New ideas for Nuclear Power

 Sometimes things get missed. A couple have come up in reactor design recently.

1. To make a reactor work you have to transport the heat from where the reaction happens to where you want it to do work. Molten salt is a poor conductor of heat, so it used to be thought that it couldn't do the job. However because it is a liquid it can transport heat by convection instead of conduction. Moltex Energy noticed this, patented it, and have it as a core part of their plan to make energy cheaper than fossil fuels.

2. Helium has various properties that make it the gas of choice in High Temperature Gas Reactor (HTGR) designs. Rod Adams has recently pointed out that isotope 15 of Nitrogen, N15, shares these properties, plus having additional benefits. In particular it is similar to air, so lots of expertise and equipment for dealing with air is applicable. It is also very abundant since it makes up 0.35% of the nitrogen in our atmosphere. Of course separating it out is not trivial, but it is commercially available, so it is being done.

These things should come in threes. Perhaps my contribution is too trivial to mention, but here it is:

3. Nuclear power plants like to operate continuously. They need to charge enough to cover the sunk cost of construction (or equivalently to cover the interest payments on the construction cost). But the marginal cost of operation is very low, and perhaps in truth negative given the costs involved in having the flexibility to reduce production. Moltex Energy is putting their money on energy storage to soak up excess energy when demand and price are low, and sell later when both are high. Meanwhile there are many things we could do with energy if it was cheap. Consider fresh water. It is seriously under-priced because we ignore the environmental impact of taking it from natural river systems and from underground aquifers. But those natural options are hitting their limits. Current desalination methods are expensive to build because the theory is "energy is expensive, so we build an expensive solution that makes efficient use of energy". And once you've built an expensive system you want to run it as much as possible. But actually, in a world where there is often excess energy with nowhere to go, this argument is wrong. What you want is a cheap solution that you only need to run when energy is more or less free. There are other industrial processes where the clever search for energy efficiency is misguided, and a cheap design is economically preferable.