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Energy Pipeline Management

One aspect of U.S. infrastructure that has begun to show signs of the need for enhanced asset management management practices is nuclear power. Over the past several years, minor corrosion incidents have caused leaks in underground or buried pipes and related systems at several U.S. nuclear power plants, contaminating groundwater with┬áminor levels of radioactive material. The plants’ safety systems continue to function properly despite these leaks. While nuclear power plants (NPPs) are highly regulated due to the extreme consequences of failure, it has become evident that some aspects of asset management for NPPs are not as comprehensive, due to the less critical nature of some systems.
NPPs in general are a complex network of systems, components and processes. The development of nuclear power can be traced as far back as the Manhattan Project and WWII, attempting to harness the power of energy released in a fission reaction for extremely powerful weapons. When WWII ended, this area of research gave way to new developments in using these same fission reactions to provide power through steam generation. The achievement of a safe and sustained reaction by means of control rods and cooling would release great amounts of energy in the form of heat. This heat could then be utilized to produce steam, moving power-generating turbines. Between the 1950s and 1980s, breakthroughs in nuclear research gave way to the development of over 10 kinds of NPPs, including graphite reactors, light water reactors, heavy water reactors, and fast breed reactrs (among other), each with their own sub-sets of variations. (Wood 2007; Lish 1972)
While the intricacies of these stations vary greatly, the principle components are essentially the same. Each contains at least one of the following components:
- Contained Reactor Vessel
- Primary Coolant/Feed water system
- Steam Turbine and Generator
- Residual Heat Removal System
- Coolant Purification System
- Spent Fuel Storage
- Radioactive Waste Handling Facility
- Closed Loop and Nuclear Service Water Systems
- Emergency System
Within these major systems of NPPs, constant asset management is essential, because the consequence of failure is extreme. All essential systems require redundancy with emergency backup in order to prevent loss of control of the fission reaction or escape of radioactive materials (Lish 1972). That being said, it has recently come into focus that numerous subsystems have lacked the same amount attention the critical systems receive. Beneath the ground at every NPP is buried piping, sometimes miles in length, generally associated with the Closed Loop and Nuclear Service Water Systems, but also feeding over 40 systems such as fire protection, fuel and lubrication oil, off gasses, and hydrogen among others (NRC 2011; EPRI 2010).
A significant issue facing nuclear power today is the management of these buried (beneath soil) and underground (within a subsurface housing) utilities; specifically the piping and tanks containing closed loop cooling water and service water. These vital components of the overall system are crucial to ensuring that cooling water is supplied to secondary and tertiary cooling systems, such as residual heat removal and cooling of turbine bearing oil (Lish 1972). While many features of a power plants are readily accessible for inspection and maintenance, these equally important utilities are buried out of sight or contained in subsurface vaults. Therefore, the corrosion and degradation of these utilities is not easily observed or monitored, and the results of these challenges are beginning to reveal themselves.

Recommended Reading

Facts Sheet on Underground Pipes At Nuclear Reactors
Buried Piping Activities
Assessment of Age-Related Degradation of Structures and Passive Components for U.S. Nuclear Power Plants
Components for U.S. Nuclear Power Plants
Recommendations for an Effective Program to Control the Degradation of Buried Pipe,
Guideline for the Management of Buried Piping Integrity
Nuclear Power Plant Systems And Equipment
Liquid Radioactive Release Lessons Learned Task Force Final Report
Memo from G. Jaczko, U. S. Nuclear Regulatory Commission, to R. W. Borchardt,
Ground Water Protection Initiative
NUREG-1801, Generic Aging Lessons Learned (GALL) Report
Groundwater Contamination Due Undetected Leakage of Radioactive Water
NUREG/CR-6876, Risk-Informed Assessment of Degraded Buried Piping Systems in Nuclear Power Plants