Update #16 – June 7, 2011
NISA's report on the re-estimated air contamination from Fukushima has been released.
The air contamination in the early days (that is after the explosions) is variously reported as now estimated to be from 770,000 terabequerels to 850,000 terabequerels. (See 3 stories below).
With the radioactive contamination in current volumes of accumulated water estimated at 720,00 terabequerels on Friday, these two estimates total approximately 1.5 million terabequerels of radioactive releases. "In the Chernobyl accident, the total amount of radioactivity reached 5.2 million terabecquerels. "
Note: this 1.5 million teraBq total does NOT reflect the total amount of radiation released to date since
1) the 770K figure is only for 6 days following the earthquake and
2) the 720K figure does not include all the contaminated cooling water that has leaked/overflowed into the ocean or been stored in tanks to date.
Here are a few articles on the NISA report:
Radioactivity of materials released in Fukushima nuclear crisis revised upward
Agency doubles radioactive release estimate in early days of crisis
http://english.kyodonews.jp/news/2011/06/95542.html
No.1 reactor vessel damaged 5 hours after quake
http://www3.nhk.or.jp/daily/english/06_33.html
Nelle's comments:
The video's for each of the 2 following stories at the NHK site links will give you a true appreciation of the damage sustained at Unit's 1 and 3.
The language in the video's is different than the printed words as well. For example, the broadcaster says in the first story that the SFP temperature has risen to 89°C, not "had" as the text below says (implying that was a past high reading). The last report I can find of the temperature in this spool is from May 7th when it was 84°C. So despite all the water spraying and continued injections of anticorrosion agent hydrazine, the temperature has risen 5 degrees in a month. If it continues at this rate, the pool could be boiling (100°C) and emitting vast amounts of radiation by the end of July when the structure is scheduled for completion. This could interfere with the construction schedule, not to mention the increase of radioactive contamination in the air and water.
Also, if you listened to the Arnie Gunderson audio interview you know that his greatest concern is with the stability of the structure supporting the SFP and the consequences if it should fail in the continuing earthquakes.
Work continues to support No.4 reactor pool
http://www3.nhk.or.jp/daily/english/07_18.html
At the Fukushima Daiichi nuclear power plant, work is continuing to shore up a pool containing spent nuclear fuel at the No.4 reactor.
Engineers are concerned that a wall supporting the pool, which holds 1,535 spent fuel rods, was damaged in an explosion on March 15.
Plant operator Tokyo Electric Power Company plans to build a new structure with concrete walls and 30 steel pillars to support the pool.
The pillars, each 8 meters long, are to be placed under the pool, on the second floor of the building housing the nuclear reactor by the end of June.
By the end of July, a concrete wall is expected to be in place to complete the structure. A circulating cooling system will be built to stably cool the pool water, which had heated to 89 degrees Celsius.
Tuesday, June 07, 2011 12:58 +0900 (JST)
This story is a continuation of the discussion of information in the NISA report released yesterday.
More hydrogen produced than TEPCO's estimate
http://www3.nhk.or.jp/daily/english/07_06.html
Japan's nuclear safety agency says about 800 to 1,000 kilograms of hydrogen was produced in each of 3 reactors at the Fukushima Daiichi nuclear power plant soon after the March 11th earthquake. The Nuclear and Industrial Safety Agency studied data provided by Tokyo Electric Power Company last month.
The agency says about 1,000 kilograms of hydrogen was produced at the No. 1 reactor when the fuel rods began to be exposed 2 hours after the quake and the metallic fuel containers oxidized one hour later. The same phenomenon took place at the No. 3 reactor some 43 hours after the quake, resulting in the production of 1,000 kilograms of hydrogen. Hydrogen explosions blew the top off the No. 1 and 3 reactor buildings.
A smaller explosion at the No. 2 reactor damaged the suppression pool. The agency has not determined the cause of the blast, but calculates that about 800 kilograms of hydrogen was formed there 77 hours after the quake when fuel rods were damaged.
The agency's calculations are 1.3 to 2.3 times more than TEPCO's original estimate.
The agency says the hydrogen is likely to have damaged the reactor buildings and containment vessels.
Tuesday, June 07, 2011 05:40 +0900 (JST)
Here is the NYT article on the NISA report, for what it is worth.
