Earthquakes and nuclear disasters

Spent way too much time surfing Wikipedia laterly. Iti is an amazing source. But some facts on earthquakes and then nuclear disasters.
Well, the Japan earthquake was big, but there have been bigger, remember every increase from say 8 to 9 is thirty times stronger. If you go from 8 to 10, it is 1000 times more energy. But from Wikipedia…here are the largest magnitude earthquakes that have been recorded…

Date↓ Location↓ Name↓ Magnitude↓
May 22, 1960 ValdiviaChile 1960 Valdivia earthquake 9.5
March 27, 1964 Prince William SoundAlaskaUSA 1964 Alaska earthquake 9.2
December 26, 2004 SumatraIndonesia 2004 Indian Ocean earthquake 9.1
November 4, 1952 KamchatkaRussia (then USSR) 1952 Kamchatka earthquakes 9.0[2]
March 11, 2011 T?hoku regionJapan 2011 T?hoku earthquake and tsunami 9.0[3][4][5]
November 25, 1833 SumatraIndonesia 1833 Sumatra earthquake 8.8–9.2 (est.)
January 31, 1906 Ecuador – Colombia 1906 Ecuador-Colombia earthquake 8.8
February 27, 2010 MauleChile 2010 Chile earthquake 8.8
January 26, 1700 Pacific OceanUSA and Canada 1700 Cascadia earthquake 8.7–9.2 (est.)[6]
July 8, 1730 ValparaisoChile 1730 Valparaiso earthquake 8.7–9.0 (est.)[7]
November 1, 1755 LisbonPortugal 1755 Lisbon earthquake 8.7 (est.)[8]

And the deadliest aren’t the biggest….

Rank↓ Name↓ Date↓ Location↓ Fatalities↓ Magnitude↓ Notes
1 “Shaanxi” January 23, 1556 Shaanxi, China 820,000– 830,000 (est.)[13] 8.0 (est.)

Estimated death toll in Shaanxi, China.
2 “Tangshan” July 28, 1976 Tangshan, China 242,419– 779,000 7.5-7.8  
3 “Antioch” May 21, 525 Antioch, Turkey (thenByzantine Empire) 250,000 [14] 8.0 (est.) Procopius (II.14.6), sources based on John of Ephesus.
4 “Gansu” December 16, 1920 NingxiaGansu, China 235,502[15] 7.8 Major fractures, landslides.
5 “Indian Ocean” December 26, 2004 SumatraIndonesia 230,210+[16][17] 9.1 Deaths from earthquake and resulting tsunami.
6 “Aleppo” October 11, 1138 AleppoSyria 230,000 Unknown The figure of 230,000 dead is based on a historical conflation of this earthquake with earthquakes in November 1137 on the Jazira plain and the large seismic event of 30 September 1139 in the Azerbaijani city of Ganja. The first mention of a 230,000 death toll was by Ibn Taghribirdi in the fifteenth century.[18]
7 “Haiti” January 12, 2010 Haiti 222,570 (Haitian sources) 50,000-92,000 (non-Haitian sources) 7.0 Estimate June 2010.[19]
8 “Damghan” December 22, 856 DamghanIran 200,000 (est) 7.9 (est.)  
9 “Ardabil” March 22, 893 ArdabilIran 150,000 (est) Unknown  
10 “Great Kant?” September 1, 1923 Kant? region, Japan 142,000 7.9 An earthquake which struck the Kant? plain on the Japanese main island ofHonsh? at 11:58 on the morning of September 1, 1923. Varied accounts hold that the duration of the earthquake was between 4 and 10 minutes. The quake had an epicenter deep beneath Izu ?shima Island in Sagami Bay. It devastated Tokyo, the port city of Yokohama, surrounding prefectures of ChibaKanagawa, and Shizuoka, and caused widespread damage throughout the Kant? region.[20] The power and intensity of the earthquake is easy to underestimate, but the 1923 earthquake managed to move the 93-ton Great Buddha statue at Kamakura. The statue slid forward almost two feet.[21] Casualty estimates range from about 100,000 to 142,000 deaths, the latter figure including approximately 40,000 who went missing and were presumed dead.

