In 1998, the Committee on Nuclear Regulatory Activities (CNRA) issued a report on future nuclear regulatory challenges which discussed the potential erosion of safety margins as an area for further research. In December 2003, the Committee on the Safety of Nuclear Installations (CSNI) set up the Safety Margin Action Plan (SMAP) expert group to develop a methodology for integral assessment of the changes of overall safety of the plant resulting from simultaneous changes in plant operations/conditions. This framework was outlined in the SMAP expert group final report ( NEA/CSNI/R(2007)9 ).
In June 2007, the CSNI initiated a follow-up task group to establish a pilot study applying the SMAP framework by evaluating the change in safety margins which would result from implementing the newly proposed rulemaking by USNRC on performing loss-of-coolant accident (LOCA) analysis. The assessment of the practicability of the SMAP framework was the main focus of the task group.
The present final report is the result of the work of the CSNI Task Group on Safety Margin Assessment and Application (SM2A).