Norway’s diving support ship, Mayo, carrying an international team of deep water divers, has arrived at the site of the sinking of the Kursk nuclear submarine. The Kursk sank after an explosion blew its bow apart during a training exercise off northwestern Russia last August, killing all 118 crewmen. Russia plans to raise the submarine in a salvage operation lasting until mid-September.

In the first phase of the operation, divers will examine the hull. Afterwards, they will clear silt beneath the vessel. The operation will include drilling holes in the submarine’s hull, attaching lifting wires and cutting away the vessel’s damaged bow. Salvagers then plan to lift the 14,000-tonne wreck with cables from a giant barge on the surface and then tow the Kursk to the Arctic port of Murmansk.

Dutch salvage company Mammoet and Rotterdam-based marine services firm Smit International are overseeing the task of raising the Kursk.

Radiation at the Kursk site remains normal, according to Lieutenant-General Boris Alexeyev, head of the ecological security department of the Russian armed forces. Measurements are taken four times a day. However, Murmansk governor Yuri Yevdokimov has expressed concerns about possible radiation leaks during the salvage operation in a letter to Deputy Prime Minister Ilya Klebanov and the head of the St Petersburg agency that designed the Kursk. “Maintaining the norms of environmental safety is the main criteria in the operation to lift the Kursk,” said Alexeyev.

The operation has a target date of 20 September to get the submarine into dock. On 15 September the submarine, including its twin 190MW reactors driving 50,000 horsepower turbines, will be hoisted by floating cranes.

The cost of the operation is estimated at $70m, but Klebanov refused to give a figure since Mammoet considers it to be a commercial secret, along with the technology to be used to cut off the bow. He says no advance payment has yet been made, noting that the Kursk International Fund has not yet confirmed the sum collected. The Russian government has decided to finance the lifting operation from the budget, which will then be replenished from the Fund.