ABSTRACT
The product must be tracked from the time it is received at the irradiation facility until it leaves the facility. Tracking and segregation of product can be divided into incoming, in-process and post-process phases. Prior to being processed, a product run needs to be scheduled into the irradiator. This is a relatively simple process at an electron beam irradiator, where the irradiation zone is confined to a single product unit, but it becomes more complicated at X-ray facilities and gamma irradiators, where multiple product units can be irradiated at a given time. The design of the gamma or X-ray irradiator also plays a role in the complexity of the scheduling process. For example, in small batch-type gamma irradiators, scheduling can often be handled simply on a first in, first out basis, while in large irradiators, more sophisticated algorithms may be required. During irradiation, cycle times must be set, and conveyor speeds must be controlled to ensure that products spend an appropriate time in the irradiation field. Timer settings and movement of product in the irradiation cell are usually controlled and monitored
through the use of programmable logic controllers (PLCs) or equivalent monitoring devices. Also, dosimeters that are dispersed at minimum and maximum dose locations within product containers in the run or at a reference location, confirm that the product was properly dosed. Control of information and documentation is usually handled using a management information system (MIS).
