Inventory of Cs-137

kirilrost

Problem:
Reactor operating at 2300 MW with specific power of 24.42 MW/MT, was shutdown on 1 January 2009. The reactor was fueled with 93.3 MT of uranium with initial enrichment of 3.8% U-235. At shutdown, core burnup 23.3 GW-day/MT.
Question:
1.What was inventory of Cs-137 when the reactor was shutdown?
2.How much Cs-137 will be left on 4 March 2009?

Actions:
Honestly, i have hard time understanding what is going here.
1.I thought that this is how many moles of the fission product Cs-137 does this reactor produce per day?
2.How much left is N(t)=N₀*(0.5)^t/t_0.5? I need to plug in t here 4 March 2009 - 1 January 2009. Right?
Steps:
1. 1 mole fissioned =223 MWD
2300/223= 10.31 moles of fissioned per day
6.19 atoms of Cs-137 per 100 fissions.
10.31*0.00619=.6384304 moles of Cs-137 produced per day.
A=λN=(ln2)(.60222*10²⁴)*(1/(365*24*3600*30.07))
Am i on the right track?
Thanks in advance.