
reduced to less than 1% after seven half-lives.<br />
5. NATURALLY OCCURRING RADIONUCLIDES<br />
Primordial<br />
Cosmogonic<br />
40<br />
K<br />
Tritium<br />
87 7<br />
Rb<br />
Be<br />
Natural U and Th C 14<br />
6. Unified Time, Distance, and Shielding formula for reduction<br />
of external dose.<br />
2 n<br />
Rem = Initial Rem/hr x T in hours x (D<br />
2) x 0.5<br />
2<br />
(D)<br />
1<br />
Where: Rem is the dose after applying reduction methods<br />
T is the exposure time in hours<br />
D<br />
1<br />
is the initial distance to the source<br />
D<br />
2<br />
is the new distance to the source<br />
n<br />
0.5 is the Shielding for ‘n’ half-value layers