Re:NASA completes full-power tests of small, portable nuclea...
by philipkglass on Thursday May 03, 2018 @02:59PM
(#16988793)
The Kilopower reactor presents far lower radiological risks than RTGs in the event of complete disassembly within Earth's environment.
Pu-238 has a specific activity of 634 billion Bq/g, nearly 8 million times that of the Kilopower reactor's U-235 fuel (80 thousand Bq/g). Once the reactor attains criticality, it produces fission products that have even higher specific activity than Pu-238. But the reactor can remain safely inactive until the risky launch phase is over. There is no way to inactivate the decay of Pu-238 for the launch phase.
The risks of RTG launch are handled by using designs with high mechanical/thermal robustness to encapsulate the plutonium ceramic. I think that they were already safe enough. But the Kilopower reactor is inherently low-radiotoxicity before criticality, which makes it safer yet during the launch phase.
Pu-238 has a specific activity of 634 billion Bq/g, nearly 8 million times that of the Kilopower reactor's U-235 fuel (80 thousand Bq/g). Once the reactor attains criticality, it produces fission products that have even higher specific activity than Pu-238. But the reactor can remain safely inactive until the risky launch phase is over. There is no way to inactivate the decay of Pu-238 for the launch phase.
The risks of RTG launch are handled by using designs with high mechanical/thermal robustness to encapsulate the plutonium ceramic. I think that they were already safe enough. But the Kilopower reactor is inherently low-radiotoxicity before criticality, which makes it safer yet during the launch phase.