Renewing the Russian Passport

So I'm confused... one of the posts said children adopted from Russia must be registered with the consulate. We did this when we adopted our son 5 years ago, but I am sure his passport is expiring soon as well. If we don't plan to travel to Russia with him, do we actually need to get a new Russian passport? I don't remember hearing anything about this before. Our agency has closed since our adoption, so I can't ask them. He has his citizenship papers for the US, a SS card, an American (foreign born) birth certificate, etc. He does not have a US passport as we do not travel internationally. Can someone tell me if we are required to have a current Russian passport if no travel to Russia is planned? Thank you, Shawna