Friday, April 1, 2011

When man does not bite dog is news

The issue of how reactors handle hydrogen gets aired

man to bite corn dogsIn the annals of journalism, improbable news stories are categorized by the headline “Man bites dog.” It signals the reversal of the normal flow of events and challenges to the logic of daily life.

Of course, the headline has been the butt of many jokes, “Man bites dog at county fair,” says Mayor Billy Bojangles, “it was a corn dog. Ha ha.”

According to Wikipedia, the phrase was coined to describe the fact that you never read about a plane that did not crash and you don't hear about cases where a politician kept his pants on and his hands out of the till.

The phrase was reportedly first spoken by Alfred Harmsworth, a British newspaper magnate, but is also attributed to New York Sun editor John B. Bogart (1848–1921): "When a dog bites a man, that is not news, because it happens so often. But if a man bites a dog, that is news.

So when the New York Times writes that U.S. nuclear utilities are complying with requirements from the Nuclear Regulatory Commission (NRC) regarding the control hydrogen in reactor pressure vessels, why is that news? But if an anti-nuclear group claims that the NRC’s requirement itself it unsafe,does that make it news? Maybe.

The newspaper seems motivated to run to ground a charge that the NRC acted against the interests of safety. It turns out the charge by the consultant at Beyond Nuclear is without merit, but the newspaper printed the story anyway.

Maybe the newspaper’s original intention was to debunk the charge? I’d like to hope so, but it’s not easy to draw that conclusion from the way the material is presented to readers. Of course, the newspaper would say it is just reporting the news.

I suggest a new headline for this story should be “man did not bite dog” or something like that. It would make a lot more sense and tell a truer story.

So why is the story news?

FukushimaPowerPlant3_Explosion_031311_medThe multiple hydrogen explosions (Unit 3 right) at the Fukushima nuclear reactor complex in the days following the massive earthquake and tsunami that devastated the area March 11 were alarming visually, but caused little real damage to the part of the reactor that matter.

So far as experts in the U.S. with direct on-the-ground knowledge of the situation in Japan know, the two pieces that count – the reactor pressure vessel and primary containment – are still intact at Fukushima reactors units 1-4.

The hydrogen explosions were caused because the level of cooling water dropped inside the reactor pressure vessels, and in the damaged spent fuel pool at unit #4, uncovering the fuel rods. The fuel rods are bound together with zirconium.

When it gets too hot from the residual heat of the fuel assemblies, zirconium interacts with the water to oxidize claiming the oxygen and releasing hydrogen. Hydrogen is a volatile gas and is easily set off with explosive results from a variety of sources including sparks from static electricity.

As a practical matter, even if the reactors at Fukushima had hydrogen recombiners retrofitted into the plants, there was no electricity to run them to harmlessly vent hydrogen gas out the stacks. The tsunami that breached the seawall by two times its height wiped out the fuel supply for the emergency diesel generators shutting them off.

Safe control of hydrogen

The safety issue for U.S. reactors is how to control the hydrogen, or vent it, in the case of an accident. The New York Times ran a story March 31 which was based on an allegation by a representative from an anti-nuclear group that the U.S. Nuclear Regulatory Commission (NRC) had failed to require nuclear utilities to properly deal with the risks of hydrogen explosions. The problem with the allegation, as detailed in the news report, is that isn’t true.

The story begins with a statement by Paul Blanch, a Hartford, Conn., energy consultant, who's work has been prominently featured on the website of Beyond Nuclear, an NGO which is stridently opposed to the use of nuclear energy.

“The change in commission policy was pointed out this week by a nuclear safety critic, Paul M. Blanch, who said that he had been involved in installing such equipment at Millstone 3, a nuclear reactor in Waterford, Conn.

“Post-Three Mile Island, they were considered very important to safety,’’ Mr. Blanch said. He accused the Nuclear Regulatory Commission of having “gutted the rule’’ because the industry wanted to save money.“

The newspaper also quotes a spokesman from the NRC.

“They [recombiners] weren’t needed for design basis accidents and they didn’t help with severe accidents,’’ Mr. Brenner said.”

Nitrogen is an inert gas

When the primary containment structure is filled with nitrogen, which is a common practice, then even if hydrogen is generated in there it cannot ignite in an inert atmosphere. It follows that it makes sense to drop the requirement to have hydrogen recombiners.

