Question

Carbon-14, with a half-life of 5,730 years, is produced in LWRs by way of an (n,p) reaction with nitrogen impurities (in both the fuel and the coolant water) and via an (n,a) reaction with 170. About 60 to 70 Ci of 14C are generated this way per GWeyear. (a) What is the total 14C activity in the fuel unloaded each year from a 1,000 MWe reactor that has operated with a 0.70 capacity factor? Assume that one third of the core is unloaded each year. (b) How much 14C will be produced per year in the year 2010 by all the reactors in the world if high or low projections of Table 4.8 come to pass and all reactors are LWRs?

Answer 1

if 1000 MWe reactor operated for year with capacity factor 0.7,

energy produced in year = 700 MWe-Year = 0.7 GWe-Year

Let us assume activity of ¹⁴C generated per GWe-Year is 65 Ci

Hence activity A of ¹⁴C produced in 1000 MWe reactor operated for year

with capacity factor 0.7 is given by

A = 0.7 65 Ci = 45.5 Ci

If one-third of fuel is unloaded per year, activity of ¹⁴C produced = 45.5/3 = 15.13 Ci

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For part(b), Table 4.8 is not available