It was a statement made by General Aleksandr Lebed, former Secretary of the Russian National Security Council, in a meeting with an American congressional delegation.
Perhaps he was drunk, or lying, or just plain unable to find the people who knew which cupboard the devices were safely locked in. But he did make those claims. And you are missing the wood for the trees.
This "wood" (and the US report) consists of exactly one person who made this claim, and a member of corrupt Yeltsin's entourage to boot. I'd say if these nukes were real, they would have exploded somewhere by now.
Try harder.
Here's the first US government report I found on it with all of the entirely negligible effort I am willing to entertain: https://commdocs.house.gov/committees/security/has078010.000...
Perhaps he was drunk, or lying, or just plain unable to find the people who knew which cupboard the devices were safely locked in. But he did make those claims. And you are missing the wood for the trees.