[en] The present invention provides a device for measuring and analyzing a pressure and a purity of a helium gas sealed in a BWR type nuclear fuel rod. Namely, a portion between a rotational shaft of an electromotive drill for perforating the fuel rod and a vacuum chamber is sealed with a magnetic fluid sealing material so that error factors can be recognized before and after the destruction detection (perforation) of a fuel rod. With such procedures, involving of an atmospheric air from the drill rotational shaft upon perforation can be eliminated. As a result, accuracy for the measurement can be improved. In addition, a filter is disposed to a pipeline connecting the vacuum chamber and the measuring system. With such a constitution, scattering of cutting dusts to the measuring system, troubles due to damages of a stop valve can be reduced. As a result, the efficiency of the measurement is improved. Further, a plurality kinds of gas collecting vessel having different capacities are connected in parallel to the pipeline of the measuring system. Then, the gas collecting vessels can be used selectively. As a result, the device can cope with a gas pressure over a wide range. (I.S.)

[en] Purpose: To provide a simple radiation shielding method for the shielding wall of a building processing radioactive substances through which pipe lines are passed. Constitution: A concrete shielding block having insertion holes for pipe lines are formed, to which engaging recesses and engaging ridges are provided for the positioning of the pipe line insertion holes. Then, the concrete shielding block is inserted to a sleeve embedded in the shielding wall of the building and shielding plugs are inserted. (Kawakami, Y.)

[en] Using grafted bone from a rabbit, we investigated experimentally whether creeping substitution of grafted bone is detectable by magnetic resonance imaging. The bone marrow/muscle ratio in T1-weighted images showed a correlation with the ratio of fat cells. The T1-weighted images of the free grafted bone initially showed a high signal intensity due to the high ratio of fat cells. This signal intensity decreased due to new bone formation. Therefore, T1-weighted images can demonstrate histological changes in grafted bone. (author)

[en] In order to prevent radioactive materials from spreading contamination from nuclear power plants outside the radiation control area, the surface contamination of all material transferred outside from the control area is monitored. This paper presents an overview and describes features of: (1) personnel surface contamination monitoring assemblies for measuring the surface contamination on workers, (2) article surface contamination monitoring assemblies for measuring the surface contamination on articles, (3) laundry monitors for measuring the surface contamination on worker clothes worn inside the control area, and (4) hand-foot-clothing contamination monitors for measuring the surface contamination on hands, feet and clothing. (author)

[en] To reduce radiation exposure and prevent contamination from spreading, each nuclear power plant has established a radiation controlled area. People and articles out of the controlled area are checked for the surface contamination of radioactive materials with surface contamination monitors. Fuji Electric has repeatedly improved these monitors on the basis of user's needs. This paper outlines typical of a surface contamination monitor, a personal surface contamination monitor, an article surface contamination monitor and a laundry monitor, and the whole-body counter of an internal contamination monitor. (author)

[en] At nuclear power plants, in order to prevent radioactive materials from spreading contamination outside the radiation control area, the surface contamination of all material transferred outside the control area is monitored. This paper presents an overview and describes features of: (1) personnel surface contamination monitoring assemblies for measuring the surface contamination on workers, (2) articles surface contamination monitoring assemblies for measuring the surface contamination on articles of all sizes, (3) laundry monitors for measuring the surface contamination on worker clothes worn inside the control area, (4) whole-body counters for measuring the worker's internal exposure, and (5) hand-foot-clothing contamination monitors for measuring the surface contamination on hands, feet and clothing. (author)

No abstract available

[en] The morphology of the lumbosacral nerve roots and dorsal root ganglia (DRG) was examined by using magnetic resonance imaging (MRI) in 11 healthy male volunteers aged 20-40 years. One hundred and twenty-three nerve roots (15 at the L1 level, 22 each at the L2-L5 levels, and 20 at the S1 level) were examined in terms of the position and angle of the bifurcation of the nerve roots, length of the nerve root, and the position and width of DRG. The nerve roots at the lower levels showed more cephalad position and smaller angle of bifurcation on MRI. The distance from the bifurcation of nerve roots to the cephalad edge of DRG was significantly longer in the upper root levels and was significantly shorter in the L5 roots than the S1 roots. The positions of DRG at the S1 level tended to become cephalad. DRG that was positioned toward more caudal direction was larger and more elliptic. MRI provided useful information concerning morphology and anatomical position of nerve roots and DRG, thereby allowing accurate diagnosis and the determination of surgical indications. (N.K.)

[en] 1.88 GeV/n Fe beams of LBL were vertically irradiated to the chambers composed of a pile of plastic track detector (CR-39) and nuclear emulsion plates. The charge number of projectile fragments in Fe interactions was carefully examined by use of CR-39. The angular distributions of emitted alpha particles have been investigated for several ranges of charge numbers of projectile fragments. The result of analysis shows that the emission angle distribution of alpha particles at large angles cannot be explained by the single mechanism of the fragmentation from a clean cut spectator. For events of central collisions with smaller charges of projectile fragments, the effective temperature for the production of alpha particles turns out to be much higher than that of the evaporation theory. The results are applied to the calibration of primary energy estimation by the opening angles of alpha particles. (author)

[en] In the radiation facilities such as nuclear power plants, surface contamination of the people accessing or articles conveyed in and out of the radiation controlled areas is detected and monitored by installing contamination monitors at the boundary of controlled areas and uncontrolled areas against the expansion of the radioactive materials to out of the facilities. It is required for the surface contamination of articles to be tightened of control criteria as 'Guidelines for discrimination ways of nonradioactive waste (not classified as radioactive waste) generated from nuclear power plants' (hereinafter referred to as 'the Guideline') was established by the Nuclear and Industrial Safety Agency of the Ministry of Economy, Trade and Industry in August, 2005. It predicts that the control criteria of monitors other than article monitors are also tightened in the future. Fuji electric has been fabricating and delivering surface contamination detecting monitors. Now we are developing the new contamination monitor corresponding to the tightening of the control criteria. 'Large article transfer monitor', 'Clothing monitor' and 'Body surface contamination monitor' are introduced in this article. (author)