How Water Chemistry in Steam Power Plants Affects Reliability
I recently learned that the water chemistry in steam power plants is critical to optimizing their reliability. Steam power plants, especially those fueled by oil, coal, natural gas, and in the case of nukes, uranium, are widely used in the U.S and around the world, so anything that can reduce their propensity to go offline is important from an emergency preparedness perspective.
Why Water Chemistry Matters in Steam Power Plants
Simply put, if water chemistry is out of whack, it could lead to equipment deterioration, cracking and corrosion. For example, corrosion caused by oxidizing metals can release rust into the water stream, leading to mineral deposits that can restrict the flow of water. This can reduce plant efficiency, and in extreme cases can lead to ruptures that put worker safety at risk.
The risk of corrosion is especially apparent when it comes to feedwater systems comprised of carbon steel and copper alloys. Stainless steel is better, but certainly not risk-free because corrosion can lead to cracking.
One especially egregious risk is something called flow-accelerated corrosion (FAC), which essentially refers to the erosion of metal surfaces that thins out internal piping and can eventually cause a rupture. According to ERPI, a whopping 60% of steam power plants have reported FAC at one time or another, and the problem has led to dozens of fatalities over the years.
The specific chemicals and treatment processes used to optimize water chemistry is beyond the scope of this post, but suffice it to say that it is one of the more important indicators of reliability. And it’s not just about using the right chemicals – the supply of certain chemicals used for this purpose is dwindling, creating a need to identify and properly deploy substitute chemicals. It’s all very complicated!
I’m sure your company employs experts to deal with such matters, but I definitely think it’s worthwhile for emergency planning professionals to be aware of the risks and implications. Our job is to be aware of all possible risks in order to maximize preparedness no matter what the scenario, and my hope is that this high-level primer on water chemistry at steam power plants will do just that!
