Radiation sickness is the result of exposure to very large doses of ionising radiation, which can be acute (a single large exposure) or chronic (a series of small exposures spread over time).
Within the workplace exposure can be accidental, as is the case with nuclear power plant accidents, or intentional, for example inside neonatal wards at hospitals where nurses often hold babies still during an X-ray.
If a link can be made between your working conditions and symptoms, leading to a diagnosis of radiation sickness, it is likely that you will be eligible to make a hazardous substance claim against your employer.
Generally radiation sickness is associated with acute exposure and has a characteristic set of symptoms that appear in an orderly fashion. Chronic exposure is usually associated with delayed medical problems, such as cancer and premature ageing, which may happen over a long period of time.