Rapid screening technique for gross α and gross β estimations in aqueous samples during radiation emergency

A portable liquid scintillation counting system has been used as a rapid screening tool for radiological characterization and in situ measurements of aqueous samples. The methodology was standardized based on the Pulse Length Index for gross α and gross β activity determinations in aqueous solutions by means of a portable Liquid Scintillation Counter (LSC). This single compact PMT system yielded precise results for aqueous test samples, which were validated against a conventional HIDEX 300SL LSC system. The sensitivity of the portable LSC for gross measurements was investigated thoroughly for various combinations of scintillation cocktails and sample proportions, and found to be well below the Operational Intervention Levels (OILs) recommended by Atomic Energy Regulatory Board (AERB) during radiation emergency scenarios. Gross α- and β-activity measurements by means of the portable LSC system have shown this procedure to be effective for preliminary screening and evaluating the total radioactivity in aqueous samples during such radiation emergencies.