Radiological Contamination Monitoring

New Automation Methods and Service Commitment Combined

As UniTech continues to develop new and efficient ways to meet customers' service requirements, one area of focus is enhancing best practices in meeting customers' monitoring needs.

Why Do We Survey Equipment and Materials?
It's green, it's sustainable and it saves our customers money. Surveying is the first step to allow us to identify loose and fixed radioactivity in materials. Decontamination and free release saves on disposal or storage costs.

There is an increasing demand to monitor tools, equipment, apparel, accessories, and other items for contamination after use and prior to free release or return to the customer. These services must be handled with the ultimate concern for accuracy, and oftentimes are both labor-intensive and time-consuming.

The Promise of Automation
UniTech continually explores effective new approaches to monitoring. One that shows great promise for many processes is automating our radiological monitoring of items. We use automated monitoring processes for flat materials such as wood, metal, drywall, planks, and more. We also automate monitoring for cylindrical materials including pipe, scaffolding, cable, wire, and respirator cartridges.

Automated surveys can work well with some surface contaminated items. When hand surveying, human performance factors present challenges even with relatively simple (flat) geometries.

The benefits of taking new approaches to automated monitoring are many:

• Increased productivity
• Improved performance
• Constant surface to detector distance
• Constant survey (scanning) speed
• Controlled survey coverage/detector overlap
• Eliminates human variability and error
• Reduced Minimum Detectable Activity (MDA); no surveyor efficiency factor
• Improve reproducibility and defensibility of survey results
• Data collection – computerized for permanence, ease of storage and quality
• Data processing is improved in several ways:
  • Statistical evaluation – data may be evaluated by a number of different tests
  • Count data may be evaluated by combining discrete counting intervals in different ways
  • Can evaluate combinations of detectors
  • Can attain constant background evaluations when not monitoring materials
  • Can receive early warning of instrument QC that is out of spec

Advanced Techniques and Monitoring Equipment
Personnel contamination monitors offer common boundary egress control and are relatively simple with no moving parts. For these, automation is limited to a timed count (MDA: 4 sec 95% CL, 1000 / 3200 DPM).

Laundry monitors are excellent candidates for automation. UniTech has optimized its Automated Laundry Monitors (ALMs), which transport garments and flat materials past various arrays of detectors. UniTech has pioneered systems with a cross-linked wire mesh belt to maximize coverage area and minimize dead space, has optimized the placement of detectors (allowing them to be adjusted for particular monitoring needs) and more.

UniTech has also made advances in respirator cartridge monitoring. To achieve high sensitivity, detectors were designed around the exact shape and size of the MSA cylindrical cartridge, the most commonly used cartridge in the nuclear industry. To get reliability and repeatability, the positioning of the cartridge near each of several different shape detectors is done robotically. Sorting of overlimit items into separate receptacles is done in a fully automated manner. To see it in operation visit here.

To learn more about UniTech's innovations in pipe and scaffolding monitoring, see our summer 2011 UniTRACK online or visit our Tool and Metal Decontamination page.