[en] A fission ⁹⁹Mo plant was constructed in 1977 at the facilities of the Japan Atomic Energy Research Institute (JAERI). UO₂ pellets (2.6% enrichment) were utilized on target material containing 120g of UO₂. The pellets were irradiated in the JRR-2 and JRR-3 reactors up to 7 days at a neutron flux of 2 or 3 x 10¹³n/cm² x sec. About 20 Ci of ⁹⁹Mo per week was routinely produced for 39 weeks. However, due to severe constraints of a research establishment, commercial production runs had been stopped. This paper provides information on the target configuration, post-irradiation separation process and waste disposal problems. (author). 14 refs, 4 figs, 3 tabs

[en] The production of ⁹⁹Mo by the reaction of ²³⁵U(n,f) using UO₂ as target material was carried out at JAERI. Medium- and high-level liquid wastes arising from this production process contained U, Pu and fission products in which radioactive ruthenium in various valency and complex states was included. For the removal of radioactive ruthenium, after testing various combinations of adsorbents, a novel method using a column packed with adsorbents composed of zinc and activated charcoal (charcoal) was developed. The effects of composition of mixtures, flow rates, pH of feed solutions, washing, and repeat use on ruthenium removal efficiency were investigated. A feature of this column method is that the efficiency of removal can be recovered by washing with dilute nitric acid and it is possible to treat a large quantity of liquid wastes. It was found that this column method was also effective for the removal of U, ²³⁹Pu, ¹⁴⁴Ce, ¹⁵⁵Eu and ¹²⁵Sb. This method was applied to the treatment of actual medium- and high-level liquid wastes, the quantities of which were 600L and 124L respectively. After the removal of U, Pu and fission products by conventional removal methods such as coprecipitation, filtration, electrolysis and adsorption with inorganic adsorbents, residual ¹⁰⁶Ru was removed by using the column packed with a mixture of zinc and charcoal. Decontamination factors for ¹⁰⁶Ru ranging from 10² to 10⁴ were obtained. The concentration of U, ²³⁹Pu, ¹⁴⁴Ce, ¹⁵⁵Eu, and ¹²⁵Sb after treatment were found to be below the limit of detection. (author)

[en] Photoproduction of charged pion on deuteron, emphasis on channels γd→π^-pp and γd→π⁺π^-np, were measured with the second generation of Neutral Kaon Spectrometer. The photon beam was provided from the tagged photon facility at the Laboratory of Nuclear Science, Tohoku University. The energy range of photon is 0.8-1.1 GeV. The aim is to investigate the pion photoproduction process on the nucleus in the second and third resonance regions. The quasi-free process inside deuteron and also non-quasi-free contributions were derived individually.

[en] Double charged pion photoproductions from the deuteron have been studied at Research Center for Electron Photon Science (ELPH), Tohoku University. Tagged photon beams in an energy range of 0.67 ≤ E_γ ≤ 1.08 GeV were impinged on the liquid deuteron target. Produced charged particles were observed with the Neutral Kaon Spectrometer2 (NKS2). The γ d → π⁺ π⁻ d process was clearly separated among the three charged tracks. We obtained the photon energy dependence of the normalized yields of this process. (author)

[en] The strangeness photoproduction processes near the threshold have been intensively studied by measuring K⁺ in reactions such as γ+p→K⁺+Λ(Σ⁰). There has been no reliable data on the neutron and as a consequence theoretical investigation suffered seriously from the lack of the data. We have an effort to measure the γ+d→K⁰(Λ)+X reaction in the π⁺π⁻ (pπ⁻) decay channel of K_S⁰ (Λ) using a liquid D₂ target and internally-tagged photon beams (E_γ=0.80–1.08 GeV) at Research Center for Electron Photon Science (ELPH), Tohoku University. We have renewed the spectrometer (NKS2) and took data with a liquid D₂ target in 2005–2007. More recently, we took data in 2010 after a detector upgrade in the vertex region to substantially increase the acceptance. The results of Λ single measurements on a deuterium target were obtained for differential cross-section as a function of momentum, as a function of angle, and integrated cross-section as a function of beam energy. The results are compared with recent theoretical studies: Isobar models (Kaon-MAID and Saclay-Lyon A) and a Regge-plus-Resonance model