Programmable Logic Controllers

The existing fleet of nuclear power plants were designed and built based on the analog technology available in the 1960’s and 1970’s. Many plant refurbishments/upgrades and new nuclear plant construction are taking advantage of digital programmable logic controllers (PLCs).

Digital PLCs offer increased control, accuracy, reliability, tracking/trending capability, and communications. Some PLC designs also offer triple redundancy and hot swappable capability to further increase their reliability.

NLI works with several PLC OEMs to best meet our clients control requirements. Custom user codes are written by NLI to meet our client’s unique control schemes.

The digital PLCs are then qualified in accordance with IEEE Standards 344, 323, 384, and 7-4.3.2 and EPRI TR-102323 at a minimum.