Radiation Understated After Quake, Japan Says
Published: June 6, 2011
http://www.nytimes.com/2011/06/07/world/asia/07japan.html?_r=2
Nelle's comments: The following story is disturbing. Note the optimism of the official that all will be well at Ibaraki beaches this summer.
Ibaraki is due south of Fukushima and experienced heavy contamination following the explosions in mid-March. A mid-March report at Zerohedge puts the contamination in perspective. The contamination was reported at 3024nGy/hr, which converts to 3 microSv/hr. This is 30 times the normal background dose which as the article points out for reference greatly exceeds the doubling over background rates experienced in Greece after Chernoybl. This was more radiation than reported anywhere except in Fukushima prefecture itself at the time.
See full article here:
http://www.zerohedge.com/article/gamma-radiation-fukushima-downwind-ibaraki-disclosed-30-times-above-normal
Monitoring of beach radiation begins in Ibaraki
http://www3.nhk.or.jp/daily/english/07_22.html
Ibaraki Prefecture, south of the crippled Fukushima Daiichi nuclear power plant, has begun monitoring radiation levels at its beaches to ensure safety before this summer's swimming season. Last year, more than 1-million 750-thousand people visited Ibaraki's beaches, but the number of visitors this summer is feared likely to decline due the nuclear disaster.
On Tuesday, officials visited Ajigaura beach in Hitachinaka City. They took samples of seawater from 1 to 1.5 meter deep for monitoring. They also checked radiation levels at 5 locations onshore. The prefecture is to complete testing at all 17 beaches by mid-June and release the results.
It also plans to carry out similar checks later this month and in July.
An official told reporters he hopes the test results will ensure the safety of swimming beaches in Ibaraki Prefecture and that many people will visit there this summer.
Tuesday, June 07, 2011 13:50 +0900 (JST)
And finally, these stories at NHK regarding more Probes and Studies into the accident and worker contamination.
Govt panel on nuclear accident holds 1st meeting
http://www3.nhk.or.jp/daily/english/07_17.html
A new government panel has decided to set up 4 teams to investigate the accident at the Fukushima Daiichi nuclear power plant.
The investigation and verification committee met for the first time on Tuesday in Tokyo. It consists of 10 experts from various fields, and 2 technological advisors.
Prime Minister Naoto Kan told the meeting that he wants the panel to broadly examine technological and other issues, such as the closed inner circle that makes nuclear-related decisions. He also singled out the fact that the industry ministry is responsible for both the promotion and regulation of nuclear power.
The committee's head and Professor Emeritus at the University of Tokyo, Yotaro Hatamura, said his panel needs to convincingly answer the public's questions. But he stressed the panel will not aim to clarify who is responsible for the accident.
The panel's 4 teams will discuss the technical problems of the accident, background social issues, the national regulation system of nuclear safety and other issues.
The panel members are expected to visit the Fukushima Daiichi plant this month. The panel plans to compile its interim report by the end of this year and finalize it after the nuclear reactors are under control.
Tuesday, June 07, 2011 13:03 +0900 (JST)
Labor Ministry inspects Fukushima plant
http://www3.nhk.or.jp/daily/english/07_28.html
Labor ministry officials have conducted onsite inspections at the Fukushima Daiichi nuclear plant, to investigate why 2 workers were exposed to excessive levels of radiation.
A team of 4 inspectors arrived at the plant on Tuesday afternoon to check working conditions and interview safety control managers.
The probe followed revelations by the Tokyo Electric Power Company that the 2 workers were exposed to over 250 millisieverts of radiation — an elevated emergency limit introduced by the government after the nuclear crisis began. The 2 men were on duty in the central control rooms of reactors No.3 and 4.
They weren't wearing protective masks when reactor No.1 was hit by a hydrogen explosion, one day after the March 11th quake and tsunami.
The health and labor ministry plans to instruct TEPCO to improve conditions, if Tuesday's inspections turn up problems with workers' safety management.
Tuesday, June 07, 2011 14:03 +0900 (JST)
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The Watershed Sentinel is proud to share Nelle Maxey's Fukushima Updates prepared for the BC environmental community.
Every day, Nelle pours over the media and other reports of the status of the reactors at Fukushima, comparing figures and trying to make sense out of the conflicting reports.