On-Site Inspection Training

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) mandates that “each inspector included in the list of inspectors and inspection assistants shall receive relevant training" upon entry into force. Such training shall be provided by the Technical Secretariat pursuant to the procedures specified in the Operational Manual for On-Site Inspections.

The resolution establishing the Preparatory Commission for the CTBTO (1996) provides the overarching mandate related to on-site inspection training – to develop a programme for the training of inspectors that will be ready for entry into force. That objective is achieved by design, implementation, validation, and evaluation of the OSI Inspectorate training programme.

Development of the OSI training programme commenced in early 1997 to initially investigate the requirements for inspectors working within the confines and requirements of the Treaty. Over the years the training programme has built on these early efforts and developed into a robust programme with the successful completion of the first, second, and third training cycles.

Thus far the PTS has established a roster of about 170 surrogate inspectors. These experts have been nominated by States Signatories or are designated PTS staff and have successfully completed the first, second, or third training cycles. Surrogate inspectors remain on the roster as long as their designations by the nominating States remain unchanged, their skills and knowledge are refreshed, and they are physically fit. 

OSI Linear Training Programme 


The Third Training Cycle, completed in 2021, was a major milestone in the development of the inspector training programme and is envisaged to serve as the model upon entry-into-force in the form of a linear training programme. The linear training programme also incorporates skills maintenance programmes (refresher training) as well as new intake training mid-stream through the biennial OSI Regional Introductory Course series.