Determination of 137Cs and 90Sr in wood fuels and their ashes available in Austria

This study assessed the radiological risk of wood fuels and their ashes in Austria, including wood chips, logs, pellets, and briquettes. Commercially purchased wood fuels are often of unknown origin and may have been imported. 137Cs activity concentrations were measured in wood fuels (69 samples) and their ashes (27 samples) using gamma-ray spectrometers with high-purity germanium detectors. 90Sr analyses were performed on 12 ash samples after chemical separation using PerkinElmer 1220 Quantulus™ liquid scintillation counters. Results showed 137Cs activity concentrations ranging from 0.327 to 8.36 Bq kg-1 in wood fuels (average 2.1 Bq kg-1) and from 11.80 to 867 Bq kg-1 in ashes (average 310 Bq kg-1). The 90Sr activity concentrations in ashes ranged from 363 to 1200 Bq kg-1 (average 655 Bq kg-1). Summarizing, this study suggests that wood fuels currently available in Austria do not pose a significant radiological risk from their ashes, negating the need for import regulations.