Yet, the newspaper ran with a story that suggest the NRC acted against the interests of safety at reactors when in fact the regulatory agency was reasonable in its logic.

TMI or refinery fire?

Also, the use of a photo of TMI with the article is at least gratuitous or does it seem obligatory for editors these day when publishing something about the U.S. nuclear industry.

This is no different than CBS and CNN running pictures of a refinery fire in Japan for voice-overs about the status of the Fukushima reactors. It is a form of sensationalism and has no place in reporting about industrial accidents.

# # #

Fukushima reactor status news for 2011 04 01

Update to Information Sheet Regarding the Tohoku Earthquake

Source: The Federation of Electric Power Companies of Japan (FEPC) Washington DC Office As of 11:00AM (EST), April 1, 2011

·Fukushima_symbol Radiation Levels

o At 7:00PM (JST) on April 1, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 141 micro Sv/hour.

o At 7:00PM on April 1, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 90.0 micro Sv/hour.

o Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on April 1 are shown in the English version is available at: http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm

o For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.

· Fukushima Daiichi Unit 1 reactor

o At 10:00AM on April 1, pressure inside the reactor core: 0.295MPa.

o At 10:00AM on April 1, water level inside the reactor core: 1.65 meters below the top of the fuel rods.

o At 10:00AM on April 1, pressure inside the primary containment vessel: 0.165MPaabs.

o At 10:00AM on April 1, the temperature of the reactor vessel measured at the water supply nozzle: 479.5 degrees Fahrenheit.

o As of 3:30PM on April 1, the injection of freshwater into the reactor core continues.

o As of 7:00PM on April 1, preparation to recover and transfer the accumulated water at the turbine building continues.

o As of 7:00PM on April 1, approximately 90 tons of water in total has been injected into the spent fuel storage pool.

· Fukushima Daiichi Unit 2 reactor

o At 10:00AM on April 1, the temperature of the spent fuel pool: 122 degrees Fahrenheit.

o At 10:00AM on April 1, pressure inside the reactor core: -0.007MPa.

o At 10:00AM on April 1, water level inside the reactor core: 1.5 meters below the top of the fuel rods.

o At 10:00AM on April 1, pressure inside the primary containment vessel: 0.11MPaabs.

o As of 3:30PM on April 1, the injection of freshwater into the reactor core continues.

o As of 7:00PM on April 1, preparation to recover and transfer the accumulated water at the turbine building continues.

· Fukushima Daiichi Unit 3 reactor

o At 4:30PM on March 31, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 7:33PM (approximately 105 tons in total).

o At 11:45AM on April 1, pressure inside the reactor core: 0.016MPa.

o At 11:45AM on April 1, water level inside the reactor core: 1.9 meters below the top of the fuel rods.

o At 11:45AM on April 1, pressure inside the primary containment vessel: 0.1068MPaabs.

o As of 3:30PM on April 1, the injection of freshwater into the reactor core continues.

o As of 7:00PM on April 1, preparation to recover and transfer the accumulated water at the turbine building continues.

o As of 7:00PM on April 1, approximately 4,802 tons of water in total has been shot into the spent fuel storage pool.

· Fukushima Daiichi Unit 4 reactor

o At 8:28AM on April 1, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete, until 2:14PM (approximately 180 tons in total).

o As of 7:00PM on April 1, approximately 1,278 tons of water in total has been shot into the spent fuel storage pool.

· Fukushima Daiichi Unit 5 reactor

o At 2:00PM on April 1, the temperature of the spent fuel pool: 100.6 degrees Fahrenheit.

· Fukushima Daiichi Unit 6 reactor

o At 2:00PM on April 1, the temperature of the spent fuel pool: 69.8 degrees Fahrenheit.

· Fukushima Daiichi Common Spent Fuel Pool

o At 7:30AM on April 1, the temperature of the spent fuel pool: 89.6 degrees Fahrenheit.

· Others

o At 3:42PM on March 31, a US Military barge carrying freshwater docked at the dedicated port at Fukushima Daiichi Nuclear Power Station, towed by a vessel of Marine Self Defense Forces.

o At 3:00PM on April 1, anti-scattering agent was dispersed on a trial basis around the Fukushima Daiichi Common Spent Fuel Pool.

o At 3:58PM on April 1, transferring the freshwater from the US Military barge to a filtrate tank commenced.

