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Tag: atomic energy

Why don’t nuclear reactors go kaboom? A reactor kinetics primer part – 1

Nuclear reactors contain tons of fissile material and nuclear bombs contain only kilograms of fissile materials, so why does one of them explode with enough force to flatten a city but the other doesn’t? I will pull out some latex skillz and geek it out with equations to describe the physics behind whats in nuclear engineering is called reactivity excursions or RIA (Reactivity Insertion Accident). The level of these blog posts will be such that an interested and fairly math savy person can understand and calculate these kind of things on their own.

Castle Romeo photo: United States Department of Energy, Source: Wikimedia

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Visit to Marviken

Sometimes the NPYP bunch tires of being rough on the roughnecks and decides to leave the jungle headquarters for a walk on the streets like normal people. Such an momentous occasion happened this week, and where else could they be found other than at the only oil fired nuclear power plant in the world (don’t tell us we don’t know how to party!)?

The power plant in question is Marviken, located about 150 km driving distance from Stockholm. It was supposed to be the first large scale electricity producing nuclear power plant built according to “the Swedish line”. The design principles behind the Swedish line was:

  • Natural uranium as fuel so that the abundant Swedish uranium resources could be utilized without any need to depend on import.
  • Heavy water as moderator because light water steals to many neutrons to be possible to use with natural uranium fuel.
  • Possibility to refuel during operation so that fuel bundles can be removed at the point where the Plutonium isotope composition is the most beneficial as weapons material.

Challenge to nuclear opponents

It has always mystified me (and I think I can speak for all of us in NPYP) that someone can be anti-something when it comes to energy. Lets suppose for instance that someone declares himself to be anti-chemical energy, the logical follow up question to the fellow would of course be “what kind of chemical energy?”. The question is logical because there are so many different ways one can extract chemical energy, everything from burning cow dung in huts to the engine in your car to high tech gas turbines to dynamite. Our friend there probably didn’t even think of those distinctions when he made his statement, but what if he did? Let’s say he rebukes by stating he really means that he is anti coal. Even that statement can be challenged, it must by necessity be conditional otherwise it is moronic. If he is anti coal because of air pollution, then would he change his mind if there was a solution to the pollution? If someone developed a filter that reduced pollution levels to insignificant amount is fossil fuels then ok? Logically he should think so. If he is anti coal because of the immensely destructive coal mining, would he change his mind if environmentally sound mining practices where developed? The guy is presumably actually anti air pollution or anti dirty mines, not anti chemical energy or anti coal. He just never bothered to go through the chain of reasoning to understand what he really opposes in chemical energy.

Same can be said of any energy source, there is no rational reason to be against the energy source itself, rather one is against some undesirable effect due to the present application of the energy source. NPYP are not fans of coal by any means, but I dare say that if there was solid solutions to its problems, then none of us would oppose its use. There just isn’t any justifiable reason to oppose it if the problems are solved. There is no other way to rationally look at energy production.

The advantage with digging deep and specifying exactly what one is actually opposed to means opening up to the possibility of finding solutions! If someone simply state that they are anti windmills then the discussion pretty much ends right there. If the person instead states that the noise from windmills is disturbing then the discussion can turn to possible solutions to reduce noise. Everyone wins on that! There is no reason to be horribly emotional about the whole thing and cling to an anti-something idea so hard that one blocks any fruitful discussion and becomes blind to solutions.

A discussion goes no where until one gets to the core of the argument, which is, what properties of a specific energy source makes you oppose it and and how can it be improved so you no longer oppose it?

The frustrating thing in the nuclear debate is that the discussion never seems to reach that point. Ask leading environmentalists that exact question and they will squirm like a worm on a hook.

If someone specifies that they are opposed to nuclear energy due to the waste problem. Fine we say, but what exactly do you mean by the waste problem and what effect does the waste have that you find repulsive? If you are bothered by the possibility that the waste will hurt future generations, then lets discuss how to safely dispose of the waste. If you are anti nuclear because you are bothered by the safety of nuclear installations, then specify what level of safety is safe enough (obviously there must be a level where an activity is considered safe enough, otherwise the person in question would never get out of bed to shower for fear of slipping and dying) and lets discuss how to reach that.

But the discussion always ends before reaching that point because the “anti person” generally never  seems to be interested in solutions to the posed problems and they are usually not even able to state clearly why they consider the issue as a problem in the first place. This is not only valid for the nuclear debate, one sees the same tendencies in all kinds of discussion where there is a clear anti side. Anti genetic engineering, anti cars, anti meat, anti space exploration, you name it! It seems very hard for people to go past the simple emotional attachment of being against something and instead engage into a meaningful discussion about the issues. It is too easy to just be opposed to something, it is damned much harder to actually find solutions.

So to move the nuclear discussion into a more fruitful direction it would be enlightening if some nuclear opponents could specify what conditions nuclear would have to fulfill to be an acceptable energy source. Believe it or not even we have such conditions. I don’t think for instance anyone in NPYP wants to see more RBMK reactors built (the type of reactor at the Chernobyl plant) and just to speak for myself I have quite strict demands on what nuclear energy should be in the long run to be an acceptable energy source. I am not anti nuclear, but I am certainly anti towards some ways of extracting nuclear energy.

To summaries and to state the challenge again clearly.


What conditions would have to be fulfilled for you to consider nuclear an acceptable energy source?