Diablo Canyon nuclear power station is self sufficient for potable and pure water. It uses a modular reverse osmosis plant with pumps powered from the plant output and a number of parallel osmosis units that remove salt when supplied with pressurized water.
The plant is licensed to a capacity of 1.5 million gallons per day, but only produces an average of 675,000 gallons per day. There is an associated 5 million gallon storage tank. Because of the plant’s isolated location, there is not a water pipeline installed that connects the plant to the local community of San Luis Obispo. That may be about to change.
California’s worsening drought has stimulated creative thinkers like the people at Californians for Green Nuclear Power (CGNP) to wonder if there are ways to take advantage of the installed RO plant that already has access to low marginal cost electricity and excess licensed capacity. CGNP helped to make the necessary connections to get the conversation started between the plant and the community about the potential of the available tool.
One of the features of reverse osmosis plants is their modularity. That allows the plant to be almost infinitely expanded as long as there is space available for installing pumps, pipes, filters and, perhaps, additional tanks.
Since the plant is already located on the site of an operating nuclear plant and has internal connections to that plant, it is possible to take direct advantage of low cost electricity available at times when demand is low. That electricity, unlike the coal and gas fired electricity that will be supplying a new 50 million gallon per day desalination plant in Carlsbad, CA, will be air pollution and CO2 free.
For now, since there is not an installed pipeline to San Luis Obispo, excess water for the city will have to be moved from Diablo Canyon by truck, which is an energy intensive and suboptimal solution. A discussion is already underway about a water pipeline installation project that can be scheduled in the near future when the existing right of way for communications and power lines is disturbed to upgrade the network connections.
Once that water pipe is installed, I suspect that the city will consider building additional water storage that can be filled during times of low demand to be ready to help when natural rain cycles are insufficient to meet demand. I suspect that there are already some creative problem solvers researching the legal and physical obstacles that will need to be overcome in order to expand the plant’s capacity if the drought continues to persist.
Not surprisingly, there are already some nuclear energy deniers that are concerned about the potential effects of disposing of additional brine into the Pacific Ocean, an impressively large body of water where the salt water came from in the first place. I’ll let them figure out how to make that illogical case to a thirsty public.