Thora
Thought I'd try something new with my class today, I handed out a copy of an article about Thorium reactors that was in the weekly Guardian a few weeks ago. The idea was that using their knowledge of physics they would be able to understand and discuss the article. Discussions become lively when people have strong opinions but since physics isn't based on opinion no fires were ignited. If you take typical SL knowledge it should be possible to understand some of the important issues. Firstly the waste. One of the main problems with fission is the waste which in the Uranium reaction contains Plutonium a rather nasty substance that can be used in the manufacture of atomic bombs. One of the reasons that thorium reactors were never developed is because "the technology offered no potential for producing nuclear weapons". Did I read that right? Another problem with the Uranium reaction is that it is a self sustaining chain reaction, the Thorium reaction isn't. Being self sustaining is good for keeping the reaction going but bad if you want to stop it. The Thorium reaction needs to be started by firing neutrons at the thorium fuel. In an Accelerator-Driven Subcritical Reactor (ADSR) these are produced by firing high energy protons at Lead. If you stop firing neutrons the reaction stops, no meltdown possible.
Thorium gets its name from Thor, the God of thunder. I guess the English girls name Thora does too. Thora Hird, who as you can tell from the photo was short sighted (see last post).