Worker radiation measurement innovations makes top 100 list
September 24, 1992
RICHLAND, Wash. –
A new technology, which provides more effective radiation measurements for nuclear workers and may play a role in environmental monitoring, has been named one of the top 100 technological developments of 1992 by Research and Development magazine. The technology was developed for the U.S. Department of Energy by the Pacific Northwest Laboratory. Battelle operates the national laboratory for DOE.
The magazine conducts the annual R&D 100 Award competition to honor the most promising new products, processes, materials or software developed throughout the world. Awards are based on a product's technical significance, uniqueness and usefulness. This is the 30th annual competition.
The radiation measurement technology likely will result in a new generation of dosimeters -- devices that measure the radiation dose received by nuclear workers. The technology is a significant improvement over current dosimetry because it is more sensitive, retains data for dose confirmation, and the materials involved last longer, cost less and can be incorporated into plastic or fabric for workers to wear.
The technology involves exposing a thermoluminescent material to radiation. These materials currently are used in personnel dosimeters worn by workers who may be exposed to radiation and also are used in environmental radiation monitoring devices.
However, the new process, called Cooled Optically Stimulated Luminescence, does not require standard high temperatures for processing the information contained in the dosimeters. In the COSL process, thermoluminescent material is removed from the dosimeter and cooled in liquid nitrogen. It then is exposed to ultraviolet light and allowed to warm to room temperature. As the material warms, it emits a glowing green light. An accompanying device measures the total amount of light released by the material, which correlates to the amount of radiation exposure the dosimeter and the worker who wore it received.
Because the material is not exposed to high temperatures, the data is not erased after a single reading. This feature allows for cumulative dose readings, re-analysis of a questionable reading and a longer dosimeter life. The ability to measure cumulative doses is of special importance for pregnant radiation workers whose cumulative dose must be kept lower than that of other workers.
The COSL process also is 100 times more sensitive than conventional thermoluminescent technology, measuring much lower levels of gamma radiation at a significantly lower cost. Detectors used in the COSL process cost 10 to 50 cents each, while those used in standard dosimetry technology cost from $4 to $15 each.
With additional research, developers believe the technology could become a highly sensitive replacement for X-ray film, reducing patient exposure time by 100 to 1,000 times. Developers also say COSL may benefit aircraft manufacturing and maintenance operations because it offers improved detection of flaws in composite and laminate materials used to build planes.
Tags: Energy, Operations