---
title: "A Taiwanese 1999 conference abstract documents lost cobalt-60 sources entering an electric arc furnace with scrap and producing contaminated rebar in 1982-83"
type: "claim"
status: "seedling"
source_url: "https://www.osti.gov/etdeweb/biblio/20243512"
source_sha: "ab4d7c3d7c693a21c59acf6c1129d8c2ab0be54255a6adcb4eca482bcb5677b9"
source_title: "Characterization of naturally occurring radioactive materials and Cobald-60 contaminated ferrous scraps from steel industries"
source_author: "H. E. Chao, H. S. Chiu, J. Y. Hunga, H. W. His, Y. B. Chen (as listed; Institute of Nuclear Energy Research and Atomic Energy Council, Taiwan)"
source_date: "2002-02-01"
source_quote: "The cobalt-60 activity and trace elements concentrations of contaminated rebars confirm that all of them were produced domestically in the period from Oct. 1982 to Jan. 1983, when the cobalt-60 sources were lost and entered the electric arc furnace to produce the contaminated rebars."
source_tier: 1
audit_status: "capture-verified — author abstract read via the OSTI ETDEWEB record; the full paper (IAEA-TECDOC-1271, pp. 209-218) was not read. Quote grounded against the abstract only."
provenance: "Promotion from 10-inbox/raw/2026-09-26-what-does-the-primary-literature-heusser-1995-and.md, 2026-09-26"
origin: "batch"
derived_from: ["10-inbox/raw/2026-09-26-what-does-the-primary-literature-heusser-1995-and.md"]
date_created: "2026-09-26T00:00:00.000Z"
writer_model: "claude-sonnet-5"
tags: ["materials","nuclear","cobalt-60","steelmaking","scrap-metal","orphan-source","technical-mechanism"]
flags: ["[unverified-quote — abstract only, full paper not read]"]
related_notes: ["claim-no-primary-source-names-atmospheric-entrainment-as-steels-cobalt-60-pathway","claim-zhang-2016-names-scrap-metal-feedstock-as-commercial-steels-cobalt-60-source","claim-heusser-1995-traces-steel-cobalt-60-contamination-to-furnace-gauge-sources"]
seek_code_commit: "f8a723c"
quote_sweep: "PASS 2026-09-27 — source_quote verbatim (normalized) in the capture-time archive (sha256 ab4d7c3d7c69…), same-night model-free sweep"
verified_verbatim: "2026-09-28 — source_quote matched verbatim (normalized) against a direct fetch of source_url by seek_verify (no model involved)"
---


A paper by Chao and colleagues, presented at TENR II (Rio de Janeiro, 12-17 September 1999) and printed in IAEA-TECDOC-1271, reports that cobalt-60 sources were lost and "entered the electric arc furnace" in Taiwan between October 1982 and January 1983, yielding contaminated rebar. The abstract dates the rebar by its cobalt-60 activity and trace-element concentrations.

The same abstract gives counts for 1994-1999: "53 discoveries of radioactivity in ferrous scraps by steel companies," comprising 15 orphan radioactive sources, 16 cobalt-60 contaminated rebars, 20 NORM-contaminated scraps, and two unknowns.

This is a demonstrated **source-in-the-charge** route: a discrete Co-60 source melted with scrap. It is a high-activity, accidental case. It does not show that the same route explains the trace (mBq/kg-scale) cobalt-60 measured in ordinary commercial stainless steel; connecting the two is inference. The route is of the same family as the generic scrap-feedstock attribution in [[claim-zhang-2016-names-scrap-metal-feedstock-as-commercial-steels-cobalt-60-source]] and the gauge-source assertion in [[claim-heusser-1995-traces-steel-cobalt-60-contamination-to-furnace-gauge-sources]]. Like them, it names no atmospheric pathway ([[claim-no-primary-source-names-atmospheric-entrainment-as-steels-cobalt-60-pathway]]).

The record's printed title misspells "Cobalt" as "Cobald"; it is reproduced as printed.

> [!note] Seek's commentary:
> This is the first source in the cluster where cobalt-60 goes into a furnace and something measurable comes out the other end. The catch is scale: rebar you can detect from the road is a different animal from the faint cobalt-60 in a GERDA cryostat. Same road, very different cargo. — Seek