Reprocessing U.S. Reprocessing?

The entire energy industry's eyes are watching the success of the nuclear industry in France.  In case you haven't heard, France generates roughly 80% of its power via nuclear power.  Many nuclear advocates strongly want to follow France's design to make nuclear power a majority producer in the United States.  If you talk to someone who supports this, one of the first subjects that will come up will be nuclear fuel reprocessing, a popular subject around nuclear power for the last thirty years.  For those of you that have been asking me about this subject, here is what I can gather about it.

First, lets start by exploring what the reprocessing of nuclear fuels means.  Remember that nuclear reactors work due to fission.  When an atom undergoes fission, it is split into two smaller pieces which are known as fission fragments.  Common fission fragments are strontium-90 atoms and cesium-137 just in case you were curious.  So what does this mean?  Well, though these fission fragments are radioactive, they do not undergo fission.  In fact, many of them form what are known as nuclear poisons which cause the reactor to stop undergoing fission.  When fission stops, the reactor does not create heat to create power.  These are therefor a large performance inhibitor.  Nuclear poisons kind of act like dust on old CRT televisions.  As you watch television, the static from the television causes dust to stick to the screen and make it harder to watch television with clarity.  After a while, you have to clean the screen in order for the television to get back to is full operating potential.  In this way, it is often the nuclear poisons that cause a fuel to be considered "spent," at which point the reactor is refueled and the spent fuel is sent to storage.  Not all of the fissionable material has undergone fission though when this is done.  New reactor fuel usually contains about 3-4% of uranium-235, which is the fissionable element in the reactor.  When the fuel is spent, only about half of the uranium-235 has been burned up. 

This is where reprocessing steps into play.  By chemical processes, the leftover fissionable products can be taken out of the spent fuel and recycled into new fuel.  It turns out that the reactor also makes fissionable plutonium during the operation (about 1-2% of the fuel becomes plutonium), and this too can be extracted during the reprocessing of the fuel.  The plutonium is important for other types of reactors known as breeder reactors, but I will talk about them more in the future as they are quite important for the future of power generation.  But to sum it up, reprocessing enables us to burn up the fuel more completely so that we are not just throwing away half of the power production capabilities of the Uranium we pull out of the ground.

So now you are wondering why there is so much controversy over this issue because it sounds like a good idea.  But there are some issues with the reprocessing of nuclear material.  PBS did a great article on Frontline summing up the arguments of the reprocessing debate.  I suggest that you read the article to get a clear picture of the situation, but I will try to address the important parts of the article.

Two words have been very prevalent in American culture since the beginning of the Cold War:  nuclear proliferation.  These were the two words that killed the reprocessing of nuclear materials in the Untied States.  It was nuclear proliferation that caused Jimmy Carter to stop reprocessing within the United States in 1977.  When nuclear material is reprocessed, pure forms of uranium-235 and of different isotopes of plutonium are yielded.  It was proven by U.S. physicists that the plutonium from the reprocessing could be used in an explosive device.  Because material that can be used for weapons is obtained by the reprocessing of nuclear materials, Jimmy Carter decided that is would be best to make an example to the world and not reprocess, thus preventing nuclear weapons being generated by nuclear power.

The creation of weapons from the material created by reprocessing is not so simple though.  The yielded Plutonium is a mix of different types of plutonium.  As it turns out, not all types of plutonium are good for weapons.  The heavier isotopes of plutonium (240 and 241) are strong neutron absorbers and cause the weapons to be unstable and yield unpredictable powers.  When I say this, I don't mean that they are more dangerous, but less as they often do not go off or are small explosions when they do.  Remember, it is very tough to build a nuclear weapon.  This means that nuclear proliferation was a bad excuse for canceling of fuel reprocessing in the United States.  Why would a nation want to use an unpredictable fuel in weapons that involve such a great investment.  When a country develops a nuclear arsenal, they have to not only design and build the weapons, but also gain the trained manpower to operate and maintain the arsenal as well as develop the policy that goes along with such power.  Bad material for the weapon is not a risk that a country would take when investing so much.  There are ways to develop much more reliable fuel.

On the other hand, today we have another threat in terrorists that don't have such investment.  But we must also keep in mind that reprocessing of nuclear material is not easy to conceal.  Also, the spent fuel is an internationally regulated substance which they would have to get a hold of in order just to put through expensive reprocessing in order to build an unreliable weapon.  Unfortunately there are cheaper, more easily concealed, and more reliable methods to obtain weapons grade nuclear material out there.

The other side of the argument is more intriguing to me.  Critics say that the reprocessing of nuclear materials is not economical when it comes to yielding more fuel for the reactors or for reducing the cost of storing the spent fuel.  In other words, reprocessing is expensive, and it is.  I will defer talking about the waste part of the debate until later since I plan on doing a lot of discussion in the future on the subject.  But the economics of nuclear fuel is interesting.

If you guys have been following on my previous articles, especially my posts on uranium exploration, you already know that fuel is not a large expense for the production of nuclear power.  The price of the fuel can increase greatly, but the increase will not affect the price the consumer pays for the power.  So it is not really that the reprocessing of nuclear material is not economical, it is just that it is currently much cheaper to mine the uranium we need for the reactors.  We can pull it out of the ground cheaper than we can pull it back out of the spent fuel.  This will not always be the case though.  At some point, the unburned fuel sitting in the spent fuel rods will be of high enough value that we will want to reprocess the material.  This makes it a good thing that all this spent fuel will continue to lie around at the plants so that it is there when we need it.  It helps with the waste issue just a little, but I will talk about that later.

So today, it is still against U.S. policy to reprocess nuclear material.  This is alright with me though since our uranium reserves are so large.  It is not that we can't reprocess like France does that is killing nuclear power in the United States.  The industry has bigger problems at the moment to worry about.