---
title: "Maneschg et al. (2008) find manmade cobalt-60 in all 13 stainless-steel batches screened for GERDA, at about 19 mBq/kg, and Heusser is a co-author"
type: "claim"
status: "seedling"
source_url: "https://www.osti.gov/etdeweb/biblio/21159194"
source_sha: "7499619a680710af306ca5d25acbad6a6351f60fb810a30fd6cd7120decad069"
source_title: "Measurements of extremely low radioactivity levels in stainless steel for GERDA"
source_author: "W. Maneschg, M. Laubenstein, D. Budjas, W. Hampel, G. Heusser, K. T. Knoepfle, B. Schwingenheuer, H. Simgen"
source_date: "2008-08-11"
source_quote: "A total of 13 different stainless steel batches have been screened by low-level {gamma}-ray spectrometry with germanium detectors located at two underground laboratories"
source_quote_2: "Only the manmade {sup 60}Co-isotope is present in all samples with a higher concentration of around 19 mBq/kg."
source_url_2: "https://www.osti.gov/etdeweb/biblio/21159194"
source_sha_2: "7499619a680710af306ca5d25acbad6a6351f60fb810a30fd6cd7120decad069"
source_tier: 1
audit_status: "capture-verified — author abstract read via OSTI ETDEWEB; full paper (Nucl. Instrum. Methods A 593(3):448-453, DOI 10.1016/j.nima.2008.05.036) not read. | 2026-09-27 cross-model audit (auditor claude-fable-5, writer claude-sonnet-5): quote_sweep FAIL re-checked — source_quote joins two non-contiguous abstract sentences with an ellipsis, which defeats a contiguous verbatim match; each sentence individually is verbatim both in the capture-time archive (sha 7499619a…) and in a live re-fetch of the OSTI ETDEWEB page this date. False negative; source_quote unchanged (the ellipsis is a marked omission of two intervening sentences, not a paraphrase). Heusser co-authorship, the 2008-08-11 date, and the NIM A 593(3):448-453 venue were also re-confirmed against the live record. | APPEND 2026-10-01 (Cali's review, Claude Opus 5.5): receipt repair — source_quote was an ellipsis join; split into one verbatim quote per passage → was A total of 13 different stainless steel batches have been screened by low-level {gamma}-ra… → now verbatim against the capture-time archive (sha256 7499619a6807…) → pointer 00-meta/cali-checklist.md §3. Claim text unchanged."
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","low-background-physics","gerda","independence"]
flags: ["[unverified-mechanism — a search-summary report that the full text links the lowest-Co-60 samples to scrap-free production; needs the full text]"]
related_notes: ["claim-heusser-1995-traces-steel-cobalt-60-contamination-to-furnace-gauge-sources","claim-no-primary-source-names-atmospheric-entrainment-as-steels-cobalt-60-pathway","claim-pandax-ii-2016-modern-steel-still-required-scrap-avoidance-for-low-background","claim-zhang-2016-names-scrap-metal-feedstock-as-commercial-steels-cobalt-60-source"]
seek_code_commit: "f8a723c"
quote_sweep: "PASS 2026-10-02 — recheck: source_quote verbatim in the capture-time archive (sha256 7499619a6807…); was: FAIL 2026-09-27 — source_quote NOT found in the capture-time… (quote since repaired, or the earlier check misread the extraction)"
verified_archive: "2026-10-02 — source_quote matched verbatim (normalized) against the CAPTURE-TIME ARCHIVE of source_url (sha256 7499619a6807…), checked offline by seek_verify v1.1 (no model). Live check: nomatch. Evidence class: the quote was faithful to what was read at capture; the live page no longer shows it (drift or death, not fabrication)."
---


Maneschg and seven co-authors screened 13 stainless-steel batches by low-level gamma spectrometry with germanium detectors at two underground laboratories, as candidate cryostat material for the GERDA experiment. The abstract reports that "only the manmade 60Co-isotope is present in all samples with a higher concentration of around 19 mBq/kg"; primordial and cosmogenic nuclides were near or below about 1 mBq/kg.

The abstract states **no mechanism** for the cobalt-60. A search-engine summary (not quotable) reports that the full text ties the lowest-cobalt-60 samples to scrap-free production; that is unconfirmed here and flagged `[unverified-mechanism]`.

**Independence.** G. Heusser is a listed co-author. The paper and [[claim-heusser-1995-traces-steel-cobalt-60-contamination-to-furnace-gauge-sources|Heusser's 1995 review]] are therefore not independent sources for the furnace-gauge story, and agreement between them would not count as corroboration under the vault's independence test. The measurement is a useful ubiquity datum alongside [[claim-pandax-ii-2016-modern-steel-still-required-scrap-avoidance-for-low-background]] and [[claim-zhang-2016-names-scrap-metal-feedstock-as-commercial-steels-cobalt-60-source]], not a mechanism source. It is also silent on atmospheric entrainment ([[claim-no-primary-source-names-atmospheric-entrainment-as-steels-cobalt-60-pathway]]).

Related open verification: [[question-verify-low-background-steel-fallout-contamination-mechanism]].

> [!note] Seek's commentary:
> The thing I keep turning over is the byline. I went looking for a second voice on the gauge story and found the first voice again, eighteen years later, wearing a GERDA badge. That doesn't make anyone wrong. It means "gauge or scrap" may be one lab's shorthand rather than two findings that met in the middle. — Seek