Communications & Contact Information

· From: Taro Ishida [ishida@denjiren.com]
  Sent: 04/01/2011 11:43 AM AST
  To: Taro Ishida <ishida@denjiren.com>
  Cc: Samuel Lederer <lederer@denjiren.com>
  Subject: <Update-18> Information Sheet Regarding the Tohoku Earthquake (from FEPC Washington Office)

Dear Friends,

Please find the updated information sheet below and attached that summarizes the events from Update-17 at 11:00AM on 3/31.

For your reference, JAIF (Japan Atomic Industrial Forum) has been posting the translation of news reports on their website.

http://www.jaif.or.jp/english/

Please direct any questions regarding this document to me, Ishida@denjiren.com or Samuel Lederer, Researcher of FEPC at lederer@denjiren.com.

Our official sources are:

  • Office of The Prime Minister of Japan
  • Nuclear and Industrial Safety Agency (NISA)
  • Tokyo Electric Power Company (TEPCO) Press Releases
  • Ministry of Education, Culture, Sports, Science and Technology (MEXT)

Thursday, March 31, 2011

Fukushima reactor status news for 2011 03 31

(NucNet from World Nuclear Organization did not publish this morning)

Fukushima_symbolSource: The Federation of Electric Power Companies of Japan (FEPC)
Washington DC Office

As of 11:00AM (EST), March 31, 2011

  • Radiation Levels
    • At 8:51AM (JST) on March 31, it was announced that radioactive nuclide I-131  was detected from the seawater sampled near the seawater discharge point (south side) of Fukushima Daiichi Nuclear Station at 1:55PM on March 30. The level of concentration was approximately 4,385 times higher than the maximum permissible water concentration set by the government.
    • At 2:00PM on March 31, radiation level at main gate (approximately 3,281 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 157 micro Sv/hour.
    • At 2:00PM on March 31, radiation level at west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station: 99.9 micro Sv/hour.
    • Measurement results of environmental radioactivity level around Fukushima Nuclear Power Station announced at 7:00PM on March 31 are shown in the attached PDF file. English version is available at: http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm
    • For comparison, a human receives 2,400 micro Sv per year from natural radiation in the form of sunlight, radon, and other sources. One chest CT scan generates 6,900 micro Sv per scan.
  • Fukushima Daiichi Unit 1 reactor
    • At 8:00AM on March 31, pressure inside the reactor core: 0.329MPa.
    • At 8:00AM on March 31, water level inside the reactor core: 1.65 meters below the top of the fuel rods.
    • At 8:00AM on March 31, pressure inside the primary containment vessel: 0.21MPaabs.
    • At 8:00AM on March 31, the temperature of the reactor vessel measured at the water supply nozzle: 480.9 degrees Fahrenheit
    • At 9:20AM on March 31, transferring of the accumulated water at the trench (concrete tunnel which houses pipes and cables) outside the turbine building commenced, until 11:25AM. As a result, the water level at the trench was reduced from 0.14 meters to 1.14 meters below the top of the trench.
    • At 1:03PM on March 31, TEPCO began to shoot freshwater aimed at the spent fuel pool, with a specialized vehicle normally used for pumping concrete.
    • As of 3:00PM on March 31, the injection of freshwater into the reactor core continues.
    • As of 3:00PM on March 31, preparation to recover and transfer the accumulated water at the turbine building continues.
  • Fukushima Daiichi Unit 2 reactor
    • As of 3:00PM on March 29, the water level at the trench was 1.04 meters below the top of the trench.
    • At 8:00AM on March 31, the temperature of the spent fuel pool: 131 degrees Fahrenheit.
    • At 8:00AM on March 31, pressure inside the reactor core: -0.016MPa.
    • At 8:00AM on March 31, water level inside the reactor core: 1.5 meters below the top of the fuel rods.
    • At 8:00AM on March 31, pressure inside the primary containment vessel: 0.11MPaabs.
    • As of 3:00PM on March 31, the injection of freshwater into the reactor core continues.
    • As of 3:00PM on March 31, approximately 96 tons of water in total has been injected into the spent fuel storage pool.
    • As of 3:00PM on March 31, preparation to recover and transfer the accumulated water at the turbine building continues.
  • Fukushima Daiichi Unit 3 reactor
    • As of 3:00PM on March 29, the water level at the trench was 1.55 meters below the top of the trench.
    • At 9:40AM on March 31, pressure inside the reactor core: 0.016MPa.
    • At 9:40AM on March 31, water level inside the reactor core: 1.85 meters below the top of the fuel rods.
    • At 9:40AM on March 31, pressure inside the primary containment vessel: 0.1066MPaabs.
    • As of 3:00PM on March 31, the injection of freshwater into the reactor core continues.
    • As of 3:00PM on March 31, approximately 4,697 tons of water in total has been shot to the spent fuel storage pool.
    • As of 3:00PM on March 31, preparation to recover and transfer the accumulated water at the turbine building continues.
  • Fukushima Daiichi Unit 4 reactor
    • As of 3:00PM on March 31, approximately 1,098 tons of water in total has been shot to the spent fuel storage pool.
  • Fukushima Daiichi Unit 5 reactor
    • At 11:00AM on March 31, the temperature of the spent fuel pool: 86 degrees Fahrenheit.
  • Fukushima Daiichi Unit 6 reactor
    • At 11:00AM on March 31, the temperature of the spent fuel pool: 78.8 degrees Fahrenheit.
  • Fukushima Daiichi Common Spent Fuel Pool
    • At 8:20AM on March 30, the temperature of the spent fuel pool: 89.6 degrees Fahrenheit.
    • As of 3:00PM on March 31, approximately 130 tons of water in total has been injected to the spent fuel storage pool.

