The WUW ML bundle detector - A flow through detector for alpha-emitters

Using conventional laboratory ware, we designed and manufactured a flow thr ough cell for monitoring cl-bearing solutions. The cell consists of a bundl e of thermoplastic, transparent tubes coated with a thin layer of the melta ble scintillator MELTILEX(TM) at the inner surface. With appropriate energy windows set, the detector can suppress beta-particles to a great extent du e to its geometrical dimensions. For pure cl-solutions, the detection limit s are 5 Bq/ml, for composite nuclide mixtures, the detector is capable to m onitor the decontamination of medium active waste (less than or equal to 10 (7) Bq/ml) down to 100 Bq alpha/g solution. At a throughput of 1 ml/s, the pressure build-up amounts to similar to 2 bar. We have developed a quality control program to ensure the regularity of the individual bundle loops. (C ) 1999 Elsevier Science B.V. All rights reserved.