An experimental platform for real-time measurement of the deformation of nuclear fuel rod claddings submitted to thermal transients.

We report on experimental development and qualification of a system developed to detect and quantify the deformations of the cladding surface of nuclear fuel pellet assemblies submitted to heat transient conditions. The system consists of an optical instrument, based on 2 wavelengths speckle interferometry, associated with an induction furnace and a model pellet assembly used to simulate the radial thermal gradient experienced by fuel pellets in pressurized water reactors. We describe the concept, implementation, and first results obtained with this system. We particularly demonstrate that the optical system is able to provide real time measurements of the cladding surface shape during the heat transients from ambient to high temperatures (up to a cladding surface temperature of 600 °C) with micrometric resolution.

Circular dichroism of ferriprotoporphyrin IX-morphine complexes in aqueous solution.

Complexes of ferriprotoporphyrin IX (FP) with (-)-morphine exhibit large optical activity in aqueous solution. Several CD bands of different signs were recorded under different conditions in the wavelength range of 300 to 450 nm. The largest CD band, centered at about 364 nm, showed molar ellipticities of about -5 x 10(5) deg.cm2.dmol-1 based on FP (rotational strength of about -3 DBM). An optimum pH range of 7.4 to 7.8 with regard to optical activity of the complex has been observed. Concomitantly with the formation of optically active complexes, large aggregates are being formed as determined by ultracentrifugation. A mole ratio of 1 between FP and morphine in the complex was estimated from both CD titration and measurement of the amounts of aggregate formed upon variation of the mole fraction of the complex components. Derivatives of morphine such as heroin or codeine do not form optically active complexes and aggregates under similar conditions. As in the analogous FP-quinine and FP-quinidine complexes investigated previously, the optical activity observed is considered to originate at least in part from optical interactions between FP molecules arrayed chirally in the FP-(-)-morphine aggregates.