Nuclear Power Plant Maintenance

Maintenance of a Nuclear Power Plant

Extensive preventive maintenance and testing (surveillance) programs exist to ensure that nuclear safety significant equipment will function when it is supposed to. Diesel generators, pumps, motor operated valves and air operated control valves are typically operated every one to three months. When you drive a car, you depend a lot on the sounds, the feel of the steering wheel and the gauges to determine if the car is running correctly. Similarly with operating equipment at a power plant - if sounds or vibration of the equipment or the gauges and test equipment indicate a problem or degradation, actions are taken to correct the deficiency. If the equipment fails to start or run, more immediate actions are taken. In some cases, regulations called technical specifications may require the plant to be shutdown if the equipment is not corrected within a certain period of time. The length of time depends on the safety significance of the equipment.

Every year to two (2) years, the power plant may be shutdown for an outage. The outage may last 30 to 60 days and depends on the amount of major maintenance to be done. Outages are used to perform activities that cannot be done when the plant is operating:

Refueling the reactor and other preparations (removal of reactor head, upper internals, and reactor refueling)
Preventive maintenance on equipment that must run all the time, e.g. turbine-generator must be inspected every 5 years or so, transformers may be checked out each outage;
Modifications or replacements of major equipment, as a steam generator, that cannot be shutdown.

The maintenance personnel who maintain the equipment at the power plant must go through craft-specific training to qualify to perform the plant maintenance. Training programs are inspected and certified by the accrediting board of the National Nuclear Training Academy.

Engineers at the power plant are often responsible for specific systems at the plant and manage the work done (preventive maintenance, repairs, and modifications) on their system. Similarly, engineer training programs are inspected and certified by the accrediting board of the National Nuclear Training Academy.