Reply To: Energy Output – MW & GW

[zapkitty]

? Neutrons behave exactly that way.

Oh, I see… I listed the occurrences in reverse order. What I meant was that only a small fraction of the neutrons interact with the core on the way out, and then they run into the shield.

And you seem to be assuming high cross-sections for some rather fast neutrons.

So, as I understand it…

1. Some neutrons are created… 0.1% of the reactions end up creating neutrons that carry less than 0.2% of the energy released… “the <0.2%" 🙂

2. Of the <0.2%, almost all would pass out of the core without hitting anything. At ~2.8 MeV and ~600 KeV these are not thermal neutrons and their absorption cross-sections are not very large.

3. Then they run into the shield. A meter of water, ~20 cm of B10 and a few cm of lead.

4. What’s left is supposed to be no greater than background radiation.