Gray-Star, Inc., has published a fact sheet on its “transportable,” 202-ton irradiator. The company describes the machine as “no more difficult to use than a microwave oven.” Even so, it offers such a sophisticated tracking system that “governmental regulatory agen–cies, such as the United States Department of Agriculture, can review the unit’s processing records with a special code number and a simple phone call from anywhere in the world.”
While concerns have existed for years about the use of cesium in irradiators -and, in fact, the Hawai’i Legislature banned cesium-sources for use in the state – the Gray-Star’s cesium source, the company claims, is absolutely, “inherently safe.” It is contained in four panels inside a 105-ton steel box. This normally sits in the ground but when products are to be treated, the box is lifted up by six hydraulic cylinders to encase the material to be irradiated.
To operate the machine, no skilled labor is needed. According to the company’s brochure, operating training requirements are “minimal; one day, on site. Only basic literacy is required.”
Another advantage that the Gray-Star manufacturer claims for the machine is that it can be operated for much longer than cobalt-based systems without the need for source replenishment. That’s because cesium-137 has a half-life of 30 years, mean–ing that its radioactive strength decays by half over this period of time. Cobalt-60, on the other hand, has a five-year half-life.
The brochure’s language implies, by use of the present tense, that the Gray-Star equipment is up and running. Not quite.
The first machine has yet to be built. Demonstrating its effectiveness and safety may take two years or more, after a proto–type is delivered to the USDA. Assuming that no problems are identified, produc–tion of the “seventh” Gray-Star may be years off.
Volume 7, Number 8 February 1997