nuclear-news

1 Comment »

1. About the geology of the Fukushima area, I was able to consult a Japanese specialist, a professor of geology at a leading Japanese university, who provided lengthy and detailed explanations. Because he has been misquoted in the press recently he is reluctant to be identified publicly here, but has agreed to let me quote him anonymously. I’ve encouraged him to sign up and participate here, and maybe he will at some point. I asked him specifically about the solidity of the rock on which Fukushima Daiichi sits, and about the groundwater system in the area and implications for the spread of contamination by that route. His replies (excerpted, and even then it’s pretty long):

   “As for your question, there are limited number of info available, and the lack of info is more severe for English-language versions. Nuclear Plants are usually built on a stable rock, and granite is an ideal one: they are not only strong, but also deep-seated. I believe most of the nuclear plants in Japan are built on granite, and if it is not available, on other hard rock such as metamorphic rocks, but not for soft rocks such as sedimentary rock (or soft sediments) which would be suicidal*in terms of nuclear safety. Fukushima`s bed rock is a hard-rock complex called Abukuma Massif, and is made of granite and metamorphic rocks (= former sedimentary rocks which*was then*hardened by high pressure and temperature in the underground). So people thought the region is relatively safer in terms of bed rocks and fault systems. But after the 3-11 earthquake, many “inactive” fault systems moved, causing some problems such as landslides or forming sink holes. Some of these faults CUT through these hard rocks, which people, including many geologists, thought quite unusual (if not impossible) utill they saw the consequence of the 3-11 Earthquake in Tohoku. Even in the areas of hard bed-rocks, it might be covered by a veneer of soft sediments or soft rocks, and if the reactor is built in such areas, the degree of tremor due to earthquake will increase. Unfortunately in the case of Fukushima Daiichi Plant, there are thick sedimentary rocks of the Quaternary (Pliocene) age called*the Taga Group covers the Abukuma Massif (hard bed rock in depth here), and there are a few active faults around*the plant*(they have been recently*found to be active after the 3-11 Earthquake).*”

   [snip]

   “As for Fukushima`s geology, *yes, it has been long known that around the Fukushima Daiichi Plant is sedimentary rock Taga Group; around the plant this rock is called the Tomioka Formation, whch is made of coarse sandstone (or Grit) and tuffaceous siltstone. It`s pity that*no*geologists*(as*far as I know)*have warned the vulnebility of the Fukushima Daiichi Plant in terms of geology, as it won’t take a rocket science (but so simple and clear) to check this out. But instead, I think most of us trusted info provided by Tepco, such as videos in*nuclear safety which states that “this region*of Fukushima Daiichi Plant have never experienced major earthquake or tsunami over the past 400 years”. *
   As for the groundwater-flow information, I don`t know. I checked several website, but I could not find one, including the one in Japanese. As the bedrock of the area is made of coarse sandstone, the rock is highly permeable and has plenty of waters flowing in the underground of the plain (but in a very very*slow speed) around the*nuke plant. The source (catchment of rain) is the nearby Abukuma mountains, and the groundwater of this nature will spend hundred or more years to flow from the mountains to the coastline. But I do not have data to prove this – I am just stating a general rule.”

   [snip]

   “I have talked with some of my colleagues (geology professors) today, and some of them knew for many years/decades that the bed rock of the Fukushima Daiichi Nuke Power Plant is soft sedimentary rock. They do not know why government (both national and local/prefectural) approved for the construction of the plant on such a bad spot, and can only think of*unethical acts of polititians and the industry.*Also,*my colleagues warn that the type of bed rock, which geologists identify,*and the strength/suitability of the*bed rock, which soil/geo-engineers determine, is different, even though I would*still support that*young sedimentary rocks below the Fukushima Daiichi Nuke Plant is NOT*suitable for constructing buildings that have to endure earthquakes. ”

   [snip]

   “One of my colleagues told me that ground water research have been usually done by local/prefectural municipal office(s), consulting firms, and AIST in Tsukuba, especially when the geothermal gradient of the region is high – as it might be leading to the discovery and development of onsen and other hot spa resort. Unfortunately Fukushima does not have such areas along the coast (but inlands such as Aizu), so he doubt that detailed measurements of groundwater have been done by these organizations (but those associated with the nuclear industry), and even if they do have such info, they might have not made it publically available (but you could try to inquire about the info to these organizations using the contact info I provided in the earlier e-mail). Just for my curiosity, I have checked the report map on the geology (or Hazard map) *of Fukushima Daiichi nuclear plant. It is in Japanese. It states/shows that the plant is away from active volcanoes and active faults (closest ones are about 8-9 km away) and supporting its safety against natural disasters. BUT THE MAP DOES NOT SHOW OR MENTION ANYTHING ABOUT THE BED-ROCK GEOLOGY OR GROUND WATER. The following is the link to this “Hazard map” issued by NUMO(Nuclear Waste Management Organization of Japan):
   *

   Click to access 07546.pdf

   [snip]

   “This is all I could answer with my knowledge (and inputs from my colleagues). I think you may be able to get info of bedrock geology and groundwater (hydrology) by contacting

   (1) GSI Japan
   *http://www.gsi.go.jp/ENGLISH/index.html
   *
   (2) Fukushima Prefecture Construction Dept
   http://wwwcms.pref.fukushima.jp/pcp_…TENTS_ID=11045

   (3) AIST (advanced institute of science and technology, Japan, in Tsukuba)
   http://www.aist.go.jp/index_en.html

   (4) other agencies/institutions re: nuclear energy and disposable sites. But I doubt that they make the info open-access.

   [end quote]
   *

   http://www.physicsforums.com/showpost.php?p=3345426&postcount=9285

   Comment by arclight2011part2 | August 14, 2013 | Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

« Previous | Next »

Site info

nuclear-news
Blog at WordPress.com.