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France's nuclear safety regulator has given the country's nuclear power plants a clean bill of health but recommended the protection of vital equipment be beefed up.
The IRSN agency has urged plants to prepare for natural disasters worse those they were built to withstand.
3.4 Loss of Power In the control rooms, as plant equipment and distribution panels flooded, lighting gradually faded and instruments began to fail. Station batteries, which were designed to last for 8 hours, were lost when the flooding grounded or damaged DC distribution systems. The loss of DC power resulted in a loss of all lighting in the units 1-2 control room within 51 minutes after the scram. (Note: Units 1 and 2 share a common control room, as do units 3 and 4.)
Normal lighting in the units 3-4 control room was lost, and only emergency lighting remained. Control room operators began checking to see which indications were still available. Three air-cooled emergency diesel generators (EDGs) had previously been installed at the station as a modification (2B, 4B, and 6B EDGs). These EDGs had independent fuel systems and were capable of providing power to vital AC systems following a complete loss of the seawater ultimate heat sink.
Furthermore, AC distribution system cross-ties had been installed between units, which allowed power to be transferred among units 1-2 and 3-4 or between units 5-6 for both the 6.9-kV and 480-V distribution systems. The air-cooled EDGs were located above grade, and some of them survived the tsunami. The distribution systems for the Unit 2 and the Unit 4 air-cooled EDGs, which were located below grade, flooded and failed during the tsunami.
The Unit 6 air-cooled EDG and portions of the electrical distribution system survived the tsunami and were used to reestablish cold shutdown on units 5 and 6. Figure 7.4-7 illustrates the damage to the electrical distribution system caused by the tsunami.
When all AC power was lost, TEPCO personnel notified the government that an emergency condition existed. TEPCO corporate offices and the Japanese government arranged for delivery of portable electric generators to the Daiichi site. The generators were located; however, damaged roads and congested traffic prevented the generators from reaching the site quickly.
Helicopters were considered, but the generators were too large and heavy to carry. Ultimately, TEPCO was able to secure some mobile generators from the Tohoku Electric Power Company. These generators, along with some TEPCO generators, began to arrive at the site late in the evening of March 11 and continued to arrive into the next morning.
The portable generators were limited in their effectiveness because they could not be connected to the station electrical distribution system as a result of the extensive damage the tsunami and flooding caused. Workers checked motors and switchgear in an attempt to find usable equipment to support cooling the reactors.
The testing revealed that the Unit 2 standby liquid control (SLC) pumps were not flooded or damaged. Based on the inspection results, the first mobile generator was placed adjacent to Unit 2, and workers began to lay temporary cables from the generator to the associated distribution panel for the SLC pumps.
The temporary power cables were approximately 4 inches (10 cm) in diameter and 656 feet (200 meters) long and weighed more than 1 ton. Forty employees began to run the cables through the debris and flooded areas. The force of the tsunami had blown manhole covers off, resulting in unmarked openings in the ground. Aftershocks and subsequent tsunami warnings further slowed progress.
In spite of the challenges, the workers completed the task on Unit 2 and terminated the temporary cable to the associated power panel on March 12 at 1530.
At 1536, an explosion occurred in the Unit 1 reactor building. This explosion was most likely caused by the buildup of hydrogen that had been generated in the Unit 1 reactor core and leaked into the reactor building. The explosion injured five workers, and debris from the explosion struck and damaged the cables and mobile generator that had been installed to provide power to the standby liquid control pumps.
The debris also damaged the hoses that had been staged to inject seawater into Unit 1 and Unit 2. Fieldwork was suspended as workers were evacuated to the Emergency Response Center for accountability.
Some of the debris was also highly contaminated, resulting in elevated dose rates and contamination levels around the site. As a result, workers were now required to wear additional protective clothing, and stay times in the field were limited. The explosion significantly altered the response to the event and contributed to complications in stabilizing the units.
Figures III-2-8(a) and III-2-8(b) show the transmission network of external power supply of Fukushima Dai-ichi NPS and the damage situation. As shown in the Figures, the Okuma Nos. 1 and 2 power transmission lines (275 kV) from Shin Fukushima Power Substation connected to the normal high voltage switchboards of Units 1 and 2 via the switchyards for Units 1 and 2, and in addition, TEPCO nuclear line (66 kV) from Tohoku Electric Power Co., Inc. connected to the normal high voltage switchboard of Unit 1 via the switchyards for Units 1 and 2. As to Units 3 and 4, the Okuma Nos. 3 and 4
transmission lines (275 kV) connected to the normal high voltage switchboard of Units 3 and 4 via the switchyards for Units 3 and 4 as well. For Units 5 and 6, the Yorunomori Nos. 1 and 2 transmission lines (66 kV) connected to the normal high voltage switchboard of Units 5 and 6, too.
