Simplified Boiling Water Reactor Research Articles

Conceptual Design and Safety Characteristics of a Natural-Circulation Boiling Water reactor

The Hitachi simplified boiling water reactor (BWR) is a natural-circulation BWR with a rated capacity of 600 MW (electric). It has been designed for the classes of small- and medium-sized light water reactors. The power density is ∼70% of that in current BWRs because of natural circulation, and the reactor pressure vessel is larger. The components and systems have been simplified by eliminating pumped recirculation systems and pumped emergency core cooling systems. Consequently, the volume of the reactor building is ∼50% that of current BWRs, with the same rated capacity. The construction period is also shorter. In addition, the lower power density allows continuous operation for a 23-month period. The safety characteristics of this BWR are investigated during transient and accident conditions, and the high standards of its simple safety systems are shown

SBWR, a simplified boiling water reactor

An advanced light water reactor concept is being developed for possible application in the 1990's. The concept, known as SBWR is a boiling water reactor which uses natural circulation to provide flow to the reactor core. In an emergency, a gravity driven core cooling system is used. The reactor is depressurized and water from an elevated suppression pool flows by gravity to the reactor vessel to keep the reactor core covered. The concept also features a passive containment cooling system in which water flows by gravity to cool the suppression pool wall. No operator action is required for a period of at least three days. Use of these and other passive systems allows the elimination of emergency diesel generators, core cooling pumps and heat removal pumps which is expected to simplify the plant design, reduce costs and simplify licensing. The concept is being developed by General Electric, Bechtel and the Massachusetts Institute of Technology Supported by the Electric Power Research Institute and the United States Department of Energy in the United States. In Japan, The Japan Atomic Power Company has a great interest in this concept.