This is just my opinion (I have no science to back this up!).
I think it's probably a good idea to let them know, to some degree, how it affects you too. Perhaps the younger child is a bit too young to understand any of that right now but your older child probably would.
Discussing how it makes you feel and how it affected your life is important. It's probably not a conversation you will have often but sharing your experience (age appropriate, content appropriate) lets them know that you are not to "blame".
Now, that might sound a bit ridiculous but, as I've said before, I have read a few posts at SR about the non-drinking parent being estranged from older children.
There are probably many reasons but I think if you grow up with an alcoholic they are usually pandered to. Go to your room and play, Dad will be home soon (everyone knows why you have to go to your room). Eggshells, don't wake him up, don't talk too loud, go and see what he wants if he calls out etc etc.
That does not stop when the parents divorce, the alcoholic is used to being tip-toed around and the children are used to their roles.
So now you have the one parent being pandered to and that other sober parent who is screwing everything up! Furthermore they abandoned the pandered one!
It probably goes against the grain right now to look out for yourself in this way but I think it's an important relationship building block with children who have been exposed and continue to be exposed to an alcoholic parent