"Their reactors are about 2 meters tall and about 1.5 meters across. They weigh around 15 to 20 tons and produce around 30 MW or power. This design is also way over engineered to counter any irrational fears about radiation and tampering. I'm sure a 10 ton unit putting out 50MW and with adequate shielding would be well within reach."

It appear this reactor produces "70 megawatts of thermal energy, or 27 megawatts of electricity when connected to a steam turbine."

I have no reason to assume it would work in orbit, though it should work on the Moon or Mars.
The steam turbine is not included in these dimension or mass.
Nor I'm I sure it is over engineered to counter any irrational fears about radiation. It may produce as much radiation as say, granite, whereas other commercial reactors don't even produce this much.
This reactor does have about the right amount fuel for purposes for interplanetary travel.

I don't share your optimism regarding 10 ton unit producing 50 MW of electrical energy and that can operate in orbit being available soon [within 2 or 3 decades].

But suppose we had one that could produce 100 megawatts of thermal energy and 50 MW of electrical power. And suppose the nuclear reactor only weighed 10 tons.
How much mass will be needed for radiators and a steam turbine to can produce 50 MW of electrical power.
Could all this be under 20 tons?