ORNL-4191 - the Molten Salt Energy Technologies Web Site

25. Modifications to MSRE Fuel Processing Facility
In order to keep reactor downtime to a minimum
during the next planned shutdown, it has been pro-
posed that the flush and fuel salts be processed
with a minimum decay time.
for Short Decay Cycle
K. R. Lindauer
1. A deep-bed backup charcoal trap downstream
of the existing charcoal canisters. These
traps will be tested under simulated operating
conditions to demonstrate at least 99.998% re-
moval of I.
IJroblems anticipated because of the short decay
are due to the much larger amount of 1311 and to
the radiation level at the UF6 absorbers because
of coabsorbed ‘’Tvlo. The processing schedule,
with pertinent radiation information, is given in
Table 25.1. Design of modifications to the MSRE
2. An activated alumina trap downstream of the
SO2 system for excess Eluorine disposal.
This will prevent fluorine from releasing iodine
on the charcoal beds in case of a malfunction
of the SO2 system.
fuel processing facility is in progress to permit 3. Shielding and revised handling procedures for
safe operation at these increased activity levels. removal of the loaded UF6 absorbers from the
These consist of: absorber cubicle.
Table 25.1. MSRE Processing Schedule and Pertinent Radiation Levels
1311
Decay Required Removal
Operation Time Curies in Charcoal
(days) in Salt Traps*
(“I)
H,-WF treatment 6 600 99.9s
of flush salt
Fluorinat-ion of 18 210 99.88
flush salt
H2-HF treatment 28 23,000 99.999
of fuel salt
Fluorination of 35 12,000 99.997
fuel salt
aFor 0.3 curie release.
251
Uranium
to Be
Volatilized
(kg)
7
230
Radiation Dose Rate
2 ft from Absorber
(millirems /hr)
620
170