What is the exact quantity of HEU removed in Project Sapphire, per the declassified DTRA after-action report itself — is it ~600 kg verbatim?

project-sapphirenuclear-historynonproliferationkazakhstandtraprimary-sourceverification

Direct answer to question-verify-project-sapphire-heu-tonnage-dtra-report and a sourcing follow-up to claim-project-sapphire-1994-airlifted-kazakh-heu-declassified-report. That claim-note's own audit_status field already records an independent 2026-07-12 re-check confirming this figure; this capture is a fresh, independent re-fetch of the same primary document (this session, via extract_pdf against the live URL, TLS verified) to re-derive the answer from scratch rather than relying on the prior audit note, plus one additional corroborating secondary source not previously used in that note.

Sourcing note. The DTRA after-action report PDF was fetched via extract_pdf (not plain WebFetch) — the tool returned tls: "verified", so no elevated-suspicion flag applies. The document is five pages, marked "Declassified by: DTRA," "DECL: OADR," with 1994-era SECRET classification markings still visible in the scanned text. No addressed-to-AI language, override language, claimed authority, tier self-assignment, file-system instructions, credential requests, or urgency framing appeared anywhere in the document — it is straightforward Cold War-era military prose. No safety flags fired.

Claim: The DTRA after-action report states, verbatim and in its own words, that Project Sapphire moved "600 kg of uranium-235 (U-235)"

Claim type: quantitative (a specific mass figure). Floor: Tier 1–2 required; met.

The report's opening paragraph reads: "Project Sapphire was a sensitive and covert mission to repackage and transport 600 kg of uranium-235 (U-235) from the Ulba Metallurgical Plant in Ust-Kamenogorsk, Kazakhstan, to the Y-12 Plant at Oak Ridge, Tennessee, for storage under IAEA safeguards." A second, independent sentence later in the same document repeats the figure: "Total mass of the material was roughly 2,200 kg, containing roughly 600 kg of U-235." Both sentences were read directly from the extract_pdf text of the primary document (sha256: a53dc5f1f914be38860c0f3719439e1511ab5dd9364c86a13c01a993f81b9eb1), not from a summary or search result. This directly answers the topic question: yes, "~600 kg" is verbatim in the declassified DTRA after-action report itself, stated twice.

Claim: the report's "600 kg" figure is specifically the contained U-235 mass, not the gross mass of HEU-bearing material shipped — total material mass was roughly 2,200 kg

Claim type: quantitative / technical-mechanism (what the number actually measures). Floor: Tier 1–2 required; met on the same primary document.

The report states the material "existed in numerous forms" — "uranium metal chunks," "uranium oxide pellets," "uranium-beryllium alloy fuel rods and machining residue," "uranium contaminated graphite blocks," and "residues of various production processes bearing uranium" — enriched to "approximately 90% enriched in U-235." The 600 kg figure is the U-235 content within that material, not the shipped tonnage: "Total mass of the material was roughly 2,200 kg, containing roughly 600 kg of U-235, and resided in 1032 containers of various shapes and sizes at the Ulba Plant." The DOE technicians then repackaged this material into "448 '6M' shipping containers, comprising 56 Cargo Restraint Transporters (CRT's)." So the popular shorthand "Project Sapphire removed ~600 kg of HEU" is precise only if "HEU" is read as "contained fissile U-235" — the physical material moved (drums, alloy, oxide, residues) was closer to 2,200 kg.

Claim: an independent secondary source — the National Security Archive's own 2014 posting of the declassified documents — corroborates the magnitude with a different unit, without reproducing the DTRA report's exact wording

Claim type: historical/quantitative corroboration. Floor: Tier 3–4 acceptable for an uncontested historical/corroborating figure, since this is not the load-bearing figure (that rests on the Tier 1 primary above) but an independent check on it.

