Abstract: A radioactive substance storage container 100 includes a body 10 and a lid 10 having a sealed structure, and a basket 5 housed in the body 1 to hold fuel assemblies. The basket 5 includes a neutron shielding material. The radioactive substance storage container 100 includes a subcritical-performance reinforcing member 20 including a neutron shielding material and located between an inner periphery of the body 1 and an outer periphery of the basket 5.

Abstract: A radioactive substance storage container 100 includes a body 10 and a lid 10 having a sealed structure, and a basket 5 housed in the body 1 to hold fuel assemblies. The basket 5 includes a neutron shielding material. The radioactive substance storage container 100 includes a subcritical-performance reinforcing member 20 including a neutron shielding material and located between an inner periphery of the body 1 and an outer periphery of the basket 5.

Abstract: A cask includes a trunk body that includes a basket having a square pipe or a plate member forming a cell that contains a spent fuel assembly, and a neutron shield that is formed by filling a composition for neutron shielding between the trunk body and an outer cover surrounding the trunk body. The composition includes a refractory material, a density increasing agent, and a neutron shielding material composed mainly of a polymer.

Abstract: A cask includes a trunk body that includes a basket having a square pipe or a plate member forming a cell that contains a spent fuel assembly, and a neutron shield that is formed by filling a composition for neutron shielding between the trunk body and an outer cover surrounding the trunk body. The composition includes a refractory material, a density increasing agent, and a neutron shielding material composed mainly of a polymer.

Abstract: The absorbing rods have a nearly the same shape as the shape of columnar control rods for PWR used in reactivity control of core in a reactor. The absorbing rods can shield neutrons, and are inserted in control rod guide pipes and measuring pipes in fuel assemblies.

Abstract: A process for producing a toner comprises the steps of mixing toner particles having a weight average particle diameter of from 2 to 15 .mu.m, with an external additive to prepare a toner, and passing the resulting toner through a sieve. The sieve has a wire cloth of twill weave that satisfies the following condition:0.052.ltoreq.d mm .ltoreq.0.208100.ltoreq.W .mu.m .ltoreq.1807.3.times.10.sup.-4 .ltoreq.d mm / W .mu.m.ltoreq.9.1.times.10.sup.-4wherein d represents average diameter of the wire used in the sieve, and W represents an aperture size of the sieve.

Abstract: A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability contains a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)-insoluble component and a THF-soluble component, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there is a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.

Abstract: A magnetic toner for electrophotography having stable triboelectric chargeability under various environmental conditions may be provided by using magnetic iron oxide particles having a moderately high surface Feo content, specified by the following conditions: (a) a dissolved Fe (II) content in dissolved total iron of 14-33.3 wt. % at a dissolved total iron percentage of 5.+-.1 wt. %, (b) a dissolved Fe (II) content in dissolved total iron of 17-33.3 wt. % at a dissolved total iron percentage of 10.+-.1 wt. %, and (c) a dissolved Fe (II) content in dissolved total iron of 18-33.3 wt. % at a dissolved total iron percentage of 15.+-.1 wt.

Abstract: A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability is provided as a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there are a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.

Abstract: A developer for developing electrostatic latent images, comprising a mixture of toner and fine powder of silicic acid wherein the mixture has a ratio of B/A of 0.9 or larger provided that the mixture contains A wt. % thereof of the silicic acid fine powder, and contains B wt. % thereof of the silicic acid fine powder after the mixture has been passed through a 200 mesh-sieve.

Abstract: A dry developer for developing electrostatic images comprises a) toner particles comprising 100 parts by weight of a binder resin and 1-20 parts by weight of polyalkylene having a ratio of weight average molecular weight to number average molecular weight of 2.0-10.0 and Z average molecular weight determined by gel permeation chromatography of 10,000-200,000, and containing 5-60% by weight of a component soluble in n-hexane at boiling point, kinetic friction coefficient of the toner particles being 0.20-0.50, and b) non-magnetic inorganic fine powders having BET specific surface area according to a nitrogen adsorbing method of 0.5-500 m.sup.2 /g.An image forming method comprises using the dry developer to develop electrostatic latent images on a photosensitive member having a surface hardness of 8 g or more, transferring the developed images to a receiving member, and removing the toner particles remaining on the photosensitive member by a cleaning means accompanying abrasion.

Abstract: A toner for developing electrostatic latent images includes a binding resin, such as a crosslinked styreneacrylate ester copolymer, and a low-molecular weight olefin copolymer, the low-molecular weight polyolefin copolymer having at least two olefinic repeating units and having two or more peaks of melting at temperatures between 90.degree. C. and 170.degree. C.

