Since the 1991 collapse of the Soviet Union left Russia's military underfunded and disorganized, the arsenal in Shchuchye, about 1,000 miles east of Moscow, has been a top security concern. After years of delays and disputes, a vast facility to destroy the weapons is to formally open there on Friday.

The plant, the size of a small town, was built with a U.S. contribution of more than $1 billion and is seen as a milestone in cooperation on disarmament between Washington and Moscow.

Russia, as a signatory of the international Chemical Weapons Convention, is obliged to eliminate its vast stores of Class I weapons -- chemicals that have no use other than in arms. Moscow already has destroyed about 30 percent of its stockpile, according to the Russian Munitions Agency.