Andy Weber was the first U.S. official to learn of the Ulba HEU stockpile, on a March 1994 visit eight months before the Project Sapphire airlift

project-sapphirenuclear-historynonproliferationkazakhstancold-war

Per the National Security Archive's account of Electronic Briefing Book No. 491, American diplomat Andy Weber was "the first U.S. official to learn of the existence of the uranium" during a visit to the Ulba Metallurgical Plant in Ust-Kamenogorsk, Kazakhstan, in March 1994 — eight months before the covert November 1994 airlift that the DTRA after-action report documents as Project Sapphire.

The DTRA report itself, an operational after-action account, begins its narrative at the airlift; it does not cover the earlier discovery. This detail fills that gap: the roughly 2,200 kg of HEU-bearing material didn't surface to U.S. attention in November 1994 — it was found, and its significance recognized, months earlier, with the intervening period presumably spent on the diplomatic and logistical arrangements the after-action report's own candor about last-minute funding ("obtained through DOE the day before the OSIA team departed") suggests were still being worked out close to the wire.

This is a historical/biographical claim, uncontested and Tier 2-sourced, which clears the sourcing floor for this claim type without needing escalation.