In situ system for direct measurement of alpha radiation, and related method for quantifying the activity of alpha-emitting radionuclides in solution

An in situ system for nuclear measurement of alpha radiation of an effluent, comprising:

• M diamond semiconductor detectors obtained by chemical vapour deposition, or silicon semiconductor detectors covered with a diamond layer, as alpha radiation detectors, configured to be immersed in the effluent, and to measure directly alpha radiation emitted by the effluent, wherein M is an integer greater than or equal to 1;
• P measuring channels connected to the M alpha radiation detectors, wherein P is an integer greater than or equal to 1 and less than or equal to M, and wherein each of the P measuring channels is configured to supply an alpha activity value or a sum of such values from the M alpha radiation detectors to which they are connected;
• wherein the system also includes, if P is greater than 1, means for adding together the results from the P measuring channels;
• and
• wherein the M alpha radiation detectors are individually calibrated by an alpha particle transport code based on Monte Carlo method, the alpha radiation detectors connected to a given measuring channel being calibrated in a same manner.

A method for in situ nuclear measurement of alpha radiation of an effluent, comprising:

• immersing in the effluent M diamond semiconductor detectors obtained by chemical vapour deposition, or silicon semiconductor detectors covered with a diamond layer, configured to measure the effluent's alpha activity, wherein M is an integer greater than or equal to 1, wherein the M alpha radiation detectors are connected to P measuring channels, wherein P is an integer greater than or equal to 1 and less than or equal to M, and wherein the M semiconductor detectors are alpha radiation detectors;
• calibrating the M alpha radiation detectors, wherein the detectors connected to a given measuring channel are calibrated in a same manner, and wherein the calibration is undertaken by an alpha particle transport code based on Monte Carlo method;
• detecting P values of the alpha radiation using the P measuring channels connected to the M alpha radiation detectors, wherein an ith value detected (where i=1 to P) is equal either to a value resulting from a single alpha radiation detector, if the corresponding measuring channel is connected only to the alpha radiation detector, or to a sum of values from the alpha radiation detectors connected by the measuring channel;
• if P is greater than 1, adding together the P alpha activity values.