In 1992, it became known to the public that the former Soviet Union dumped
large amounts of radioactive waste in the Arctic Ocean. The waste was dumped
in liquid and solid form, sealed in barrels or containers, as reactor parts
but also as complete ship reactors including spent fuel. Wrecks of nuclear
submarines were sunk near the coast of Novaya Zemlya, in depths less than
50 m. The kind of waste, the distance of the dump sites to the coasts and
the depth of deposition was a despise of international rules and contracts.
At first there was some confusion and overestimation of the total radioactive
inventory. Meanwhile, the amount of the waste and the dump site locations
are well known. This was effected by international pressure and the improved
information policy of Russia. The dumped objects in the Kara Sea encompass
mainly 17 nuclear ship reactors, seven of them still carrying spent fuel.
Four dump sites are located in small and shallow fjords at the east coast
of Novaya Semlya, and in the Novaya Semlya Trough, max. depth 420m (see figure).
The total radioactive inventory was at the time of dumping 37 PBq. Up to
1994 it decayed approx. to 4.7 PBq. The dominant isotopes are 90Sr, 137Cs,
63Ni and 241Pu.
1 Bq = 1 Becquerel = 1 Decay per second
1 PBq = 1 Peta Becquerel = 1015 Bq
1 TBq = 1 Tera Becquerel = 1012 Bq