Thursday, October 06, 2022

Is tiny nuclear really much use?

This may be mainly all PR to help university funding, but there's a story on phys.org about a new-ish reactor design (which doesn't really explain if one has been built):

BYU professor and nuclear engineering expert Matthew Memmott and his colleagues have designed a new system for safer nuclear energy production: a molten salt micro-nuclear reactor that may solve all of these problems and more.

The standard nuclear reactor used in America is the Light-Water Reactor. Uranium atoms are split to create energy, and the products left over will radiate massive amounts of heat. They are kept in solid fuel rods, and water is run through the rods to keep everything cool enough. If there is not enough of a flow of cooling water, the rods can overheat, and the entire facility is at risk for a nuclear meltdown. Memmott's solution is to store these radioactive elements in molten salt instead of fuel rods...

In Memmott's new reactor, during and after the occurs, all the radioactive byproducts are dissolved into molten salt. Nuclear elements can emit heat or radioactivity for hundreds of thousands of years while they slowly cool, which is why nuclear waste is so dangerous (and why in the past, finding a place to dispose of it has been so difficult). However, salt has an extremely high melting temperature—550°C—and it doesn't take long for the temperature of these elements in the salt to fall beneath the melting point. Once the salt crystalizes, the radiated heat will be absorbed into the salt (which doesn't remelt), negating the danger of a nuclear meltdown at a power plant.

Another benefit of the molten salt nuclear reactor design is that it has the potential to eliminate dangerous nuclear waste. The products of the reaction are safely contained within the salt, with no need to store them elsewhere. What's more, many of these products are valuable, and can be can be removed from the salt and sold.

But how small is this design?   Pretty small:

A typical is built with a little over one square mile to operate to reduce radiation risk, with the core itself being 30 ft x 30 ft. Memmott's molten salt nuclear reactor is 4 ft x 7ft, and because there is no risk of a meltdown there is no need for a similar large zone surrounding it. This small reactor can produce enough energy to power 1000 American homes. The research team said everything needed to run this reactor is designed to fit onto a 40-foot truck bed; meaning this reactor can make power accessible to even very remote places. 

 I have my doubts this is useful.  Maybe good for somewhere like Antarctica, though?

3 comments:

GMB said...

Its important because we have to get started. We must get our foot in the door. Make our mistakes and gain our experience on something small. Its quicker to make a small prototype then a bigger item then it is to make the bigger item first up. Because you have to coax the supply chain into being, and train the workers or you'll get cost over-runs. Make haste quickly said Caesar. Who knew what he was talking about. We have to also put tens of thousands of public servants onto a cheaper form of welfare. So we can do everything from surplus.

GMB said...

"Memmott's molten salt nuclear reactor is 4 ft x 7ft, and because there is no risk of a meltdown there is no need for a similar large zone surrounding it. This small reactor can produce enough energy to power 1000 American homes."

Its good for every small town. We must build up small towns by replacing the one and two storey buildings with five storey buildings and upgrading their rail and light-rail facitlities. Not by always creating more suburbs. So we want these all over the place. If they prove inefficient we ought to mothball them and then start them back up for when someone bombs the Hunter Valley. We need distributed power as a vital backup need in wartime.

GMB said...

Any sane management of Australia has us aspiring to be the molten salt global experts. A weak AUD combined with tight money combined with molten salt expertise has us never worrying that our people can’t make their way in the world. Molten salt expertise is not only the key to safe nuclear. Its the key to distributed war-safe electricity as such. Its the key to battery power, if batteries are in basements and not in cars and if batteries are all about those elements of the periodic table that are most plentiful.

Our grid was never war-ready. We put our faith in planes, submarines and allies. Thats all over now. We need a grid that will hold up under the challenge of bombing. We need every town to have a backup electricity supply. We need to export energy and still have unlimited energy for our home, without squandering our hydro-carbon paternity. What the Russians have shown us is that some old technologies are important. Steel manufacturing. Diesel engines. Rail lines. Energy supremacy. All important and artillery is still the God Of War like it was when Clausewitz said it was.