Parts Quality Initiative - Powerlabs

Parts Quality Initiative


Parts Quality Initiative (PQI) Ensures Equipment Reliability

In 2006, Constellation PowerLabs’ PQI program was founded to safeguard against downtime due to critical parts failure. Constellation PowerLabs uses historic model-specific failure data trends to identify which parts to PQI test.

PQI data and testing ensures defective parts are identified before installation, reducing downtime, labor and logistics costs, and yielding substantial parts replacement savings.


How Does PQI Work?

A PQI Membership includes a subscription to Constellation’s web-based OneLab portal, which reveals Constellation’s extensive PQI Analysis database comprised of proven PQI test plans for more than 2,000 models and historical failure trends on more than 80,000 parts.

Since 2006, Constellation has compiled data revealing trends in failure variables specific to part type, manufacturer and model number for safety and non-safety related applications.

Send the hardware to Constellation PowerLabs for PQI critical characteristics testing. PQI ensures defective parts are identified before inventorying and installation, reducing downtime, labor and logistics costs. Testing newly procured parts before inventorying allows failed parts to be replaced at no additional cost, resulting in substantial part replacement savings and reduced cost of quality. PowerLabs can also PQI test inventoried parts to verify older parts still perform their critical function.


PQI Parts Quality Initiative Exceeds INPO's IER L2 21-4 Parts Quality Recommendation


Nuclear Energy Institute (NEI) recognized Constellation’s Parts Quality Initiative in 2018 and awarded the program with the coveted Top Innovative Practice (TIP) Award.



Learn more about how our PQI program became recognized as one of the leading innovations in nuclear.


Top Failed Component Categories in the Last 5 Years by the Largest Number of Failed Samples

Constellation PowerLabs’ PQI program is a living program that is continually evolving as we test more parts each year. The average parts failure rate across the PQI community is 7%.

CategoryNumber of Samples TestedNumber of Failed SamplesFailure Rate
Relays12,946 Tested1,029 Failed7.95% Failure Rate
Regulators3,474 Tested270 Failed7.77% Failure Rate
Circuit Breakers3,914 Tested354 Failed9.04% Failure Rate
Fuses12,239 Tested287 Failed2.34% Failure Rate
Solenoid Valves4,332 Tested102 Failed2.35% Failure Rate

View PQI Case Studies

Find Out Why 6 Out of 7 Regulators Failed PGI Testing

warehouse inventory parts quality

Constellation Nuclear Improves MWh Output with PQI

nuclear cooling towers and American Flag

PQI Saved Plant $3 Million in Savings Due to Avoided SCRAM

Tech Service Testing Circuit Board

PQI Savings: Three Clear Cost Saving Solutions


The cost savings of identifying newly procured deficient parts and sending back to the manufacturer for replacement at no additional cost. For most nuclear sites, this cost avoidance more than pays for the cost of the PQI program year after year.


When a newly procured part fails PQI testing and can be sent back to manufacturer for a replacement, sites can also void procurement/OSD&D costs. Constellation PowerLabs, in collaboration with nuclear industry partners, estimates $1,200 in avoided procurement costs for each project resulting in a PQI test failure.


The greatest financial benefit of the PQI program, however, is identifying failed parts at PQI testing and avoiding post-installation consequential events. Constellation PowerLabs, in collaboration with nuclear industry partners, estimates each PQI failed part that is kept out of a plant could help prevent costly unit trips or other events. Cost avoidance estimates are outlined by part criticality category below.

Criticality CategoryEvent Cost Avoidance by Part FailedInputs to Cost Avoidance
Single Point Vulnerability $ 1,500,000.00Unit Trip, Investigation Costs, Lost Generation, OCC Staffing, Reporting
Critical Component$ 500,000.00Lost Generation, Investigation Costs, OCC Staffing, Reporting (non-NRC)
Critical Component Tech Spec Equipment$ 150,000.00Safety System Unavailability, OCC Staffing, Schedule Adherence, MSPI and Maintenance Rule Clock Time Accrual
High Criticality Work Order$ 2,500.00Failed Bench Testing or Post-Maintenance Test, Delay of Critical Work Order, Schedule Adherence Impact

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