boiler

direct cycle of coolant system

double circuit system of coolant cycle

multi pass system

1 tonne of high grade coal

4.5 tonnes of high grade coal

10 tonnes of high grade coal

100 tonnes of high grade coal

gas cooled

liquid metal cooled

pressurised water

boiling water

lead or concrete

lead and tin

graphite or cadmium

thick galvanised sheets

X-rays

infra-red rays

a, P, and y rays

neutrons and gamma rays