The Science Show had an interesting interview on the weekend, in which this (new to me) feature of Pebble Bed nuclear reactors was mentioned:
Now, I would still like to know the answer to a question I asked earlier this year: do they need to use much water in their operation? If not, we can forget about the Labor scare campaign of a string of nuclear power plants along the Australian coast.Martin Sevior: The Chinese are pursuing pebble bed reactors and those are about four times as efficient in the use of uranium as light water reactors.
Robyn Williams: Could you explain how the pebble reactors work?
Martin Sevior: The pebble bed reactors basically have...your uranium is embedded in a carbon matrix which serves as the moderator. In a standard nuclear reactor, light water is the moderator. Water is also a very good absorber of neutrons, so carbon is much more efficient in that way, it doesn't absorb neutrons. So you can actually employ less uranium for the same about of power because instead of your neutrons being lost through absorption in water, they can initiate more reactions.
The Pebble Bed Modular Reactor is a direct cycle gas cooled reactor, thus you need very little water compared to other nuclear reactors. You do not need to build these reactors on the coast.
ReplyDeleteThanks for that anon. You seem to be from South Africa? Do you have any connection with the pebble bed project there?
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