In 1987, an IEU-1 type 2,5-tonne RTG was dumped in the sea while being lifted and towed by an Mi-8 helicopter of the Far Eastern Administration of Civil Aviation to Cape Nizky in the Okha region on the eastern coast of Sakhalin. The Defence Ministry military unit no.13148 put the order for the transportation . The pilots explained that the unusually windy weather was rocking the helicopter so violently that they had no other option but to dispatch the load and dump it into the sea to avoid a crash landing. In August 1997, another IEU-1 type RTG fell from a helicopter into the sea in the Cape of Maria area of the northern part of Sakhalin in the Smirnykh region. The generator sank at a distance of 200 to 400 metres off the coast in 25 to 30 metres of water. According to military officials, the cause of the accident was the disengagement of the lock of the sling load system due to human error.
The local authorities struggled many years to get financing for the salvage operations from the Russian Parliament and the Government. On August 10 this year the Russian tycoon and Chukotka Governor Roman Abramovich sent a letter about the accident to president Putin. On August 11, the letter was passed to the defence minister with the presidents remark Make the order. Report about the measures taken. Urgent. V.Putin. Immediately the money from the Emergency Government fund was allocated to solve this problem, Rossiyskaya Gazeta reported.
The special hydrographic survey vessel of the Pacific Fleet examined 2.7 square kilometres and went over 60 miles while searching for the lost generator. The expedition included the scientists from the Pacific Fleet Hydrographic Service, Krasnoarmeysk Scientific Research Institute of Mechanisation, Moscow Scientific Company Fort-21 as well as the group of the Sakhalin divers. The radioisotope thermoelectric generator was found at 34 meters depth one mile from the shore. The representative of the Krasnoarmeysk Scientific Research Institute Vyacheslav Fedorchenko said the most modern survey equipment had been used. The previous expeditions were unsuccessful due to the lack of such equipment. According to Fedorchenko, the second stage of the operation should be lifting of the generator, which weighs 2.5 tonnes, has size 1.5×1.5m, contains strontium-90. The producers guarantee that strontium can remain intact in the seawater for 10-15 years, RIA-Novosti reported.
The second nuclear generator will be harder to find, as the search area is 25 square kilometres although the depth is only from 3 to 5 meters. The generator is likely covered with 1-2 meters sediment.
The radioactivity of each generator is 1.5 million curies. This is 6 times higher than radioactivity of all the solid radioactive waste dumped by the USA, UK, Japan and the Netherlands from 1946 till 1972. It is expected that the generator found in October will be lifted next summer.