The scary thing about the two other big nuclear disasters was how much the whole chain of failure included human and system errors and missed assumptions. You can just never know. I need to finish documenting, but here were some things I learned…

  1. Chernobyl was incredibly serious. There was no containment building and the thing was made of graphite which essentially exploded. Plus the government didn’t even tell the firefighters that it was a reactor!. Basically what happened was the design of the RBMK reactor running at low power was unstable. It went from 30MW produced to 30GW (1,000x) increase in seconds and then the steam basically exploded followed by a nuclear criticality (e.g., short term the core actually went nuclear). Then the whole thing melted down and the graphite caught on fire. Whew.
  2. At Three Mile Island, the operators didn’t know that the core didn’t have water. They didn’t have a direct reading, a valve had a habit of getting stuck, so it vented tons of water out of the reactor but the light on the console indicated it was closed. But what happened is that it just meant the valve was depowered, it didn’t indicate it was stuck on. It took five hours and another shift to realize it. By that time, the core had melted. Fortunately there was a containment builiding, but unfortunately the water was highly radioacrtive and escaped. In this case also, there was a real lack of information.

And if you want to be really worried, read this from Newsweek. Remember 8.0 vs. 6.7 is about 100x more powerful.

Assessing the risks to California—or any other vulnerable locale—and its chances of withstanding them comes down to two calculations: the likelihood of a particular disaster occurring and the adequacy of mitigation and recovery plans. California has a 99.7 percent chance of being hit by an earthquake with a magnitude of 6.7 or greater within the next 30 years, explains Richard Allen, associate director of the Seismological Laboratory at the University of California, Berkeley. The most likely sites are along the Hayward fault, which runs through the San Francisco Bay Area, and the southern San Andreas, east of Los Angeles. “We think that the longest sections of the faults that can rupture are equivalent to a magnitude-8 earthquake,” says Allen. An 8.0 would cause some $100 billion in damage, he says, and kill hundreds and possibly thousands—“way beyond the scale of what people think is possible in a modern, industrial state.”

Diablo Canyon, 12 miles southwest of San Luis Obispo, is near the Hosgri fault and (as was discovered in 2008?) the Shoreline fault. San Onofre, in San Diego County next to I-5, sits near the Oceanside and Newport-Inglewood/Rose Canyon faults. Because the Nuclear Regulatory Commission requires that a nuclear plant be able to withstand the most severe natural phenomena in the historical record, with a safety margin, both were built (or retrofitted) to withstand a 7- to 7.5-magnitude earthquake, the strongest quake either plant is likely to experience, says seismologist Thomas Jordan of the University of Southern California.

The crisis at Fukushima has shown that one of the greatest risks to a nuclear plant comes from the loss of power, which leaves the facility unable to circulate cooling water to the core and spent-fuel pools. In Japan, that calamity arose when the quake crippled the electric grid and the tsunami knocked out backup generators. California is thought to be less likely to suffer the one-two punch of an earthquake followed by a tsunami. Off its coast are mostly “strike slip” faults, where one tectonic plate grinds along another. This kind of fault is less likely to cause a tsunami than is a subduction fault, where one plate dives under another and can cause the huge vertical displacement of water that initiates the monster waves. Nevertheless, it is “possible for a strike-slip fault to generate major tsunamis under certain conditions,” concluded a 2009 report by the Nuclear Regulatory Commission. And the Cascadia subduction fault, which begins off northern California, is thought capable of causing a tsunami.

Diablo Canyon sits on a rise 85 feet above the ocean, beyond reach of what scientists calculate is the largest possible tsunami, says Jim Becker, PG&E’s site vice president at the reactor. San Onofre is 50 feet above the sea, and behind a concrete tsunami wall 30 feet high, 50 percent higher than the largest tsunami thought possible there. Both store cooling water at higher elevations; if everything else fails, gravity should work.

In one important respect, the threat in the U.S. might be even greater than what befell Japan. Because the U.S. has failed to establish a permanent nuclear-waste depository, the NRC allows plant operators to move from “open rack” configurations, which cool the rods most effectively, to a “dense pack” design that eventually fills pools “almost wall to wall,” argues Alvarez. As a result, said physicist Edwin Lyman of the Union of Concerned Scientists at a press conference, “it might be just hours [before spent-fuel rods begin releasing radioactivity] if there were a seismic event or terrorist attack.” Diablo Canyon has 1,126 tons of spent fuel; San Onofre, 1,430 tons.

 

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