Consider the following statements regarding nuclear reactors:
1. In a gas – cooled thermal reactor, if CO2 is used as the coolant, as separate moderator is not necessary as the gas contains carbon.
2. Fast reactors using enriched uranium fuel do not require a moderator.
3. In liquid metal- cooled fast breeder reactors, molten sodium is used as the coolant because of its high thermal conductivity.
4. Fast reactors relay primarily on slow neutrons for fission.
Which of these statements are correct?
(a) 1 and 2 (b) 2 and 4
(c) 2 and 3 (d)1 and 3