With reference to radioisotope thermoelectric generators (RTGs), consider the following statements:R

Question

With reference to radioisotope thermoelectric generators (RTGs), consider the following statements:RTGs are miniature fission reactors.RTGs are used for powering the onboard systems of spacecrafts.RTGs can use Plutonium-238, which is a by-product of weapons development.Which of the statements given above are correct?

Accepted Answer

Radioisotope Thermoelectric Generators (RTGs) are lightweight, compact spacecraft power systems that are extraordinarily reliable. RTGs provide electrical power using heat from the natural radioactive decay of plutonium-238, in the form of plutonium oxide. The large difference in temperature between this hot fuel and the cold environment of space is applied across special solid-state metallic junctions called thermocouples, which generates an electrical current using no moving parts.Elimination technique could have been used if statement 3 was difficult especially because of its second part. Statement 1 is not correct as the principles are different. Thus, options (a), (c) and (d) are incorrect. Statement 2 is correct as its use in the spacecrafts has been its primary applications. NASA has been using the technology since the 1960s. Statement 3 is correct: Pu-238 is used due to its low half-life.