Siemens Aktiengesellschaft

Infineon Technologies Ag

Framatome Anp Gmbh

Siemens Aktiengesellscaft

Joachim Schulze

Godehard Rauch

Dieter Kreuter

Gerhard Kuhn

Klaus Schulz

Alfred Hartl

Peter Froscher

Christoph Maczey

A safe start-up of a boiling water reactor is achieved when two conditions are adhered to and monitored when the control rods are being moved out of the core: First, the drive of a control rod should be activated only when the directly and diagonally adjacent control rods remain at rest simultaneously, and, second, when all the directly adjacent control rods are still in the fully moved-in initial position.

Method for starting up and monitoring an apparatus for controlling a boiling water nuclear reactor

A method and a device are provided for monitoring a power rise during startup of a nuclear reactor (diversitary excursion monitoring). In order to be able to shut down the reactor during startup in the event of prompt critical states, a power band situated in a lower measuring range is prescribed for a signal of power range channels which detects the reactor power in the power range. Startup is continued only when the signal does not exceed an upper limit within a minimum time, after the last occasion of exceeding a lower limit of the power band.

Method and device for monitoring the power rise during startup of a nuclear reactor (diversitary excursion monitoring)

A coupling configuration for connecting an optical fiber provided with a coupling end face at one end to an optoelectronic element is described. A coupling element is disposed between the end of the optical fiber and the optoelectronic element in order to reduce back-reflections. The coupling element, which is made of an optically transmissive material, is in physical contact with the coupling end face of the optical fiber, and its side facing the optoelectronic element has a surface region which reduces back-reflections. To simplify and shorten the coupling housing, the coupling element is of lens-like configuration, for example in the form of a ball, and is held directly in the coupling housing.

Coupling configuration for connecting an optical fiber to an optoelectronic component

The optoelectronic coupling element is adjustable, during production, with regard to an optimal light path. A coupling part has a coupling device for coupling light out of a light path into at least one light guide element and/or for coupling light out of the at least one light guide element into the light path. A component carrier has one or more optical semiconductors. A first and a second optical deflector are sandwiched between the coupling part and the component carrier. The two optical deflectors, which are disposed parallel to one another, form a light path between the coupling device and the optical semiconductor(s). The light path is optimized by moving the second optical deflector relative to the first, parallel-mounted, optical deflector and by thereby minimizing a loss in conducting the light through. Then the elements are fixed relative to one another.

Optoelectronic coupling element and production method

A transiently unstable state of a boiling-water reactor is damped by measuring the oscillating neutron flux and, after a first threshold value is exceeded over a plurality of oscillation periods, the rate of increase of the oscillation is determined. Depending on the slope of the increase, and after a further threshold value (in particular one dependent on the rate of increase) for the oscillating flux is exceeded, a selection is made which one of various stabilization strategies for damping the oscillation should be triggered before a SCRAM becomes necessary. A hierarchy of stabilization strategies is available: blocking a power increase, for instance, in the control system, controlled slow reduction of the power, or rapid power reduction by a 'partial SCRAM'. The monitoring of the unstable state is effected with a system of sensors strategically distributed throughout the core and which redundantly measure the flux in one region of the core. The sensors act on a plurality of redundantly operating systems, and the signal from each sensor is effective in only one of the redundant systems.

Method and device for operating a reactor in an unstable state

A fast shutdown system and a process for the fast shutdown of a nuclear reactor, include a reactor core and a plurality of control rods which are disposed side by side and can be inserted into and withdrawn from the reactor core. The plurality of control rods has a number of operating groups into which the control rods are categorized or fitted for regulating the power of the nuclear reactor, as well as a number of shutdown groups into which the control rods are categorized or fitted for the fast shutdown of the nuclear reactor. The control rods of at least two operating groups are allocated to each shutdown group or the control rods of at least two shutdown groups are allocated to each operating group. Due to such an allocation of the control rods among shutdown groups and operating groups, it is assured that even upon startup of the nuclear reactor, when not all of the control rods have yet been withdrawn, at least some of the already withdrawn control rods will be reinserted into the reactor core during a fast shutdown involving failure of the insertion of the control rods of one shutdown group. Preferably, two shutdown groups are provided, and each shutdown group is assigned to a single hydraulic insertion system.

Fast shutdown system and process for fast shutdown of a nuclear reactor

A system for controlling control rods which can be moved into and out of a reactor core of a nuclear power plant, includes a selector device, a monitor device and a rod control device. The selector device contains travel sequences which are selectable and defined for regulating the nuclear power plant, i.e. allocation and movement sequences of the control rods, and it transmits the selector signals allocated to each travel sequence to the rod control device. The monitor device checks the selector signals for acceptability while taking into account the structural features of the reactor core and the control rods, which are allocated to the respective travel sequence, in particular proximity relationships of the control rods. If the selector signals are acceptable, an enable signal is transmitted to the rod control device and the rod control device induces a displacement of the control rods according to the selector signals. From the point of view of process control, the selector device and the monitor device are separate from each other so that the system and method have a high degree of reliability which corresponds to safety regulations for nuclear power plants.

System and method for controlling control rods of a nuclear power plant

Method for assembling a light wave guide switch

In a method and apparatus for coupling a test piece to the transmitter and the receiver of an apparatus for measuring the attenuation of light waveguides, either a large area light emitter is inserted into the measuring path on the input side of the test piece, or a large area photo receiver is inserted on the output side of the test piece. The insertion of the large area photo receiver can be accomplished by means of a semitransparent or hinged mirror.

Growing community of inventors

Frankfurt-am-Main, Germany

Joachim Schulze