of the argon plasma, where temperatures reach nearly 10000oC. At these temperatures chemical compounds of the mist dissociate into the component atoms and then ionised towards the end of the plasma. The ions are then brought into the mass spectrometer via the interface cones, where they are separated by their mass-to-charge ratio. The ions then exit individually and come into contact with a dynode of an electron multiplier, which detects the electrons released by the impact of the ions[8]. At the end of each leaching test a 20 ml sample from the leachate was collected in a centrifuge tube. The samples were filtered and acidified with nitric acid to ensure stability and comparability with calibration standards. The samples were submitted to the Sheffield Assay Office where the ICP-MS was performed. Table 3.5 summarises the solutions analysed. Table 3.5: Solutions analysed using ICP-MS. Solution Elements Analysed calcium, aluminium, Blank (B) magnesium, sodium calcium, aluminium, Caesium Nitrate (C) magnesium, sodium, caesium calcium, aluminium, Strontium Nitrate (S) magnesium, sodium, strontium 3.4 The calcium, aluminium, Caesium Nitrate and impact magnesium, sodium, caesium, Strontium Nitrate (CS) of strontium on leaching behaviour Introduction The aforementioned complexing behavior of superplasticisers and its impact on leaching of radionuclides, was investigated by comparing the concentration of cerium in a leachate from two static leaching tests. Furthermore in the storage environment any leached radionuclides from the cement would then come into contact with cement backfill, this project also tested the permeability of the Nirex Reference Vault backfill (NRVB) used in industry to assess how much of the leached cerium will actually escape to the surrounding
of the argon plasma, where temperatures reach nearly 10000oC. At these temperatures chemical compounds of the mist dissociate into the component atoms and then ionised towards the end of the plasma. The ions are then brought into the mass spectrometer via the interface cones, where they are separated by their mass-to-charge ratio. The ions then exit individually and come into contact with a dynode of an electron multiplier, which detects the electrons released by the impact of the ions[8]. At the end of each leaching test a 20 ml sample from the leachate was collected in a centrifuge tube. The samples were filtered and acidified with nitric acid to ensure stability and comparability with calibration standards. The samples were submitted to the Sheffield Assay Office where the ICP-MS was performed. Table 3.5 summarises the solutions analysed. Table 3.5: Solutions analysed using ICP-MS. Solution Elements Analysed Blank (B) calcium, aluminium, magnesium, sodium Caesium Nitrate (C) calcium, aluminium, magnesium, sodium, caesium Strontium Nitrate (S) calcium, aluminium, magnesium, sodium, strontium Caesium Nitrate and Strontium Nitrate (CS) calcium, aluminium, magnesium, sodium, caesium, strontium 3.4 The impact of on leaching behaviour Introduction The aforementioned complexing behavior of superplasticisers and its impact on leaching of radionuclides, was investigated by comparing the concentration of cerium in a leachate from two static leaching tests. Furthermore in the storage environment any leached radionuclides from the cement would then come into contact with cement backfill, this project also tested the permeability of the Nirex Reference Vault backfill (NRVB) used in industry to assess how much of the leached cerium will actually escape to the surrounding
Wail%20Gashier%20Thesis.docx