2.4) Assume that a decision is made to start ordering reactors at such a constant rate per year from 1990 until 2030 at which time orders will stop, so that all known uranium reserves of 2.3 million tonnes (with prices up to $260/kgU ) will be used up. Assume: a) All plants are identical and need 150 tons of natural uranium per year. b) It takes 10 years to build a plant c) Every plant has a 30 year lifetime. d) There are 120 plant operating in 1990. e) Reactors operating in 1990start retiring in 2000, at the rate of 10/yr. For these reactors, consider their needs only after 1990. Calculate how many reactors per year could be ordered and the maximum number of reactors operating at any single time