Abstract: Compliance with administrative limits on cumulative exposure of control rod groups in the reactor core, is monitored by computing the incremental effective exposure for each group commensurate with core power, for each time increment at which each group is within the position range where an administrative limit is imposed. The increments of effective exposures for each group are accumulated, and the accumulated effective exposure for each group is compared with the administrative limit to each group. This comparison is then displayed to the reactor operator, preferably using either a “rolling wheel” or “sliding bar” format.

Abstract: A technique for cooling furnace walls in a multi-component working fluid power generation system is disclosed. In a first embodiment, the technique involves removing process heat from a furnace having an inner tubular wall and an outer tubular wall. In a second embodiment, the technique involves removing process heat from a furnace system utilizing a fluid combiner. In a third embodiment, the technique involves removing process heat from a furnace having tubular walls formed of a plurality of fluid tubes.

Abstract: A system (10) and method (42,44,46,48,52,54) for generating an index (38,132,40,134) commensurate with the degree to which a tube array degrades over a period of time due to corrosion in a particular operating environment. A data array (62,114) is created defining the number of tubes in the tube array, a plurality of time points defining time intervals during which the degradation is to be assessed, and operating conditions that induce corrosion during each time interval. The expected degradation value of the array is computed over each of a plurality of time points using a deterministic failure model (88) having at least one parameter (102,104,106) that is assumed constant at each time point. For each time point and at least one parameter, a plurality of values of the parameter (108,110) that deviate from the assumed constant value, are generated.

Abstract: A combined cycle system has a gas turbine for generating an exhaust gas stream and a heat recovery steam generator with a housing for defining a horizontal exhaust gas flow path for the exhaust gas stream. Positioned within the housing is a heat recovery assembly having vertical rows of horizontally oriented heat transfer tubes transverse to the direction of gas flow and spaced apart in the direction of the gas flow path. The heat transfer tubes are supported by a plurality of vertical support plate assemblies oriented parallel to the exhaust flow path. Each support plate assembly has a plurality of coplanar support plate segments, each support plate segment supporting less than three rows of heat transfer tubes.

Abstract: A top mount canopy seal mechanical clamp assembly 20 for repair of a leaking canopy seal weld 16 between a nuclear reactor head penetration nozzle 12 and a mating part 14 has an annular housing 24 with insert support halves 28 and 30 for surrounding the nozzle. A top plate 34 is urged toward the support halves and housing by Belleville washers mounted on cap screws 42 threaded in bores 44 of the housing. A flexible graphite seal annulus 22 is compressed by the clamping action against the canopy seal weld 16 to create a flexible graphite leak stopping seal at the weld.

Abstract: The water flow circuit for a heat recovery steam generator is a hybrid system which combines a circulating drum type circuit and a once-through circuit. A low pressure evaporator is designed for natural or forced circulation and a high pressure evaporator is designed for once-through flow. Orifices may be located in the inlet of the evaporator tubes for flow stability and an intermediate header between the evaporator and high pressure superheater improves stability, minimizes orifice pressure drop and equalizes pressure losses between evaporator tubes.

Abstract: Compliance with administrative limits on cumulative exposure of control rod groups in the reactor core, is monitored by computing the incremental effective exposure for each group commensurate with core power, for each time increment at which each group is within the position range where an administrative limit is imposed. The increments of effective exposures for each group are accumulated, and the accumulated effective exposure for each group is compared with the administrative limit to each group. This comparison is then displayed to the reactor operator, preferably using either a "rolling wheel" or "sliding bar" format.

Abstract: The flue gas temperature coming from an air preheater to a particulate collection device such as an electrostatic precipitation or fabric filter is reduced to improve the operation of the particulate collection device. This may be done by reducing the exit flue gas temperature from the air preheater or reducing the temperature after exiting. In one embodiment, air in excess of that needed for combustion is passed through the air preheater with the heated excess air either being dumped or used for a variety of purposes in the plant. A particular embodiment involves segmenting the air outlet side of a rotary regenerative air preheater and withdrawing the excess air from the segment where the dust loading is the lowest. Further, additional cooling of the flue gas can be provided by reducing the quantity of primary air that typically bypasses the air preheater and then providing other ways to control the primary air temperature to the pulverizers.

Abstract: A minimum recirculation flame control (MRFC) solid fuel nozzle tip (12) that is suited to being cooperatively associated with a pulverized solid fuel nozzle (34) of a firing system in a pulverized solid fuel-fired furnace (10). The MRFC solid fuel nozzle tip (12) includes a secondary air shroud (46), secondary air shroud support (50) operative for supporting the primary air shroud (48) relative to the secondary air shroud (46), and a splitter plate (52) mounted in supported relation within the primary air shroud (48).

Abstract: An arrangement for supporting a vane wheel assembly of a pulverizer bowl mill that is operative to effect therewith a reliable and accurate securement of a vane wheel assembly to the rotating grinding table of the pulverizer bowl mill.

Abstract: An energy-efficient grinding roll for employment in a pulverizer operative for effecting the pulverization of solid material therein. The energy-efficient grinding roll includes a body portion formed of a first type of material, an external surface formed of a second type of material, and tread-like means of preestablished dimensions and preestablished spacing provide on the external surface such that the energy-efficient grinding roll is capable of achieving as much as a 15% reduction in the energy required to pulverize solid material when compared with the use of standard grinding rolls.

