[en] Nuclear energy continues being commonly used nowadays in spite of the general tendency to substitute it by cleaner ways of energy production. In any case, one of the disadvantages of this method of energy production is the necessity of environmental control of the radioactivity especially close to the vicinity of nuclear facilities. Another important drawback is the large amount of residues that it produces. These are originated either in the normal activity of the nuclear power plants and/or on the decommissioning of these plants. A big part of these residues will need to be stored in special facilities especially designed for this purpose. In order to optimise this process, it is very important to characterize them very well so that only the ones that strictly need this storage treatment are sent to these special stores. This would reduce strongly the amount of material that must be treated as radioactive and, consequently, the loading rhythm of the stores and their economic and social impact. The long-lived radionuclides fulfil two important characteristics: they remain for a very long time in the nuclear residues and, in many cases, they are very difficult to detect by radiometric methods, as these do not have always enough sensitivity. In spite of this, the knowledge of their activities is essential for their appropriate evaluation. In these cases, a maximum level is fixed although the real level of the radionuclide in the residue will be much lower. The lack of sensitivity is clearly also an inconvenient for environmental samples.

[en] Nuclear energy continues being commonly used nowadays in spite of the general tendency to substitute it by cleaner ways of energy production. In any case, one of the disadvantages of this method of energy production is the necessity of environmental control of the radioactivity especially close to the vicinity of nuclear facilities. Another important drawback is the large amount of residues that it produces. These are originated either in the normal activity of the nuclear power plants and/or on the decommissioning of these plants. A big part of these residues will need to be stored in special facilities especially designed for this purpose. In order to optimise this process, it is very important to characterize them very well so that only the ones that strictly need this storage treatment are sent to these special stores. This would reduce strongly the amount of material that must be treated as radioactive and, consequently, the loading rhythm of the stores and their economic and social impact. The long-lived radionuclides fulfil two important characteristics: they remain for a very long time in the nuclear residues and, in many cases, they are very difficult to detect by radiometric methods, as these do not have always enough sensitivity. In spite of this, the knowledge of their activities is essential for their appropriate evaluation. In these cases, a maximum level is fixed although the real level of the radionuclide in the residue will be much lower. The lack of sensitivity is clearly also an inconvenient for environmental samples.