A method is for controlling a nuclear power plant comprising pressurized water nuclear reactor (3) having a reactor core producing power, a primary circuit (5) connecting the reactor core to a steam generator (9), one or more of control rods (16), which can be moved into the reactor core for controlling the power of the reactor core, an injecting device (22, 23, 24, 26, 28, 30) for injecting boric acid and/or deionized water into the primary circuit (5) for controlling the reactivity of the reactor core.

A method is for controlling a nuclear power plant comprising pressurized water nuclear reactor (3) having a reactor core producing power, a primary circuit (5) connecting the reactor core to a steam generator (9), one or more of control rods (16), which can be moved into the reactor core for controlling the power of the reactor core, an injecting device (22, 23, 24, 26, 28, 30) for injecting boric acid and/or deionized water into the primary circuit (5) for controlling the reactivity of the reactor core.

Thorium-based fuel bundles according to one or more embodiments of the present invention are used in existing PHWR reactors (e.g., Indian 220 MWe PHWR, Indian 540 MWe PHWR, Indian 700 MWe PHWR, CANDU 300/600/900) in place of conventional uranium-based fuel bundles, with little or no modifications to the reactor. The fuel composition of such bundles is 60+ wt % thorium, with the balance of fuel provided by low-enriched uranium (LEU), which has been enriched to 13-19.95% 235U. According to various embodiments, the use of such thorium-based fuel bundles provides (1) 100% of the nominal power over the entire life cycle of the core, (2) high burnup, and (3) non-proliferative spent fuel bundles having a total isotopic uranium concentration of less than 12 wt %. Reprocessing of spent fuel bundles is also avoided.

A composite nuclear reactor component comprises a support and a protective layer (2). The support contains a substrate (1) based on a metal. The substrate is coated with an interposed layer (3) positioned between the substrate (1) and the protective layer (2). The protective layer (2) is composed of a material which comprises amorphous chromium carbide. The nuclear reactor component provides for improved resistance to oxidation, hydriding, and/or migration of undesired material.

An apparatus for removing irradiated Co-60 capsules from a plurality of burnable absorber rodlets. The apparatus comprises a solenoid that induces an electromagnetic flux into a Co-60 capsule and locks the Co-60 capsule in parallel with the apparatus. The apparatus is slideable along a longitudinal axis of the burnable absorber rodlet and causes the Co-60 capsule to overcome a plurality of forces exerted on it.

An apparatus for removing irradiated Co-60 capsules from a plurality of burnable absorber rodlets. The apparatus comprises a solenoid that induces an electromagnetic flux into a Co-60 capsule and locks the Co-60 capsule in parallel with the apparatus. The apparatus is slideable along a longitudinal axis of the burnable absorber rodlet and causes the Co-60 capsule to overcome a plurality of forces exerted on it.

Thorium-based fuel bundles are used in existing PHWR reactors (e.g., Indian 220 MWe PHWR, Indian 540 MWe PHWR, Indian 700 MWe PHWR, CANDU 300/600/900) in place of conventional uranium-based fuel bundles, with little or no modifications to the reactor. The fuel composition of such bundles is 60+ wt % thorium, with the balance of fuel provided by low-enriched uranium (LEU), which has been enriched to 13-19.95% .sup.235U. According to various embodiments, the use of such thorium-based fuel bundles provides (1) 100% of the nominal power over the entire life cycle of the core, (2) high burnup, and (3) non-proliferative spent fuel bundles having a total isotopic uranium concentration of less than 12 wt %. Reprocessing of spent fuel bundles is also avoided.

To provide is a fuel assembly capable of easily adjusting average MA enrichment in an inner blanket region. An inner core fuel assembly 7 loaded in an inner core region 2 of a core of a fast reactor includes a plurality of fuel rods 10 and a plurality of fuel rods 19. Each of the fuel rods 10 includes a lower core fuel region 12, an inner blanket region 11, and an upper core fuel region 13. A U—Pu—Zr metal fuel is disposed in the lower core fuel region 12 and the upper core fuel region 13, and a U—Zr metal fuel is disposed in the inner blanket region 11. Each of the fuel rods 19 includes a lower core fuel region 12, an inner blanket region 20, and an upper core fuel region 13. A U—Pu—Zr metal fuel is disposed in the lower core fuel region 12 and the upper core fuel region 13 of the fuel rod 19, and a MA-Zr metal fuel is disposed in the inner blanket region 20. By adjusting the number of the fuel rods 10 and the number of the fuel rods 19, MA enrichment in the inner blanket region 9 of the fuel assembly 7 can be easily adjusted.

Nuclear reactor fuel assembly comprising fuel elements installed in a frame having guide channels and spacer grids; a bottom nozzle; and a removable head. The head comprising collet tubes, an upper shell, a support element in the form of a tube, and springs. The collet tubes comprise two coaxially arranged tubes that are movable relative to each other and that each have stops on their side surfaces. The stops interact with each other to select the length of the collet tubes. The upper shell has a tube with a rigidly fixed plate interacting with the springs. The plate has plural holes having a shape corresponding to a shape of a respective boss of the support element. The clearance in plan view between a respective hole and a respective boss being at least the mounting clearance between the tube of the support element and the tube of the upper shell.

Nuclear reactor fuel assembly comprising fuel elements installed in a frame having guide channels and spacer grids; a bottom nozzle; and a removable head. The head comprising collet tubes, an upper shell, a support element in the form of a tube, and springs. The collet tubes comprise two coaxially arranged tubes that are movable relative to each other and that each have stops on their side surfaces. The stops interact with each other to select the length of the collet tubes. The upper shell has a tube with a rigidly fixed plate interacting with the springs. The plate has plural holes having a shape corresponding to a shape of a respective boss of the support element. The clearance in plan view between a respective hole and a respective boss being at least the mounting clearance between the tube of the support element and the tube of the upper shell.