Evaluation Results cont'd

DOE-STD-3007-93

6.1.2.7 Tank D-2403 is limited to a total of 200 grams Pu and U235 in support of Building 374

waste transfer contingencies. Reference section 6.8 for this discussion.

6.2 Glovebox 2401 (GB-2401): GB-2401 is located in room 1105. It is constructed of stainless

steel with 0.25" lead and is nominally 17'long x 2.33'wide x 4'high. This glovebox contains a

pipe manifold which has fifteen nominal " ID inlet feed pipes (tie-points) from specific building

tanks joined to a nominal 2" ID header pipe, which in turn, is connected to a nominal " ID

outlet pipe to tanks D-2401 A/B/C/D and a separate nominal " return pipe from pumps P2401

A/B. Currently only tie point 45 (Process Support Tanks), tie point 46 (PROVE Vacuum Tanks),

Tygon-tubing tie point, and the outlet pipe to tanks D-2401 A/B/C/D are connected (reference

CWTS Solution Collection Process sketch in Appendix F). A vacuum pickup wand connected to

fulflo filter Fl-2403 (filter housing is nominally 3.75" ID x 10" H) for spill pickup and transfer to

tanks D-2401 A/B/C/D is also in this glovebox. Since the maximum credible concentration in

Building 371 is 150 g/l, thus meeting the concentration limit on the D-2401 A/B/C/D tanks, the

vacuum pickup wand may be used for spills both internal and external to GB2401. A standard

SG-508 criticality drain is installed in GB-2401, thus flooding above a two inch depth is

precluded.

In Appendix M it was shown that the cross sectional area of the equipment in GB-2401 is

equivalent to that of 7.82" diameter cylinder, which per TID-7016 is subcritical with nominal 1"

water reflection up to 300 g/l or twice the maximum credible concentration. Note that full

reflection of this cylinder would be at least double contingent since it would require the criticality

drain to clog and a source of liquid to fill the glovebox. Note that 3 used ful-flo filters were

included in the calculation to address the removal of ful-flo filters, as was a 3/4" ID tygon tubing

for direct draining of Building 371 tanks.

In reality, the fixed equipment in GB-2401 is well spread out and at least 12" off of the glovebox

floor. Thus it would contribute only negligible reactivity to items on the glovebox floor.

Accordingly, these items can be grouped together and evaluated separately. The total volume of

two 4.4 liter containers and 6 used ful-flo filters (each approximately 800 ml) was estimated at

13.6 liters. The total volume increases to 15.8 liters with the addition of a 2.2 liter container of

kimwipes used to collect spills. This volume is subcritical for the maximum credible concentration

of 150 g/l in an equivalent hemispherical volume with 1" of water reflection. As calculated in

Appendix O, a nominally reflected hemispherical volume of 20.2 liters is equivalent to a 10.5 liter

nominally reflected sphere, which is subcritical for a concentration up to at least 1000 g Pu/l.

Note that the hemispherical volume calculation was selected to more realistically envelope

available containers in the glovebox. Note that 6 used ful-flo filters were considered, as stated

above, with the solution containers to account for filters stored on the glovebox floor. It can,

thus, be concluded that one 4-liter container in GB-2401 is double contingent, as unlikely

contingencies of overbatch and extra container, together, are subcritical. The double contingency

argument for the 4-liter container clearly bounds contingencies of overbatch and extra container

for the 2-liter container of kimwipes due to its smaller volume.

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