Dounreay

Dounreay, Scotland (north coast) near U.K. AEA Technology Dounreay Establishment R D (nuclear reactor, reprocessing) ... 

Baron, P., Boullis, B. 1987. Modeling of uranium/plutonium splitting in PUREX process. I. Chern. E. Symposium, Series No. 103, Extraction 87, June 23-26, Dounreay, UK, p. 323. 

Kumar, Sh., Koganti, S.B. 2005. FBR MOX fuel reprocessing B Computer simulation of mixer settler experiments (reprocessing of 70%UO2 + 30%PuO2 Dounreay and KNK fuels) by indigenous computer code SIMPSEX. Proc. ISEC 2005, Beijing, China, September 19-23. 

Large amounts of sodium waste arise from fast neutron reactors (Phenix and Superphenix in France, Dounreay in the UK, Monju in Japan), which are cooled by large amounts of liquid sodium, which is contaminated by 137Cs during its functioning. We shall see that it is possible to remove radioactive cesium after conversion of liquid sodium to sodium hydroxide. 

Isotopic analysis has been used extensively in addressing questions of fundamental physics. Walker et al. used the Dounreay reactor to refine values of... 

MINERALOGICAL AND PARTICLE SIZE CONTROLS ON Cs ABUNDANCES IN DOUNREAY OFFSHORE AND FORESHORE SANDS... 

Particles Monitoring Manager, UKAEA, Dounreay, Caithness... 

The Dounreay site was established as the site of the UK Fast Breeder Nuclear programme in 1955 and became operational in 1958. It accommodated three reactors, the Materials Test Reactor, (DMTR, 1958-1969), the Dounreay Fast Reactor (DFR, 1959-1977) and the Prototype Fast Reactor (PFR, 1974-1994). With all reactor operations now finished and the reactors already de-fuelled the site is undergoing active decommissioning which is planned to be completed by 2032. The Dounreay site has been cited by UKAEA as being the second biggest nuclear decommissioning challenge in the UK with similar liabilities to those at Sellafield but with smaller waste volumes. 

Mineralogical and Particle Size Controls on Abundances in Dounreay 2 METHODOLOGY... 

The uptake of Cs by uncontaminated Dounreay offshore sand was investigated to confirm which mineral were involved in caesium sorption (DST-R 250pm fraction was tested). The results showed that the more-magnetic mineral fraction had a higher sorption capacity than the non-magnetic fractions. It is notable that the interaction time of 24hr may have been too short to establish maximum uptake potential. 

Dounreay Offshore sand Dounreay Foreshore sand... 

Figure 1. General bulk mineralogical composition (%) for Dounreay Offshore and Foreshore sand...

Figure 3. Particle size distribution (%) and total Cs activity (Bq) for Dounreay offshore sand (DST-MTR)...

I. W. Croudace and P. E. Warwick (2005) Mineralogical and particle size controls on Cs abundances in Dounreay offshore and foreshore sands. GAU634 Feb 2006 Commissioned study by UKAEA 04-1005extension. 

The metals are employed in a variety of alloys. Lithium generally hardens and strengthens, but also causes embrittlement from 0.05 to 0.1% is used in Al, Zn and Mg alloys. Sodium is an important additive to lead such an alloy is the basis of the manufacture of lead tetraethyl, and another, containing 0.6% Na, 0.6% Ca and 0.05% Li, is a bearing metal. Ternary alloys of caesium with aluminium and either barium or strontium are used in photoelectric cells. Liquid sodium or sodium-potassium alloy is employed to transfer heat from the core of certain atomic reactors, e.g. Dounreay fast breeder. 

From ref. 245 PFR = Prototype Fast Reactor at Dounreay, UK HLW= High Level Waste in which the bulk of the fission products (FP) are concentrated. 

Plants in the UK, USSR and France are now reprocessing irradiated UO2/PUO2 fuels and LMFBR fuel reprocessing has been the subject of international conferences. " The plant at Cap la Hague, France, employs a 30% TBP solution and no U/Pu separation is undertaken, so that a mixed U/Pu product is obtained. Fluoride is added to the process feed to complex zirconium and suppress its extraction." The Dounreay plant in the UK employs a 20% TBP/OK solution and uses sulfuric acid to effect the U/Pu separation. TBP poorly extracts Pu or U from sulfuric acid solutions, but in mixed HNO3/H2SO4 the equilibria shown in equations (206) and (207) must be considered. The equilibrium constants for these reactions, Kj, and K i, are given... 

Figure 47 An outline flowsheet for the reprocessing of Prototype Fast Reactor fuel at Dounreay Table 14 Equilibrium Constants " for Nitrate Complexes of Pa ...

PROBLEMS EXPERIENCED DURING OPERATION OF THE PROTOTYPE FAST REACTOR, DOUNREAY, 1974-1994... 

Performed in parallel to reactor defueling was the design and construction of the Sodium Process Facility. The design and construction of the Sodium Process Facility is an application of known and demonstrated technology. The conversion of alkali metal to alkali hydroxide compounds by reaction with alkali hydroxide is routinely performed around the world, e.g. DFR/PFR, at Dounreay and as planned at Superphenix. 

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