PhD-chemical speciation of long-lived 99Tc

On behalf of the DTU, we are looking for: PhD Scholarship - chemical speciation of long-lived 99Tc and its environmental behaviour The project The project aims to establish analytical methods for chemical-speciation analysis of the long-lived radionuclide 99 Tc and investigate its environmental and geological behaviour.The behaviour of radio nuclides in the environment, their bioavailability and toxicity are determined mainly by their physico-chemical forms, i.e.speciation, and to a lesser extent by their gross concentrations.99 Tc , the only technetium isotope that occurs in significant quantities in the environment, is produced in nuclear reactors, and has been released to the environment particularly from reprocessing of spent nuclear fuel.The chemical valences of technetium range from -1 to +7, but in aqueous solution, the oxidation states +4 (TcO2) and +7 (TcO4-) predominate.In an oxidizing environment, the lower oxidation states are converted to the highly soluble pertechnetate TcO4, while in reducing conditions, pertechnetate is transformed into particle reactive (or insoluble) TcO2.The study of the behaviour of 99 Tc in the environment requires reliable analytical methods for the chemical speciation of 99 Tc in various samples, such as seawater, plants and sediment.Technetium has no stable isotope and occurs in the environment at very low concentrations, which makes the investigation of its chemical speciation and environment behaviour difficult.Rhenium has chemical properties similar to those of technetium, but rhenium is more abundant in the environment than technetium.Therefore, Re can be used as a chemical analogue of 99 Tc in the environment.Thus, information on chemical speciation of environmental Re is useful for the project.Qualifications * Master degree in radiochemistry, analytical chemistry or a similar degree * The candidate is expected to have a good background in analytical chemistry, environmental chemistry, radiochemistry and nuclear-measurement techniques * It is an advantage if the candidate is familiar with flow/injection analysis ICP-MS and analytical apparatus design Terms of employment The salary and appointment terms are consistent with the current rules for PhD degree students.The PhD stipend has a fixed duration of 3 years starting 1 September 2009.The employment will take place at Ris National Laboratory for Sustainable Energy in Roskilde.The scholarships for the PhD degree are subject to academic approval, and the candidates will be enrolled in one of the general degree programmes of DTU.Application http://www.ingenjorsjobb.se/j/2498 All interested candidates irrespective of age, gender, race, religion or ethnic background are requested to apply.