Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Spent nuclear fuel radiolysis

The effect of irradiation on the extractability of sulfoxides towards plutonium, uranium and some fission products were studied by Subramanian and coworkers . They studied mainly the effect of irradiation on dihexyl sulfoxide (DHSO) and found that irradiation did not change the distribution coefficient for Ru, Eu and Ce but increases the distribution coefficient for Zr and Pu. When comparing DHSO and tributyl phosphate (TBP), the usual solvent for the recovery and purification of plutonium and uranium from spent nuclear fuels, the effect of irradiation to deteriorate the extraction capability is much larger in TBP. Lan and coworkers studied diphenyl sulfoxides as protectors for the gamma radiolysis of TBP. It was found that diphenyl sulfoxide can accept energy from two different kinds of excited TBP and thus inhibits the decomposition of the latter. [Pg.911]

Christensen, H. Sunder, S. 2000. Current state of knowledge of water radiolysis effects on spent nuclear fuel corrosion. Nuclear Technology, 131, 102-123. [Pg.86]

The inherent radioactive characteristics of the spent nuclear fuel condition determine many of the key processes to be studied. Owing to its energy content, spent fuel relaxes by transferring alpha, beta, and gamma radiation to water when contacting it. This originates what is known as radiolysis reactions. The key processes occurring at the spent fuel water interface are depicted in Fig. 8. [Pg.521]

As can be seen, the dose rate decreases significantly with distance from the surface within the maximum range for a-radiation. It is also obvious that, in this particular case, the contribution from /3-radiation within the a-volume is insignificant. As can be seen, radiolysis due to radiation from the spent nuclear fuel inherently introduces a concentration gradient in the surrounding aqueous phase. Hence, diffusion of radiolysis products will also be of significant importance. [Pg.303]

Upon contact between the spent nuclear fuel and the groundwater, radiolysis of water will begin. From the point of view of a safety assessment it is relevant to define the worst-case, but still realistic, scenario. Hence, the maximum possible dissolution rate for the UOj fuel matrix (assuming congruent dissolution) must be defined. As shown above, oxidation of U(IV) to U(VI) is required for dissolution to occur. Consequently, the rate of dissolution can never exceed the rate of oxidation and the rate of oxidation can be used to estimate the maximum dissolution rate. It has also been shown that, for longer irradiation times, the only oxidant that must be taken into account is H2O2 and that the surface concentration of H2O2 approaches the steady-state concentration fairly rapidly. The concentration will never exceed the steady-state concentration and therefore we can use the steady-state approach to make a realistic estimate of the maximum dissolution rate. [Pg.319]

Nielsen F, Jonsson M. (2006) Geometrical a- and f-dosc distributions and production rates of radiolysis products in water in contact with spent nuclear fuel. JNuclMater 359 1-7. [Pg.321]

Reactions of the solvent with species in a feed mixture may also adversely affect an extraction system. Because of the radiation field from fission products in spent nuclear fuel, TBP reacts by radiolysis and acid hydrolysis to form dibutyl and monobutyl phosphoric acids (DBP and MBP, respectively). These latter species are also highly effective in extracting U and Pu, but at conditions... [Pg.715]

In an effort to reduce the nuclear waste produced from the acid dissolution of spent nuclear fuels, Nenoff et al. have used a room temperature radiolysis process to prepare UO2 nanoparticles from the dissolved uranyl salts found in these acid solutions. The nanoparticles can be subsequently... [Pg.200]

LILW from conditioning and HLW from reprocessing have different impacts on deep geological repositories. The most important one relates to thermal effects and radiolysis shortly after disposal. However, the low amount produced in comparison with the co-disposed nuclear power plant spent fuel makes this effect negligible. [Pg.39]


See other pages where Spent nuclear fuel radiolysis is mentioned: [Pg.911]    [Pg.65]    [Pg.71]    [Pg.303]    [Pg.51]    [Pg.2814]    [Pg.277]    [Pg.722]    [Pg.164]    [Pg.722]   


SEARCH



Nuclear fuels spent fuel

Spent fuel

© 2024 chempedia.info