Safety Performance of Se-75 Radiography Sources

Shilton, Mark; QSA Global Inc; United States

Shilton, M.G.; QSA Global; USA

ID: ECNDT-0120-2018
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Se-75 is a versatile gamma radiography nuclide. Its energy is optimum for the range of materials and thicknesses of common interest to gamma radiographers and it is an excellent choice for Small Controlled Area Radiography (SCAR). Its use is continuing to grow with the introduction of new Se-75 exposure devices, enabling the SCAR technique to be implemented simply, safely and effectively. SENTINEL has developed an optimized, third-generation Se-75 source using metal-alloy selenium for use with both SCAR and conventional exposure devices. This source has improved near-spherical focal geometry and is available in higher activities up to 120Ci. Its focal dimension of 3.5mm is the smallest on the market at this activity level.
• Highest specific activity and smallest focal dimension: better images
• Inherent safety with source tested to 1250C – intrinsically safer
A radiological incident in Europe in 2016 resulted in the rupture and leakage of 75Se from a commercial source that had been made using elemental selenium. Due to the ensuing high financial and commercial costs associated with such an incident, it prompted SENTINEL to carry out a new series of high temperature integrity tests to verify the superior performance of SENTINEL’s proprietary metal-alloy source technology and to compare the results with sources made using elemental selenium. This paper describes the thermal test program and discusses the implications for the safety and performance of gamma radiography using Se-75.