Because in a failure you’ll have only one pressure vessel between the two cores. If everything else goes right.
Neutron diffusion is a statistical process, so yeah, a small amount of neutrons will escape through the reactor wall. But not enough that the neutron flux from one reactor would influence the next one in any measurable way.
> Because in a failure you’ll have only one pressure vessel between the two cores. If everything else goes right.
Yes, also in this case.
The reactor modules are partially immersed in a pond, the ultimate heat sink. Cooling is passive, i.e., no cooling pumps, and does not require electrical power.
The odds that a concentrated site has an event are much higher with colocation. But the changes of having an event at multiple locations are higher if they're spread out.
Some things that I believe would matter for colocation would be:
- chance of cascading failures
- economies of scale/safety in numbers (1 large team vs many small)
- plant-to-home efficiency (n fewer reactors due to smaller transmission losses)
That depends on what risks you are trying to mitigate. IF you are talking about site specific natural disasters and freak occurrences damaging a site. Then spreading them out increases risk of failure.
If you are worried about power loss after a site destroys a site, then colocation is worse. Of the two, damage to a site is the more pressing concern.