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?
- 1 and 2 only
- 2 and 3 only
- 1 and 3 only
- 1, 2 and 3
Explanation
Statement 1 is incorrect
- RTGs do not involve nuclear fission reactions. Instead, they utilise the heat generated from the radioactive decay of isotopes to generate electricity.
Statement 2 is correct
- RTGs have been used in various space missions to provide power to spacecraft where solar power is not feasible (e.g., missions beyond the orbit of Mars).
Statement 3 is correct
- Plutonium-238 (a by-product of weapons development) is a suitable isotope for RTGs due to its long half-life and the high heat it generates during decay. The half-life of an isotope is the time required for half of the atoms in a sample of the isotope to undergo radioactive decay. It tells you the rate at which the isotope decays.
