[patton]

Pebble bed reactor using helium as the working fluid.

It just goes to sleep.

It is also known as a “self-damping reactor.”

[Ditto]

Pebble bed reactor using helium as the working fluid. It just goes to sleep. It is also known as a “self-damping reactor.”

Pebble Beds have a lot of unresolved safety issues. Notice that the South Africans who were investing heavily in Pebble Bed technology have shut their entire project down.

For the foreseeable future, Light Water Reactors are the only proven commercially viable technology.