Subject : Power Plant Engineering

Topic: Chap 5- Nuclear Power Plants

Difficulty: Medium

In this reactor the core containing U235 in surrounded by a blanket (a layer of fertile material placed outside the core) of fertile material U238. In this reactor no moderator is used. The fast moving neutrons liberated due to fission of U235 are absorbed by U238 which gets converted into fissionable material Pu239 which is capable of sustaining chain reaction. Thus this reactor is important because it breeds fissionable material from fertile material U238 available in large quantities. Like sodium graphite nuclear reactor this reactor also uses two liquid metal coolant circuits. Liquid sodium is used as primary coolant when circulated through the tubes of intermediate heat exchange transfers its heat to secondary coolant sodium potassium alloy. The secondary coolant while flowing through the tubes of steam generator transfers its heat to feed water.