Source Term cont'd - h3010v10298

DOE-HDBK-3010-94

7.0 Application Examples; Liquid Storage and Ion Exchange Examples

For the purposes of example, five separate source terms will be calculated. The first

will be a bounding initial source term for the example facility. The second

calculation will provide perspective on the potential conservatism of that answer. To

demonstrate use of all ARF x RF values and correlations for the flashing spray

release, the remaining calculations will assume that the ion exchange columns are

made of steel instead of Pyrex. The third and fourth calculations will be for normal

and abnormal operations using the largest bounding flashing spray value provided in

this handbook. The final calculation will use the flashing spray release empirical

correlation provided in subsection 3.2.2.3.3.

The Pyrex ion exchange vessels in the example facility will fail at pressures below

0.69 MPa (100 psia). Therefore, the maximum flashing spray ARF x RF is 6E-3,

which is less than the burning resin value of 1E-2. Therefore, the largest source term

will occur if the exotherm happened with all plutonium absorbed on resin. The

bounding source term would occur if the loading cycle was complete and the

exotherm initiated during the resin wash cycle. The exotherm in one column leads to

a rupture and subsequent resin fire on the glovebox floor. If the fire is not

suppressed and the majority of the resin burns, the heat generated leads to subsequent

failure of the other resin columns. If the DR is assumed to be 1.0, a very

conservative assumption, the source term is:

6500 g * 1.0 * 1E-2 * 1.0 = 65 g.

The potential conservatism of the assumption that all resin burns is obvious, as the

source term would decrease in direct proportion to whatever amount of resin less than

100% is assumed to burn. A different configuration would also reduce the source

term. For example, assume the exotherm occurs during the loading cycle after

1000 g is loaded onto resin. It will be assumed that the columns are being operated

abnormally (i.e., no loading on column 1) so that a total of 266 g of plutonium is

available in solution. The exotherm occurs in column 1, leading to eventual

exotherms in the remaining two columns as before. However, to maximize release, it

could also be assumed that the glovebox pump remained on. If a new oxide

dissolution feed tank had just been lined up to the pump before the incident, another

1322 g of plutonium solution can be pumped into the glovebox before the tank runs

dry. This material will spill and boil from the heat of the fire, with a combined ARF

x RF of 2E-3 (subsection 3.2.1.3) (Note: This assumption would require failure of

the sump level-pump interlock). The source term for this situation is:

(6500 g * 0.15 * 1E-2 * 1.0) + (6500 g * 0.04 * 1E-2 * 0.6)

+ (6500 g * 0.2 * 2E-3 * 1.0 ) = 13.9 g.

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