control room with operator outside picture of the MIT reactor view of the reactor from above
On Monday, our class was lucky enough to be able to tour a research nuclear reactor on the MIT campus. I was surprised at how simplistic the building was when I first arrived, but what went on inside, was anything from simple. When we first got there safety was of the upmost concern and we were given radioactive trackers to make sure that their levels did not increase after we left the tour of the plant. Our tour guide started off by explaining how the reactor functioned.
The core of the reactor has fuel in the center and is the size of a 30 gallon trash can. It is 1 of 2 in the country that is HEU based but is going to be changing over to LEU soon. There are 2200 gallons of water pumping through every minute to cool the fission and lower the energy taking place. There are also D20 reflectors that scatter and bounce back into the core. 6 boron/stainless sleel blades expose the fuel to the reactor around it. With this, borons absurb the neutrons formulated and remove the harmful chemicals within. If the reactor were to reach the super critical point, power would be greatly increased to stable the fission.
The reactor is generally kept at 50 degrees Celcius and the captured heat goes to the secondary system into the cooling towers with large fans and evaporation equipment are used to where the temperature drops to 30 Celcius.
The whole point of this specific MIT reactor is to make radiation for research purposes. From a saftey precaution, it is designed to keep water from boiling around the aluminum and is inspected every 6 months to make sure that the core is not blocked. Design flaws do happen which was the case with Fukushima where there wasa decay in chain energy being produced and the backup reactors were destroyed by the Tsunmai ocean wall. Here at MIT they have natural convection valves so that water can not get past is and as horrific as Fukushima was, it was a learning and research case for reactors all over the world in the hopes that a disaster of this nature will not happen again. Since the MIT reactor looks to research there is a tube in the core made of an alumninum dummy and they can project how the material will be damaged with the release of neutron damage.
There is a misconception between radiation and contamination which our tour guide explained. Radiation is the energy coming off of the radioactive particle, and the particle is the contamination. The particle can be looked at as metaphorical radioactive “weeds” and radiation is the grass that it is grown on and the contamination is not wanted. To keep all systems acting appropriately, refueling occurs within the reactor. Surrounding the core, there is static and neutrons that change over time so refueling occurs every 2 to 3 months to shuffle the fuel. To asist is absurbing neutrons, cadmium is used.
From a safety standpoint, steel and lead is used to protect reactor workers from radiation contamination and they are allowed 5 REM of contamination a year. Various research projects are being utilized at the MIT reactor and one of them previously was brain cancer research where patients who were terminally ill were given doses of radiation from the neutron beam and showcased 6-8months more life in many cases. Prostate cancer was also tested on and gold was placed in the body to irradiate tumors in the specific area and the decay was about a 2.5 day half life.
Overall I got an amazing impression for those individuals who work at the reactor. Safety was the top of the list and I got to step on a radiation contamination detector which not many people can say, and saw that the depths of scientific discovery are endless and we owe these people great thanks for providing us with energy sources and even possibly curing diseases in the future.
source: tour guide MIT representative