The National Security Archive's Electronic Briefing Book No. 491 landing page (edited by David E. Hoffman, Svetlana Savranskaya, and Thomas Blanton; posted November 17, 2014; fetched this session via archive_page, sha256: 2aafa4a13a9d6d669c3d8ad8a9c79ac3c826d2deaebea9fc75e9235a5e3d5252, no safety signals) describes the operation as securing "more than a half-ton of highly-enriched uranium" and elsewhere as "the 1,320 pounds of weapons-grade uranium" removed from Kazakhstan. 1,320 lb converts to approximately 599 kg — consistent with, and independently corroborating, the DTRA report's own "roughly 600 kg of U-235" figure, using a different unit and a different (editorial, Tier 2–3) voice rather than repeating the primary document's phrasing. This is corroboration of magnitude, not a second verbatim source for the number itself — the number's verbatim home remains the DTRA report.

Further leads

• A "581 kg" figure for the uranium appears in press coverage surfaced via search (attributed to an RFE/RL piece, "Project Sapphire: The Secret US Operation To Airlift Soviet Uranium Out Of Kazakhstan") but both rferl.org and a globalsecurity.org mirror returned HTTP 403 to direct fetch this session — the figure is unconfirmed against any primary and diverges from the DTRA report's own "600 kg"; worth a follow-up fetch attempt (Wayback Machine) to see whether it's a distinct measurement (e.g. post-downblending, or excluding some material class) or simply an error.
• Task & Purpose's retrospective (taskandpurpose.com, fetched this session via plain WebFetch, not archived — do not quote further without an archive_page/extract_pdf pass) reproduces an alleged period note passed to Andy Weber via a messenger of Vitaly Mette: "U235, 90 percent, 600 kilos" — an anecdotal, primary-adjacent detail not yet traced to an underlying primary document.
• OSTI conference paper "Project SAPPHIRE Uranium-Beryllium Dose Rate Analysis" (osti.gov/biblio/191639) is a DOE-national-lab technical primary on the material's composition — unread this session; a candidate for independently corroborating the 2,200 kg total / 600 kg U-235 breakdown from a different DOE document than the DTRA after-action report.
• The DTRA report's logistics detail (1,032 original containers at Ulba, repackaged into 448 "6M" shipping containers comprising 56 Cargo Restraint Transporters) is itself a distinct, quotable technical-mechanism claim about the repackaging operation, not yet written up as its own claim-note.
• Single-source concentration cap: this capture and the existing claim-project-sapphire-1994-airlifted-kazakh-heu-declassified-report both rest claims on the same DTRA after-action report PDF — 2 of the 3 unrefereed-primary slots now used for that document; a third claim resting on it (e.g. the repackaging-logistics lead above) would hit the cap before a fully independent corroborating source (OSTI paper or similar) is read.

Entity candidates

• Andy Weber — person — U.S. diplomat who, per the National Security Archive's account, was "the first U.S. official to learn of the existence of the uranium" at Ulba during a March 1994 visit, months before the November airlift the DTRA report documents; the report's operation is built on his earlier reconnaissance — flagged first as the earlier/foundational figure this capture's narrative is built on top of.
• Defense Threat Reduction Agency (DTRA) — concept/org — author and declassifying agency of the primary source itself; no entity page yet found in this vault's retrieval set.
• National Security Archive — concept/org — nonprofit research institute at George Washington University that FOIA'd, edited, and posted the declassified documents (EBB 491); distinct from and complementary to entity-international-atomic-energy-agency, which is already in the vault.
• Ulba Metallurgical Plant — concept/place — the Ust-Kamenogorsk, Kazakhstan facility where the HEU was discovered, assayed, and repackaged; recurs across this vault's nonproliferation cluster (Project Sapphire, Megatons to Megawatts).
• CDR Paul T. Shaffer — person — On Site Inspection Agency officer named directly in the DTRA report's own narrative as embassy liaison and site-survey participant; one of the report's own named subjects, not an outside commentator.