Abstract: A method for investigating a volume of material at an investigation location for radioactive material includes: detecting signals from a first detector caused by the interaction of one or more types of emission from the radioactive material with the first detector; detecting signals from a second detector caused by the interaction of cosmic rays and/or one or more types of particle generated by cosmic rays with the second detector; processing the signals from the first detector to provide information on the amount of radioactive material associated with the volume of material; processing the signals from the second detector to provide information on the amount of cosmic rays and/or one or more types of particle generated by cosmic rays incident on the investigation location; and correcting the information on the amount of radioactive material associated with the volume of material using the amount of cosmic rays and/or one or more types of particle generated by cosmic rays incident on the investigation locati

Abstract: A method of correcting a measure of radioactive material within a body of material includes measuring a characteristic of the radioactive material to provide a measure, such as gamma emissions; detecting muons and/or electrons generated by muons which have not passed through the body of material to give a first value; detecting muons and/or electrons generated by muons which have passed through the body of material to give a second value; processing the first value and second value to give a factor, for instance indicative of the density of the body of material; and correcting the measure using the factor to obtain a corrected measure of the radioactive material with the body of material, for instance to correct for the density of the body of material and attendant issues such as attenuation and shielding.

Abstract: A method for investigating a volume of material at an investigation location for radioactive material includes: detecting signals from a first detector caused by the interaction of one or more types of emission from the radioactive material with the first detector; detecting signals from a second detector caused by the interaction of cosmic rays and/or one or more types of particle generated by cosmic rays with the second detector; processing the signals from the first detector to provide information on the amount of radioactive material associated with the volume of material; processing the signals from the second detector to provide information on the amount of cosmic rays and/or one or more types of particle generated by cosmic rays incident on the investigation location; and correcting the information on the amount of radioactive material associated with the volume of material using the amount of cosmic rays and/or one or more types of particle generated by cosmic rays incident on the investigation locati

Abstract: The method includes providing the volume of waste in a monitoring space; providing a support, the support being provided with a plurality of detectors for radioactive material; monitoring the volume of waste for radioactive material, in one or more parts, to give a monitoring results; and correcting the monitoring result for geometry and/or attenuation to give a corrected result using a correction factor. The correction factor is obtained by a method that includes providing a simulation of an equivalent volume of waste free of radioactive material in an equivalent monitoring space, with equivalent detectors; providing a known activity radioactive source at one or more positions in the volume of waste; determining the detector response to the source in a position, a comparison of the response and known activity contributing to a correction function for that equal volume, one or more such correction functions providing the correction factor.

Abstract: Methods and apparatus are provided for measuring emissions from radioactive material in a matrix. Consideration is made in the variation in counts observed at different rational positions of the body of material so as to establish the information about the position of the radioactive material within the matrix.

Abstract: A method of monitoring radioactive emissions which includes obtaining a data set, the data set including a record of an event together with an indication of the time of the event and/or the detector which detected the event. The method also includes processing the data set by analyzing the whole of the data set according to a first set of criteria to provide a first analysed data set and analysing the whole of the data set according to a second set of criteria to provide a second analysed data set, one or more criteria of the second set being different to the criteria of the first set. The first set of criteria and the second set of criteria both include a first time period and a second time period.

Abstract: Method and apparatus is provided for monitoring an item for radioactive material on or associated with the item, the apparatus including an enclosed volume, an item monitoring location, a detection location, ion detectors provided within the detection location, a mover of gas for providing a flow of gas past the item monitoring location to a detection location, so as to revel the level and/or presence of radioactive material on the item. The item may be supported within the monitoring location by one or more rollers to ease its insertion and/or removal. The item monitoring location may be extremely elongate so as to measure pipes and the like. Various designs of roller and gas flow controllers are provided to optimize monitoring.

Abstract: A method of correcting a measure of radioactive material within a body of material includes measuring a characteristic of the radioactive material to provide a measure, such as gamma emissions; detecting muons and/or electrons generated by muons which have not passed through the body of material to give a first value; detecting muons and/or electrons generated by muons which have passed through the body of material to give a second value; processing the first value and second value to give a factor, for instance indicative of the density of the body of material; and correcting the measure using the factor to obtain a corrected measure of the radioactive material with the body of material, for instance to correct for the density of the body of material and attendant issues such as attenuation and shielding.

Abstract: By considering ratio of emissions at one or more pairs of energies to threshold values, the invention provides for the determination of the dispersion format of a radioactive material within a matrix, wherein said radioactive material is potentially present in a dispersion format which is self-shielding against emissions arising from said radioactive. In particular the presence of lumpy material or the confirmation that lump material is absent may be provided. The following pairs of energies: 143.8 keV and 185.7 keV; 163.3 keV and 185.7 keV; 205.3 keV and 187.5 keV may be used.