1. Too many containers/material 1. Limited to three 2" deep
pileup from seismic activity, etc. pans, two 1-liter containers,
and three used filters.
Operations are also only
performed by specially trained
process specialists, i.e., Core
2. Fissionable material
2. It would be unlikely for the
following barriers to
a. Only precipitate from one
"run" per pan.
b. Clarifier columns limited to
a maximum of 25 g/l
c. Fissionable liquid
concentrations known before
blending in tanks D-2401
d. l-liter containers limited to
a maximum of 1000 grams
e. Process design results in
clarifier column operating
volume less than 20 liters.
3. Criticality drain.
Tanks, equipment, and waste transfer activities involved with the CWTS are shown double
contingent as follows.
6.1.1 SAT Design: SATs were designed at RFETS for the critically safe storage of large
volumes of high-level fissionable solutions. The design consists of a nominal 3"annular tank
surrounded on both sides by shielding composed of a 2.5" annulus of polyethylene sandwiched
between two 1/8" annual nuclear poison regions. This shielding is fully encased by stainless steel
to assure its integrity and as a fire barrier. Reference figure 1 for a cross section view of a SAT.
Note that the robust nature of the cladded shielding precludes loss of the poison/moderator
regions, such that further verification of those regions is not required. Note also that no corrosion
of the shielding is observed.
Various monte-carlo computer calculations (KENO analyses, reference Appendix G), were
performed in support of SAT design. The shielding uses a polyethylene moderator to thermalize