Tank Farm

DOE-HDBK-3010-94

Appendix B; Plutonium Recovery Facility

flow of heated acid, the reaction rate in the spray chamber, and thus the rate of

hydrogen production, will decrease rapidly.

When dissolution is complete, the product solution is diverted into a 150-liter

accountability slab tank. The spray chamber slab tank is then filled with 4% nitric

acid that is recirculated through the spray chamber to passivate hydride if any is

formed due to errors or unforeseen circumstances. This solution is then diverted to

the accountability tank as well. Residue material is removed from the spray chamber

and packaged for transfer from the facility. If any hydride is found, it is placed in a

small milliliter plastic bottle with 4% nitric acid to keep it wet and passivated. A

small portion of this material is transferred to the lab annex for assay and then

returned to the oxide dissolution line, where it is added to the dissolver along with a

special reduced oxide charge.

Before sampling and transfer out of the glovebox, 35% nitric acid is added to the

accountability tank for additional cooling and to raise the acid concentration. An in-

glovebox sampling system is used, and a gear pump is again used to transfer the

product solution to tank #5 or #6 in the tank farm. There, 35% nitric acid and a

limited amount of 64% nitric acid are added to reduce plutonium concentration to the

range of 5 to 7 g/l and increase acid concentration.

The slab tanks have mechanical agitators, purge and chemical addition lines, always

open vessel vent lines, and blowout plugs. Temperature and level indication are

provided for both vessels, and pressure indication is provided for the spray chamber

slab vessel. Installed detectors monitor plutonium holdup in both lines. Temperature

indication for the steam heat exchanger is available as well. The sump level interlock

stops major chemical addition to the glovebox as in all liquid processing gloveboxes.

2.2.2.3 T an k F arm

The tank farm consists of three separate enclosures containing annular storage tanks for

process plutonium solutions and waste. There are a total of 21 tanks in the tank farm, which

is located on the maintenance side of the wet processing line. It is placed there so the

potential for tank leaks exists in only one maintenance room as opposed to multiple rooms or

operating rooms. An additional advantage of placement in this room is immediate proximity

to the sample glovebox, which minimizes the length of sample piping runs.

The tank farm enclosures are stainless steel rooms designed for ease of cleaning in the event

of contamination from leaks. These enclosures are equipped with small exhausters leading to

the room exhaust header to maintain them at a slight negative pressure with respect to the

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