METHOD OF SAMPLING NUCLEAR FALL-OUT FROM STORAGE CAPACITIES AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2010 - IPC G21F9/34 

FIELD: power industry.

SUBSTANCE: inventions are intended for sampling of fall-out of high activity level from nuclear waste storage capacities of radiochemical manufacture. Besides the proposed method can be used during drilling of expendable wells. Method involves operations of the well full-diametre drilling, supply of flushing liquid to drill string and transportation of drilled solids (bit cuttings) through an annular gap between well walls and drill string to the surface. First, portion of flushing liquid is supplied to lower drill pipe of the string, to which then the drilled settling is supplied. Then by alternating pulse short-time compressed air supplied to drill string and air discharge, first, the drilled settling is suspended in flushing liquid, and then by means of supply of dosed portion of compressed air the obtained suspension is forced out through annular gap between the well walls and drill string to the settling surface in storage tank. Device includes drill string, screw rod with cutting drilling tool, sampler and movable sealing guide conductor string with a branch pipe located in side wall. Device is provided with receiving chamber the connection pipe of which is attached to upper drill pipe of the string. On the connection pipe of the receiving chamber there installed is movable sealing guide conductor string with a branch pipe; in connection pipe coaxially to the branch pipe there made are side holes; branch pipe is connected by means of a flexible hose to the distributor consisting of three quick-acting valves connected to flushing liquid, compressed air and blowdown supply pipelines, and lower drill pipe is equipped with a sleeve with internal bore the diametre of which is less than inner diametre of drill pipes; to the sleeve there attached is screw rod installed in the bushing with ribs, which is located between the sleeve edge and cutting drilling tool; diametre of circumscribed circle of ribs is more than diametre of cutting drilling tool the cutters of which are provided with chamfers directed towards the centre.

EFFECT: minimising liquid nuclear fall-outs appeared during drilling process.

10 cl, 4 dwg