LARGE QUANTITIES OF LOW-LEVEL RADIOACTIVE WASTE IS PRODUCED DURING REFURBISHING, MAINTENANCE AND DISMANTLING OF NUCLEAR INSTALLATIONS, WHICH COULD BE RE-USED OR RECYCLED. IN ORDER TO FULFIL AUTHORITY REGULATIONS, PRECISE AND SAFE MEASUREMENTS SHOULD BE USED, EVEN ON CURVED SURFACES (E.G. INSIDE TUBES AND PIPES).
THE OBJECTIVE OF THIS RESEARCH IS THE DEVELOPMENT AND TESTING OF A DETECTOR SYSTEM FOR MEASUREMENT OF VERY LOW-LEVEL RADIOACTIVITY EVEN NEAR BACKGROUND LEVEL, SUITABLE FOR IRREGULARLY-SHAPED SURFACES LIKE INSIDE SMALL DIAMETER TUBES.
Work was aimed at the development of equipment for contamination measurement at places where access is difficult (eg in tubes or around corners). Special problems are associated with alpha-emitter contaminated surfaces and low energy beta-radiation. The complete range of possible measurement situations had to be taken into account including small source distances, high efficiency and low measuring levels. The proportional counters were optimised and tested in accordance with their physical and mechanical characteristics. Additionally, different types of electronic equipment arrangements were assessed. The initial aim of devising a comprehensive and easy to use measurement system has been satisfied.
B.1. DEVELOPMENT OF A BASIC ELECTRONIC EQUIPMENT, SUITABLE FOR THE EXISTING VARIOUS PROTOTYPE ROUND AND FLAT DETECTORS WITH INTEGRATED GAS SUPPLY AND ANALOGIC PART; TESTING WITH PROTOTYPE DETECTORS IN THE LABORATORY AND UNDER REAL CONDITIONS (KRB-A, GUNDREMMINGEN); DEVELOPMENT OF FURTHER DETECTORS TO COMPLETE THE RANGE.
B.2. DEVELOPMENT OF AN OPTIMISED STATIONARY AND PORTABLE DIGITALLY WORKING UNIT WITH BACKGROUND SUBSTRACTION; DEVELOPMENT OF SEMI-AUTOMATED OR AUTOMATED MEASUREMENT SYSTEMS FOR IRREGULAR SURFACES AND IMPROVEMENT AT LABORATORY SCALE.