GB834965A - Measuring device for radioactive fluids - Google Patents

Abstract

834,965. Nuclear reactors. BERGSTEDT, B. A. April 17, 1958 [April 23, 1957; Aug. 7, 1957], No. 12212/58. Class 39(4). [Also in Group XL(b)] A method for detecting and measuring the radioactivity of solids dissolved in a liquid comprises spraying the liquid into a hot gas stream to form an aerosol, filtering the aerosol in an electrostatic precipitator so that solids are deposited on a movable tape, and moving the tape past one or more detectors. The liquid, which may be the heavy water coolant of a nuclear reactor, enters the system through a pipe 10 and valve 13 and passes through a pump 12, by-passed by a valve 14, to nozzles to produce a fine spray in the chamber 25 containing hot carrier gas, which may be air or pure oxygen. The gas passes from chamber 25 to an electrostatic precipitator 28 where solid particles are precipitated on to a metal tape 29. The gas then passes to a filter 16, where fresh gas may be introduced through pipe 15, to a condenser 33 which removes the liquid and thence through an ion chamber 17 which detects any radioactive gases present and is connected to an alarm. The chamber 17 is connected to a blower 18, from which the gas passes to a junction 19 where gas may be extracted from the system through a pipe 20. After the junction 19 the gas passes to a further junction arranged so that part of the gas goes direct to chamber 25 and part goes past a heating element 26 and then to chamber 25. The tape 29, after collecting a radioactive deposit from the precipitator 28, moves past three detectors 36, 37, 38 which detect alpha, beta and gamma radiation respectively. The tape may then be fed over a long path, to allow a considerable time delay, to three further detectors for a further measurement after a known time interval.