Tuesday, July 10, 2012

#Fukushima I Nuke Plant Reactor 3 Torus Room Survey Planned on July 11, 2012

TEPCO is sending 11 TEPCO employees and one robot (Survey Runner, which looks like a smaller version of Quince and has already gone inside Reactor 2's Torus Room in April this year - photo, video) down to the basement of Reactor 3 to survey the inside of the Torus Room. Planned radiation exposure for the human workers is 8 millisieverts.

No information of how long each worker will have to stay there to assist their robot co-worker. They won't go inside the Torus Room, as the very high radiation levels are expected inside. Instead, Survey Runner will go. The human workers will carry the robot through the narrow passage in the basement to the Torus Room door, which they will open for the robot.

8 millisieverts of radiation exposure. Before the Fukushima accident, it was rare even for the nuclear plant workers to get 1 millisievert exposure in one year. Now, the workers may get 8 years' worth of radiation in a day's work at Fukushima I Nuke Plant.

When the workers tried to enter the Reactor 3 Torus Room in March this year, the access door was warped and didn't open. The workers didn't stick around to open the door, because the radiation levels were probably too high for the work (it was 75 millisieverts/hour in front of the door). TEPCO sent workers again in June to measure the water level in the basement.

From TEPCO's handout for the press, 7/10/2012:

Investigation Outline

Purpose: As water leak investigation and water stop measure implementation are planned for the area from PCV / Reactor Building to the Turbine Building, it is critical to understand the current condition of the Torus Room. A robot will investigate the inside of Torus Room with high radiation dose to obtain inputs to be leveraged for planning the water leak investigation and water stop measures.

Investigation Items

The following will be done in the Torus Room in Unit 3 Reactor Building basement.
-Visual confirmation (Acquire photos and moving images)
-Dose rate measurement
-Collect sound samples in the Torus Room

Equipments: Remote control robot (Survey runner)
Members involved: 11 TEPCO employees
Investigation date: Wednesday, July 11, 2012

Planned expose dose
8 millisievert: 6 Carrying the robot through the triangle corner, opening doors
2 millisievert: 5 Robot operation, preparation

*Robot operation control is done in Unit 3 S/B (0.1mSv/h)


Anonymous said...

8 years dosage in less then as many hours, is that survivable ?

So if they need to do one years work of work, they'll need over 300 people who are willing to be dosed with 8 years worth of rads for their days work.

Will they be paid 8 years in wages for their sacrifice ?

8 years salary time 300 people a year, that's 2400 man years salary in one year.

This is not going to go well.

Anonymous said...

Additional maximum exposure coming from nuclear generation etc. for common population was 1 mSv/yr in Japan, before Fukushima. In theory still is.
For nuclear workers there are several limits; I believe one of them was 100 mSv for the whole life of the worker, temporarily raised to 250 after the accident (did workers get stronger?). Also there might have been a 5mSv limit that would grant a period of rest.

This is to put the 8mSv in a more precise perspective.

Having said so, walking volountarily in there knowing that the plan is to take 8mSv requires a fair dose of heroism.

Anonymous said...

Isn't the 8 millisieverts a guess based on what they think the exposure should be? I'm sure the salaried nuclear workers rarely saw 1 millisievert of exposure pre-Fukushima but I bet that wasn't and isn't the case for the Burakumin workers who do the actual dirty work around the plants.

I have been reading that the Japanese nuclear industry is scraping the bottom of the barrel to find enough workers to continue the cleanup and one of the methods they are using is to fudge the exposure numbers for the contract labor. Add to this many Burakumin hide their exposure levels in order to work longer hours because they need the money more than their health.

Anonymous said...

heres the rules as i remember them

avg dose for most workers normally never exceeded 1 mSV.

allowed annual dose for radition workers was 20 mSV without
restricitions on annual basis
, normal work limit was one time 100 mSV then forcibly retired to non-rad work.

Emergency one time dose was 250 mSV but required signoff by plant manager and forcible retirement of worker.

so if you work there for say 2 days then you have to go on leave for a year, so they need some 180 teams they can rotate.

Anonymous said...

Saying 180 teams is tantamount to saying they cannot go in there -- unless they start using the Chernobyl model; forget the robots and involve a huge number of people: pay them for 30min work and see them again in a year.
Also, I believe there were talks about revising the regulations for radiation "workers" (radiation cannon fodder?), including those handling radioactive debris but I do not know how they have been changed. I would not be surprised if they allowed more exposure.

Anonymous said...

@5:48 I doubt very much that if they get 20mSv (one year max exposure) they will get one year pay. Furthermore, unless workers are hired permanently, their employer will not have to find them another job for the rest of the year and, assuming the temp worker is someone in his sixties out of a job, there is a fair chance he will not be a burden on the national health system either :(

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