NDTnet 1998 Aug, Vol.3 No.8

Abstract

The paper describes the development and application of a new type of radioactive isotope container and shielding system. The Small Controlled Area Radiography (SCAR) system enables a 500 Gbq, Iridium 192 isotope to be exposed within a controlled area of only 3 metres from the isotope. This is significantly smaller than the standard projection container controlled area for the same isotope type and strength, and provides the major benefit that other site work can be undertaken close to the area of radiography in complete safety. Furthermore, site radiography with the SCAR system can be undertaken on a continual 24 hours per day basis, instead of the normal practice of specific time periods being made available with resultant large areas of the site being cleared for radiography.

The system comprises of an integral isotope container and collimator, and a film holder backed by either lead or "radishield" to attenuate the radiation beam. A total of 40 systems are now being operated by OIS, not just in the UK but also in South Africa, and the Middle and Far East.

The SCAR system was originally developed for offshore use on BP platforms in the North Sea, where conventional radiography is difficult due to limited space and the close proximity of nucleonic production monitoring systems which will close production if triggered. Following successful use on a number of offshore installations, the SCAR system was reconfigured for more general use in onshore applications. The same container was used but additional jigs were produced to meet an ever increasing number of applications in the petro-chemical, power generation, gas transmission pipeline and heavy engineering fabrication industries.

The SCAR system has been designed to be completely fail safe, and together with its jigs is probably the safest isotope exposure system in existence. Significant cost benefits can be derived when used for site radiography, because of the low level of disruption to other nearby site activities during either construction or outages.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com