Abstract: A traveling wave nuclear fission reactor, fuel assembly, and a method of controlling burnup therein. In a traveling wave nuclear fission reactor, a nuclear fission reactor fuel assembly comprises a plurality of nuclear fission fuel rods that are exposed to a deflagration wave burnfront that, in turn, travels through the fuel rods. The excess reactivity is controlled by a plurality of movable neutron absorber structures that are selectively inserted into and withdrawn from the fuel assembly in order to control the excess reactivity and thus the location, speed and shape of the burnfront. Controlling location, speed and shape of the burnfront manages neutron fluence seen by fuel assembly structural materials in order to reduce risk of temperature and irradiation damage to the structural materials.

Abstract: Most modern integrated circuit transceivers, especially wireless LAN, utilize a direct conversion radio architecture, which is highly advantageous from the perspectives of cost and flexibility, there exist several performance impairments, including gain and phase imbalances between the in-phase (I) and quadrature (Q) of a transmitter or receiver. Disclosed herein is a signal processing methodology and system for compensation of I/Q imbalance for a direct conversion packet-switched OFDM communications system. The imbalance, which accounts for transmitter I/Q imbalance, RX I/Q imbalance, phase/frequency error, and dispersive multipath fading. Both frequency dependent I/Q imbalance and frequency independent cases are considered, covering both wideband and narrowband modulation. The proposed estimation algorithms operate within the fully compliant framework of existing multi-user OFDM radio standards (WLAN, LTE, WimAX).

Abstract: Disclosed herein is a high Cr Ferritic/Martensitic steel comprising 0.04 to 0.13% by weight of carbon, 0.03 to 0.07% by weight of silicon, 0.40 to 0.50% by weight of manganese, 0.40 to 0.50% by weight of nickel, 8.5 to 9.5% by weight of chromium, 0.45 to 0.55% by weight of molybdenum, 0.10 to 0.25% by weight of vanadium, 0.02 to 0.10% by weight of tantalum, 0.21 to 0.25% by weight of niobium, 1.5 to 3.0% by weight of tungsten, 0.015 to 0.025% by weight of nitrogen, 0.01 to 0.02% by weight of boron and iron balance. By regulating the contents of alloying elements such as nitrogen, born, the high Cr Ferritic/Martensitic steel with to superior tensile strength and creep resistance is provided, and can be effectively used as an in-core component material for sodium-cooled fast reactor (SFR).

Abstract: A system, method and apparatus for demodulating a received signal using a configurable receiver. The receiver performs the demodulation of a signal according to a selected interference cancellation demodulation scheme. The same receiver can be configured, by setting certain parameters, to behave as a successive interference cancellation (SIC) scheme receiver, a parallel interference cancellation (PIC) scheme receiver, or a hybrid interference cancellation (HIC) scheme receiver. In another aspect of the present invention, the receiver performs its demodulation operation using a single interference cancellation unit (ICU). In addition, the ICU's despreading and respreading functions may be performed by the same processing element.

Abstract: A neutron radiation installation for treatment of different types of cancer tumours, comprising a source of neutrons (11), like a nuclear reactor or an accelerator dependent source of radiation, a conventional filter (14) for reducing the radiation energy to a suitable level for radiation treatment of cancer tumours, having low energetic neutron beams of an energy of between 1 eV and 40 keV, or preferably between 1 keV and 20 keV, and a radiation tube (22) out of which radiation beams are emitted towards a patient (10) having a cancer tumour (23), whereby an optimum radiation is obtained at a distance of between 50 and 100 cm from the output surface of the conventional filter (14), and in which the installation comprises an additional radiation filter (21) mounted between the conventional filter (14) and the output of the radiation tube, which additional filter is of a material which filters off neutrons in the epithermic spectrum from low energetic neutron beams up to an energy of about 1 keV, in particular

Abstract: A unitary, transportable, assembled nuclear steam supply system (NSSS) with a lifetime fuel supply utilizes a fast or epithermal spectrum reactor core immersed in a pool of light water together with a plurality of steam generators through which the coolant is circulated by up to 100% natural circulation at full power, augmented by reactor coolant pumps also immersed in the pool. Redundant steam generators and reactor coolant pumps, together with the fast or epithermal spectrum reactor core and pool configuration, make it possible to operate the NSSS for 10 to 15 or more years without maintenance on the internals or refueling, thereby rendering the system proliferation resistant.

