Mitsubishi Heavy Industries (MHI), the supplier that sold four new steam generators to Southern California Edison (SCE) for the San Onofre Nuclear Generating Station (SONGS), has issued a redacted version of its root cause analysis of the u-tube failures that have kept both of the station’s 1100 MWe units shut down since January 31, 2012. My analysis of the report tells me that a large, skilled, experienced team of engineers (both at the supplier and at the utility) made a design choice that resulted in unexpected and unintended consequences.
Early last month, two technically unqualified politicians (that phase is a bit redundant, isn’t it) – Senator Boxer and Congressman Markey – took it upon themselves to demonize selected nuclear energy professionals. They extracted a few isolated phrases from a version of the root cause analysis that was not publicly available and proclaimed to the world that they had found a smoking gun “proving” that SCE had knowingly installed faulty equipment.
Aside from the fact that such an assertion was absurd – why on earth would any corporation take the risk of installing components known to be faulty into a vital, multi-billion dollar production facility capable of producing between $1-$10 million in daily revenue – it exposed a visceral dislike of a power source that has been cleanly and safely supplying 20% of the electricity in the United States for several decades.
It also exposed a profound distrust of one of the most squeaky clean industries in the United States; say what you want to about nuclear energy, but it does not take much time in the industry to realize just how differently it is led compared to all other money making enterprises.
One of the major difficulties in this saga is the fact that politicians rarely understand engineering, especially the constant need to make informed decisions and to balance competing requirements. No mechanical system is flawless and no material is perfectly matched to its environment. That statement is especially true when the environment is a complex heat exchanger required to operate over a wide range of temperatures in a variable mix of fluid conditions over several decades.
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