Our trip to MIT’s reactor in cambridge was very interesting. However, it took me a little bit of time to get there, since I have decided to meet the rest of the class inside of the facility. First thing they asked us to do is to attach a simple metal device that could measure the amount of radiation that we might get exposed to from being inside of the laboratory. Thankfully they were running some maintenance inside of the facility so everything was on shutdown. We learned a lot about how does those kind of reactors work and how to maintain their safety.
The MITR-II, is the major experimental facility. The average core power density is about 70 kW per liter. And what making this facility a safe one is as the following:
- The use of anti-siphon valves to isolate the core from the effect of breaks in the coolant piping.
- Having the core located within two concentric tanks
- The design of the core-tank that promotes natural circulation in the event of a lows-of-flow accident.
- Negative reactivity temperature.
The fission process in the nucleus of each atom of Uranium-235 fuel are 92 protons and 143 neutrons. And 92 electrons around the nucleus, which are smaller particles. Fission is when nucleus absorbs an extra neutron, it breaks into two parts or splits. Every time they split, it releases two or three neutrons. The primarily use of the MIT research reactor is to produce neutrons, having neutrons traveling at a very high speed within the core. There are six control blades of boron-stainless steel that control the uranium nuclei, which they are inserted vertically alongside the fuel elements. In order to operate the reactor, we have to slowly raise the blades, so they absorb very few neutrons. Until it reach enough neutrons that causes the split of uranium nuclei, and then sustain a chain reaction. Another essential factor to operate the reactor is the moderator coolant. Which is very important since uranium nuclei do not readily absorb neutrons that moves really fast, which they leave fissioning nuclei. It is essential to slow them down with a moderator. And because of this problem about one-half the volume of the reactor’s core contains water.