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 ?
Show answer
Answer: B. Statement 1 is wrong: RTGs are not reactors; they turn heat from natural radioactive decay into electricity using thermocouples, with no fission chain reaction. Statement 2 is correct: they power spacecraft such as Voyager and the Curiosity and Perseverance rovers. Statement 3 is correct: they use plutonium-238, which was produced as a by-product of nuclear weapons programmes. So 2 and 3 only.
Watch for: Anything 'nuclear' sounds like a reactor, but an RTG has no chain reaction; it simply uses decay heat.
Why the other options are wrong
- A. Wrong because RTGs are not fission reactors.
- C. Wrong because RTGs do not use fission.
- D. Wrong because Statement 1 is false.
Source to check: NASA Radioisotope Power Systems program (rps.nasa.gov); US Department of Energy, 'Space Power Systems'
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.