The present invention relates to a method for the quantification of radionuclides in liquid media comprising measuring a gamma-ray spectrum, a device for the quantification of radionuclides in liquid media and the use for the quantification of radionuclide concentrations in hydrometallurgical processing media, especially the quantification of uranium and/or radioactive uranium decay product concentrations in uranium mining solutions or in uranium recovery solutions or the quantification of thorium and/or radioactive .sup.232Th decay products in rare-earth element processing solutions.

A method for generating a response function of a scintillator to incident gamma rays of energy within a range of energies of interest, the method including: obtaining the responses {S.sub.i} of the scintillator to a plurality of known radionuclides i (i=1, . . . N), each radionuclide i emitting gamma rays with known energetic properties (E.sub.ij, Y.sub.ij), decomposing, for each radionuclide i, response S.sub.i into primary responses of the scintillator S.sub.ij=ƒ(λ.sub.ij, Y.sub.ij, X.sub.ij), each primary response corresponding to the response of the scintillator to a received gamma ray of a known energy E.sub.ij for this radionuclide i, deriving from the primary responses {S.sub.ij} the response function ƒ(λ, X) of the scintillator to an incident gamma ray of any energy E within the range of energies of interest.

A device for measuring large-area radioactive surface contamination can simultaneously obtain a plurality of detection values. The measurement device includes a frame body having a plurality of holes; a mover that is connected to, and moves, the frame body; and a plurality of radiation detectors that rest in the plurality of holes. The detectors detect one or more of: alpha rays, beta rays, or gamma rays. The location and level of radioactive contamination are accurately identified according to a comparison of the detection values of the plurality of radiation detectors.

A device for measuring large-area radioactive surface contamination can simultaneously obtain a plurality of detection values. The measurement device includes a frame body having a plurality of holes; a mover that is connected to, and moves, the frame body; and a plurality of radiation detectors that rest in the plurality of holes. The detectors detect one or more of: alpha rays, beta rays, or gamma rays. The location and level of radioactive contamination are accurately identified according to a comparison of the detection values of the plurality of radiation detectors.

Methods and apparatus for calibrating radioactive sources are described. An array of scintillation detectors form a receptacle within which a sample or sample container can be retained by a holder. The scintillation detectors are coupled via light transducers such as photomultiplier tubes (PMTs) to independent electronic counters. Coincidence processing of time-tagged events yields a correlated event rate. One or more corrections can be applied as needed, for background counts, deadtime, or random coincidences. Voltage tuning of PMTs yields improved reproducibility. Variations are disclosed. 1% accuracy has been demonstrated over a range of 10 kBq-3 MBq, covering a gap in the capabilities of conventional technology.

Methods and apparatus for calibrating radioactive sources are described. An array of scintillation detectors form a receptacle within which a sample or sample container can be retained by a holder. The scintillation detectors are coupled via light transducers such as photomultiplier tubes (PMTs) to independent electronic counters. Coincidence processing of time-tagged events yields a correlated event rate. One or more corrections can be applied as needed, for background counts, deadtime, or random coincidences. Voltage tuning of PMTs yields improved reproducibility. Variations are disclosed. 1% accuracy has been demonstrated over a range of 10 kBq-3 MBq, covering a gap in the capabilities of conventional technology.

A planar-symmetry device for high-sensitivity gamma ray detection, which allows real-time tomography image reconstruction with very good spatial resolution. Advantageously, the multi-pinhole collimators of the device move during data collection and/or one or more of the pinholes thereof moves independently, thereby allowing possible artifacts resulting from overlap areas of the detector to be completely eliminated.

The present invention relates to a method for measuring radioactivity of radioactive waste, the method comprising an adsorption step (A) of selectively adsorbing a radioactive substance comprising at least one from among radioactive iodine and radioactive cesium from radioactive waste containing radioactive substances on an adsorption member for adsorbing a radioactive substance, and a measurement step (B) of measuring radioactivity of the radioactive substance.

The present invention relates to a method for measuring radioactivity of radioactive waste, the method comprising an adsorption step (A) of selectively adsorbing a radioactive substance comprising at least one from among radioactive iodine and radioactive cesium from radioactive waste containing radioactive substances on an adsorption member for adsorbing a radioactive substance, and a measurement step (B) of measuring radioactivity of the radioactive substance.

The present invention relates to a system for monitoring electrical properties of materials of deep bedrock samples for estimating nuclide movement in disposal site of spent fuel and, more specifically, to a system for monitoring electrical properties of materials of deep bedrock samples for estimating nuclide movement in disposal site of spent fuel which installs a tube wherein ring-shaped potential electrode is formed in multi layers inside a column; adheres the potential electrode to deep bedrock samples by pressing on the external side of the tube while filling the deep bedrock samples inside of the tube; and reproduces real condition of deep bedrock and monitors precisely by measuring electrical resistivity for each location of the deep bedrock samples while injecting nuclide and underground water to the inside the tube.