Radioactive Decay as a Power Source
Strontium-90 is to be used in a radioisotopic thermoelectric generator (RTG) for powering a navigation beacon located in the arctic.
a) How much of the Sr-90 activity is required to generate 50 W of electric power if the conversion efficiency from heat to electricity is 30%? Tip: You must take into account the fact that Sr-90 is in equilibrium with its daughter, Y-90.
b) What is the mass of Sr-90 required?
c) Weight is an important factor in the design of a portable, isotopic heat source. If weight is to be kept at a minimum and if the source is to generate 50 W after 1 year of operation, would there be an advantage to using Po-210 compared to Sr-90?