The licensee dose assessment methods are inaccurate under some circumstances. Title 10 of the Code of Federal Regulations, Section 50.54(q)(2) requires, in part, that power reactor licensees follow and maintain the effectiveness of an
emergency plan that meets the requirements of Appendix E to Part 50 and the standards of
10 CFR 50.47(b). Section 50.47(b)(9) requires that adequate systems, methods, and equipment for assessing the actual and potential offsite consequences of a radiological emergency condition are in use. Contrary to the above, between December 5, 2009, and April 23, 2014, Callaway Plant did not maintain the effectiveness of an
emergency plan that fully met the standards of
10 CFR 50.47(b). Specifically, the licensee failed to maintain adequate systems, methods, and equipment for assessing the actual and potential offsite consequences of a radiological release to the environment. The licensee identified circumstances which could cause their dose assessment program to overestimate offsite doses by a factor of 24. This finding was assessed using Manual Chapter 0609, Appendix B,
Emergency Preparedness Significance Determination Process, and was determined to be of very low safety significance (Green). The finding was a failure to comply with NRC requirements, was not a loss of risk significant planning standard function, and was not a degraded planning standard function. The finding was determined not to degrade the planning standard function because the calculation was not inaccurate in its normal operating configuration, the circumstances in which the inaccurate calculation would be used were rare, a method existed for the operator to correct the error, and because the error could be readily detected from examination of the dose assessment report. The issue was entered into the licensees corrective action program as Corrective Action Request 201402814.
