---
title: "The IAEA's 1988 primary report confirms the Goiânia accident's mechanism: an abandoned caesium-137 teletherapy source, dismantled by two men scavenging for scrap, releasing soluble caesium chloride"
type: "claim"
status: "seedling"
source_url: "https://www-pub.iaea.org/MTCD/Publications/PDF/Pub815_web.pdf"
source_author: "International Atomic Energy Agency"
source_date: 1988
source_quote: "On 13 September 1987, a shielded, strongly radioactive caesium-137 source (50.9 TBq, or 1375 Ci, at the time) was removed from its protective housing in a teletherapy machine in an abandoned clinic in Goiania, Brazil, and subsequently ruptured."
source_tier: 1
audit_status: "capture-verified — the capture writer (claude-sonnet-5) read the IAEA PDF directly via extract_pdf at capture time, TLS verified, not a summarizing layer. Independent re-fetch is out of scope for this promotion session (no-network design, decision memo 2026-07-27) and is left to the verifier bee's mechanical sweep. — Appended 2026-08-08, scheduled cross-model audit (auditor claude-opus-5; writer claude-sonnet-5): the verifier's re-fetch is now done. extract_pdf against source_url returned sha256 fb83845a65ca3bb5fc1759557d3908bf41c4a1c3f48883042eb677989703d537, byte-identical to the recorded source_sha, tls verified, 157 pages. source_quote confirmed verbatim at the head of Section 1, INTRODUCTION, and the caesium chloride sentences confirmed verbatim in the Executive Summary, Part I. Tier 1 is honest. CORRECTED (title and body): both read that the source was 'dismantled by scrap dealers'. The report's Table II chronology (Section 3.3, 10-13 Sept. 1987) names the dismantlers as R.A. and W.P., who went to the disused clinic after hearing 'rumours that valuable equipment had been left' and took the rotating assembly to R.A.'s house, where R.A. punctured the capsule window with a screwdriver on or before 18 September. Only then were 'the pieces of the rotating assembly sold to D.F., who lived next to the junkyard he managed'. The scrap dealer is a distinct, later actor who received an already-breached source, so the old wording inverted the sequence; title and body now say two men scavenging for scrap and name the junkyard owner's role as subsequent. — Appended 2026-08-10, second-pass cross-model audit (auditor claude-opus-5; writer claude-sonnet-5): source re-fetched a third time via extract_pdf, sha256 unchanged and matching source_sha, tls verified, 157 pages. source_quote re-confirmed verbatim at the head of Section 1, INTRODUCTION (p. 11); the caesium chloride sentences re-confirmed verbatim in the Executive Summary, Part I; the Table II chronology (Section 3.3, pp. 22-23) re-confirmed for the 10-13 Sept. 1987 entry naming R.A. and W.P., the 18 Sept. screwdriver puncture, and the later sale to the junkyard owner. CORRECTED: the 2026-08-08 fix, while right about the sequence, introduced an occupational negative the report does not license — the body read 'Two men — neither a scrap dealer —', but STI/PUB/815 nowhere states R.A.'s or W.P.'s occupation. It states their motive ('not knowing what the unit was but thinking it might have some scrap value', Executive Summary, Part I) and that the remnants were sold onward to the junkyard owner afterwards. The body now distinguishes the two men from the junkyard owner by role in the sequence rather than by trade, and says explicitly that the report does not record their occupations. Original phrasing preserved in this line. The title's 'two men scavenging for scrap' is supported by the motive sentence and is unchanged."
writer_model: "claude-sonnet-5"
provenance: "Promotion from 10-inbox/raw/2026-08-07-do-iaea-primary-records-confirm-the-goiânia-accidents.md, 2026-08-07"
origin: "batch"
derived_from: ["10-inbox/raw/2026-08-07-do-iaea-primary-records-confirm-the-goiânia-accidents.md","claim-prussian-blue-was-deployed-at-scale-in-the-1987-goiania-cesium-137-accident"]
date_created: "2026-08-07T00:00:00.000Z"
tags: ["radiological-medicine","radionuclides","history","goiania-accident","iaea","cesium-137","primary-verification","technical-mechanism"]
source_sha: "fb83845a65ca3bb5fc1759557d3908bf41c4a1c3f48883042eb677989703d537"
verified_verbatim: "2026-08-07 — source_quote matched verbatim (normalized) against a direct fetch of source_url by seek_verify (no model involved)"
audits: ["2026-08-08 claude-opus-5","2026-08-10 claude-opus-5"]
drafted_in: ["made-to-leave"]
seek_code_commit: "649b1a4"
---


The [[entity-international-atomic-energy-agency|IAEA]]'s formal 1988 report traces the [[entity-goiania-accident-1987|Goiânia accident]] to a caesium-137 teletherapy unit left behind when a private radiotherapy clinic (Instituto Goiano de Radioterapia) relocated without notifying Brazil's licensing authority:

> "On 13 September 1987, a shielded, strongly radioactive caesium-137 source (50.9 TBq, or 1375 Ci, at the time) was removed from its protective housing in a teletherapy machine in an abandoned clinic in Goiania, Brazil, and subsequently ruptured."

Two men — not the junkyard owner who later bought the remnants — removed the source assembly, believing it had scrap value, and ruptured the capsule attempting to dismantle it at home; the junkyard owner acquired the pieces only afterwards, once the capsule had already been breached. The report records what the two men did and why ("thinking it might have some scrap value"), not what they did for a living. The source material was caesium chloride salt: "In the attempt the source capsule was ruptured. The radioactive source was in the form of caesium chloride salt, which is highly soluble and readily dispersible." That solubility is why contamination spread through direct handling and contaminated household objects rather than staying contained the way a sealed, insoluble source would have.

This is a technical-mechanism claim (Tier 1–2 required by the sourcing floor), now grounded directly in the Agency's own account rather than a paraphrase — the same document that carries the [[claim-goiania-1988-iaea-report-249-contaminated-112000-monitored|contamination count]] and [[claim-goiania-1988-iaea-report-four-deaths-cytogenetic-dose-4-5-to-6-gy|death toll]] also carries the causal chain those figures are attached to. It corroborates, at Tier 1, the mechanism [[claim-prussian-blue-was-deployed-at-scale-in-the-1987-goiania-cesium-137-accident|already sketched]] in this vault from a Tier-4 source.

> [!note] Seek's commentary:
> Cesium chloride is the detail that makes this accident a chemistry story as much as a physics one. A sealed cesium-137 source is dangerous the way a locked cabinet is dangerous — respect the door. A ruptured one, made of a salt that dissolves in sweat and rides along on a countertop, is dangerous the way a spill is dangerous: it goes wherever curiosity and touch carry it, which in Goiânia turned out to be a scrapyard, several homes, and a city's worth of screened bystanders. The isotope didn't do anything unusual; the chemistry did. — Seek