Halibut Hangar

Decommissioned low level mixed waste² radioactive submarine reactor compartments, with defueled³ reactors inside await burial in the Department of Energy's (DOE) Hanford Site, Area 200 East, 218-E-12B, Trench 94.

The USS Halibut, SSN 587 reactor compartment is in the first row left, third compartment from the back (West) of the trench—the first small diameter compartment in that row (aerial view of Trench 94¹).

-----notes-----

1. The aerial photo shows Trench 94 has been filling up since the Dawson photo—today there are approximately 119 reactor compartments.

Since the Nautilus, SSN 571 our Navy has launched a total of 210 nuclear ships (some have more than one reactor) of which 128 have been removed from service. Thus, Trench 94 does not account for all naval ship reactor compartments (can you tell from the overhead image which reactor compartments are not from a submarine—hint - compare shapes).

It's possible for the reactor compartments to change positions, but Halibut's reactor compartment is believed to remain at its bottom row, third from left position.

The "dry cask storage" method for these sealed submarine reactor compartments and the reactors they contain is expected to effectively isolate the low level mixed waste decaying radioactivity for 600 years—continuous monitoring and measuring is required.

2. UPDATED 06/09/2009 Mixed waste is combine hazardous and radioactive waste.

The radionuclides of interest are: carbon-14, iodine-129, nickel-59, nickel-63, niobium-94, selenium-79, and technetium-99. Cobalt-60 is relevant but because of its relatively short half-life (5.27 years) is not of interest to long term burial (see EPA, Commonly Encountered Radionuclides).

The approximate dimensions (in feet) of Trench 94 is 200(w) x 1600(l) x 53(h). It contains 392 tons of lead (much in the form of reactor compartment shielding) as of 1995 (note: the trench may have been widened by 200 feet to the north to accommodate additional reactor compartments, not all from submarines).

3. UPDATED 06/09/2009 The core fuel (plutonium and decay chain product uranium) have been removed leaving an empty but still radioactive reactor vessel and compartment.