Tuesday, March 13, 2012

TEPCO Is Sending Its Own Employees to Survey the Basements of Reactors 2 and 3 at #Fukushima

Expected radiation exposure for the 30-minute work: 10 millisieverts per person.

The 4 workers (2 each for each reactor, I assume) will measure radiation levels, temperatures and humidity, water level, and take pictures.

The torus (Suppression Chamber) of Reactor 2 is considered to have sustained a damage on March 15, though TEPCO says it was not an explosion. TEPCO and NISA both agree that Reactor 2 has released the most radioactive materials, some of which though may have come from the dry vent.

From TEPCO's handout for the press in English, 3/13/2012:

Field Survey on the semi-basement floor of the reactor building
of Unit 2 and 3 at Fukushima Daiichi Nuclear Power Station

◎Survey Purpose

In order to grasp the leakage route (damaged part) of the reactor cooling water in the torus room*, the inflow part of the groundwater into the torus room and working circumstances in the torus room, we are planning to conduct survey in the torus room in the future. This time we are planning to conduct field survey of the semi-basement floor of Unit 2 and 3 which connects to the torus room as the preliminary survey. (The reactor building of Unit 1 is exempt from this survey because the water level of the accumulated water is higher than semi-basement floor.)
*Torus room: The room that holds large torus-shape suppression chamber which store water for Emergency Core Cooling System. It is located at the bottom of the Primary Containment Vessel and around it.

◎Survey contents (Plan)

・Measurement of air dose, dust density, temperature and humidity and taking pictures on the semi-basement floor of the reactor building
・Confirmation of opening and closing condition of gate of the torus room and measurement of door surface dose
・Confirmation of water level at stairway which connect to the basement floor of the reactor building and any obstacles

◎Working Organization (Plan)

・Survey date: March 14, 2012 12:00~12:30
・Worker: Four TEPCO staffs
・Expected dose: 10 mSv/person
・Place: Northeastern and northwestern corner on the semi-underground floor of the reactor building of Unit 2, northeastern corner on the semi-underground floor of the reactor building of Unit 3

The expected dose of 10 millisieverts is high. TEPCO is using own employees for works at high radiation locations. Probably many of the employees of the affiliate companies have already maxed out on the annual dosage limit and waiting for a reset on April 1.

The worker who tweets from Fuku I said in his tweet from yesterday that there are workers wearing tungsten vests on the operation floor of Reactor 3 building, removing the debris.

Carbon-based workers acting as robots.


Anonymous said...

10 sieverts

Outbound said...

Ikut menyimak artikelnya :-)


Steve From Virginia said...

I guess they will find out soon enough how much water is in the basement level of unit 2. According to their own info there are 9 tons of water pumped into the reactor every hour, this has to go somewhere, it isn't at the bottom of the drywell:


This comes across as more Tepco nonsense, there isn't a strategy behind the expedition. They could drill holes in the first floor safely and lower video cameras and telemetry into the torus room from above. First thing is they would learn if there was any corium in the basement.

The ideal would be to map the corium and determine its condition. If the corium is inside the building and underwater it would make it easier to set priorities and make realistic removal plans.

Just having people wander around in the basement -- provided this is possible -- just exposes workers needlessly IMHO.

Anonymous said...

@Anonymous 7:58pm - It will be 10 sieverts but they won't say that until 10 months later ...

steve the jew said...

wow, it only took 12 months to start officially sacrificing people... who ever said the soviets weren't more efficient than the japanese??!!

Atomfritz said...

I suppose there won't be any worrying radiation counts above 1 Sievert as Tepco usually takes much care that the maximum range of the dosimeters is not too high, just to avoid "baseless" worries.

We still don't know about the actual radiation at the water pools (meter maxed out at 1 Sv) or the vent stack (meter maxed out at 10 Sv) as Tepco seems to be notorically incurious to re-check with meters of appropriate range.

Wouldn't even wonder if the workers at top of unit 3 are equipped with normal cheap particulate filters instead of carbon air filters.

But we can probably be sure that they have to wear the dosimeters at their chest to avoid them meter the high radiation at floor level.

Andrew Spagnoli said...

I have heard of putting the dosimetry badges inside the boots or under the arm inside the clothing... they have all sorts of cute tricks to hide excessive worker doses. Some workers desperate for the money hide doses from management and regulators (who are quite happy to believe the lies). Some workers are bullied or tricked into accepting larger doses or altering records...

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