A nuclear waste dump in Arctic Russia may be in danger of exploding because of corrosion caused by salt water in enormous storage tanks, the Norwegian environmental group Bellona warned today.

A giant barge hauling the battered Kursk submarine pulled into waters of a Russian shipyard today, in the final stage of an ambitious salvage effort made riskier by the ship’s two nuclear reactors and missile arsenal.

A Dutch consortium on today began raising the Kursk nuclear submarine from the bottom of the Barents Sea, where it lay for more than a year following the explosion and sinking that killed 118 Russian seamen.