My latest at the National Interest looked at the loss of K-8, a Soviet November class submarine:
The Bay of Biscay is one of the world’s great submarine graveyards. In late World War II, British and American aircraft sank nearly seventy German U-boats in the Bay, which joined a handful of Allied and German subs sunk in the region during World War I. On April 12, 1970, a Soviet submarine found the same resting place. Unlike the others, however, K-8 was propelled by two nuclear reactors, and carried four torpedoes tipped by nuclear warheads.