SnowLeopard

That's sort of correct .................. and sort of not correct.

First of all, this link can give one a pretty good start of sinkings and other incidents, ship wise:

en.wikipedia.org/wiki/Nuclear_marine_propulsion

Of course, it does leave out the US boat that sunk during construction and the Palomares (sp?) incident, but the former wasn't a reactor accident and the latter was a nuclear bomb in deep water that was recovered.

But about the surface ship icebreaker Lenin: essentially, Lenin supposedly suffered a reactor accident around 1966. The damage reactors were dumped in locations in the Kara Sea.

See: Energy Citations Database (ECD) - Sponsored by OSTI

AND the first NY Times article

Further, the accounts of Soviet naval nuclear material dumping makes quite interesting reading and in some ways, makes the loss of operation submarines like the Mike boat and K-219 compartively minor.

See: The New York Times:

"Soviets' Secret Nuclear Dumping Causes Worry for Arctic Waters; Wastes From Vessels Discarded for 3 Decades Secret Nuclear Dumping by the Soviets Is Raising Fears for Arctic Waters"
By PATRICK E. TYLER Special to The New York Times. New York Times (1857-Current file). New York, N.Y.: May 4, 1992. ; p. A1 (2 pages)

"RUSSIANS DESCRIBE EXTENSIVE DUMPING OF NUCLEAR WASTE; DISPOSAL ON OCEAN FLOOR Government Says 18 Reactors Went in the Sea as Rules Were Often Violated Russians Describe Dumping of Nuclear Waste Moscow says it has not checked the dump site of 16 reactors."
By WILLIAM J. BROAD. New York Times (1857-Current. Apr 27, 1993. ; p. A1 (2 pages)

Finally, this site might provide one with nights of interesting reading:
Energy Citations Database (ECD) - Basic Search
------------------------------------------------
("Hell No, we won't glow! Hell No, we won't glow! Hell No, we won't glow!"--protesters outside a nuc power plant demostrating, (wtte))