Release Estimation - h3010v10305

DOE-HDBK-3010-94

7.0 Application Examples; Dry Processing Line Example

fluoride. The hydrofluorinator operates over a temperature range of 400 oC to ~ 600 oC.

Both the calciner and the hydrofluorinator are electrically heated.

64% nitric acid is directed to a scrubber in the calcination glovebox to dissolves entrained

plutonium oxide from the calciner offgas. This solution is collected in a 100-l slab tank

similar to those in the dissolving lines for recycle as ion exchange feed. Hydrogen fluoride

is metered on the second floor to a flowrate of ~ 1 scf per minute. 30% potassium

hydroxide solution is added to the offgas scrubber in the hydrofluorinator scrubbing glovebox

to neutralize the excess hydrogen fluoride. Process air enters both the calcining and

hydrofluorinating glovebox lines at 0.24 MPag (35 psig). Dry process air provides internal

glovebox ventilation flow at 0.21 MPag (30 psig) for the calcination glovebox and 0.14 MPag

(20 psig) for the hydrofluorination glovebox.

The internal sheath of the calciner rotates during operation to ensure even heating. This

rotation is driven by a hydraulic unit mounted in the floor of the glovebox. The hydraulic

fluid used has a flammability rating of 1, which means "materials that must be preheated

before ignition can occur. Materials in this degree require considerable preheating, under all

ambient conditions, before ignition and combustion can occur" (NFPA 704). Materials such

as this are classified as Class IIIB combustibles, the lowest hazard rating available.

The similar rotation in the hydrofluorinator is driven by an all-electric unit that replaced the

hydraulic unit 5 years ago. The hydrofluorination glovebox is also not normally visible from

the operating room. Due to the high neutron density associated with the interaction of alpha

particles and fluorine, the entire operating side is shielded by a large, Benelex wall with

sliding cabinet doors to allow access. Other than windows, the actual surfaces of the

glovebox are equipped with such shielding as well. This material is supposed to be painted

with an intumescent paint to prevent it from serving as a source of fuel to initiate a large

fire.

7.3.7.2

Release Estimation

The major energetic phenomenon of concern for the "dry" line is a large fire.

A. Large Room Fire. Plutonium in a damp or dry powder configuration is the

primary material-at-risk in the calcining and hydrofluorination gloveboxes. Rounding

upward, approximately 23,000 g of plutonium as plutonium peroxide can be stored in

the 10 receipt storage positions available. Between 2 and 4 kg of predominantly

plutonium oxide could be in the calcining vessel at any one time, with the 4 kg upper

limit based on the size of the vessel. If this amount of material is assumed, it must

be subtracted from the amount considered stored. A complete operating cycle up to

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