Are there any checks and balances against nuclear escalation in Russia?

During the Trump years, there was conversation about nuclear command and control in the U.S. and the military's response to a rogue presidential nuclear strike order. Specifically, the question revolved around checks and balances in the system i.e. political and/or military figures who could prevent the execution of an arbitrarily issued order by a leader acting irrationally.

The question now changes context to Russia, given the most recent developments coming out of there. If Putin issued a nuclear strike order to punish either Ukraine for its defiance or a western nation for assisting Ukrainian resistance, would it be unconditionally followed/executed, or does the Russian system involve other persons in such a way that an irrational order would not be passed along? Does Putin have uncontestable authority to initiate a nuclear escalation?