TY - JOUR
T1 - Plutonium from Mayak
T2 - Measurement of isotope ratios and activities using accelerator mass spectrometry
AU - Oughton, Deborah H.
AU - Fifield, L. Keith
AU - Day, J. Philip
AU - Cresswell, Richard C.
AU - Skipperud, Lindis
AU - Di Tada, Marianne L.
AU - Salbu, Brit
AU - Strand, Per
AU - Drozcho, Eugeny
AU - Mokrov, Yuri
PY - 2000/5/15
Y1 - 2000/5/15
N2 - Accelerator mass spectrometry (AMS) has been used to measure Pu activities and 240Pu/239Pu isotope ratios in samples contaminated by releases from the Mayak nuclear installation. Determination of Pu isotopes in high-level samples indicated that the ratio of 240Pu/239Pu in waste has increased toward the present. The lowest 240Pu/239Pu atom ratios, 0.012-0.024, were found at the Asanov Swamp, where the primary source of contamination was discharge of intermediate-level radioactive waste between 1949 and 1951. The highest ratios, 0.06-0.29, were found in industrial reservoirs contaminated by various sources of waste up to the present day. Measurement of Pu isotopes in low-level samples collected from the Techa, Iset, and Ob Rivers showed that while activity levels decrease with distance from Mayak - from 2000 Bq/kg at 7 km downstream to less than 1 Bq/kg sediment at 250 km - 240Pu/239Pu isotope ratios increase. Results suggest that most of the plutonium in the Upper Techa River originates from the early waste discharges, although enhanced atom ratios in surface sediments downstream (0.035-0.099)indicate a contribution from other sources. On the basis of procedural blanks, detection limits for AMS were below 1 fg of Pu.
AB - Accelerator mass spectrometry (AMS) has been used to measure Pu activities and 240Pu/239Pu isotope ratios in samples contaminated by releases from the Mayak nuclear installation. Determination of Pu isotopes in high-level samples indicated that the ratio of 240Pu/239Pu in waste has increased toward the present. The lowest 240Pu/239Pu atom ratios, 0.012-0.024, were found at the Asanov Swamp, where the primary source of contamination was discharge of intermediate-level radioactive waste between 1949 and 1951. The highest ratios, 0.06-0.29, were found in industrial reservoirs contaminated by various sources of waste up to the present day. Measurement of Pu isotopes in low-level samples collected from the Techa, Iset, and Ob Rivers showed that while activity levels decrease with distance from Mayak - from 2000 Bq/kg at 7 km downstream to less than 1 Bq/kg sediment at 250 km - 240Pu/239Pu isotope ratios increase. Results suggest that most of the plutonium in the Upper Techa River originates from the early waste discharges, although enhanced atom ratios in surface sediments downstream (0.035-0.099)indicate a contribution from other sources. On the basis of procedural blanks, detection limits for AMS were below 1 fg of Pu.
UR - http://www.scopus.com/inward/record.url?scp=12944252975&partnerID=8YFLogxK
U2 - 10.1021/es990847z
DO - 10.1021/es990847z
M3 - Article
SN - 0013-936X
VL - 34
SP - 1938
EP - 1945
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 10
ER -