Answer: a. 0.8 tons p. month.
Explanation:
Given: Total nuclear waste = 60,000 metric tons
Time take = 60 years = 12 x 60 months [ 1 year = 12 months]
= 720 months
Total nuclear power plants = 104
Now , Average waste produced by each plant = 
Hence, 0.8 tons p. month is produced by each plant.
So, option a. is correct.
Atoms are electrically neutral because the number of protons, which carry a 1+ charge, in the nucleus of an atom is equal to the number of electrons, which carry a 1- charge, in the atom. The result is that the total positive charge of the protons cancels out the total negative charge of the electrons so that the net charge of the atom is zero. Most atoms, however, can either gain or lose electrons; when they do so, the number of electrons becomes different from the number of protons in the nucleus. The resulting charged species is called an ion.
Since the reaction gives off heat energy it is considered to be an exothermic reaction