In addition, the normal high voltage switchboard of Unit 1, the normal high voltage switchboard of Unit 2, and the normal high voltage switchboard of Units 3 and 4 were connected mutually, and electric power interchange was possible.
However, the switchyard for the Okuma No. 3 transmission line in the switchyards of Units 3 and 4 was under construction on the day when the earthquake occurred, and as a result, external transmission line in the total of six lines was connected to Fukushima Dai-ichi NPS. The Shin Fukushima Power Substation is located approximately 8 km from the site, and the seismic intensity of this earthquake is estimated to be 6 upper.
The earthquake caused damage to the breakers of the switchyards of Units 1 and 2. As to TEPCO nuclear line from Tohoku Electric Power, although it is not possible to estimate the cause, cables were damaged. Concerning Units 3 and 4, in addition to the Okuma No. 3 transmission line under construction, the breakers of Nos. 3 and 4 transmission lines on the side of Shin Fukushima Power Substation failed. In addition, for Units 5 and 6, one transmission line tower (tower No. 27) connecting to the switchyards of Units 5 and 6 was collapsed. As a result, all external power supplies of Units 1 to 6 were lost.
The transmission network of external power supply of Fukushima Dai-ni NPS contain four lines including two lines of the extra high voltage switchyard on the site used in combination among Units 1 to 4 and the Tomioka Nos. 1. and 2 transmission lines outside the site (500 kV), and two lines of the Iwaido Nos.1 and 2 transmission lines (66 kV), and they connect to Shin Fukushima Power Substation, 8km upstream, and further, connect to Shin Iwaki Switchyard, approximate 40 km upper.
Out of these transmission lines, power supply from Iwaido No.1 had been stopped for maintenance. The seismic intensity in the area around Shin Fukushima Power Substation is estimated to be 6 upper. The Tomioka No. 2 transmission line (500 kV) and the Iwaido No. 2 transmission line (66 kV) to Units 1 to 4 of Fukushima Dai-ni NPS stopped transmission due to failure of devices on the side of the switchboard, caused by strong ground motion in this earthquake. However, the power supply to Units 1 to 4 was continued since the Tomioka No. 1 transmission line could supply electric power (refer to Fig.III-2-8(a)).
Originally posted by qmantoo
I have only read this thread once, all the rest is processing I am afraid. :-) In the early digital globe images there was steam coming from R1 I think. Maybe also in the old, old south end webcam there may be stuff in the distance.
which reminds me Q, Ive been meaning to ask, when going through the early stages of the disaster via this thread, did you ever come across anything relating to steam coming from R1. Ive been wondering a long time why R1 never seemed to contribute much steam in relation to R2-R4.
Originally posted by Aircooled
In the early days of the thread folks thought this was reactor #4 but this is west of the pool, not north of the pool, so is our info wrong or is this something else?
The Savannah River Site (SRS) is a nuclear reservation in the United States in the state of South Carolina, located on land in Aiken, Allendale and Barnwell Counties adjacent to the Savannah River, 25 miles (40 km) southeast of Augusta, Georgia. The site was built during the 1950s to refine nuclear materials for deployment in nuclear weapons.
It covers 310 square miles (800 km2) and employs more than 10,000 people.
A major focus is cleanup activities related to work done in the past for the nation's nuclear buildup. Currently, none of the reactors on-site are operating (see list of nuclear reactors), although two of the reactor buildings are being used to consolidate and store nuclear materials. more
...As the Obama administration and Senate leaders move to scuttle a proposed repository for the waste in Nevada, the Hanford nuclear reservation in Washington state — along with federal facilities in Idaho and South Carolina — could become the de facto dump sites for years to come.
Under Secretary of State for Arms Control Ellen Tauscher said on Monday, September 19, 2011, that high-level nuclear waste once destined for the Yucca Mountain repository will be sent, instead, to the Department of Energy’s Savannah River Site.
