CHAR Services

CHAR Services

For over 20 years, AMS Corporation, through its CHAR Services Division, has been providing cable testing and EMI/RFI troubleshooting services to support the health and maintenance of cable circuits in nuclear power plants. Further, extensive research and development activities have also led to recent advancements in cable testing techniques that have been incorporated into the latest release of the CHAR (pronounced ‘care’) Cable Condition Monitoring System.

Example applications for AMS cable testing and CHAR services include a variety of low voltage cable circuits such as nuclear instrumentation, radiation monitors, rod control and rod position indication systems, pressurizer heaters, and motors. AMS has also developed a multiplexer that can be paired with the CHAR system which allows for testing up to 80 cables at a time thus facilitating high speed electrical characterization of large volumes of cables, connecters, and end devices.

Our CHAR cable testing system, together with our expertise in performing this work for over 20 years, provides a powerful tool for diagnosing and resolving issues in nuclear plant I&C cable circuits prior to an unexpected impact to plant operations.

Examples include:

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.
CHAR Services

  • Degraded connectors
  • Moisture intrusion into cracked cable insulation
  • Intermittent connections
  • Noise coupling from damaged or degraded shielding
  • Open circuit faults
  • Short circuit faults – between conductors, conductor to ground
  • Turn to turn shorts in motors and coils
  • Foreign material or moisture contamination in connectors


  • Instrumentation and power cables, including connections, penetration and splices
  • Rod drive mechanism cables and coils
  • Rod position indication system cables
  • Nuclear instrumentation cables, connectors, and detector
  • Baselining newly installed cables & connectors
  • Motor coil and valve cables and connectors


  • Distance to fault
  • Fault severity
  • Effect of fault on cable circuit performance
  • EMI/RFI analysis
  • Recommendations for repair
  • Automated report generation