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

Question

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
(c) 1 and 3 only
(d) 1, 2 and 3

Answer 1

(b) 2 and 3 only

Explanation:

• Statement 1: Incorrect. RTGs are not fission reactors; they are devices that convert the heat released by the decay of a suitable radioactive material (such as Plutonium-238) into electricity using thermocouples. Fission reactors, on the other hand, generate energy through nuclear fission reactions.

• Statement 2: Correct. RTGs have been widely used in space missions to provide power to spacecraft and rovers, especially in environments where solar power is not feasible, such as deep space or shadowed regions on planetary surfaces.

• Statement 3: Correct. Plutonium-238 is commonly used in RTGs because it provides a consistent heat output through its radioactive decay, and it is a by-product of nuclear reactors, not specifically from weapons development but from nuclear fuel production processes.

Therefore, statements 2 and 3 are correct, making option (b) the right answer.