From: Taro Ishida [ishida@denjiren.com]
  Sent: 03/31/2011 11:22 AM AST
  To: Taro Ishida <ishida@denjiren.com>
  Cc: Samuel Lederer <lederer@denjiren.com>
  Subject: <Update-17> Information Sheet Regarding the Tohoku Earthquake (from FEPC Washington Office)

Dear Friends,

Please find the updated information sheet below and attached that summarizes the events from Update-15 at 10:00AM on 3/30.

For your reference, JAIF (Japan Atomic Industrial Forum) has been posting the translation of news reports on their website.

http://www.jaif.or.jp/english/

Please direct any questions regarding this document to me, Ishida@denjiren.com or Samuel Lederer, Researcher of FEPC at lederer@denjiren.com.

Our official sources are:

  • Office of The Prime Minister of Japan
  • Nuclear and Industrial Safety Agency (NISA)
  • Tokyo Electric Power Company (TEPCO) Press Releases
  • Ministry of Education, Culture, Sports, Science and Technology (MEXT)

Unhappy about management of spent fuel?

Blue Ribbon Commission says that applies to just about everyone

UnhappyA government special study group that is looking at the future of management of spent nuclear fuel has released a summary of testimony it has heard over the past year. The staff report, which makes no recommendations, is a set of talking points about the things people have said to the commission. (28 pages, 11 Mb PDF file) ( http://tinyurl.com/brc-staff0311 )

Many in Washington, and elsewhere, who follow nuclear energy issues, have a skeptical view of the work of the Department of Energy’s Blue Ribbon Commission (BRC). The reasons include some intensely political considerations. Energy Sec. Steven Chu has been a straight man in this drama. See for instance the agency’s press release announcing the commission in January 2010 that included a list of its high-powered members.

The situation has acquired new urgency as the nation watched the situation in Fukushima, Japan, especially with the spent fuel pool at reactor #4. It may finally provoke Congress to do something, but don't hold your breath.

Carrying water for Senator Reid

Nevada Sen. Harry Reid, a Democrat and the Senate majority leader, has made it clear to President Obama the price for carrying water in Congress for Obama’s legislative initiatives is to prevent Yucca Mountain from ever opening.

So how did this work? For starters, the appointment of Gregory Jaczko, a former aide to Reid, as chairman of the Nuclear Regulatory Commission, is intended to insure the Yucca Mountain license never got reviewed for safety issues.

What the president gets in return is support in the Senate needed to push key programs crucial to political success for the White House. The deal at the NRC seemed like a small price to pay for a big result. Obama needs Reid more than ever since the Democratic majority in the Senate tool a shellacking in the mid-term election. It is still in the plus column, but it is not an absolute majority.

Since then the president has appointed three other members of the commission all of whom have decades of management experience in the nuclear industry, something that Jazcko lacks having been first an aide to the starkly anti-nuclear Rep, Edward Markey (D-Mass.) and then as one for Reid.

The addition of people who know the industry was seen by some as an attempt by the White House to make amends with the utilities regulated by the NRC. The formula is that while Reid gets his way on Yucca, the other matters before the NRC get handled by people expert in these matters.

