Missouri’s First Nuclear Reactor

Our reactor plays a vital role in the education and training of the next generation of nuclear professionals. It is used by Missouri S&T faculty and students for research projects and hands-on learning experiences in a variety of fields, including nuclear engineering, radiation protection, and materials science.

In addition to its research capabilities, the Missouri S&T Nuclear Reactor also serves as a valuable educational resource. Students at the university have the opportunity to learn about nuclear science and technology through hands-on training and laboratory projects, as well as the possibility to become an officially licensed reactor operator. These programs give students a competitive edge in their careers.

Along with the programs and opportunities given to the nuclear engineering department, MSTR provides similar facilities and assistance to other departments at S&T as well as other colleges around the world through onsite tours and distance education technology. This, coupled with tours for pre-college institutions and individuals, and several camps hosted by S&T throughout the summer, creates an environment to constantly learn about Nuclear Engineering and how it affects our daily lives.

Explore Nuclear Engineering

Basic Physics

Our reactor operates on the principle of nuclear fission, an event that occurs when a nucleus (the heart of an atom) is struck by a neutron and splits (fissions). A fission event releases daughter products, more neutrons, and a host of other particles in addition to a significant amount of energy. Fission most easily occurs in fissile materials, such as Uranium-235 or Plutonium-239.  Because additional neutrons can be produced during fission, these neutrons can, in turn, cause other fission events in the surrounding fuel, leading to a chain reaction.

Most of the resulting energy from fission goes into the daughter products, which slam into surrounding materials, creating heat. While the MSTR does not utilize this heat for electrical production (it doesn't produce enough heat), a nuclear power plant will use the heat to boil water into steam, turn a turbine, and generate electricity.



Control of nuclear reactions in our core is achieved using four Control Rods. Three of the control rods are safety rods, made of stainless steel containing natural boron which is a strong neutron absorber. These rods are used for a coarse reactor control and safety shutdowns, or "scrams". The fourth rod, called the Reg Rod, is made of just stainless steel and provides fine power control. It is connected to an autocontroller, which, when activated, automatically stabilizes the reactor power to a set value.

Nuclear FAQ

At full power (200 kilowatts), the MSTR core produces approximately 6.4 trillion fissions per second. Each fission event creates a tremendous amount of energy, a portion of which is carried away by fission products which then decay and produce high-energy beta particles. Often, these beta particles are emitted with such high energies that their velocities exceed the speed of light (300 million meters per second) in water. When this occurs, photons, seen to the eye as blue light, are emitted and the reactor core "glows" blue.

While no particle can exceed the speed of light in a vacuum, it is possible for particles to travel faster than light in certain mediums, such as water. The speed of light in a particular medium, v, is related to the speed of light in a vacuum, c, by the index of refraction, n, by v = c/n. Water has an index of refraction of 1.3, thus the speed of light in water is only 230 million meters per second. Therefore, beta particles with kinetic energies of 0.26 MeV can travel at speeds higher than that!

When a charged beta particle moves through water it tends to "polarize" (orient) the water molecules in a direction adjacent to its path, thus distorting the local electric charge distribution. After the beta particle has passed, the molecules realign themselves in their original, random charge distribution. A pulse of electromagnetic radiation in the form of blue light is emitted as a result of this reorientation. When the speed of the beta particles is less than the speed of the light in water, the pulses tend to cancel themselves by destructive interference; however, when the speed of the beta particle is greater than the speed of light in water, the light pulses are amplified through constructive interference. The phenomenon is analogous to the acoustic "sonic boom" observed when an object exceeds the speed of sound in air.

The intensity of the blue glow is directly proportional to the number of fissions occurring and the reactor power level. This property is utilized in Cerenkov detectors that measure the magnitude of Cerenkov radiation produced in a detector made of Lucite. Cerenkov radiation becomes visible in the MSTR core at a power of about 6 kW. At 200 kW the core glows brilliantly with a soft blue glow. The blue glow continues for some time after the reactor has been shut down due to the decay of fission products.

Our reactor uses the water in the pool as the main method of shielding against radiation. With over sixteen feet of water between the core and anyone in the reactor building, it is perfectly safe to be in the reactor bay to see the core, even at full power. Our main concern for radiation deals with our staff, who often handle radioactive samples and spend over 40 hours a week inside the reactor. Interestingly enough, at most times, our Chancellor’s house is more radioactive than our reactor building. This is due to the fact that the marble in the Chancellor’s house comes from a mine where trace amounts of Uranium and Thorium are present.