Cesium
137 (L. caesius, blue sky); Cs; at. Mass. 136,9070895; at. n° 55; m.p. 28,44°C;
b.p. 671°C; sp. gr. 1,873; half-life 30,07 years; 86,84 Ci/gr; β-; 0,514 MeV; β- range in tissues ~1560 μ.
Assessing the rationality of official internal dose
factor (4,8E-9 Sv/Bq) or what body mass is necessary to explain the IRCP dose factor for this
element ?
The cesium 137 have a physical half-life
of 30,07 years, a biological half-life of 70 days an a effective half-life of
69,56 days. (λ
phys. 7,309E-10, λ bio. 1,146E-7, λ
effect. 1,153E-7.) His official inhalation dose factor is
The incorporation of 1 Bq of cesium 137
conduce after 50 years to suffer (1 Bq/1,153E-7 λe) *
1-(EXP(50*31536000*-1,153E-7)) = 8,670E6 disintegrations β-
and absorb 8,67E6 disintegrations * 0,514 MeV * 1,602E-13 Joule per MeV =
7,140E-7 Joule and 7,14001 Erg which dissipate, for IRCP, in a impossible human
body mass of 148,75 kg...
((8,67E6 Emissions * 0,5140 MeV * 1,602E-6 Erg par MeV * 1 EBR)/(4,800E-9 Sv/Bq
* 1 Bq * 100 Erg/gr * 100 Rad/Sv) = 148,75 kg)
with a radius of (148750,2595 cm3/(4/3*3,14159))^(1/3) = 32,8693 cm. The particle β- which penetrate no
more than 1560 μ in tissues travel in “rational”
calculation 210,7 times far away it can physically go... (328692,43 μ/1560
μ
= 210,7.) In other words the real absorbed dose is reduce 9,35 millions times.
(210,70^3 = 9,35E6 or 1,49E5 gr/1,59E-2 gr = 9,35E6.)
Calculating the dose produce by one β-
particle with 0,514 MeV energy and 1560 μ penetration capacity in tissues: (1 Bq
* 0,5140 MeV * 1,602E-6 Erg par MeV * 1 EBR)/((4/3 * 3,14159 * (1560 *
0,0001^3)) gr * 100 Erg/gr * 100 Rad/Sv) = 5,18E-9 Sv/Bq or 5,18 nanoSievert
per desintegration.
The committed dose for 1 Bq in 50 years
is then (1 Bq/1,15E-7 λ effect. s-1 * (1-Exp(50*365*24*60*60 *
-1,15E-7 λ
effect.))) * 5,18E-9 Sv/Bq) = 4,490E-2 Sv/Bq or 44,90 milliSievert per
Becquerel.
Official internal dose factors are like SS which name shower a chamber
gas.
