Mitsubhisi - Pressurized Water Reactor

 Mitsubishi -pressurized  water reactor

In 1970 Mitsubishi constructed  first nuclear power plant in Japan using pressurized water reactor (PWR) technology. Mitsubishi has been improving PWR plants with own  operational experience as well as through extensive research and development . With vast knowledge Mitsubishi able to supply PWR plants with unparalleled level of reliability, safety and out put capacity to their customers. PWR technology is used two-third of nuclear power plants now operating in the world.

Mitsubishi are now planning next generation plants, the Tauruga 3 and 4 using Advanced PWR (APWR) technology. These scheduled for operation by Japan Atomic Power Company beginning 2015.At over 1500 MW out put, they will have highest capacity  in the world. These units will be capable of producing 30 per cent more total energy than conventional 4 loop plant. The APWR  design will also will also incorporate a high performance core that loads (MOX) fuel and operates over longer cycles.

For four decades, Mitsubishi Heavy Industries (MHI)  has been supplying reliable products and services to utilities operating nuclear power plants using pressurized water reactor technology. Mitsubishi provides basic plans and design component manufacturing, plant construction, on going maintenance, the full nuclear fuel cycle ( from uranium enrichment to final waste disposal ) and heavy investment in research and development of new technology.

The basic design of PWR plant is simple pressurized water is used as reactor coolant and reactor turbine systems are separated by steam generators in indirect cycle system.

Mitsubishi use PWR technology in their plant because Mitsubishi believe Mitsubishi design provides and enable a compact design for entire power plant. The chief benefits are reduced generation  costs and enhanced operatically and maintainability.

The special features of Mitsubishi PWR plants include

. The higher moderator density allows minimization of rod pitch by reducing the no of fuel assemblies and reactor core size

. The absence of bulk boiling in the core limits cladding corrosion thus increasing fuel reliability.

.The open -lattice fuel assembly design contributes to efficient use of neutrons, resulting in fuel economy.

 . The inherent self controlled mechanism in design use gravity to ensure a safe shut down  capability.

. Mitsubishi PWR plants  generate extremely low quality of radioactive wastes.

. The no activated turbine system can be easily operated and maintained.

. The emergency heat -removal capability of secondary system enhances reactor safety.

. The plant design adopts a system equivalent to dry -type reactor containment systems.

.The low centre of gravity plant design provides stronger seismic resistance.

U.S. - APWR design

As a result of extensive verification and qualification testing Mitsubishi developed an Advanced Pressurized water reactor (APWR) design that is more efficient with greater out put than any previous power plant. The design slightly modified to satisfy U.S. and international quality requirements as U.S.-APWR, and it will be become design that Mitsubishi sell around globe. The US-APWR satisfy Mitsubishi customer requirements with best performance for safety, economy,operation and maintenance.
The main features of the U.S.-APWR DESIGN  reactor
. Electric power    --- 1700 Mwe
. Core thermal  power ----4,451MWt

Other features of US-APWR include
Enhanced safety
. A four tram safety system for enhanced redundancy
. An advanced accumulator
. An -in containment refueling water   storage fit
Enhanced reliability
. A steam generator with high corrosion resistance.
. A neutron reflector with improved internals.
. A 90 per cent reduction plant shut down compared other four loop PWRs.

Attractive economy
. A large core with thermal efficiency  of 39 percent
. Building volume per Mwe  that is four fifths of other four loop PWRs.

More environmental friendly
. A 28 percent reduction in spent fuel assemblies per Mwh compared to other four loop PWRs.
. Reduced Occupational radiation exposure.
. Capacity to use mixed oxide (MOX) fuel made from reprocessed nuclear fuel waste.