Currently, millions of gallons of high-level nuclear waste are stored in 49 leaking tanks on the site as well as [color=Chartreuse]huge amounts of surplus plutonium.
[color=Cyan]Deadly chemicals and radiation will contaminate the facility for thousands of years.
'The Bomb Plant,' as locals refer to the site, is uniquely unsuitable for a permanent nuclear waste repository, according to leading geologists. It sits on an earthquake fault and one of the most important aquifers in the South. The sandy soil and swampy conditions make it highly vulnerable to waste seepage.
The Obama Administration has spent more than $1 billion in Stimulus Act funds cleaning up legacy Cold War nuclear and chemical waste at the site. Despite this effort, [color=Chartreuse]there is now more radioactive waste at SRS than when the clean-up started.
The idea of bringing nuclear reactor waste and surplus weapons plutonium from around the world to SRS only exacerbates already chronic problems.
The 312 square mile site near Aiken, South Carolina, was once the home of five reactors that churned out nuclear materials for H-bombs.
The last reactor at SRS had to be shuttered for safety reasons during the Reagan Administration. Tritium, which is needed for nuclear weapons, is produced by Tennessee Valley Authority reactors and processed into gas for nuclear weapons at SRS.
The $4.8 billion MOX facility, scheduled to open in 2016, is designed to dispose of 34 metric tons of surplus weapons-grade plutonium by using small amounts to make fuel for commercial reactors. (...)
After spending $10 billion to $12 billion over the past 25 years studying a nuclear waste dump at Yucca Mountain, President Barack [color=3BB9FF]Obama is fulfilling a campaign promise to kill it as a site for the repository.
If Yucca is closed, a search for a new site for a national repository likely would start with the 31 states on the original list of potential locations. In addition to Hanford and the Idaho National Laboratory, the states with possible sites include Texas, Georgia, North Carolina, South Carolina, Mississippi and Pennsylvania.
Scrapping Yucca Mountain also could have national security ramifications. The Navy would have no place to permanently store the used reactor fuel that's powered its aircraft carriers and submarines.
In a report late last year to Congress, the department (DOE) warned that by not providing adequate and timely storage for the defense nuclear waste, it would be "unable to honor" its commitments to the states where the waste is currently stored, including Washington, Idaho and South Carolina.
SRS was never intended, nor is it equipped to be, a final nuclear waste repository, [color=8AFB99]but through redefinition of legal terms and the closing of the Yucca Mountain site, [color=3BB9FF]it has become one.
SRS, with all its nuclear ruins and more curies of radioactivity than any place in America,
is now the storage site for the world’s most dangerous materials.
SRS is also home to the Savannah River National Laboratory and the nation's only operating radiochemical separations facility.
Its tritium facilities are also the United States' only source of tritium, an essential component in nuclear weapons. And, the nation's only mixed oxide fuel (MOX) manufacturing plant is being constructed at SRS. When operational, the MOX facility will convert legacy weapons-grade plutonium into fuel suitable for commercial power reactors.
... will convert legacy weapons-grade plutonium into fuel suitable for commercial power reactors.
Future plans for the site cover a wide range of options, including host to research reactors,
a reactor park for power generation, and other possible uses. (...)
Originally posted by Purplechive
Here's the original release:
OK (Z) et. all - these numbers mess me up...
Are TEPCO's "Corrections" better or worse?
The radioactive density and detection limit of rare gases（Kr-85,Xe-131m,Xe-133,Xe-135）are evaluated by the
result collected at the gas vial container of charcoal filter’s rare gas capture ratio.
TEPCO nuclear line (66 kV) from Tohoku Electric Power Co., Inc. connected to the normal high voltage switchboard of Unit 1 via the switchyards for Units 1 and 2......In addition, the normal high voltage switchboard of Unit 1, the normal high voltage switchboard of Unit 2, and the normal high voltage switchboard of Units 3 and 4 were connected mutually, and electric power interchange was possible.
As to TEPCO nuclear line from Tohoku Electric Power, although it is not possible to estimate the cause, cables were damaged.
In addition, the TEPCO Nuclear Line (66 kV) from Tomioka Substation of the Tohoku Electric Power was connected to Unit 1 as the spare line.
With regard to recovery and reinforcement of the power supply, TEPCO completed checking and the trial energizing of the facilities to receive power from the nuclear power line of Tohoku Electric Power Co., Inc. on March 16. From March 20, the Power Center received power to ensure the power supply from an external power source.
