Nuclear Energy Systems HeadquartersMitsubishi Advanced PWR Plant Top
Improved Economy Enhanced Safety Improved Reliability Advanced Operability and Maintainability Harmonization with the Environment
3.Improved Reliability
Reliable Reactor Vessel

1.Reactor Vessel

  • Houses the large capacity reactor core(compared with the latest 4-loop) Inner diameter:φ 4.4m to φ 5.2m/Total height:12.9m　to 13.6m
  • Improved stress corrosion crack resistance Improved head adapter material(Inconel690)/Reduced ambient temperature(Top Tcold)

[figure]Reactor Vessel

2.Circular Tie Plate

  • Stabilized flow state of the lower core
    The tie plate are round in shape to increase the lower space of the reactor vessel, and to homogenize the flow to the core.

[figure]Circular Tie Plate

3.Advanced pressure housing for control rod drive mechanism

  • Improved reliability of the equipments
    1)Improved resistance against stress corrosion cracking
    2)Improved ease of inspection

[figure]Advanced pressure housing for control rod drive mechanism

4.Neutron reflector

Comparison with conventional baffle structure

  Baffle mounting plate structure
(Latest 4-loop)		 Neutron reflector structure
(APWR)
Basic structure Baffle structure by thin sheet Ring block 8-stage layer stack
Total number of parts Approx. 4,000 Approx. 200
Number of bolts Approx. 2,000 Approx. 50
Fitting method Bolting to the core layer via mounting plate Fitting the bottom above the support rack using tie rod/independent structure
Thermal shielding material Yes Not needed
Neutron irradiation - 1/3 as compared to the latest 4-loop

[figure]Neutron reflector

* 3-2.High-performance Compact Steam Generator

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