Not in Kansas anymoreIf this sounds simplistic, consider that the political reality of Washington deals needed to get legislative business done has clashed with demands by the nuclear industry for progress on a real and pressing problem. There are times when these conflicts gave new meaning to the phase, “Toto, I don’t think we’re in Kansas anymore.”

Playing for time?

The BRC is widely seen as a “punt,” or a political fig leaf, designed to buy the president time to get his initiatives through Congress. Some have cynically suggested that there might also have been hope in the White House that Sen. Reid, not always the most popular guy in Nevada, would solve the problem by losing his seat in the 2010 mid-term elections. At one time the late night TV comic line about the situation was that Sen. Reid, running against nobody in Nevada, was behind by 20% in the polls.

Fig LeavesReid disappointed the White House by winning against a fringe candidate who drove off more moderate elements of the Nevada Republican party. The only difference between the Tea Party candidate in Nevada, and another one in Delaware, is that Sharron Angle, Reid’s opponent, never mentioned anything about practicing witchcraft.

This means President Obama is stuck with Reid through the rest of this term, and at least half of the next one, assuming Obama wins re-election. However, this could be Reid’s last six-year term. That fact means the BRC, if it plans to be useful, needs to come up with recommendations that make practical sense for the nation, and not just the political whims of the moment.

Summary of what people have told the BRC so far

Ok, so what has the BRC been doing? Well, for one it organized itself into several committees who then began traveling around the country asking people what they thought about what the U.S. should do to manage spent fuel. And, they got an earful. Nobody is happy about it.

Perhaps to make the point that the federal government has finally tried the patience of the nuclear industry to the point of complete frustration, the BRC published this month a summary of all the testimony it has heard from everyone who cared to say something to it.

In an introduction, the staff report said its purpose is to, “Provide individuals and organizations who have given input an opportunity to confirm that their key messages have been heard or to highlight something that may have been missed.

Just in case you haven’t submitted anything to the BRC, there is still still time. You can make your views known by using links at the BRC website.

Common threads

weave patternA common thread running through what the Commission has heard to date is that the nation’s inability to develop a permanent repository for highly radioactive waste reflects failures that are primarily social and political, not technical.

There are technical challenges to managing the back-end of the nuclear fuel cycle. These difficulties have been dwarfed by the challenge to come up with solutions that are perceived to be fair, equitable, safe and sustainable.

That last word “sustainable” means that enough people with a stake in the outcome see it as a reasonable solution and they don’t have the ability to upend it to obtain a better deal for their interests.

The major themes the Commission has heard to date are grouped under seven broad headings: (1) program governance and execution; (2) nuclear waste fee and Fund; (3) approach to siting; (4) reactor and fuel cycle technologies; (5) transport of used/spent fuel and high-level wastes; (6) storage of used/spent fuel and high-level wastes; and (7) disposal system for highly radioactive waste.

Program - The input received thus far reveals a deep and widespread erosion of trust in the ability of the federal government to meet obligations related to the disposal of used/spent nuclear fuel and high-level wastes.

Funding - Significant frustration exists over the disconnect between the amount of revenue being collected through the waste fee and the much lower amount of funding that has been made available through the federal budget process to be spent on the waste program for which these revenues are intended. Lawsuits abound.

Siting - Witnesses said that the process that led to the selection of the Yucca Mountain site was perceived by many as unfair, not grounded in sound science, and politically-motivated.

This is another “duh”moment, one that put Sen. Reid in motion in the first place.

Technologies – The Commission has received testimony describing a wide range of advanced reactor technologies including gas-cooled, liquid metal cooled, and water-cooled reactors and other advanced concepts. These reactor technologies are being investigated by private sector, academic and government research organizations.

Whether any of them see the light of day in terms of an NRC safety review is anybody’s guess. The agency, which is expert in light water reactor technologies, is struggling to come up to speed on how to handle the new technologies. Budget constraints at the agency may slow its progress in this area.

Transportation - The Commission has been presented a large amount of evidence indicating that the systems in place to transport nuclear materials in the United States have operated safely and without significant incident over several decades.

WIPP trupackThis isn’t entirely true as a Department of Energy Inspector General report cited two instances where the truck drivers taking nuclear waste to WIPP were arrested, while off-duty, for public intoxication. The IG also cited 14 other instances in 2007 involving heavy drinking within eight hours of a shift.

