ScribbleLive

Stabilizing reactors by year's end may be impossible: Tepco
Kyodo
Stabilizing the crisis at the Fukushima No. 1 power plant by the end of the year may be impossible, senior officials at Tokyo Electric Power Co. said Sunday, throwing a monkey wrench into plans to let evacuees return to their homes near the plant.

The confirmation of core meltdowns hitting reactors 1 through 3, accompanied by breaches to the critical pressure vessels that hold the nuclear fuel, has led officials to believe that "there will be a major delay to work" to contain the situation, one official said.

Tepco, the plant's operator, announced on April 17 its road map for bringing the troubled reactors into a cold shutdown within six to nine months.

Even though the fuel in the No. 1 reactor was later found to have melted through the pressure vessel, the utility said as recently as May 17 that it did not see a need to revise its projections.

But "the nine months is just a target deadline for which we are making efforts," a senior Tepco official said, indicating that the likely delay will affect the plan to review the evacuation of local residents. The government is hoping to review the order once the reactors are brought under control.

Tepco was taking steps until early May to completely fill the containment vessels housing the pressure vessels with water so the fuel could be cooled.

But on May 12, it was confirmed that a meltdown had occurred at the No. 1 reactor, forcing the utility to abandon the water entombment idea and try to install a new cooling system that decontaminates and recycles the radioactive water flooding the reactor's turbine building instead.

Given that the contaminated water has leaked from the No. 1 reactor's containment vessel, a Tepco official said, "We must first determine where it is leaking and seal it."

The official added, "Unless we understand the extent of the damage, we don't even know how long that work alone would take," noting the need for one or two months more than previously thought to establish an entirely new cooling system.
search.japantimes.co.jp

@elainekirk what kind of trouble?

@estacion :)

@elainekirk always fun in NE Asia! ty

glowing mushrooms

High radioactivity level at No. 2 reactor

The operator of the crippled Fukushima Daiichi nuclear plant says the radioactivity level and humidity are high in the Number 2 reactor building, which will make internal operations hard.

Workers entered the building last week to measure humidity and to gauge levels of radioactive substances in the atmosphere.

The results show the Number 2 reactor building's radioactive cesium level is twice as high as the cesium level in air not purified in the Number 1 reactor building. Steam is filling the Number 2 building, and humidity has reached 99.9 percent.

The high humidity means an air purification unit cannot be used to lower the level of radioactivity.

In order to cool the spent fuel storage pool that's causing the steam, TEPCO will put in place a heat exchanger on Tuesday to serve as a cooling system.

But TEPCO does not know how effective the system will be, so it will be a while before it can install the purifier to lower the radioactivity level.

Monday, May 30, 2011 07:04 +0900 (JST)
www3.nhk.or.jp

and now the good news:

Expert: no threat of radiation from rain

Professor Shunichi Yamashita of Nagasaki University says there's no need to prepare for radioactive rain.

Yamashita said on Sunday that no radiation has been detected in dust in the atmosphere. He was referring to an investigation conducted last week in areas more than 20 kilometers away from the crippled Fukushima Daiichi nuclear power plant.

He says the rains mean radioactive substances on the ground will be washed away and thinly diffused, except for in areas that collect rain.

Monday, May 30, 2011 06:05 +0900 (JST)
www3.nhk.or.jp

@Edano Don't you find that 99.9% humidity weird?

@pedro @edano the stats for all 3 reactors seem very unstable - oscillating rads in #1, and very unstable temperature readings in #2 www.tepco.co.jp and #3 www.tepco.co.jp Surely all the sensors can't be faulty! (@edano - these are the latest that should feed into your and @radioguy's excellent graphs)

@Pedro Jesus @Edano.
No if temperatures are high into the building

@Edano I mean, how can radiation releases increase when you don't have more than .1% radiotiactive particulates in suspension? Those figures have got to be wrong or someone is making the wrong assumptions on that article (which wouldn't surprise me).

and now - because i love it - the news of the week from yesterday:

Emergency manual to protect tourism from being affected by unfounded rumors stemming from natural disasters or epidemics

www3.nhk.or.jp

@hudebnik : make me shiver, those bad rumors.

@edano - me too, thank goodness they aren't true!

@edano - actually the events of the last few days have almost completely proved that the rumours/speculation about what happened when have been largely very accurate.

This board has an excellent record in that respect (thanks @all).

@pedro - well they were before it all melted down. The sensor position is shown on the Tepco graphic (if it's acccurate) as somewhere below the RPV.

My guess is that it is still inside the containment in all 3 reactors, but that the containment is breached in some way, maybe cracked. If the containment had a big hole in the bottom I reckon we would have had either a big bang or much higher ground/sea water readings.

@hudebnik I'm with you there. I'm still asking myself the same question... if the core would have mostly melted through there should be way higher radiation readings all around.

@pedro - well there are rather a lot of sensors giving very high readings in all 3 reactors, personally I can't imagine a situation in which, as they are all providing readings, they can ALL have failed at the same time. I believe they are specified to be robust enough to survive 'normal' disasters.

@Pedro Jesus : hey, they admiited meltdowns and holes in rpv two months ago. i don't think the corium would stay in there like waiting for the bus.