Minimum Required Free Gas Volume per Kilogram

DOE-STD-3013-2000

is correspondingly reduced and the pressure decreases. The maximum pressure occurs at the

bulk density at which the convenience can is just full. In this case, the maximum bounding

pressure is 690 psia, or 675 psig. Note that this particular model demonstrates compliance with

Criterion 6.3.2.3 for all material densities and would eliminate the need to measure density or

determine free gas volume. The development and use of such a model will be governed by the

Quality Assurance program applicable to the packaging site (and acceptable to the storing site)

in terms of regression coefficients and confidence levels.

B.3.4.4

Minimum Required Free Gas Volume per Kilogram

Assume now that we wish to find the minimum required free gas volume of a container holding

1 kg of material that has a heat generation rate of HS w and a moisture content of 0.5 wt%.

The other parameters are as assumed before, except that an evaluation temperature of 211C

will be used, representing a configuration in which the storage package is in a 9975

transportation package in the sun. The resulting pressure is required to be 714 psia (699 psig).

714 = 23.2 + 0.67*1*0.5*484/Vmin + 7.517x10-5* HS *50*484/Vmin

After rearranging, the equation becomes

-5

Vmin (714-23.2) =.67*1*0.5*484+ 7.517x10 * HS *50*484

V1 = 0.2348 + 0.00263HS l.

Based on the previous example, the worst case

Table B-4

is when the maximum loading just fills the

Minimum Free Gas Volumes

innermost container. For that case, HS will be

FGV*

SHGR

Vmin

l/kg

w/kg

19/5, or 3.8 w/kg oxide, and Vmin will be 0.246 l

4.3

0.246

1.230

per kilogram of material, or 1.230 l for the 5 kg

5.4

0.249

0.996

loading. Table B-4 provides results for other

7.2

0.254

0.762

heat generation rates. In each case, the limiting

10.8

0.263

0.526

combination of heat generation and mass

21.5

0.291

* FGV is the minimum container free gas

loading are used to determine the total free gas

volume for the mass loading indicated

volume required. For the BNFL container

system, a free gas volume of 0.996 l

corresponds to a density ratio of 0.656, which is larger than density ratios observed in the shelf

life items. That, in turn, implies that such a value is conservative. For simplicity, a value of 0.25

is used in the Standard.