The Kursk lies on the sea-bed at a depth of 108 metres north-east of Murmansk in the Barents Sea. This is an important fishing site for Russia and western Europe. Just west of it is a famous fishing ground called Kildinbanken.
The reactor section of the submarine is flooded so some of the barriers between the sea water and the radioactivity in the reactors are more than likely damaged. However, to date there is no information about the damage to the reactor compartment which is located behind the conning tower of the submarine.
The explosion that sank the Kursk might very well have caused severe damage to the reactors themselves, the cooling pipelines or other parts of the reactors' installation.
A comprehensive analysis of the wreck and a proper risk assessment may take several months. Judging by the way Russian officials have handled the rescue operation so far, presenting misleading information and keeping facts secret, the risk assessment would preferably be undertaken in co-operation with a Russian civilian institution and by international nuclear experts.
To start a lifting operation before all necessary facts on the wreck's condition are established might very well increase the danger of a discharge of radioactivity. Therefore, a thorough examination of the wreck should be carried out beforehand.
Before raising the submarine it is necessary to establish the extent of the damage to the hull structure and to clarify the condition of the two reactors. Raising the Kursk would require international assistance, since Russia has neither the requisite equipment nor experience. The lifting could prove risky if the submarine is as damaged as the present information indicates. If there is an accident to the reactors as the Kursk is taken to the surface radioactivity could be spread to the atmosphere and by sea currents over a large area.
Russian navy officials have said they are considering a partial lift so they could tow the Kursk to shallower waters (less than 60 metres deep). This would enable divers to recover the bodies trapped inside.
If the research concludes that it is safe to raise the submarine, such an operation can be undertaken by using floating cranes, possibly in conjunction with flotation balloons.
The raised submarine might be taken into a floating dry-dock and then shipped to the naval yards outside Murmansk. Alternatively it may be taken to the Severodvinsk shipyards in the White Sea.
Preparing the submarine for decommissioning would involve removing the spent fuel elements in the reactor cores and storing the reactor compartment. If the risk-assessment studies conclude that it would be impossible or too dangerous to lift the submarine from the sea-bed, there are several options for leaving the Kursk where it is in the Barents Sea.
One of these is to try to cut out the reactor compartment and raise it to the surface. The cutting operation would require specialist equipment which Russia is unlikely to possess. A large-scale
cutting of superstructure steel at 108 metres depth in Arctic waters has never been attempted before.
Even if a removal and lifting of the reactor compartment were successful, the nuclear cores of the Kursk would have to be stored in safety. At present all Russia's on-shore storage facilities for spent nuclear fuel are full.
Another option is to leave the submarine with its two reactors on the sea-bed. It may be possible to seal the reactor compartments and minimise the risk of leakages. Russia has developed a special material to seal naval reactor sections, and Russian specialists claim this material can successfully seal reactor compartments for 500 years.
A last option would be to build a sarcophagus around the submarine, as was done with the Chernobyl reactor. The sarcophagus would probably be built of concrete, but other materials might also be used.
This solution is probably not a very good one, given the Chernobyl experience, where the sarcophagus showed leakages after only 10 years. Besides, this option would make it even more problematic and expensive to lift or work on the submarine and its reactors if future generations develop new methods and want to raise the wreck.
The Bellona Foundation is the Norwegian environmental agency whose area of expertise includes the Barents Sea
The environmental pressure group Greenpeace demanded yesterday that the Kursk be recovered from the sea-bed to prevent leaks of radiation. Greenpeace also called on all states with nuclear-powered vessels to withdraw them from service.
"If the Kursk is left on the seabed it is not a matter of if but when the reactors will leak nuclear material into the Barents Sea," Mr William Peden, the group's international disarmament campaigner, said.