Evaluation of Accidental Personnel Exposure to Plutonium-238

Abstract

An explosion inside a 238Pu glove box line at iMound Laboratory resulted in significant inhalation exposures being received by three personnel. The three employees were sent to the Dow Chemical Company's Rocky Flats site for whole body counting three weeks after the incident. Whole body counting measurements were made using the 17 keV (Average) X-ray associated with the decay of 238Pu. These measurements indicated that the employees had lung burdens of 0.134 pCi, 0.141 pCi, and 0.091 pCi.The urine data obtained on these three employees during the first 180 days post-exposure is given. These data show an elimination pattern which differs from the pattern observed in previous inhalation exposures to 238Pu at Mound Laboratory. Long term systemic burdens are estimated to be 0.03 pCi, 0.29 pCi and 0.21 pCi.

Characterization of Plutonium Aerosol Collected During an Accident

“…A number of historical studies have shown that the physicochemical properties of plutonium oxide particles can vary depending on the source and history of the material (Anderson et al 1970;Ramsden et al 1970;Newton et al 1983;Carbaugh et al 1991;Guilmette et al 1994;Hickman et al 1995). Lung scans were taken to measure initial lung burden (Anderson et al 1970;Newton et al 1983;Carbaugh et al 1991), and bioassay samples were taken from the exposed workers to assess the excretion rates of plutonium from the body and to estimate lung burden and radiation dose based on an assumed dissolution rate of plutonium aerosols (Anderson et al 1970;Ramsden et al 1970;Newton et al 1983;Carbaugh et al 1991;Guilmette et al 1994;Hickman et al 1995).…”

“…Lung scans were taken to measure initial lung burden (Anderson et al 1970;Newton et al 1983;Carbaugh et al 1991), and bioassay samples were taken from the exposed workers to assess the excretion rates of plutonium from the body and to estimate lung burden and radiation dose based on an assumed dissolution rate of plutonium aerosols (Anderson et al 1970;Ramsden et al 1970;Newton et al 1983;Carbaugh et al 1991;Guilmette et al 1994;Hickman et al 1995). In one case, samples were taken for a solubility test (Anderson et al 1970), and in another case, airborne filter or personal samples were taken for measurement of activity concentration and particle size distribution (Ramsden et al 1970).…”

ICRP Publication 141: Occupational Intakes of Radionuclides: Part 4

“…’ The concept was not new in 1977. For example, Anderson et al. (1970) noted that part of the rapid urinary excretion observed after accidental inhalation of 238 Pu was: ‘thought to be due to refractory particles of colloidal dimensions which were transferred very rapidly to the systemic system …’. (789) As described above, high-fired 239 Pu dioxide particles dissolve extremely slowly in the lungs, although a small fraction of ILD, usually <1%, is absorbed rapidly.…”

“…’ The concept was not new in 1977. For example, Anderson et al. (1970) noted that part of the rapid urinary excretion observed after accidental inhalation of 238 Pu was: ‘thought to be due to refractory particles of colloidal dimensions which were transferred very rapidly to the systemic system …’.…”