CFM Updates Employee Dose Assignments
January 30, 2013
An internal review of the process used since 2003 to calculate internal radiation dose for employees at Cameco Fuel Manufacturing (CFM) identified errors in the formula that resulted in small miscalculations of dose for some employees. Even with the recalculated internal doses, no CFM employee exceeded the regulatory dose limit for nuclear energy workers, and no employee has received a dose that has or is expected to pose any health issues.
Recalculations indicate that some employee doses were lower than originally reported and some were higher. In total, the corrected calculations now indicate that there was one action level exceedance reported in 2010 that was not an actual exceedance and seven unreported action level exceedances between 2005 and 2010. Action levels are set well below regulatory limits to provide an early warning that something unusual is occurring. It is important to recognize that an exceedance of an action level does not represent a danger to workers. When an action level is exceeded, Cameco launches an investigation to determine the cause, with corrective measures implemented if needed. In response to this situation, Cameco initiated a root cause analysis that is underway to identify how it developed and recommend actions to ensure it does not happen again.
Cameco has recalculated internal doses for all employees and provided a summary of the revised numbers to the Canadian Nuclear Safety Commission. Employees have been briefed on the situation. The formula has been corrected and CFM is reviewing options for its dosimetry program going forward.