With reference to radioisotope thermoelectric generators (RTGs), consider the following statements : 1. RTGs are miniature fission reactors. 2. RTGs are used for powering the onboard systems of spacecrafts. 3. RTGs can use Plutonium-238, which is a by-product of weapons development. Which of the statements given above are correct ?
A
1 and 2 only
B
2 and 3 only
Correct answer
C
1 and 3 only
D
1, 2 and 3
Explanation
Statement 1 is wrong: RTGs are not reactors and involve no fission; they turn the heat released by the natural radioactive decay of an isotope into electricity using thermocouples. Statement 2 is correct: RTGs power spacecraft such as Voyager, Cassini and the Curiosity and Perseverance rovers, where sunlight is too weak or unreliable. Statement 3 is correct: they commonly use plutonium-238, which was produced in reactors built for nuclear weapons programmes. So 2 and 3 only.
Space & Astronomy