[gambiting]

"Depending on the height and mode of an eventual launch failure, the result could be anything from Tchernobyl to a less-dramatic yet more deadly dispersal of nuclear material in the upper atmosphere."

The thing about this reactor is that it doesn't work until you switch it on - so in case of an explosion you are spreading a near-stable isotope that you could handle without any health risks. Chernobyl doesn't compare, because the ashes were spreading isotopes produced as a result of operating the reactor, and are simply not present here until the reactor is actually switched on.