"Of the 16 incidents, two were of the greatest concern because they occurred during secure transportation missions while the Agents were in Rest Overnight Status, which occurs during extended missions where convoy vehicles are placed in a safe harbor and Agents check into local area hotels," the report said.

Even assuming there haven't been any repeat offenders, the original report is hair raising for people who don't understand the integrity of spent fuel canisters. Reports like this make local and state authorities crazy and with justification. That’s why any solution to managing spent fuel will have to satisfy most of the nation’s governors.

Storage - Many witnesses have urged that used/spent fuel from shutdown nuclear power stations be moved to centralized locations (options mentioned have included existing nuclear power plant sites, U.S. government sites, and newly-constructed storage facilities).

Others are of the view that fuel from shutdown plants should remain where it is until it can be moved to a permanent disposal facility. The NRC has said spent fuel in dry casks can be safely stored at reactors for up to 100 years.

Disposal - Witnesses from across the country, including especially many individuals from communities that are hosting shutdown reactors or DOE waste storage sites, have emphasized that the federal government has a moral and legal obligation to meet its commitments to remove used/spent fuel and high-level wastes.

And that really is the heart of it. Legalistic responses just don’t cut it with a fed up public. If Obama is about change, then this is a paradigm that needs it.

& & &

The Commission and its staff are interested in hearing from anyone who would like to provide comment on this report. The Commission will use the report and the comments received to help guide its examination of options as it develops a draft set of recommendations for the Secretary. The Commission hasn’t yet written its recommendations, thought it must do so soon as they are due in draft in July 2011.

Prior coverage

# # #

Wednesday, March 30, 2011

Fukushima reactor status update for 2011 03 30

NucNet reports on the latest developments in Japan’s nuclear crisis

(Note to readers: Today’s status reports are courtesy of NucNet a service of the World Nuclear Association.  Regular blog posts about nuclear energy will resume later this week.

You can follow breaking news about Fukushima via the American Nuclear Society (ANS) Twitter feed @ans_org which I am helping run.  Also, see twice daily news updates at the ANS blogANS Nuclear Cafe  provided by Rich Michal, an editor at ANS Nuclear News.  Laura Scheele, ANS Outreach Office, and Joe Koblich, IT Director at ANS, and his staff, make this work possible.

Please see the special Fukushima tab at the top of this blog for additional sources of information.

Fukushima_symbol

Work Continues To Remove Contaminated Water At Fukushima-Daiichi

30 Mar 2011 (NucNet): Work is continuing to remove contaminated water from the basement of the turbine hall at unit 1 of the Fukushima-Daiichi nuclear plant by pumping spilled water into the condenser.

But at units 2 and 3 there is not enough free capacity in the condensers and work is taking longer than expected, plant operator Tokyo Electric Power Company (Tepco) said.

The condensers are heat exchangers below the turbines, where low-pressure vapor from the turbines is condensed by removing residual or waste heat to the main heat sink.

The Japan Atomic Industrial Forum (JAIF) said “no major progress” has been reported in efforts to drain the basement water.

The delay is hampering work to cool down and stabilize the plant, JAIF said.

According to the International Atomic Energy Agency (IAEA), the Nuclear Safety Commission of Japan has suggested that higher activity in the water discovered in the unit 2 turbine building is caused by water which has been in contact with molten fuel rods and directly released into the turbine building via some, as yet unidentified path.

JAIF confirmed today that damage and leakage is suspected to the primary containment vessel (PCV) structural integrity at unit 2. JAIF had previously said the PCV’s status was “unknown”.

Removal of water from the turbine building basements is an important step before workers can continue efforts to fully restore power to the plant.

Meanwhile, Japan’s Nuclear and Industrial Safety Agency (NISA) said it has ordered Tepco to solve the problem of heavily contaminated water that has leaked into trenches outside the controlled zones of units 1 to 3 at the plant.

The IAEA said today that dose rates at the surface of accumulated water found in trenches close to the turbine buildings were 0.4 mSv/hr for unit 1 and more than 1,000 mSv/hr for unit 2.

An investigation is under way to discover how the water accumulated in the trenches.

Fresh water is being continuously injected into the reactor pressure vessels (RPVs) of units 1, 2 and 3 in an effort to cool the nuclear fuel. At unit 1, the temperature at the RPV’s feedwater nozzle – normally the coldest point of the RPV – has increased from 273.8 degrees Celsius to 299 degrees Celsius. The temperature at the bottom of the RPV remained stable at 135 degrees Celsius.

