This article from The Economic Times says radiation monitoring systems stopped working for various reasons ranging from power failure to damage from earthquake and tsunami.
Author: Dan Sythe
Dan is CEO of IMI (International Medcom, Inc.). He has been designing and manufacturing innovative radiation detection instruments for over 40 years. Many thousands of these instruments are in use throughout the world in support of public safety, security, nuclear arms control, medical and laboratory safety programs, educational programs, and personal safety applications.