19–23 Jun 2023
Hofburg Palace & Online
Europe/Vienna timezone

A Comparison of Portioning Samples Under the Comprehensive Nuclear-Test-Ban Treaty Organization, the Organisation for the Prohibition of Chemical Weapons and the International Atomic Energy Agency

20 Jun 2023, 15:15
Prinz Eugen Saal

Prinz Eugen Saal

Oral T3.3 On-Site Inspection Techniques O3.3 On-site Inspection Techniques


Mr Brian Milbrath (Pacific Northwest National Laboratory (PNNL))


The Comprehensive Nuclear-Test-Ban Treaty language on an Inspected State Party’s right to portions of samples taken during an on-site inspection (OSI) is very similar to sampling language in the Chemical Weapons Convention (CWC), reflecting an overlap amongst negotiators involved. There are small differences in the treaties’ wordings, however, and in the case of the CTBT these differences have made it difficult for State Signatories to reach consensus on how to implement portioning of samples during an OSI. Meanwhile the CWC has been in force for 25 years, during which time the OPCW has developed procedures for inspectors to portion samples, though not all aspects of inspections or portioning have been fully exercised. Likewise, IAEA inspectors take samples during inspections and, while the concept of portioning may not be as explicit, procedures allow for the ISP to retain their own relevant samples. We examine how the ISP right to sample portions is practiced at the OPCW and IAEA and draw insights from their experiences to compare with the approaches considered at Preparatory Commission meetings.

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This work compares sample portioning under the CTBTO, OPCW, and IAEA with the goal of enlightening the discussion on how to implement sample portioning under CTBT.

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Primary author

Mr Brian Milbrath (Pacific Northwest National Laboratory (PNNL))


Mr Jonathan Forman (Pacific Northwest National Laboratory (PNNL)) Stephan Vogt (Pacific Northwest National Laboratory (PNLL) - retired)

Presentation materials