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Akaoka, Katsuaki; Maruyama, Yoichiro; Oba, Masaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo
no journal, ,
For the remote analysis of low DF TRU (Decontamination Factor Transuranic) fuel, Laser Induced Breakdown Spectroscopy (LIBS) was applied to uranium oxide including a small amount of calcium oxide as a sample, and the spectrum emitted from laser-breakdown plasma was measured. In order to obtain the stable intensity of spectrum, the parameter of observation delay time of spectrum, laser power and Ar gas pressure were optimized. The calibration curve was determined by experiments with the various concentration of Ca.
Oba, Masaki; Maruyama, Yoichiro; Akaoka, Katsuaki; Miyabe, Masabumi; Wakaida, Ikuo
no journal, ,
We have been developing LIBS technique suitable for the elemental analysis of nuclear fuel. Emission characteristics in the orthogonal double-pulse LIBS were studied by means of nanosecond and femtosecond laser pulses for ablation. As the oxide fuel pellets are used on the nuclear reactors, gadorinium oxide (Gd
O
) was used as simulated fuel pellets which has complex spectra as well as uranium. The optimum focus position of the ablation laser pulse is 5 mm from the sample surface in the reheating mode. This defocus effect is caused by the ablated volume. Therefore, the ablated volume was measured by observing the crater volume using a confocal laser microscope. Consequently, the ablated volume decreases as the focus position comes close to the sample surface. As a result, the most ablated volume can be obtained in the defocus condition. Therefore, the air plasma pulses might be absorbed efficiently in the defocus condition.
Wakaida, Ikuo; Akaoka, Katsuaki; Oba, Masaki; Maruyama, Yoichiro; Miyabe, Masabumi; Otobe, Haruyoshi; Niki, Hideaki*
no journal, ,
In the Fast Reactor nuclear fuel cycle system of the next generation, the development and utilization of the low-decontaminated nuclear fuel will be strongly required from the viewpoint of sustainable use of nuclear fuel resources, reduction of the environmental burden, simplification of the reprocessing process and resistance to nuclear proliferation. In JAEA, we are now developing the remote analytical technique for simultaneous measurement of the element, impurity and the isotope ratio by the combination of Laser Induced Breakdown Spectroscopy (LIBS) and resonance absorption spectroscopy for ablated plume. In this presentation, some topical results on the conventional LIBS of the detection limit of order 100 ppm, double pulse LIBS for higher sensitivity and the performance in isotopic measurement of the detection limit of 0.3 % and the success to detect 
U in natural uranium, will be described.
Miyabe, Masabumi; Oba, Masaki; Akaoka, Katsuaki; Maruyama, Yoichiro; Wakaida, Ikuo
no journal, ,
By combining the resonant absorption spectroscopy with laser ablation, we are developing a technique enabling such a remote fuel analysis. To improve the isotopic selectivity and detection sensitivity, we have performed absorption spectroscopy under various conditions and also evaluated some of the analytical performances.