Free Radicals in Cell Nuclei?

[kgpl at uno.edu]

Someone has suggested to me that a lot of age-related damage may
be the result of accidental miscopying of DNA due to the presence
of free-radicals in cell nuclei messing up the copying process.
Is this possible?  What kinds of free-radicals are generated within,
or can get into, the nucleus of a cell?  Is there any reason to
suspect that this sort of damage is more likely to occur during
the process of cell division?
 
Thanks,
Kevin