Last week, our class visited Massachusetts Institute of Technology for a lecture and a tour of their nuclear reactor.  When we first arrived, we needed to present a government issued ID and were given a pen-like object that measured radiation exposure.  This was to make sure we weren’t being exposed to too much radiation while on the tour.  Before the tour of the reactor began, we had a lecture that lasted about half an hour.  The lecture was all about the reactor and its history.

MIT’s reactor was built in 1958 and was later upgraded in 1975.  The reactor is a 6 megawatt (MW) reactor, meaning it can produce up to 6MW of thermopower.  This is small in comparison to other nuclear reactors that produce far more. It could fit inside a trashcan!  The reactor is used for research and educational purposes only, although it produces enough energy to heat the buildings at MIT.  It operates constantly, except when maintenance is being carried out.  The reactor also has a two-loop cooling system and automatic relieve valves.  Should the cooling system fail, the water inside will begin to boil and evaporate.  Air will then forcefully shoot out of the “chimney” and outside.  The automatic relieve valve serves as a way for the reactor to release built up hydrogen that can become dangerous.  There is also no risk of a meltdown because not enough energy is produce and there are many safety features in place.  The reactor uses Uranium 235 (92 Protons and 143 Neutrons).  When an extra neutron is absorbed, the process of fission takes place.  This neutron splits into two and releases two or three neutrons.  This keeps the chain reaction going.  Once the neutron splits, the “glue” that was holding it together get turned into energy.  To absorb these extras, boron is used.

After the lecture we went on the tour of the reactor.  Before we went on the tour we were told cell phones, bags, and gum were prohibited and anyone who had recently undergone radiation therapy was not advised to participate in the tour.  To get inside, we first had to go through a chamber that slightly changed the pressure.  The place where the reactor is located is large, even though the reactor itself is small.  We saw the many different things that occur inside of the facility, which was very interesting.  Before leaving the facility we had to be checked for radiation.  First we had to step onto a machine and place our arms through slots on either side of a screen.  The machine would then tell you if you were “clean” and you could exit.  Then, there was another machine where our hands and shoes were scanned.  After that we retuned the pens that record how much radiation we were exposed to.  Overall, the lecture and the tour of the MIT research reactor were very informative.