Nuclear desalination: An inter-regional collaborative effort at CEA

This paper summarises ongoing investigations on the possible application of nuclear energy for sea water desalination under the CEA's own research and development programme and in the context of several international collaborations, coordinated by CEA: with South European Countries under EU R and D programmes, with the International Atomic Energy Agency (IAEA), with India and with some North African countries. Rather than limiting the work to conventional generic studies, the basic aim of the research undertaken is to bring substantial innovative advances in the use of nuclear reactors as an economically competitive and environmentally friendly energy source for the cogeneration of electricity and water. The results reported in this paper include: - Elaboration of optimised coupling schemes between the nuclear reactors PWR-900, AP-600, GT-MHR and PBMR and the desalination processes MED (Multiple Effect Distillation) and RO (Reverse Osmosis). - The use of the waste heat rejected by nuclear reactors, such as the GT-MHR and the PBMR, for a 'virtually free' desalination with the MED process. - The development of an innovative Reverse Osmosis process, with the preheating of the feed-water (ROph process), leading to a significant reduction of the desalination costs as compared to traditional RO process. The preheating in particular could also use the waste heat evacuated through the main condenser of PWRs. - The results of two technical-economical evaluations of integrated nuclear desalination systems for sites in Southern Europe (the EURODESAL project) and for la Skhira site in Tunisia (the TUNDESAL project). It is observed that for fossil fuel costs superior to 150 US Dollars/toe, the desalination costs by GT-MHR + MED system is 46% lower than that by the gas turbine combined cycle plant, (CC600) + MED system. It should be recalled that the CC600 is the cheapest fossil fuelled option. Similarly, desalination cost by PWR-900 + ROPh is respectively 18 and 24% lower than the CC600 + MED and CC600 + RO systems. - The development of a dynamic simulator for the Multiple Effect Distillation (MED) process. - The development and incorporation of new models in the IAEA code DEEP, which has now become an international reference for desalination cost evaluations. (authors)