Low-level radioactivity proficiency testing program in Taiwan.

Seven kinds of spiked low-level activity samples were used for the 2004-2007 proficiency testing program in Taiwan. There were 711 reported data of Gross-beta, (3)H, (60)Co, (90)Sr and (137)Cs were collected, and the bias, precision and traceability were evaluated. All the results were "Acceptable" for bias and precision, but 102 data were "Not Acceptable" for traceability. It reveals that the laboratories had good proficiency and well QA/QC management in routine practices, but the measurement uncertainty may be underestimated or overestimated.