Corrosion Science and Engineering

Another of DEI's specialty areas is the evaluation of the effects of corrosion on engineering systems. In the electric power industry, for example, corrosion of components involved in generation, transmission, and distribution of electricity is estimated to cost $17 billion per year (about 8 percent of homeowners' electric bills). We specialize in identifying the causes of corrosion that affect different power plant systems (e.g., heat exchangers, reactor vessel head nozzles, and buried piping networks) and offshore oil structures, aiding our clients in developing cost-effective mitigation and repair plans.

Recent DEI work in this area includes:

Nuclear plant component degradation
Boric acid corrosion guidebook
Flow accelerated corrosion

Nuclear Plant Component Degradation
DEI is an industry leader in the development and application of statistical analysis methods for analyzing the degradation of steam generator tubes and Alloy 600 (nickel-iron-chromium) penetrations in a wide range of pressurized water reactor systems. This area includes prediction of future degradation rates, identification of repair methods, and development of methods for mitigating the degradation—and can also involve economic evaluations to determine the optimum long term strategy to address the underlying corrosion.

Boric Acid Corrosion Guidebook
Boric acid is used in the primary coolant systems of pressurized water reactor plants to control the nuclear reaction. When the borated water leaks through gaskets, valves, threaded joints, or cracks in pressure boundary parts, the acid can concentrate and cause rapid corrosion of the carbon and low-alloy steels typically used in pressure boundary parts. DEI prepared a comprehensive boric-acid corrosion guidebook for the nuclear industry under sponsorship of the Electric Power Research Institute (EPRI). This document is widely used in the industry to create boric-acid control programs and to assess the potential for degradation in the event of primary coolant leaks.

Flow Accelerated Corrosion
Flow accelerated corrosion (FAC) is a mechanism in which the normally protective oxide layers on carbon and low-alloy steel dissolve into a stream of flowing water or water-steam mixture. As the oxide layer thins, the metal corrosion rate increases, often to very high rates. Catastrophic failure of power piping due to FAC has been responsible for numerous fatalities at both nuclear and fossil-fuel power plants.

DEI has provided engineering support to FAC inspection programs since 1993, including comprehensive reviews of all piping systems, application of specialized software and experience to recommend specific piping components for inspection, analysis of the inspection results, and recommendations for future action.