The Fission Process
The MIT Research Reactor
produces heat in addition to neutrons. In a power reactor, heat
would be converted through steam into electricity. In the MIT Reactor,
the 5000 kilowatts of heat is produced at a temperature so low (50
degrees Celsius -- about the temperature of warm bath water) as
to be useless for the production of power. The heat is carried away
via heat exchangers and a secondary water system to cooling towers.
The water that
flows through the core, in addition to being a moderator essential
to the operation of the reactor, also serves as a coolant (see The
Fission Process for more). It circulates in a closed "primary"
loop from the core to the heat exchangers and back to the core.
The heat produced in the core is transferred to the water which
is called the "primary coolant." In the heat exchangers,
water in a "secondary" loop picks up the heat and carries
it to the cooling towers outside the reactor building and dissipates
it in the air. Because the secondary water does not come in contact
with the primary water or with the reactor core, it carries no radioactivity.
The MIT Reactor has over
twenty area and effluent radiation monitors operating continuously
to provide an indication of radiation levels at various points both
inside and outside the reactor. Several of these monitors take automatic
actions, such as automatically sealing off the containment building
ventilation, should they detect abnormal radiation levels.