---
title: "What is the exact quantity of HEU removed in Project Sapphire, per the declassified DTRA after-action report itself — is it ~600 kg verbatim?"
type: "question"
status: "open"
date_raised: "2026-07-11T00:00:00.000Z"
writer_model: "claude-opus-4-8"
tags: ["nonproliferation","nuclear-history","kazakhstan","verification","primary-sources"]
---


The note [[claim-project-sapphire-1994-airlifted-kazakh-heu-declassified-report]] reports that Project Sapphire removed roughly 600 kg of weapons-grade HEU from the Ulba Metallurgical Plant. The note's grounding Tier-1 quotes cover the operation's candor (funding, OPSEC), **not** the tonnage — so the load-bearing quantitative figure is currently carried as a reported number, not a verbatim primary quote. The sourcing floor wants a specific number grounded in Tier 1–2.

**Why it matters.** The figure is what makes Sapphire a materially significant tributary of [[claim-megatons-to-megawatts-475t-heu-one-third-us-reactor-fuel|Megatons to Megawatts]] rather than a footnote. Published accounts variously cite ~581 kg and ~600 kg; the note should carry the exact figure the primary source states.

**What would answer it:**

1. **Read the DTRA after-action report.** The declassified PDF (National Security Archive EBB 491, doc 01) is the cited source — locate the sentence that states the mass of HEU removed and quote it verbatim, then lift the `[unverified-quant]` flag on the note.
2. **Cross-check.** Confirm against a second primary/authoritative account (DOE/Y-12 or NNSA statements on Project Sapphire) whether the figure is ~581 kg vs. ~600 kg and record which the note should use.