Мощное землетрясение и цунами в Японии

[Yurcha]

UPDATE AS OF 1:30 P.M. EDT, MONDAY, MARCH 14:

Unit 2 at the Fukushima Daiichi nuclear power plant lost a significant amount of reactor coolant for a second time on Monday. Some of the uranium fuel rods were uncovered for a period of time. A malfunctioning safety relief valve at the plant caused an increase in reactor pressure and hindered injection of coolant back into the reactor. The cause of the relief valve failure is under investigation.

The Japanese government has distributed 230,000 units of potassium iodine to evacuation centers in the area surrounding the Fukushima Daiichi and Fukushima Daini stations, according to officials. Ingestion of potassium iodine can help prevent the accumulation of radioactive iodine in the thyroid.

At the Fukushima Daini site all units have off-site power, and water levels in all units are stable. Plant operators at Daini Unit 1 were able to restore a residual heat remover system, which is now being used to cool the reactor. Work is in progress to achieve a cold shutdown. Workers at Daini Units 2 and 4 are working to restore residual heat removal systems. Unit 3 is in a safe, cold shutdown.

Radiation dose rate measurements observed at four locations around the Daini plant´s perimeter over a 16-hour period on Sunday were all normal.


http://www.nei.org/newsandevents/inf...n-that-region/

[YUM]

не пойму как вышла из строя система охлаждения из за отключения электроэнергии. как то не по японски честно говоря. даже если реактор старый, но надо бы иметь супер технологию и triple backup.

там какая-та трабла с генераторами автономки. Не запустились, току нет- насосы встали.

[Милька]

не пойму как вышла из строя система охлаждения из за отключения электроэнергии. как то не по японски честно говоря. даже если реактор старый, но надо бы иметь супер технологию и triple backup.

знаешь ли
никакая технология не справится с природными катаклизмами
всего не учтешь

еслиб такая ситуация возникла где то тут
я уверена, жертв былоб больше
проблем былоб больше

[Винни1]

не пойму как вышла из строя система охлаждения из за отключения электроэнергии. как то не по японски честно говоря. даже если реактор старый, но надо бы иметь супер технологию и triple backup.

Как, как....
Водород взровался, вот и вышла.

[Винни1]

еслиб такая ситуация возникла где то тут
я уверенаЮ, жертв былоб больше
проблем былоб больше

Ага, согласна.

[Yurcha]

знаешь ли
никакая технология не справиться с природными катаклизмами
всего не учтешь

еслиб такая ситуация возникла где то тут
я уверенаЮ, жертв былоб больше
проблем былоб больше

Could an accident like the one at Japan’s Fukushima Daiichi nuclear plant happen in the United States?
It is difficult to answer this question until we have a better understanding of the precise problems and conditions that faced the operators at Fukushima Daiichi. We do know, however, that Fukushima Daiichi Units 1-3 lost all offsite power and emergency diesel generators. This situation is called “station blackout.” U.S. nuclear power plants are designed to cope with a station blackout event that involves a loss of offsite power and onsite emergency power. The Nuclear Regulatory Commission’s detailed regulations address this scenario. U.S. nuclear plants are required to conduct a “coping” assessment and develop a strategy to demonstrate to the NRC that they could maintain the plant in a safe condition during a station blackout scenario. These assessments, proposed modifications and operating procedures were reviewed and approved by the NRC. Several plants added additional AC power sources to comply with this regulation.

In addition, U.S. nuclear plant designs and operating practices since the terrorist events of September 11, 2001, are designed to mitigate severe accident scenarios such as aircraft impact, which include the complete loss of offsite power and all on-site emergency power sources.


U.S. nuclear plant designs include consideration of seismic events and tsunamis’. It is important not to extrapolate earthquake and tsunami data from one location of the world to another when evaluating these natural hazards. These catastrophic natural events are very region- and location-specific, based on tectonic and geological fault line locations.

Выделенное красным - правда.http://www.nei.org/resourcesandstats...uation/?page=2

[Винни1]

NISA - Nuclear and Industiral Safety Agency.
Пресс-релизы от японцев.
http://www.nisa.meti.go.jp/english/f...20110314-3.pdf

[Yurcha]

Как, как....
Водород взровался, вот и вышла.

What happened?

 The plant was immediately shut down (scrammed) when the earthquake first hit. The automatic power system worked.
 All external power to the station was lost when the sea water swept away the power lines.
 Diesel generators started to provide backup electrical power to the plant’s backup cooling system. The backup worked.
 The diesel generators ceased functioning after approximately one hour due to tsunami induced damage, reportedly to their fuel supply.
 An Isolation condenser was used to remove the decay heat from the shutdown reactor.
 Apparently the plant then experienced a small loss of coolant from the reactor.
 Reactor Core Isolation Cooling (RCIC) pumps, which operate on steam from the reactor, were used to replace reactor core water inventory, however, the battery‐supplied control valves lost DC power after the prolonged use.
 DC power from batteries was consumed after approximately 8 hours.
 At that point, the plant experienced a complete blackout (no electric power at all).
 Hours passed as primary water inventory was lost and core degradation occurred (through some combination of zirconium oxidation and clad failure).
 Portable diesel generators were delivered to the plant site.
 AC power was restored allowing for a different backup pumping system to replace inventory in reactor pressure vessel (RPV).
 Pressure in the containment drywell rose as wetwell became hotter.
 The Drywell containment was vented to outside reactor building which surrounds the containment.
 Hydrogen produced from zirconium oxidation was vented from the containment into the reactor building.
 Hydrogen in reactor building exploded causing it to collapse around the containment.
 The containment around the reactor and RPV were reported to be intact.
 The decision was made to inject seawater into the RPV to continue to the cooling process, another backup system that was designed into the plant from inception.
 Radioactivity releases from operator initiated venting appear to be decreasing.

[смешно]

там какая-та трабла с генераторами автономки. Не запустились, току нет- насосы встали.

такие системы надо строить с учётом любых катаклизмов, тем более землятрясений. уверен на 100%, что ВСЕ системы охлаждения/энергопитания будет upgraded после этого "инцидента" и будет расчитанны на различные "природные" явления. у меня есть подозрение что американцы учавствовали в той "системе", а американская система бывает не далека от совковой.

[Винни1]

What happened?

Да, поправка принимается.
Водород взровался как раз потому, что бэкап накрылся.