A major cause for this accident was a failure in securing the necessary power supply......The most urgent task at the site along with recovery of power supply and continuation of water injection to reactor vessels was water injection to the spent fuel pools.
The earthquake caused damage to the breakers of the switchyards of Units 1 and 2. As to TEPCO nuclear line from Tohoku Electric Power, although it is not possible to estimate the cause, cables were damaged.
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow.
Whereas a fuse operates once and then has to be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city.
lectrical power transmission networks are protected and controlled by high-voltage breakers. The definition of high voltage varies but in power transmission work is usually thought to be 72.5 kV or higher, according to a recent definition by the International Electrotechnical Commission (IEC). High-voltage breakers are nearly always solenoid-operated, with current sensing protective relays operated through current transformers. In substations the protective relay scheme can be complex, protecting equipment and buses from various types of overload or ground/earth fault.
High-voltage breakers are broadly classified by the medium used to extinguish the arc.
Some of the manufacturers are ABB, GE (General Electric) , Tavrida Electric, Alstom, Mitsubishi Electric, Pennsylvania Breaker, Siemens, Toshiba, Končar HVS, BHEL, CGL, Square D (Schneider Electric).
Due to environmental and cost concerns over insulating oil spills, most new breakers use SF6 gas to quench the arc.
Circuit breakers can be classified as live tank, where the enclosure that contains the breaking mechanism is at line potential, or dead tank with the enclosure at earth potential. High-voltage AC circuit breakers are routinely available with ratings up to 765 kV. 1200kV breakers were launched by Siemens in November 2011.
High-voltage circuit breakers used on transmission systems may be arranged to allow a single pole of a three-phase line to trip, instead of tripping all three poles; for some classes of faults this improves the system stability and availability.
Radiation meters installed at parks and primary schools across Fukushima Prefecture do not meet the central government's minimum accuracy requirements, it was learned on Nov. 18.
The Ministry of Education, Culture, Sports, Science and Technology cancelled its contract with the meters' supplier the same day. The ministry will begin removing the 600 devices soon, and reopen bidding on the radiation meter contract.
The meters were scheduled to start operating in October, but that has now been pushed back to February next year at the earliest. According to the ministry, five firms bid on the meter supply contract in July, won by Tokyo-based telecommunications equipment firm Alpha Tsushin K.K. for some 370 million yen.
The contract requirements demanded that radiation measurements be accurate to within plus or minus 20 percent, but soon after they were installed in October the ministry discovered the meter readings were off by as much as 40 percent.
However, the status of the molten nuclear fuel is unclear. It is not known how the fuel, believed to have partially melted through pressure vessels of the reactors and into containment vessels, has dispersed and how much lies in water. It is questionable to assess the situation as nearly a cold shutdown.
Usually, to achieve a cold shutdown, all fuel rods should be cooled under water, and nuclear fuel, pressure and containment vessels should be intact and in good condition. The situation at the nuclear plant does not meet this definition. Is it appropriate for the government and TEPCO to call the current status nearly a cold shutdown?
Plant Status Water temperatures inside the Fukushima Daiichi reactor pressure vessels remain below boiling as operator Tokyo Electric Power Co. reports on progress toward stabilizing the damaged reactors. The company expects to reach what it calls a “cold shutdown condition” in the three reactors by the end of the year, with temperatures below 212 F and radiation contained.
The exact status of the fuel in the reactors is not known. But if damaged fuel has leaked from the reactors into the primary containments, however, TEPCO said “it is sufficiently cooled to suppress steam from being generated and [the] accompanying release of radioactive materials.
” Radiation measured at the site boundary is 10 millirem per year, one-tenth of the government safety limit. The circulating reactor cooling systems continue to function, as pumps maintain the total volume of accumulated water on the site at a level that can withstand heavy rain or an extended outage of processing facilities.
Originally posted by Aircooled
Readings from LA. and St Louis.
I know that it would be good to have details, but an air filter is very much like a human lung - it gets particles inside it and they stay there, contaminating the human. To know what volume of air has passed through the filter is good if you are measuring things scientifically, however, the amount of radiation in the filter probably has some relevence to what a human would be collecting in their lungs while they are walking around in different places.
what kind of information is behind a reading of an Airfilter
without knowing the amount of washed Air, the time, the location of the filter, etc