NUCLEAR REACTOR ARRANGEMENT AND METHOD OF OPERATING SAFE EFFECTIVE TO INCREASE THE THERMAL AMARGIN IN HIGH POWER DENSITY REGIONS

摘要

A nuclear reactor cooled by a moderating fluid and a method of operating such a reactor wherein a portion of the coolant directed through the reactor and over the fuel elements is conveyed in bypass relation with the first portion of the reactor core such that it maintains generally its initial or entering temperature. This bypassed portion is then introduced at spaced intervals into regions of high power density so as to decrease the enthalpy of the coolant at these regions and thereby improve the margin to burnout and, accordingly, improve the power generation capability of the reactor.