Year
2012
Abstract
This paper is an attempt to clarify and enhance the means by which relevant detection, measurement systems and technique can be evaluated and implemented into NDA programs. All relevant programs involving Special Nuclear Materials (SNM) must meet primary defined quality requirements which in the USA are exemplified by DOE Order O 414.1D1). Special Nuclear Materials (SNM) are fissile materials, in a variety of forms, and are distributed or contained in differing conditions and process equipment scenarios2,3). Assays are performed for varied purposes, including process monitoring, support of Decontamination and Decommissioning (D&D) efforts, nuclear criticality safety, and safeguards4,5). All NDA programs, procedure and their control must meet the requirements of the above mentioned order. A knowledge gap exists between the detector and system manufacturer and the NDA engineers who use the systems in the field. The focus of the detector manufacturer is to create new products, encompassing both hardware and software that hopefully present a maximum range of dynamic performance. Manufacturer performance claims may be difficult to interpret by the NDA engineer because field conditions are rarely an exact match to conditions tested by the developers. Likewise, the manufacturer may have difficulty in understanding field measurement needs and providing sensors with measurement performance with properly defined quality. Comparative studies and measurement can be time consuming and expensive. To aid developers both sides of this gap we highlight and define the primary requirements of major NDA quality assurance programs and how these might be meshed with appropriate and quantified detector performance requirements. Suggested detector measurement and quality criteria are examined and proposed to identify detector suitability for given measurement geometries. These include spatial performance, heterogeneous matrices and SNM distributions, interfering background counts and sources, energy resolution and detection efficiency. Examples are discussed for uranium and plutonium bearing compounds, using HPGe detectors and portable hand held detectors used for “holdup” measurement.