Abstract: A light water cooled and moderated nuclear reactor for breeding fissile material on a uranium-plutonium cycle and also a method of operating a light water cooled and moderated reactor having a prebreeder section fueled from plutonium extracted from fuel discharged by a uranium burner or converter burner core. Subsequently, the prebreeder section, together with a breeder section, operated as coupled cores or modules, becomes self-sustaining and able to breed fissile plutonium fuels at a relatively high rate of gain.

Abstract: For operating a PWR with spectral shift during all combustion cycles and with undermoderation during some cycles only, the reactor structure is designed for receiving either one of two types of fuel assemblies, having the same geometry. All fuel assemblies have guide tubes for receiving spectral shift clusters containing fissile material but with different elements bundles so as to be able to choose the type of operation.

Abstract: Fuel array for an undermoderated nuclear reactor, comprising rods (6) arranged in a prism-shaped casing (1) parallel to the height of this casing (1). The internal surface of each of the walls (2) of the casing (1) is provided with channels (5) each of the channels (5) is located opposite a rod (6) arranged at the periphery of the array. The projecting parts (9) of the walls (2), between two channels (5), occupy part of the space between two peripheral rods (6). In this way, the moderating level remains constant throughout the cross-section of the array.The invention applies, in particular, to pressurized water reactors.

Abstract: A method and apparatus for extending the life of a core of a water moderated nuclear reactor by spectral shift comprising the displacement of a portion of the moderator in the core by a gas having a low neutron cross-section during the initial stage of the life of the core and displacing the gas and replacing it with moderator during the latter part of the life of the core.

Abstract: In a water-cooled nuclear reactor for producing energy and having seed and blanket zones, which reactor is cooled by pressurized water and contains fissile material of plutonium and uranium, the reactor is provided, in its seed zones and blanket zones, with a plutonium composition such as obtained from light water power plant reactors after a normal service life and recycle, and with fuel elements whose geometry in the seed and blanket zones, with respect to the coolant water, is selected to produce an epithermal neutron spectrum.

Abstract: The invention relates to a core for a nuclear reactor cooled with water under pressure.The core comprises a first group of zones (1, 2) extending over its entire height and over a fraction of its transverse section where the fuel rods contain mainly enriched uranium oxide, and a second group of zones (3) inserted between the zones (1, 2) of the first group where the rods contain mainly plutonium. The rods of zones (1, 2) of the first group emit neutrons and maintain the neutron reactions. The energy spectrum of the neutrons is in the thermal region in the zones (1, 2). The rods of the zones (3) of the second group are spaced at a distance which is appreciably smaller than the distance separating the rods of the zones (1, 2) so that the neutrons produced therein are in the high energy region.The invention applies, in particular, to nuclear reactors with spectral shift control.

Abstract: A complementary shutdown device for an undermoderated nuclear reactor, comprising, inside certain arrays (3) of the core, guide tubes (7) of which the cross-section is at least equal to the sum of the cross-sections of three rods (6), and which are surrounded by at least one row of fertile rods (8), and a set of shutdown rods, the cross-section of which matches the cross-section of the guide tubes (7). The shutdown is obtained by allowing the shutdown rods, containing a neutron-absorbing material, to fall into the arrays (3) of the core, in the position of maximum insertion. The invention applies, in particular, to pressurized water nuclear reactors.

Abstract: Upper internal equipment of a pressurized water nuclear reactor, comprising guide tubes containing guide plates and sleeves adapted to two different types of charge of the reactor core, one for obtaining a thermal neutron spectrum and the other for obtaining an epithermal spectrum. The plates (20) and the sleeves (33, 34) have, for each of the guide tubes, a first set of perforations (31, 36) and a second set of perforations (30,35) for guiding the control rods in either case. The invention applies to a pressurized water reactor operating either as a conventional reactor or as an undermoderated reactor.