Iodine-129 in Rabbit Thyroids Near a Nuclear Fuel Reprocessing Plant in Idaho

Abstract

Thyroids were collected from rabbits on and near the Idaho National Engineering Laboratory (INEL) Site in southeastern Idaho and analyzed for 129I and stable iodine, 127I. The 129I/127I atom ratios in rabbits collected on the INEL site were larger than ratios in rabbits from a control area. Maximum 129I/127I atom ratios (9.1 x 10(-4)) occurred near the Idaho Chemical Processing Plant (ICPP). Based on rabbit thyroid concentrations, the 129I appeared to be deposited primarily in the direction of the predominant winds from the ICPP, northeast and southwest. Dose rates from the 129I to thyroids of INEL rabbits varied from 0.1 to 260 muGy/y (0.01 to 26 mrad/y). Iodine-129 atmospheric releases from the ICPP appeared to have increased the 129I/127I atom ratios on and near the INEL site.

Environmental Science and Research Foundation annual technical report to DOE-ID, January , 1995--December 31, 1995

“…These levels were found in several environmental media including vegetation (McGiff 1985), waterfowl tissues (Halford and Markham 1984), rabbit thyroids (Fraley et al 1982) and mule deer thyroids (Markham et al 1983). Concentrations in vegetation decrease with distance from the ICPP.…”

“…investigated at the SDA. Arthur and Trace elements and organics have Radionuclide transport by biota was well Markham (1982) estimated that 270 kBq y-' of radioactivity was exported from the SDA by coyotes due to their consumption and subsequent elimination of contaminated small mammals (Arthur and Janke 1986). Approximately 49% of deer mice (Peromyscus maniculatus) and 20% of kangaroo rats (Dipodymus ordii) inhabiting the SDA encounter areas of buried radioactive waste or contaminated soil (Arthur et al 1987).…”

Guidance Manual for Conducting Screening Level Ecological Risk Assessments at the INEL

“…Fraley et al (1982). Thyroids were collected from four species of rabbits on and near the INEL and analyzed for 1291and 1271.…”

“…Studies of vegetation (McGiff 1985) and rabbit thyroids (Fraley et al 1982) have identified 1291contamination in these media greater than background out to 30 km from the ICPP. 1291has been detected above background concentrations in pronghorn tissues site-wide (Markham 1974) and as far offshe as Craters of the Moon National Monument and Monida Pass ).…”

“…As indicated in Section C-3.1.2, 1291has been detected in vegetation and mammal thyroids at great distances from the ICPP including areas well offsite. The source of this contamination and the mechanism of transport have not been conclusively demonstrated, but it is presumed to be wind-borne contamination from ICPP (Markham 1974;Fraley et al 1982;Markham et al 1983;McGiff 1985).…”