5 ms·

Diablo Canyon is designed to withstand an earthquake of shaking amplitude ten times larger than that which the Shoreline fault is capable of triggering, based o

Diablo Canyon is designed to withstand an earthquake of shaking amplitude ten times larger than that which the Shoreline fault is capable of triggering, based on an analysis by plant owner Pacific Gas & Electric (PG&E) https://en.m.wikipedia.org/wiki/Diablo_Canyon_earthquake_vulnerability https://en.m.wikipedia.org/wiki/Diablo_Canyon_earthquake_vul...

petschge 5y ago
Plants owners will always say that they analyzed their own plant being safe...
- heisenbit 5y ago
  And that is before they start storing spent fuels on site.
- CameronNemo 5y ago
  NRC's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Diablo Canyon was 1 in 23,810 according to an NRC study published in August 2010.
- Beldin 5y ago
  Indeed. This sort of thing should be called "toilet ducking", in recognition of the (Dutch) brand whose ads poked fun at this very idea in the 90s. "Therefore, we of Toilet Duck recommend ... Toilet Duck!" ("Toilet duck" is a transliteration of their name.) Moreover, it sounds suitably silly to be used for such silly nonsense.
  - kevin_thibedeau 5y ago
    Toilet Duck is sold as such in the US.
adanto6840 5y ago
Just note that PG&E is the entity who has stated the Shoreline fault is only capable of a 6.5 magnitude earthquake - while the plant is designed to be capable of handling [after post-construction updates] an earthquake up to 7.5 magnitude (10X since it's a log scale). Also note, the linked page states there are four "nearby" faults -- it doesn't state the distance to them, but included is the San Andreas fault, and I'm relatively confident we know it's capable of producing >= 7.5 magnitude earthquakes. I don't know, nor claim to know, much of anything about how susceptible [or not] this plant is to seismic events -- and I'm generally quite pro-nuclear -- but it's worth noting that there are other seismic concerns here, and potentially some questionable incentives for PG&E who is the one attesting to the capabilities of the area & this specific plant.
- CameronNemo 5y ago
  The first part of what you say is not valid: outside groups have estimated the capabilities of the close Shoreline fault. The rest of your comment I agree with. Although I would point out that if San Andreas quaked at (eg) 8, it would not be 8 when it reached Diablo Canyon. According to USGS seismologist, Jeanne L. Hardebeck, the Shoreline Fault has potential to trigger an earthquake of 6.4–6.8 magnitude
  - SkittyDog 5y ago
    Your point is clear enough, but both the parent & grandparent comments are misuing the terminology. Earthquake sizes are usually expressed via Richter scale or Moment Magnitude Scale values, which both attempt to quantify the total energy released by the quake. These scales do NOT quantify the force experienced at any particular location, which depends heavily on distance from the epicenter and local geology. For that kind of quantity, you would use a seismic intensity scale (https://en.m.wikipedia.org/wiki/Seismic_intensity_scales https://en.m.wikipedia.org/wiki/Seismic_intensity_scales). So it's wrong to say that a quake "...would not be 8 when it reaches Diablo Canyon" because the value '8' is an MMS or Richter value. Instead, you could say that "...the damage potential would be reduced by the distance to Diablo Canyon."
  - SkyMarshal 5y ago
newbamboo 5y ago
Do you trust pg&e after the whole French laundry lobbyist thing? https://www.abc10.com/article/news/local/abc10-originals/newsom-pge-protection/103-65ca1d41-8efe-45b4-87bc-0cdecc714378 https://www.abc10.com/article/news/local/abc10-originals/new...
- CameronNemo 5y ago
  No, I would definitely support an audit of their claims. With my comment, I intended to point out that a seismically active location may not be game over for a nuclear plant if proper consideration is taken.
- dv_dt 5y ago
  The same PG&E also fell behind on maintenance of vegetation around power lines, causing wildfires. As well as gas pipe infrastructure, causing a neighborhood scale explosion.
  - ethbr0 5y ago
    On the other hand, distributed, statewide maintenance (vegetation, gas pipelines) is very different than centralized maintenance (nuclear power plant). It doesn't speak well to their competence, but "inspect and maintain 1,000s of miles of line" is different than "inspect and maintain 1,000 items in one place."
    - dv_dt 5y ago
      If the risks were equivalent, but it’s maintain many more than 1000 items to at a tolerance 1000 times more sensitive with a outcome 1000 times worse than a wildfire or gas explosion.