Abstract: A buckstay system of an associated furnace having a combustion cavity with a front waterwall, a rear waterwall, and opposed left and right side waterwalls joining the front and rear waterwalls and where the waterwalls are arranged in a generally square pattern about the cavity. The cavity has four corners and each buckstay an attachment module welded to each end, each attachment module includes first and second planar plates. The first and second planar plates are disposed in side abutting relationship to the web of the buckstay and extend beyond the end of the buckstay, each of the first and second plates have coaxial pivot holes disposed in a part thereof that extends beyond the end of the buckstay. The planar plates in the attachment module may be rectangular. Or have a notch or recess for clearance.

Abstract: A feedwater control system for a pressurized water steam generating system, and a method for using such, includes a steam generator, at least one feedwater pump which receives an output signal from the feedwater control system, an economizer feedwater control valve which receives the output signal and automatically controls flow of feedwater to the steam generator when a power level of the feedwater control system is at a first predetermined range, preferably between about 10 and 100%, and a downcomer feedwater control valve which receives the output signal and automatically controls the flow of feedwater to the steam generator when the power level is at a second predetermined range, preferably between 0 and about 10%. A first input signal is provided, determined by the feedwater flow of the steam generator, along with a second input signal, determined by the steam flow of the steam generator, and a third input signal, determined by the level of the steam generator.

Abstract: A heat recovery generator has a housing defining a horizontally oriented exhaust gas stream. The exhaust gas stream passes through a first heat recovery unit having horizontally oriented heat transfer tubes and forced circulation of a heat transfer fluid therethrough. The exhaust gas stream then is passed through an air pollution control assembly having a catalyst for reduction of exhaust emissions. The exhaust gas stream is subsequently passed through a second heat recovery steam generator having vertically oriented heat transfer tubes and natural circulation therethrough.

Abstract: A multi-lift tool and method for moving control rod assemblies in a nuclear reactor. The multi-lift tool comprises a frame having an upper end and a lower end. A control rod grapple is supported by the frame for engaging a lifting handle of a control rod. The control rod grapple is movable along a length of the frame for raising and lowering the control rod relative to the frame. A fuel support piece grapple is secured to the lower end of the frame for engaging and lifting a fuel support piece together with the control rod. A blade guide grapple is secured to the upper end of the frame for engaging and lifting a blade guide together with the fuel support piece and the control rod. An unlatching grapple is supported near the lower end of the frame for engaging and lifting an unlatching handle of the control rod. The unlatching grapple is movable along a length of a lower portion of the frame for raising the unlatching handle of the control rod relative to the frame.

Abstract: There is provided a circulating fluidized bed steam generator (CFB) having an improved structural support system and an improved combined hot solids-gas separator for separating gas and solids from a combined gas-solids stream. The combined hot solids-gas separator is in the form of a cyclone assembly having a plurality of wall portions forming a separation chamber and an inlet for passage of a combined gas-solids stream into the separation chamber. The lowermost extent of the inlet forms a threshold over which the combined gas-solids stream flows in entering the separation chamber. The separation chamber is operable to separate the combined gas-solids stream into a predominantly gas exit stream and a predominantly solids exit stream in a manner by which separated out solids to be discharged from the separation chamber via the predominantly solids exit stream are collected within the separation chamber at a location lower than the inlet.

Abstract: A method is provided which refurbishes a Rankine cycle vapor generator initially having a plurality of Rankine heaters for supporting a Rankine cycle subsystem. The method removes at least one of the Rankine heaters, and replaces the at least one removed Rankine heater with a non-Rankine heater for a Kalina cycle subsystem. The vapor generator comprises a first plurality of tubes for receiving a first working fluid, and a second plurality of tubes for receiving a second working fluid. The first plurality of tubes are directed along a first path exposed to heat from a heat source to increase the temperature of the first working fluid within the first plurality of tubes. The second plurality of tubes are directed along a second path exposed to heat from the heat source to increase the temperature of the second working fluid within the second plurality of tubes.

Abstract: A pulverizer shaft rotation support assembly includes a rolling element sub-assembly for rotationally supporting the shaft of a pulverizer of a bowl mill of the type which is operative for pulverizing material such as coal into smaller particles, and includes a separator body having a bore, a rotating shaft supported within the bore, and a grinding table supported on the shaft. The rolling element sub-assembly includes an inner race secured to the shaft at a first shaft location, an outer race and a plurality of cylindrical bearings for rolling movement along and intermediate the inner and outer races. The pulverizer shaft rotational support assembly also includes an annular cutout in a gearbox housing structure for radially limiting the outer race while permitting axial movement thereof.

Abstract: A system and method of managing, storing, and accessing cross references between related kinds of sub-record information in a computerized engineering database. A generic cross reference table which contains all the cross reference links for all the data items in all the data tables of the engineering database, is provided. Each link in the generic cross reference table is constituted by two records (1) a forward record with a specified link from a data item in a first data table to a record or a data item in a second data table, plus (2) a reverse record (partner record) with the link from the data item in the second data table to the record or an item in the first data table. Preferably, the link record in the cross reference table contains a link type value selected from a set of pre-defined link types for the pair of link points, comments associated with the link at the time of creation, and other link-creation information such as the identification of the user who created the link.

Abstract: A CEDM data acquisition system (40) receives analog coil-current signals from control element drive mechanism coils (18, 20); conditions the analog signals to remove noise induced therein by the electronic circuitry (44) associated with the control element drive mechanisms; digitizes the conditioned analog signals; displays the acquired test data; and records the data for future use. The inventive data acquisition system preferably has the ability to simultaneously measure, display and record coil-current data for all of the five coils associated with each CEDM rod-group with respect to time. Further, the inventive data acquisition system preferably allows the user to monitor, display and record data for up to eight CEDMs simultaneously. It also allows the measurement of rod-drop times during rod-drop testing of the CEDMs.