written 29 September, 2024
published 6 October, 2024
PG&E's Diablo Canyon nuclear plant, located on the coast near San Luis Obispo, is the last operating nuclear facility in California. The two 1,100MW reactors came online in 1985 and 1986, designed to operate for 40 years. In 2016, PG&E announced plans to close both reactors by 2025, rather than incur costly upgrades.
Nuclear power is baseload power, meaning it operates 24 hours a day, but output can't easily be adjusted to meet variable grid loads. These days, it is the most expensive form of utility scale electricity. As with all combustion power sources, uranium is a finite fuel, and most deposits easy to access have been depleted, driving up fuel costs. Each reactor holds tens of tons of enriched uranium fuel, but the nuclear decay by-products degrade the energy efficiency of the fuel rods, requiring refueling after just 5 percent of the uranium has been consumed, contributing to the high operating costs. After 70 years of commercial nuclear power, there is still no adequate storage for the highly radioactive used fuel rods.
While it is accurate that a normally functioning nuclear reactor does not emit any greenhouse gases, there is great concern about what happens when a reactor fails. Greenhouse gases last for ten centuries, but radioactive contamination lasts for a thousand centuries. There have been three major reactor malfunctions that made the news (Three Mile Island, Chernobyl, and Fukushima), so we know such failures are possible.
The Diablo Canyon reactors are at the end of their design life, without any upgrades, and it is known that prolonged, intense radiation embrittles metal, weakening it, increasing risk of failure. There are three active seismic faults within three miles of the Diablo Canyon plant, each capable of a magnitude 7 event, including one running right through the site. PG&E tested for embrittlement in 2006, but refused to make the results public, claiming "proprietary information", and has postponed any further testing. A structural failure of a weakened reactor cooling system due to an earthquake could cause wide spread radiation contamination.
Fukushima failed when the tsunami flooded the emergency backup generators, causing several reactors to overheat and melt down, with resulting hydrogen explosions. This was a direct result of original cost cutting decisions about how high to build protective sea walls, and sea level placement of the generators. Safety is always sacrificed when decisions prioritize maximum profit.
The reactors at Fukushima broke thirteen years ago, and real clean-up has yet to begin because the site is still too lethal for even robots to operate. Cleanup costs are estimated at over a trillion dollar, and will take 4 decades, considered optimistic, as clean up on this scale has never been accomplished before.
PG&E is not liable for any radiation contamination damages, or cleanup costs, by long standing federal legislation. No insurance policy in the country has ever covered such losses, because the price is indeterminant and the risk is completely unknown.
In 2021, the California Energy Commission became concerned about summer blackouts resulting from increasing air conditioning loads due to growing planetary heating, and recommended Diablo Canyon continue operating until 2035. Recently, all electric utilities were told they must share the cost of keeping the plant open, even if they aren't in PG&E territory.
Despite plans to operate past the original design life of the system, PG&E has not been required to make any major plant upgrades, which would be expensive and time consuming. In addition, PG&E has not been required to make public the embrittlement testing done 18 years ago, or make any new tests on the current state of the system. We are supposed to just "trust them", and hope for the best.
This is the nuclear gamble: operate an aging nuclear plant, in an unknown operating condition, sitting on known fault systems, hoping for no seismic events for the next decade. On the one hand, it has worked so far, and PG&E continues to get massive profits from the most expensive power on the grid. However, should a low probability seismic event occur, and the reactors break, contaminating the center of California, PG&E is fiscally responsible for nothing. However, we all get to deal with, and pay for, the result.
This is typical corporate financial reasoning: capitalize the profits and socialize the losses. Sweet deal for the company, which has already demonstrated its complete disregard for customer welfare over the last few decades.
