A Nuclear Powered Nuclear Waste Dispenser
Currently we bury it somewhere and hope it will not escape any time soon. This is rather naive. Give it enough time and it will leak into our environment. So how can we improve? Shooting the nuclear waste straight into space is a compelling option, either on a stable orbit leaving our solar system or directly into the sun.
Current rocket technology is not gonna do it. So let’s try something else: Make a big bullet containing our nuclear waste. Accompanied with a giant cannon that is fueled by water steam produced by nuclear power. Build up high enough pressure to accelerate the bullet to earth's escape velocity.
How to build the capable cannon? Dig a cylindrical hole down into earth, add a sufficient amount of pressure chambers along the cannon barrel. The shooting mechanism: Release pressure of the chambers from the bottom to the top sequentially, accelerating the waste bullet to the needed escape velocity. Before all that, calculate where to dig the hole according to the needed trajectory. There it is: A nuclear powered nuclear waste dispensing cannon.
Biggest potential hurdle: This nuclear waste dispenser design only works out if it can dispense more waste than is produced in order to operate it. Figuring that out is key to success and is left as an exercise for the curious reader.
Biggest potential failure: The nuclear waste bullet does not reach escape velocity and comes right back at spaceship earth. Mitigation: Simulate several failures without real nuclear waste but the same bullet case design and a realistic non-toxic replacement material for the waste.