Environmental Engineering Reference
In-Depth Information
Tomsk-7 had been discharged into reservoirs and injected into deep underground strata.
The plutonium-producing reactors at Tomsk were shut down in 1998.
In 1993, a chemical explosion at the site occurred in a tank containing uranium nitrate
that resulted in uncontrolled emissions to the atmosphere. A study by Porfiriev in 1996
indicated significant contamination over an area of about 189 square kilometres. A report
on the event was published by the IAEA in 1998. Using two different methodologies, the
IAEA estimated that the average value for the total activity of all material released was
about 30 TBq. These figures are substantially higher than early estimates.
The Krasnoyarsk-26 facility is located on the Yenisei River, which also eventually
flows into the Arctic Ocean. It was originally used for the production of weapons-grade
plutonium and for the storage of radioactive wastes. More recently, it developed electrical
power for the region. At the time of the 1998 AMAP assessment, it was estimated that
between 26,000 and 37,000 PBq of radioactive waste had been injected into underground
storage. I am not aware of any information of what this may mean to local groundwater
contamination now or in the future.
Attempts to quantify how much of the radioactive discharges from the three Siberian
facilities mayhavereachedtheArcticOceanhavebeeninconclusive.Thisispartlybecause
of the lack of monitoring data from the 1960s-1980s along the rivers from the nuclear fa-
cility to marine waters. The most likely signal of marine contamination attributable to these
facilities would be from Mayak. In this case, it is clear from the 2009 AMAP assessment
that
90
Sr activity progressively declines from Mayak along the Techa-Iset-Tobol-Irtysh-Ob
river system. Upstream of the Irtysh River's confluence with the Tobol River,
90
Sr activity
in the Irtysh River is essentially at background levels but is at an order of magnitude higher
downstream of the confluence, which also suggests significant input from Mayak-related
sources. A little upstream of the same confluence,
90
Sr activity in the Tobol River is about
200 times higher than in a typical Russian river (5-6 Bq per cubic metre). The influence
of Mayak
90
Sr discharges can be detected downstream as far away as the confluence of the
Irtysh and Ob rivers.
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