Partners in the radiation management program included Electric Power Research Institute, Fiatech and CSA.
Advanced algorithms and state-of-the-art visualization software are being combined into powerful tools that can be used by nuclear plant workers to more effectively plan maintenance activities by simulating how dose exposure will change as an avatar moves through a work environment. Various what-if scenarios can be visualised and evaluated at multiple locations and elevations in advance to minimise worker exposure and to communicate potential risks.
Work activities at nuclear power plants are planned to an exceptional level of detail to protect the health of plant workers and to ensure the plant is maintained in a safe condition. Nuclear plants therefore, conduct detailed surveys of work environments to measure radiation levels, and work planners then use this information to determine how a specific task can be performed with minimal exposure.
Traditional dose estimation techniques, however, have limitations and do not fully capture dose variations in a particular work environment. These limitations hamper the ability of work planners to determine the actual dose a worker may receive when standing near a particular piece of equipment.
Using information collected from radiation surveys and laser scanning, 3D data and visualization software can now be used to produce high-quality simulations of nuclear plant work environments. When coupled with an improved dose estimation capability, this software can help ensure individual and task exposure levels that meet ALARA (as low as reasonably achievable) planning and compliance requirements in maintenance tasks.
The new solution was developed collaboratively with the Electric Power Research Institute (EPRI) first developing a subroutine using the three-dimensional aspects of radiological conditions to estimate dose rates for workers during each step of the work activity, including predictions of dose rates for locations that had not been surveyed. The algorithm relies on survey or real-time radiation data and technician knowledge of radioactive sources, including possible hot spots.
Working with Fiatech, various advanced technology companies including Siemens PLM Software and CSA, have developed visualization software packages that can produce accurate models of industrial work environments using 3D laser scanning and 3D CAD technology. These software systems can integrate the EPRI dose estimation algorithm and generate visual models that represent the differences in dose levels in three dimensions.
Using more accurate dose estimates, planners can develop the most efficient plan for individual work tasks to minimise radiation exposure. The 3D models enable various simulations to be conducted, such as simulating a constraint on worker time while performing a task in a particular location, or installing protective shielding.
EPRI validated the dose estimation algorithm in a 2011 pilot scale demonstration using data from a Midwest U.S. nuclear plant, and the 3D software vendors subsequently validated the integration of their individual products with the algorithm.
EPRI coordinated a full-scale demonstration of the combined algorithm and software visualization products at the same Midwest plant in 2012.
Additional adjustments will be made to the EPRI algorithm based on the full demonstration scenario. The participating vendors will be working with host plants to test and refine their prototypes in preparation for commercial application.
Key benefits of the solution:
- More effective planning of work activities to minimise worker exposure and cost
- More accurate dose estimation in work environments
- Visual representation facilitates scenario analysis and evaluates use of dose reduction strategies such as shielding
- More effective use of radiation surveys by integrating data with a laser scan or 3D representation of the facility
- Improved communication of radiological conditions and risks to workers
- Enhanced training of new workers using modern tools
- Support of compliance reporting