petschge 5y ago

Plants owners will always say that they analyzed their own plant being safe...

heisenbit 5y ago
And that is before they start storing spent fuels on site.
CameronNemo 5y ago
NRC's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Diablo Canyon was 1 in 23,810 according to an NRC study published in August 2010.
Beldin 5y ago
Indeed. This sort of thing should be called "toilet ducking", in recognition of the (Dutch) brand whose ads poked fun at this very idea in the 90s. "Therefore, we of Toilet Duck recommend ... Toilet Duck!" ("Toilet duck" is a transliteration of their name.) Moreover, it sounds suitably silly to be used for such silly nonsense.
- kevin_thibedeau 5y ago
  Toilet Duck is sold as such in the US.

adanto6840 5y ago

Just note that PG&E is the entity who has stated the Shoreline fault is only capable of a 6.5 magnitude earthquake - while the plant is designed to be capable of handling [after post-construction updates] an earthquake up to 7.5 magnitude (10X since it's a log scale). Also note, the linked page states there are four "nearby" faults -- it doesn't state the distance to them, but included is the San Andreas fault, and I'm relatively confident we know it's capable of producing >= 7.5 magnitude earthquakes. I don't know, nor claim to know, much of anything about how susceptible [or not] this plant is to seismic events -- and I'm generally quite pro-nuclear -- but it's worth noting that there are other seismic concerns here, and potentially some questionable incentives for PG&E who is the one attesting to the capabilities of the area & this specific plant.

CameronNemo 5y ago
The first part of what you say is not valid: outside groups have estimated the capabilities of the close Shoreline fault. The rest of your comment I agree with. Although I would point out that if San Andreas quaked at (eg) 8, it would not be 8 when it reached Diablo Canyon. According to USGS seismologist, Jeanne L. Hardebeck, the Shoreline Fault has potential to trigger an earthquake of 6.4–6.8 magnitude
- SkittyDog 5y ago
  Your point is clear enough, but both the parent & grandparent comments are misuing the terminology. Earthquake sizes are usually expressed via Richter scale or Moment Magnitude Scale values, which both attempt to quantify the total energy released by the quake. These scales do NOT quantify the force experienced at any particular location, which depends heavily on distance from the epicenter and local geology. For that kind of quantity, you would use a seismic intensity scale (https://en.m.wikipedia.org/wiki/Seismic_intensity_scales https://en.m.wikipedia.org/wiki/Seismic_intensity_scales). So it's wrong to say that a quake "...would not be 8 when it reaches Diablo Canyon" because the value '8' is an MMS or Richter value. Instead, you could say that "...the damage potential would be reduced by the distance to Diablo Canyon."
- SkyMarshal 5y ago

newbamboo 5y ago

Do you trust pg&e after the whole French laundry lobbyist thing? https://www.abc10.com/article/news/local/abc10-originals/newsom-pge-protection/103-65ca1d41-8efe-45b4-87bc-0cdecc714378 https://www.abc10.com/article/news/local/abc10-originals/new...

CameronNemo 5y ago
No, I would definitely support an audit of their claims. With my comment, I intended to point out that a seismically active location may not be game over for a nuclear plant if proper consideration is taken.
dv_dt 5y ago
The same PG&E also fell behind on maintenance of vegetation around power lines, causing wildfires. As well as gas pipe infrastructure, causing a neighborhood scale explosion.
- ethbr0 5y ago
  On the other hand, distributed, statewide maintenance (vegetation, gas pipelines) is very different than centralized maintenance (nuclear power plant). It doesn't speak well to their competence, but "inspect and maintain 1,000s of miles of line" is different than "inspect and maintain 1,000 items in one place."
  - dv_dt 5y ago
    If the risks were equivalent, but it’s maintain many more than 1000 items to at a tolerance 1000 times more sensitive with a outcome 1000 times worse than a wildfire or gas explosion.