TREAT (Transient Reactor Test Facility) is an air-cooled
test facility designed to evaluate reactor
fuels and structural materials under conditions simulating various contingencies
in nuclear reactors. TREAT was used to study
fuel meltdowns, metal-water reactions, interactions between overheated
fuel and coolant, and the transient behavior of fuels for high-temperature
systems. TREAT's purpose was to simulate accident conditions
leading to fuel damage, including melting or vaporization in test specimens,
while leaving the reactor's "driver" fuel undamaged. In its steady-state
mode of operation, TREAT was also used as a large neutron-radiography facilitiy
and could examine assemblies up to 15 feet in length.
Construction of TREAT started in February 1958 and finished in
November of 1958. The reactor first achieved criticality on February 23, 1959. Major
reactor building addditions were made in 1963, 1972, and 1982. In 1988, the reactor
also underwent a major upgrade, which included installation of new instrumentation
and control systems, and refurbishment of the rod drive systems.
The reactor was operated from February of 1959 until April of 1994, generating over
720 megawatt-hours of energy.
The TREAT facility was very diverse in its abilities. Its easily accessible core
accomodated a wide variety of experiments. There was a wide variety of utility support,
neutron radiography
facilities, and plenty of room for experiment support equipment.
TREAT's computer and control system was designed so that it could simulate a "run" before
an experiment. This provided a check on the control system, and more
importantly, provided a high degree of confidence that the
transient would
run as planned with a high degree of reproducibility.
TREAT also included shielded viewing slots on two of the reactor faces. This feature
was a unique to TREAT. Both optical and gamma camera
systems were developed for use with these two slots, so that reactive
mechanisms taking place in samples could be recorded on film for detailed
study.
The overall condition of the facility is excellent. The
facility is radiologically clean and is free of industrial hazards. The
instrumentation and control systems are in excellent condition and have
been maintained in an operable status. The original TREAT fuel is still
in excellent condition and can be expected to remain in service indefinitely.
Some of the data acquisition systems are relatively old, and while they are fully
functional, they lack adequate vendor support.
Although the TREAT reactor was placed on standby status in 1994, the facility is
currently used for a variety of experiments. One area of interest is developing methods
for quickly determining the composition of various nuclear materials.