The Canadian Nuclear Laboratories Ltd. (CNL) successfully implemented a set of upfront sampling characterization works for the Nuclear Power Demonstration (NPD) reactor.  The NPD reactor is presently in the Storage with Surveillance (SWS) phase of decommissioning and CNL is planning for the final stage of decommissioning. The preferred decommissioning approach is in-situ decommissioning due to the below-grade configuration of the reactor and unavailability of nuclear waste disposal within Canada.

Development of the detailed decommissioning plans included the post closure safety case requiring verification of the radiological inventory of the CANDU reactor.  The majority of the radiological inventory within the NPD facility is associated with activation of reactor core components (calandria and pressure tubes), the concrete biological shield (reactor vault), the heat transport system, and the moderator system. The heat transport and moderator systems were expected to contain fission product and tritium surface contamination as a result of fuel failures.  Radiological inventory estimates on the reactor core components have been calculated using neutron activation modeling and previous coring characterization. 

CNL requested NMNTI who as a first of its kind in the world accomplished deep drilling and sampling and characterization of the NPD reactor components into the Aluminum Calandria and Zircaloy 2 Fuel Pressure Tubes and also performed the processing of Characterization data (i.e. sample collection and analysis) required for correlation to the calculated estimates in order to characterize the uncertainty associated with the radiological inventory present in the activated reactor core components, provided a NPD reactor Sampling Plan, and also provided the characterization results in a report to enhance data confidence and certainty to meet radwaste exemption levels and complement the Environmental Impact Statement for submittal to the Canadian Nuclear Safety Commission (CNSC).