An inventor claims to have devised a cyclical engine for use in space vehicles that operates with a nuclear-fuelgenerated energy source whose temperature is 920 R and a sink at 490 R that radiates...

An inventor claims to have devised a cyclical engine

for use in space vehicles that operates with a nuclear-fuelgenerated

energy source whose temperature is 920 R and a

sink at 490 R that radiates waste heat to deep space. He also

claims that this engine produces 4.5 hp while rejecting heat at

a rate of 15,000 Btu/h. Is this claim valid?