Neptunium (Np) is one of the daughter elements included in the decay chain of Pu. The quantitative analysis of Np isotopes is required for radioactive waste characterization, research on actinide chemistry, etc. Np-237 has a long half-life (2.144 million years), but its daughter Pa-233 has a relatively short half-life (26.975 days). For this reason, after a sufficient time elapses following the chemical preparation process of the analyte, the two nuclides are in radiation equilibrium in the sample. Np-237 emits alpha-rays while Pa-233 emits beta-rays. Both nuclides also emit gamma- and X-rays. In this study, alpha-rays were measured using liquid scintillation counting (LSC) method and alpha spectrometry. Gamma-spectrometry with a HPGe detector was used for the analysis of gammaand X-rays. In addition, we compared the radiometric results with quantitative analysis of Np using UV-Vis absorption spectrometry. The LSC method and the HPGe gamma-spectroscopy do not require extensive sample preparation procedures. Alpha spectroscopy requires a standard material spiking, separation by coprecipitation, and disk-type sample preparation procedure to obtain measurement efficiency and recovery factor. A reference material sample with a concentration of 5.8 mM was analyzed by the four analysis methods, and all of the measured results agreed well within a difference level of 4%.

알파분광법에 의한 의 정량방법을 검토하였다. 황산염 매질에서 전류세기, 전착시간 및 유기물 첨가제 둥의 변화에 따른 의 전착조건을 찾은 결과 A에서 유기첨가제 없이 시간 동안 전착하는 것이 효율적이었다. 을 4.16 Bq에서 0.0264 Bq(1ng) 까지 전착한 결과 농도가 낮을수록 전착율 및 재현성이 낮아졌으며 1 ng 까지 측정이 가능하였다. 사용후 핵연료 합성용액에서 을 분리한 후 알파분광법으로 측정하여 정량한 결과 (n=4)의 회수율을 나타내었다. 사용후 핵연료 시료용액 중 을 정량하였으며 계산 값과 비교한 결과 10% 이내에서 서로 일치하였다.

237Np is very important material in the fission products of nuclear reactors. Resonance integral(RI) tests of this material is necessary to check between the experiments and the evaluated data. Such feedback to the evaluated data is very important to correct data and improve of codes. The RI for the 237Np(n,γ)238Np reaction were measured by using the 46-MeV electron linear accelerator (linac) at the Research Reactor Institute, Kyoto University (KURRI). The measurement was performed in the energy region from 0.005 eV and 10 keV. RI obtained as 804.7 barns, compared with those of the evaluated data in JENDL-4.0 and Mughabghab.