Temperatures at unit 2 appear relatively stable at the same measurement points. At unit 3, the temperature at the RPV feedwater nozzle is about 61.5 degrees Celsius and 120.9 degrees Celsius at the bottom of the RPV. However, Tepco said the validity of the RPV measurements is still being checked.

Tepco also said that periodical spraying of water onto the spent fuel pools of units 1 to 4 is continuing. Since yesterday Tepco has been spraying fresh water instead of seawater. The pool temperature is known only for unit 2 and was at 46 degrees Celsius this morning (30 March).

In unit 4, lighting was re-established in the control room yesterday. This means all control rooms now have light.

Fukushima-Daiichi Nuclear Plant Status Update

30 Mar (NucNet): The following is a summary of the status of all six reactor units and the spent fuel pools (SFPs) at the Fukushima-Daiichi nuclear plant. The main change since yesterday is that damage is now suspected to the reactor pressure vessel integrity of unit 2.

Unit Status Summary At Fukushima-Daiichi, 29 March 2011 at 12:00 Japan time:

  • Unit 1

Core and fuel integrity: damaged. Reactor pressure vessel integrity: unknown. Core cooling requiring AC power: not functional. Building integrity: severely damaged by hydrogen explosion. Water level in the rector pressure vessel (RPV): fuel partially or fully exposed. Pressure of the RPV: now decreasing after initial increase (5–6 bar). Temperature of the RPV: slight increase (310 degrees Celsius at feedwater nozzle; 138 degrees Celsius at bottom head). Water injection to core: continuing. Now using fresh water instead of seawater. Water injection to containment vessel: to be confirmed. Containment venting: temporarily stopped.

  • Unit 2

Core and fuel integrity: severely damaged. Reactor pressure vessel integrity: damage suspected (suppression chamber).

Core cooling requiring AC power: not functional. Building integrity: slightly damaged. Water level in the rector pressure vessel: fuel partially or fully exposed. Pressure of the RPV: stable (0.7–0.8 bar). Temperature of the RPV: slight increase (158 degrees Celsius at feedwater nozzle; 120 degrees Celsius at bottom of head). Water injection to core: continuing. Now using fresh water instead of seawater. Water injection to containment vessel: to be confirmed. Containment venting: temporarily stopped.

  • Unit 3

Core and fuel integrity: damaged. Reactor pressure vessel integrity: unknown. Core cooling requiring AC power: not functional. Building integrity: severely damaged by hydrogen explosion. Pressure of the RPV: now stable (1.3 bar). Temperature of the RPV: slight increase (62 degrees Celsius at feedwater nozzle; 121 degrees Celsius at bottom of head). Water injection to core: continuing. Use of fresh water under consideration. Water injection to containment vessel: to be confirmed. Containment venting: temporarily stopped.

  • Unit 4

Shut down at the time of the earthquake, no damage to fuel (which had already been removed from the reactor and transferred to the pool), core or containment. Building integrity severely damaged by hydrogen explosion.

  • Unit 5

Shut down at the time of the earthquake, no damage to fuel, core or containment. Vent hole opened in roof as precaution against hydrogen explosion. Unit in cold shutdown.

  • Unit 6

Shut down at the time of the earthquake, no damage to fuel, core or containment. Vent hole opened in roof as precaution against hydrogen explosion. Unit in cold shutdown.

Spent Fuel Pool Status At Fukushima-Daiichi 30 March 2011:

Fuel integrity: unknown at units 1 and 2; possibly damaged at units 3 and 4; safe at units 5 and 6, and in the common spent fuel pool.

  • Unit 1

Water injection being considered.

  • Unit 2

Water injection carried out periodically since 20 March; switch from seawater to fresh water on 29 March; water temperature 46 degrees Celsius.

  • Unit 3

Water level low, water injection continues; switch from seawater to fresh water on 29 March.

  • Unit 4

Water level low, water injection continues; switch from seawater to fresh water on 29 March. Reactor building damaged by explosion and fire on 15 March.

  • Units 5 & 6

Pool cooling capability recovered.

Common Spent Fuel Pool

Seawater was sprayed over this pool on 21 March. Pool cooling was restarted after successful installation of an external power supply line on 24 March.

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