Equipment Enhanced LPRM (EEL) System

Local power range monitor (LPRM) detectors are inserted inside the BWR reactor core to measure neutron flux.

A typical failure mechanism for LPRMs is metal whisker growth between the plates of the detector. These whiskers can short circuit the LPRM detector, which must then be placed in bypass mode. Each plant must have a certain percentage of LPRMs operational to remain online.


The EEL-1 hardware is a new test system designed to repair failed LPRM detectors in BWR plants. Failed detectors can now be repaired remotely from the control room LPRM cabinets.


The EEL-1 test equipment has successfully restored failed LPRM detectors to normal operation in several BWR plants. This repair technique does not damage LPRM detectors as compared to the traditional capacitive discharge method.