ScribbleLive

Fukushima Daiichi nuclear power plant operator 'ignored tsunami warning'

Tokyo Electric Power rejected report warning the nuclear plant could be at risk from 10-metre high tsunami, media claim. The operator of the Fukushima Daiichi nuclear power plant ignored warnings that the complex was at risk of damage from a tsunami of the size that hit north-east Japan in March, and dismissed the need for better protection against seawater flooding, according to reports.

Tokyo Electric Power (Tepco) officials rejected "unrealistic" estimates made in a 2008 internal report that the plant could be threatened by a tsunami of up to 10.2 metres, Kyodo news agency said. www.guardian.co.uk

Help to relocate or "escape" options offered by Geographic Communities Listed by Country and State or Province. directory.ic.org

@lillymunster I will try to find the source for this link and post it. It was offered to Japanese residents who need to find alternative housing so they are able to leave Japan. A number of these communities list free housing in exchange of helping the community in their gardens, making meals, building repair or whatever. Stays can be temporary, others can be permanent. Each location gives a description of the site's housing, acreage and etc, along with contact phone numbers and email addresses to obtain additional information.

Found something interesting while researching rpv embrittlement. Tepco contradicts itself on IC of Unit 1. Recall, a tepco official exclaiming that even had it performed, the IC was not going to make a difference in the course of events? In the NISA report to IAEA last June, page IV-46, I read: "The basic means of cooling the reactor after the MSIV is closed are cooling via the IC and water injection via the HPCI."

Here is something important for the interpretation of rpv temps on p IV-45 of the NISA June IAEA report: "As a result of increasing the amount of water injected when the injection was changed from the feed water line on March 23 the temperature of the RPV bottom dropped from being higher than the measurable maximum (greater than 400°C),..." Hence, 400°C can be any greater temp.

@lillymunster , imagine people were sent into the building during these hours. Makes you wonder whether tepco reported their absorbed doses accurately.

In an entirely different vain, I was still thinking about Fukushima Plant Director Yoshida who just left his post because of health reasons. Sometime ago, Dean posted a National Geographic video on the Chernobyl accident. We were hoping to get a glimpse on the actual explosion, but it turned out to be a re-enactment. The video contained interviews with the two operators whose actions caused the accident. Though they acted on instructions, it seemed none felt responsible for what happened. By contrast, Yoshida's first statement contained an apology for the distress (inconvenience in Japanese) that his plant had inflicted. In my mind Yoshida did not have to apologize. Without him and his crew much worse could have happened, whereas the mentality that the Soviet Union bred gives me the creeps.

Report: Huge blast heard in Iranian city of Isfahan
Iran's Fars news agency reported a large explosion in one of Iran's largest cities, located near uranium conversion plant. Report removed from website shortly afterwards; security officials deny incident Conflicting reports?
Less than two weeks after a mysterious explosion destroyed an Iranian missile base near Tehran, the Islamic Republic's official news agency Fars reported Tuesday that a loud blast was heard in the city of Isfahan at 2:40 pm local time, but later removed the report. According to the initial report, search and rescue teams called to the scene confirmed the blast, but reported no injuries. Iran's uranium conversion plant is located just outside Isfahan – one of the country's largest cities. The report also stated that a security official confirmed that the explosion had occurred, but refused to give further details. The district's security department head Muhammad Mahdi Ismaili told the news agency that he hadn't received "exact information, but the incident is being investigated." In a curious turn of events, shortly after the initial report was published, the item was removed from the news agency's website, which is affiliated with the country's Revolutionary Guard. Hours later, conflicting reports began to surface, the deputy governor of Isfahan province telling Iran's Mehr news agency that there was no report of a major explosion in the province. "So far no report of a major explosion has been heard from any government body in Isfahan," he was quoted as saying. However, the news agency also quoted another Iranian media outlet as saying that a blast took place at a petrol station in a town near Isfahan.Meanwhile, the head of Isfahan province judiciary told Isna news agency that an explosion-like sound was heard across the city. "In the afternoon, there was a noise like an explosion, but we don't have any information from security forces on the source of the noise," Gholamreza Ansari was quoted as saying.The uranium conversion plant is an integral part of Iran's nuclear program, where urania, also known as Yellowcake, is processed into uranium hexafluoride gas (UF6).From there, the gas is transferred to Iran's nuclear facilities in Natanz and Qom.
www.ynetnews.com

The 11 March Japan Disaster/Comprehensive Nuclear-Test-Ban-Treaty (CTBT) Preparatory Commission. The CTBTO's measuring stations help Japanese authorities issue timely tsunami warnings and traced the dispersal of radioactivity from the Fukushima power plant globally. www.ctbto.org

I found this description pbadupws.nrc.gov on IC function. We had some posted before, but this piece gives the most detailed explanation:
"6.3.2.1 The isolation condenser
The isolation condenser, figure 6.3-1, operates by natural circulation. During system operation, steam flows from the reactor condenses in the tubes of the isolation condenser,and returns (by gravity) to the reactor. The water head, created
by condensate flow to the reactor, serves as the driving force for the system.

The isolation condenser is approximately 55 feet long, 12 feet in diameter, and holds approximately 29,000 gallons of water at normal level. Two tube bundles are immersed in Water, one bundle at each end of the condenser. The shell side of the condenser vents to atmosphere. Baffles are installed in the shell above the tube bundles to prevent the boiling action from driving shell water out through the shell vents.

The steam inlet valves are normally open so that the tube bundles are at reactor pressure even when in standby. The tube side of the isolation condenser is vented to the main steam line during normal reactor operation. A sustained high reactor pressure automatically puts the isolation condenser system in operation. An automatic initiation will signal the dc motor operated valve on the condensate return line to open and vent valves to the main steam line to close. Steam then flows, under reactor pressure, to the isolation condenser. The steam is routed to both condenser tube bundles where it is condensed by the cooler water in the shell side of the condenser. To obtain the desired flow of condensate from the isolation condenser to the reactor vessel, the normally closed condensate return valve can be throttled by the operator in the control room.

During operation, the water on the shell side of the condenser will boil off and vent steam to the atmosphere. Two radiation monitors are provided on the shell side vent so that in the event of excessive radiation levels, the control room operator will be alerted and can take necessary corrective actions.

Following a reactor isolation and scram, the energy added to the coolant will cause reactor pressure to increase and may initiate the isolation condenser. The capacity of this system is equivalent to the decay heat rate generation 5 minutes following the scram and isolation. With no makeup water, the volume of water stored in the isolation condenser will be depleted in 1 hour and 30 minutes. This allows sufficient time to initiate makeup water flow to the shell side of the condenser.
Makeup water is normally added from the demineralized water makeup system to avoid concentrating radioactive matter resulting from normal water evaporation that occurs in standby mode. Additional water is available from the condensate and fire protection systems." So the operator did not have to shut the valves entire. Rather he could have throttled the flow thereby maintaining functionality. Besides, there is quite some wishful thinking in this design.

Alert Map. Event: Environment Pollution in Japan (Fukushima wide) on Tuesday, 29 November 2011. Event Description: Radioactive rice has been detected again in Japan... hisz.rsoe.hu