A Designers View of Nuclear Energy - Department of Materials ...

Boiling Water ReactorBWR overview• Operating conditions:• Pressure (saturated) ~7.3 MPa• Average temperature 310 o C• Reactor core consist of bundles of enriched ~3% UraniumOxide fuel in shrouded bundles with Zircalloy fuel clad tubes;• Vertical control rods operated from bottom of core – do not dropinto core to shut-down reactor;• Reactor cooling flow by augmented natural convection;• Steam separators above the core with direct feed to wet steamturbines – some carry over of contamination;• Complex power control and multi-level emergency core coolingsystems;• Refuelling at 2 year intervals from top of core by means ofremovable vessel head;• Coolant chemistry has to cover contamination from condenserwater as well as core requirements – not preferred for coastsites because of potential chloride contamination?• Defence against major accident must take account of reactor &turbine building – containment, aircraft crash etc.8