Plus an update on California nuclear plants. . .
While 9/11 are numbers burned into the American mind, to Japan the equally ominous digits are 3/11, the month and day of the 2011 Tōhoku earthquake and tidal wave that would claim 18,465 lives and trigger one of the world’s worst nuclear disasters.
Three reactors melted down at the Fukushima Daiichi Nuclear Power Plant, leading to radiation releases still ongoing five years later, as Scientific American reported this week:
Today the disaster site remains in crisis mode. Former residents will not likely return anytime soon, because levels of radioactivity near their abodes remain high. Even more troublesome, the plant has yet to stop producing dangerous nuclear waste: its operator, the Tokyo Electric Power Company (TEPCO), currently circulates water through the three melted units to keep them cool—generating a relentless supply of radioactive water. To make matters worse, groundwater flowing from a hill behind the crippled plant now mingles with radioactive materials before heading into the sea.
TEPCO collects the contaminated water and stores it all in massive tanks at the rate of up to 400 metric tons a day. Lately the water has been processed to reduce the concentration of radionuclides, but it still retains high concentrations of tritium, a radioactive isotope of hydrogen. Disputes over its final resting place remain unresolved. The same goes for the millions of bags of contaminated topsoil and other solid waste from the disaster, as well as the uranium fuel itself. Health reports, too, are worrisome. Scientists have seen an increase in thyroid cancers among the children who had lived in Fukushima at the time, although it is too early to tell if those cases can be attributed to the accident.
The nuclear disaster resulted in a mandatory shutdown order for all of Japan’s nuclear plants and a comprehensive review of their sites for seismic safety issues.
As a result of that review it now appears that one of the nation’s other nuclear power plants may have to be shuttered, given that it sits on an active earthquake fault.
From the Yomiuri Shimbun:
One of the faults that run under the premises of Hokuriku Electric Power Co.’s Shika nuclear power plant in Ishikawa Prefecture can be reasonably concluded to be active, according to an evaluation compiled Thursday by an expert panel at the Nuclear Regulation Authority.
The No. 1 reactor at the Shika plant may have to be decommissioned under the new nuclear regulatory standards, which ban the construction of important facilities above an active fault. The fault in question lies directly under the No. 1 reactor building.
The power company has already submitted an application for a safety inspection of the No. 2 reactor, asserting that the fault is not active. The utility also intends to file a similar application regarding the No. 1 reactor in the near future.
After taking the panel’s conclusion into account, the NRA will make a decision during safety reviews as to whether the fault in question is active.
California only has one functioning nuclear power plant complex, with five others in various stages of decommissioning.
The one function facility is the complex in Diablo Canyon in Northern California, a power plant that caused the Union of Concern Scientists to issue a warning in November 2013:
California’s Diablo Canyon Nuclear Power Plant sits near several earthquake fault lines. One of these—discovered in late 2008—is a mere 2,000 feet from Diablo Canyon’s two reactors, and could cause more ground motion during an earthquake than the reactors were designed to withstand.
Despite enforcing seismic regulations in similar situations elsewhere, the Nuclear Regulatory Commission (NRC) hasn’t enforced them at Diablo Canyon—exposing Americans to undue risk.
The risk of an earthquake at Diablo Canyon is due to the site’s location near a number of fault lines, both offshore and inland from the plant. In fact, dozens of earthquakes have already occurred at or near Diablo Canyon.
Two years later the San Francisco Chronicle issued another warning:
Pacific Gas and Electric Co. replaced $842 million of equipment at the heart of the Diablo Canyon nuclear plant without first making sure the new gear could pass a vital seismic safety test required in the facility’s license, The Chronicle has learned.
Starting in 2008, PG&E swapped out the plant’s old steam generators and reactor vessel heads without evaluating whether the replacements could withstand a major earthquake on the Hosgri Fault — just 3 miles away — and a simultaneous loss of cooling water within the reactors.
Instead, PG&E evaluated each scenario — the earthquake and the loss of coolant — separately, even though Diablo’s license requires that the two be considered together. A severe quake, after all, could rupture pipes connected to the reactor vessels and cause the water to drain, potentially leading to a meltdown.
Pacific Gas & Electric, the plant operator, insists Diablo Canyon is safe.
Until three years ago, California has a second operating nuclear power facility at San Onofre in Southern California. However a serious of mistakes by plant operators and the installation of a tubing system for the plant’s steam generators ultimately led to regulatory investigations culminating in the announcement that the plant would be commissioned, leaving ratepayer to foot the bill for errors made by San Diego Gas & Electric, the facility’s operator.
Here’s a 30 October 2015 video report from KPBS in San Diego on the problems and SDG&E’s failure to notify federal regulators of the crisis:
Edison Never Told Federal Regulators Of San Onofre Equipment Design Flaw
In the cases of both facilities, previously unknown faults not included in the plants’ designs were discovered long after they were up and running, including one major new system at San Onofre capable of producing an 8.0 shocker, ten times larger than the Fukushima shaker and 32 times stranger than the plant was designed to withstand.
We’ve posted extensively about the problems at California’s nuclears plants, both Diablo Canyon and San Onofre.