25 SOURCES OF FALLOUT R4DIATION AT RONGELAP TABLE 3 #l Principal Halflife Radionuclide aj &b’ /$c’ years Strontium-90 -240 c,d/ MeV MeV 0.187 .66 ICRP-derived limit on da~ y ) oral intake Fraction absorbed fr:t:u},in f/ pCi/d 1.13 29 Plutonium-239 9860 5920 ● 2470 1480 ● 1.0 ** ● * .3 24,065 S.23 - 30 ● * (60) .001 6,537 5.24 - 30 ● * (60) .001 5.57 - 37 ● * (67) .001 Americium-241 432 a’ ICRP Publication b’ c/ Quality factor, 20 Quality factor, 1 d/ MeV 30 Cesium-137 a/ radiations 38. X and gamma rays are be less than 10%. (Radionuclide omitted whose transformations) total contribution to dose would e/ Derived from ICRP Publications 30 and 48. The ICRP limit on intake for workers was divided by 30 (*) to bring the annual committed effective dose-equivalent to 170 mrem, or by 50 (**) for 100 mrem. The ICRP limit includes a factor of 2 to prevent any one tissue receiving more than 50 rem. That factor is unnecessary in the present low-dosage case. The numbers in parentheses give the applicable guide without such correction.* f/ ICRP Publication Publication 48 for 30. Supplement transuranics. to ●John Part 1. (Annals, Vol. 3), and ICRP Dunster adds: ●pply to adults. For children, The intake limits the strontium linit should be divided by a factor of about 3, and those for plutonium and americium by about 2. (National Radiation Protection Board G 87, Aug 81.) . .: