Reactor internal pump

The goals of this development were (1) Enhanced safety and reliability, (2) Reduced occupational radiation exposure and radioactive waste, (3) Enhanced operability and maneuverability and (4) Improved economy. Significant improvements were induced by the adoption of the reactor internal pump, fine motion control rod drive mechanism, integral type reinforced concrete containment vessel and digital control system. Cross-section of reactor buildings for 1100MW(e)-class BWR and ABWR are described in Figure 2. 

Reactor System Compo- nent Reactor Internal Pump 10 5 Outage 2 2 2 2 2... 

We plan to adopt some design improvements. They are simplification of reactor internal pump power supply system, change of FMCRD motor from stepping motor to induction motor, change of process computer from special ordered computer to work station computer, down sizing of radioactive dispersal system, change of flammability control system (FCS) from thermal recombiner to passive autocatalytic recombiner, size up safety relief valve and so on. 

Simplification of reactor internal pump power supply system... 

Ten reactor internal pumps are located at the bottom of the reactor pressure vessel. In order to simplify the power supply system for the reactor internal pumps, a new inertia-increased reactor internal pump was developed, which allows eliminating the Motor-Generator (M-G) sets. The rotating inertia was increased approximately 2.5 times of current reactor internal pump inertia by addition of flywheel on its main shaft. 

Recirculation system inside RPV Two external loop recirculation system with jet pumps Vessel-mounted reactor internal pumps Natural circulalion... 

The ABWR design enhancements include elimination of the external recirculation loops and pumps and installation of reactor internal pumps (Figure 3.10). The ESBWR transitions... 

The palladium catalyst supported on the dendrimer with 24 phosphine end groups (2) was used in a CFMR. In the continuous process a solution of allyl trifluoroacetate and sodium diethyl 2-methylmalonate in THF (including -decane as an internal standard) was pumped through the reactor. Figure 4 shows the conversion as a function of the amount of substrate solution (expressed in reactor volumes) pumped through the reactor. The reaction started immediately after the addition of the catalyst, and the maximum conversion was reached after two reactor volumes had passed, whereupon a drop in conversion was observed. It was inferred from the retention of the dendrimer (99.7% in dichloromethane) that the decrease was not caused by dendrimer depletion, and it was therefore ascribed to the... 

Fukada, S., Y. Edao, M. Terashita (2009), Chemical Heat Pump System Working at Exhaust Temperature of High-temperature Gas-cooled Reactor , International Journal of Hydrogen Energy, 34, 540-546. 

Thermocyclic cracks were revealed in pipes connecting a reactor with pressurizers, in internal headers for water supply from purification system to reactor coolant pumps, in internal shells of pumps flow chambers, etc. The indicated defects became the reason for in-depth analytical and experimental studies of equipment operating conditions in the propulsion and test reactor plants, particularly thermal and strain parameters monitoring. 

Ihe operating ejqjerience has shown that abnqit changes in a primary pressure can be the reason of damages in internal structures made as semi-closed plena which walls were not designed for the primary coolant pressure. That was the reason of feilure of a partition in the reactor coolant pump of icebreaker "Arctica". 

Recent boiling water reactor (BWR) designs with internal pumps or natural circulation, which eliminate bnUcy external reactor equipment like jet pumps and steam generators, permit extremely compact containment buildings. Because modular construction technology can be readily applied to these BWR containments, the qnantities of material and constrnction times are reduced substantially. In the absence of snbsidies, BWRs can be expected to increasingly dominate the economic competition in the LWR market. 

At present, there are two arrangements for the MBR the membranes may be submerged in the biological reactor (internal), or the membranes are separated from the reactor and an intermediate pumping step is used (external) (Fig. 23.4, upper and lower panels respectively). 

The pressurizer, as shown in Figure 5.4.10-1, is a vertically mounted, bottom supported, cylindrical pressure vessel. Replaceable direct immersion electric heaters are vertically mounted in the bottom head. The pressurizer is furnished with nozzles for the spray, surge, and safety lines, and pressure and level instrumentation. A manway is provided in the top head for access for inspection of the pressurizer internals. The pressurizer surge line is connected to one of the reactor coolant hot legs and the spray lines are connected to two of the cold legs cit the reactor coolant pump discharge. Heaters are... 

A small SFR, commonly referred to as the 4S (Super Safe, Small, and Simple), is under development with the aim of commercialization in the early 2010s (O Fig. 58.14). The reactor is intended to serve as a dispersed supply source of power and heat for local areas with an electric output of 10—50 MWe. This reactor is designed for continuous operation up to 30 years without refueling by steadily driving upward a removable radial reflector surrounding the core. This also has the advantage of nuclear nonproliferation because it is capable of sealed operation with no need to unseal the reactor for maintenance. This can be achieved by a reactor internal structure composed only of passive components, such as an electromagnetic pump with no active parts for in-vessel coolant circulation. There have also been studies on the application of... 

Reactor internals include both fixed and movable components. Examples of such components are control rods (movable), in-core instrumentation (fixed and movable), the core shroud, core plate, jet pumps, top guide, and steam separators and steam dryers (all fixed). Austenitic stainless steels are used for the majority of these components for their corrosion resistance. In other specific applications such as in the control rod drives and jet pumps, precipitation-hardened nickel-base alloys (for example. Alloy X-750, UNS N07750) are used where greater corrosion resistance and strength are required. 

In the fuel subassembly, fuel pins are assembled with grid spacers and a top shield is installed to prevent activation of the EM pumps and the secondary sodium in the MX. Coolant inlet modules located beneath the fuel subassembly provide a lower shielding for the reactor internal structures including the core support plate and air in the RVACS. 

Reactor equipment Recirculation system Internal pump method External recirculation type... 

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