7.3.2 Precipitation in GB-18 is controlled by procedure 4-U84-CO-6090.
7.3.3 Manual valves MV-24401 and MV-24527 are closed when clarifier columns T2411 A/B
are filled, per section 7.1 of procedure 4-U84-C0-6090.
7.3.4 Operations order or procedure requires fissionable liquids to be characterized as less than
150 g/l Pu before acceptance by Bldg 371 Operations for processing.
7.3.5 Bag-in procedures require bag-in bags to be secured such that fissionable liquids cannot
accumulate within them when unattended.
7.3.6 Procedure 4-U84-CO-6090 is to provide instructions that precipitate from only one
processing "run" is to be placed into any single pan.
7.3.7 Procedure 4-U84-CO-6090 is to provide instructions that each column is to be adjusted to
a volume of 20 liters or less before Magnesium Oxide is added for precipitation.
7.3.8 Procedure 4-U84-CO-6090 does not allow bottles of caustic liquid from other facilities
without approval from Building 371 Operations and can only be introduced into the system if the
receiving tank is empty.
7.3.9 Procedure 4-U84-C0-6090 requires inlet to tanks D-2401 AIB/C/D to be valved closed if
greater than four liters of caustic liquid is in any glovebox or room which drains to CDS "A". A
tank may only receive these liquids if it is empty and isolated from the other tanks.
7.4 Other Administrative Controls
7.4.1 Valve MV-24425 is closed and locked out per HSP-2.08.
SUMMARY AND CONCLUSIONS
The Caustic Waste Treatment System (CWTS) is comprised of tanks and equipment of
geometrically favorable dimension which have been demonstrated subcritical for fissionable
solutions well in excess of historical and future generated process liquids in Building 371. In
addition, the processing of liquids from other facilities characterized as less than 150 g/l Pu +
U235 are bounded by the controls and safety basis in this evaluation. Waste transfers to Building
374 are conducted using multiple samplings by several independent organizations and interim tank
transfers. The activities associated with direct draining of tanks, CWTS operations, and waste
transfer to Building 374 are accordingly double contingent.