The Reactor at MIT

The MIT Reactor (MITR) is the major experimental facility of the NRL. It is a light-water cooled and moderated, heavy-water reflected, nuclear reactor that utilizes flat, finned, aluminum-clad plate-type, fuel elements. The average core power density is about 70 kW per liter. The maximum fast and thermal neutron flux available to experimenters are 1.2x1014 and 6x1013neutrons/cm2-s, respectively. Experimental facilities available at the MIT research reactor include two medical irradiation rooms, beam ports, automatic transfer facilities (pneumatic tubes), and graphite-reflector irradiation facilities. In addition, several types of in-core experimental facilities are available. MITR generally operates 24 hours a day, 7 days a week, except for planned outages for maintenance. The MITR encompasses a number of inherent (i.e., passive) safety features, including negative reactivity temperature coefficients of both the fuel and moderator; a negative void coefficient of reactivity; the location of the core within two concentric tanks; the use of anti-siphon valves to isolate the core from the effect of breaks in the coolant piping; a core-tank design that promotes natural circulation in the event of a loss-of-flow accident; and the presence of a full containment. These features make it an exceptionally safe facility.

Building the Reactor

Check out the video below to see how the MITR-I was constructed back in 1956! The core was upgraded in 1974 but the containment dome and other structural elements remain the same.