Abstract: A developer for developing electrostatic images, containing a magnetic toner having a binder resin and magnetic powder, the developer containing 17-60% by number of magnetic toner particles of 5 microns or smaller, containing 1-23% by number of magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of magnetic toner particles of 16 microns or larger; wherein the magnetic toner has a volume-average particle size of 4-9 microns, and the magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following:N/V=-0.04N+k,wherein N denotes % by number of magnetic toner particles of 5 micron or smaller, V denotes % by volume of magnetic toner particles of 5 microns or smaller, k denotes a positive number of 4.5-6.5, and N denotes a positive number of 17-60.

Abstract: An image forming apparatus, comprises: an electrostatic image-bearing member for holding an electrostatic latent image; a developing means for developing the electrostatic latent image to form a toner image on the electrostatic image-bearing member, the developing means including a non-magnetic color toner developing means for development with a developer comprising a non-magnetic color toner and a magnetic toner developing means for development with a magnetic toner, wherein the non-magnetic toner has a volume-average particle size of 4 to 15 microns, the magnetic toner contains 17 to 60% by number of magnetic toner particles having a particle size of 5 microns or smaller, 1-23% by number of magnetic toner particles having a particle size of 8.0-12.7 microns and 2.

Abstract: An image forming method, comprising the steps of: providing an electrophotographic photosensitive member comprising an organic photoconductor, and a toner-carrying member carrying thereon a magnetic toner disposed opposite to the photosensitive member with a predetermined clearance in a developing region; the photosensitive member comprising at least two species of charge-generating substances and carrying thereon a digital and an analog electrostatic images; carrying the magnetic toner on the toner-carrying member to the developing region while regulating the magnetic toner so as to provide a thickness smaller than the clearance, the magnetic toner having a specific particle size distribution and a volume-average particle size of 4-10 microns; and developing the electrostatic images with the magnetic toner.

Abstract: A developer for developing electrostatic images, comprising a non-magnetic toner, the toner containing 17-60% by number of non-magnetic toner particles of 5 microns or smaller, containing 1-30% by number of non-magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of nonmagnetic toner particles of 16 microns or larger; wherein the non-magnetic toner has a volume-average particle size of 4-10 microns, and the non-magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following formula:N/V=-0.04N+k,wherein N denotes % by number of non-magnetic toner particles of 5 microns of smaller, V denotes % by volume of non-magnetic toner particles of 5 microns or smaller k denotes a positive number of 4.5-6.5, and N denotes a positive number of 17-60.

Abstract: Magnetic iron oxide containing silicon element is produced in the form of generally octahedral particles having a sharp particle size distribution through a reaction of an aqueous solution of a ferrous salt having a controlled Fe(II)/Fe(III) ratio and containing a silicic compound with a little excess of an alkali, followed by oxidation of the resultant ferrous hydroxide. The magnetic iron oxide particles have an overall content of silicon element of 0.1-1.5 wt. % based on the iron element with the silicon localized at the core of the particles. The magnetic iron oxide particles have uniform surface properties not markedly changed under various conditions and have good dispersibility in a resin.

Abstract: A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability is provided as a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there are a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.

Abstract: A developer for developing electrostatic images, comprising a magnetic toner comprising a binder resin and magnetic powder, the developer containing 17-60% by number of magnetic toner particles of 5 microns or smaller, containing 1-23% by number of magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of magnetic toner particles of 16 microns or larger; wherein the magnetic toner has a volume-average particle size of 4-9 microns, and the magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following formula:N/V=-0.04N+k,wherein N denotes % by number of magnetic toner particles of 5 micron or smaller, V denotes % by volume of magnetic toner particles of 5 microns or smaller, k denotes a positive number of 4.5-6.5, and N denotes a positive number of 17-60.

Abstract: A magnetic toner comprising a binder resin, magnetic powder and 0.1-10 wt. % (based on resin component) of a low-molecular weight polyalkylene, the binder resin comprising a vinyl-type polymer having 5 to 80 wt. % of a tetrahydrofuran (THF)-insoluble; the magnetic toner having a melt index of 0.2 to 12 g/10 min. (125.degree. C., 10 kg load); the residual magnetization .sigma..sub.r and the volume-average particle size d of the magnetic toner satisfying the following formula:3.7-0.11d.ltoreq..sigma..sub.r .ltoreq.6.5-0.23d,wherein .sigma..sub.r represents a residual magnetization (emu/g) under an external magnetic field of 1 KOe and d represents a volume-average particle size of 3 to 16 microns.