FAQ

1. How is nuclear engineering different from all other fields of engineering?

Nuclear Science and Engineering (NSE) is based on a fundamental discipline which is easily distinguishable from other forms of engineering. Namely we deal with nuclear reactions, i.e. originating with the nucleus of protons and neutrons, not from molecules/atoms.  In NSE we produce, manipulate and exploit the resulting radiation to provide useful applications for mankind. An analogy would be that a chemical engineer does the same thing by exploiting electron reactions in atoms/molecules. But because the energy density and radiation energy of nuclear reactions are million times larger than those of electrical/chemical reactions, it makes the discipline and applications very different.  This enormous “quantum” difference between the disciplines simply arises from the enormous jump in size between a nucleus and the atom, which contains the electrons.

Of course it is exactly this factor of millions which makes nuclear power so attractive. Nuclear energy requires millions of times less fuel per mass to extract the same energy as any chemical reaction, such as burning coal. This makes nuclear energy and science a very potent tool in fighting the environmental impact of burning fossil fuels.

2. Can nuclear engineering help other fields in a positive way, for example in medicine?

Absolutely. Nuclear Science and Engineering (NSE) has had an enormous positive impact on medicine and other fields. A perfect example is “Nuclear Medicine”: the special properties of nuclear radiation, as opposed to just “regular” radiation like visible light, allow it be used extensively in both diagnosing disease and treating disease. One of our faculty, Professor Yanch, is working on cutting-edge methods to improve radiation therapy. Many of our undergraduates end up studying and working in this field, and even use NSE as pre-med.

But the impact of NSE outside of energy production does not stop at medicine. NSE can be used for the development of advanced detection systems for national security. Quantum information and computing is another area of interest in NSE. Our faculty work in these areas too. Information on our faculty research activities can be found on our department website.

3. Coal, gas and oil, all of which are used to generate electricity, are limited resources. Wind and solar power, are good alternatives, but are not entirely dependable sources. Will nuclear energy be able to provide all the energy we need?

Right now nuclear energy from fission provides about 20% of the US electricity supply. And it could provide more. Approximately 80% of electricity in France, and 50% in Japan, is generated by nuclear power (and by the way France has the cleanest air in the industrialized world since nuclear emits no carbon or particulates from burning).

Wind and solar could and should increase, however, the wind and sun aren’t always there so probably cannot be used for so-called “base-load” electricity, i.e. the steady source of electricity you need to run an industrialized society. For non greenhouse emitting, base-load electricity, the present viable options are nuclear and hydroelectric (dams). But hydroelectric is set by geography and rainfall, and we’ve almost maxed out these sources. This is why nuclear power is SO important in our future energy plans.

The energy future of our nation and the world is complex. There is probably no single answer or “silver bullet”. But the fundamental science, i.e. that nuclear energy is million times more potent, always tells us that nuclear power will always be our most critical tool in decreasing the environmental footprint of the energy production we need for our economy and society.

4. I have heard that nuclear waste could contaminate our soil and the water we drink, thus threatening the health of human beings and other life forms. Are there scientists who are striving to solve these problems? If so how?

Yes there are scientists working on this problem, and several of them are in our NSE faculty. However it would not be fair to say that we are working on solutions: we have already technically “solved” the nuclear waste issue. This is obvious from the fact that we safely deal with these wastes from our present nuclear power plants. No people or other lifeforms are harmed by these wastes, and we know this because we keep very careful track of the wastes (unlike in burning fossil fuel where they more or less are just released into the atmosphere).

However there is ongoing research to improve the management of waste. There are many different approaches:

• change the type of reactor so it produces less waste;
• do something to the waste—like bombard it with other kinds of radiation—to transmutate it into less dangerous forms (i.e. change its elements into other elements);
• or come up with safer material forms and containers for the waste for long time storage.

In fact the word “waste” is not very accurate—almost all “waste” from a reactor is just unspent fuel. The most efficient solution would be to re-purify the fuel and put it back in the reactor. Even though this can be done there are other issues and implications to consider.

The most important thing to remember is that nuclear energy produces millions time less waste than other energy production, again because of its much larger energy density. One must respect this potency, but because the sheer volume of waste is so much smaller it makes handling the waste much easier.

5. Could you give other examples of energy research within nuclear engineering?

Several faculty work on a future source of nuclear power called “nuclear fusion”. In this nuclear power we “fuse” two hydrogen nuclei, rather than split apart large nuclei as in ‘fission’, which is what all present nuclear power plants work on. Nuclear fusion is the process that powers our sun and all stars in the universe. It has the advantage of producing non-radioactive helium as its waste product, further reducing issues about nuclear waste disposal.  Fusion is inherently safe since it does not run on a chain reaction and its physically impossible to get a “meltdown” accident.  And the fuel you use is water from which you get the hydrogen!! Sounds great! 

The problem is that it requires temperatures in excess of 100 Million Celsius, kind of like the interior of stars. Amazingly we’ve achieved these temperatures in our laboratories. We have a small test fusion reactor at MIT called Alcator C-Mod that achieves temperatures akin to this level, but there are several hurdles to overcome to make this fusion a practical and economic supplier of electricity, such as: confining and stabilizing these “stars on earth” and developing materials that can withstand the fusion environment. Not surprisingly, the disciplines of NSE are perfectly aligned to take on these multidisciplinary research areas and our faculty are heavily engaged in that research. This also provides an opportunity for NSE students, as undergraduates and graduate students, to engage in fusion energy research.

6. Can working with all these radioactive material be dangerous?

Radiation can be a hazard to human health; in fact one of the core subjects that we teach in NSE deals with this subject. This issue has to do with the fact that nuclear reactions, and therefore radiation, have very different properties than our everyday experience of radiation. However by using NSE science, the hazards of radiation are well known and avoided.

First, if you know the proper science, radiation is super easy to measure compared to biological or chemical hazards. Secondly radiation is easy to shield so your body doesn’t get exposed. Third, it turns out humans have quite a resilience to radiation since we evolved in an environment (the Earth) that is literally filled with radiation.  You may not be aware of this, but as you read this you are being bombarded by natural sources of radiation. So radiation turns out to be a relatively mild and known toxin for humans (but you should still respect it!).

7. What are some of the positive aspects of working in nuclear engineering?

One of the best things is that NSE is one of the most multi-disciplinary fields imaginable and you don’t get bored doing just one thing. Plus, you’re doing something practical to help the world.

8. How do you think nuclear engineers will impact the future?

Provide safe, carbon-free energy that will save the world. And exploit the fascinating and fundamental discipline of Nuclear Science and Engineering to produce amazing new products and inventions.