NRC KICKS OFF EFFORTS TO ADDRESS ‘PHANTOM FOUR’ ISOTOPES

Nuclear Regulatory Commission kicked off efforts to address the ‘phantom four’ isotopes during a public hearing held in conjunction with the Waste Management Symposium in Phoenix, Ariz. last week. The consistent over-reporting of Carbon-14, Technetium-99, Iodine-99 and Cesium-137 came up as an issue as the NRC began work on the ongoing Site Specific Assessment rulemaking. Stakeholders told the agency that allowing generators to use alternative methods for measuring the isotopes’ concentration, more sophisticated manifests that allow non-scientists to accurately estimate the actual content of radiological shipments, and prioritizing accuracy over excessive conservatism would help disposal sites get a more realistic picture of the amount of certain isotopes they are receiving.  “From an activity standpoint of what we’re manifesting, it could be 100 times greater than what is present,” Billy Cox with the Electric Power Research Institute said at the March 1 meeting. “We need an accurate activity value on the manifest. That’s important, so we’re not biasing the disposal site inventory adversely or positively, but it’s also important from a performance assessment perspective that we have an accurate representation.”