#Fukushima I Nuke Plant: Alpha Nuclides Found in Condensed Water from Reactor 3's PCV Gas Control System

As the sudden and renewed media attention (latest I found today was from Bloomberg News, informing the readers about that "300 tons of water laced with radioactive particles") is being focused on contaminated water (highly contaminated water in the underground trenches, low-contamination water in the observation holes along the embankment which is a reclaimed land along the ocean) at Fukushima I Nuclear Power Plant, there are other curious surveys and examinations being done at the plant, without any media attention.

The probe of Reactor 2's Containment Vessel into the pedestal area is one. Here, I think, is another.

On August 12, 2013, TEPCO announced the result of the alpha-nuclide analysis of condensed water from the gas control system of Reactors 1, 2 and 3. I believe this is the first time that TEPCO has ever tested alpha nuclides in gas/condensed water coming out of any Containment Vessel.

All-alpha was not detected in the condensed water from the gas control system of Reactors 1 and 2, but there was a small amount of all-alpha, max 0.19 Bq/cm3 (cubic centimeter) detected from the condensed water from the gas control system of Reactor 3.

Reactor 3 was using MOX-fuel with extra plutonium as part of fuel when it was shut down on March 11, 2011.　32 MOX-fuel assemblies were installed in the fuel core when Reactor 3 was restarted in October 2010 after a scheduled maintenance.

From TEPCO's handout for the press in English, 8/12/2013:

Sampling Results (All α) of Condensed Water at Unit 1-3 PCV Gas Control System (the Entrance of HEPA Filter) in Fukushima Daiichi Nuclear Power Station

TEPCO had done the nuclide analysis for condensed water for gamma nuclides (including radioactive cesium) back in June, and there was no statistical difference between the reactors.

Even though TEPCO hasn't identified which alpha nuclides were found in the condensed water from the Reactor 3 gas control system, it seems the company suspects the contamination of Reactor 3 building may be different from that of other reactor buildings, which may pose problems in the future decontamination work.

TEPCO has been injecting nitrogen gas into the Primary Containment Vessels of Reactors 1, 2 and 3 to prevent the concentration of hydrogen gas. The gas control system with HEPA filter has been installed to treat the gas being pushed out of the PCV, and there are particulate filters and charcoal filters to collect radioactive materials in the gas. There are also drains to collect condensed water.

The nitrogen injection system and the gas control system of Reactor 3 were installed in July 2011, with TEPCO workers and affiliate company workers getting 5.34 millisieverts radiation for 9-minute work. The hose for the nitrogen injection had to be installed in the area with 55 millisieverts/hour radiation.

(There are several, curious loose ends about Reactor 3. I'm writing a post for my record.)

Tweet

#Fukushima I Nuke Plant Reactor 3: Radiation Level Gone Up Since November Last Year, to 4.78 Sieverts/Hr Near NE Equipment Hatch

TEPCO sent in Packbot and Quince 2 on November 27 to check the soundness of the PVC Gas Management System duct which runs above the guide rails for the equipment hatch in the northeast corner of the Reactor 3 building.

For the work that lasted for one hour and 40 minutes, Packbot received 650 millisieverts, and Quince 2 received 185 millisieverts. Their human coworkers who operated them received maximum 0.52 millisieverts, according to TEPCO's press release on November 28, 2012.

It's the same location where Packbot was sent in twice, in November last year, first to clean the guide rail of the equipment hatch on the northeast corner of the Containment Vessel, then to check up on its cleanup job (radiation levels went up).

It is also the same equipment hatch that TEPCO finally admitted had been open, probably since March 2011.

In 12 months, the radiation level at one location near the surface of the guide rail has gone from 1.3 sieverts/hour to 4.78 sieverts/hour. At 40 centimeters off the floor along the guide rail, the radiation levels now exceed 1 sievert/hour.

From TEPCO's Photos and Videos Library (Japanese), 11/28/2012:

So, that means TEPCO used the human workers to install this duct in the environment of extremely high radiation to guide the air from inside the Containment Vessel and feed it to the system that removes radioactive materials, while the equipment hatch there was and is open, leaking radioactive water.

And the company and the national government who owns it refuse to give free annual cancer checkups for 96.3% of workers.

But not to worry. Anti-nuclear citizens on Twitter are dancing a happy dance with the creation of a new party called "Japan's Future Party", promising fairy tales including "graduating from nuclear power".

Reality is too bleak.

Tweet

Slowly Degrading #Fukushima I Nuke Plant: Leak from Reactor 3 Gas Management System, Patched Up With Tape (Temporary I Hope)

Meanwhile in TEPCO land in Fukushima, it's a steady stream of slowly degrading systems and equipment that were hastily assembled last year.

According to TEPCO's plant status report on June 19, 2012 (Japanese only; there is no English version), a TEPCO worker noticed a hissing sound coming from the flexible duct from the Reactor 3 Containment Vessel Gas Management System on June 19 at about 12:19PM. The Gas Management System is located on the 1st floor of the Reactor 3 turbine building. The duct had been damaged for some unknown reason, and TEPCO says the damage has been temporarily patched up with tape while the cause is being investigated. The company says there has been no effect on the pressure inside the Containment Vessel, the amount of hydrogen gas inside the CV, or the amount of gas flowing through the Gas Management System.

TEPCO's handout for the press (6/19/2012):

Tweet

#Fukushima I Nuke Plant: Video of Packbot Cleaning Reactor 3's 1st Floor in Extremely High Radiation

Why? Because TEPCO is going to send carbon-based workers to install the gas management system to purify the gas coming from inside the Containment Vessel.

Utterly meaningless endeavor as far as I am concerned. What good would cleaning the gas in the Containment Vessel do, when just outside the CV you measure 620 millisieverts/hr radiation? Something more deadlier than xenon and krypton is outside the CV, and the company is willing to risk both non-carbon based worker (Packbot) and carbon-based co-workers in order to keep up the appearance that everything is under control at the plant.

Nonetheless, here's the effort by Packbot on November 2, when it removed the junk out of the way, as released by TEPCO on November 5. Actually, TEPCO used 3 Packbots on November 2 and 3 for the work, according to Jiji Tsushin (11/5/2011):

You can also see the "before and after" photos in TEPCO's handout for the press on November 5. From that handout, here's the radiation on the 1st floor where Packbot had to work to prepare for the gas management system (north-east corner of the 1st floor):

For human co-workers of Packbot, working near that 620 millisieverts/hour location (which is unavoidable) for one minute would get them over 10 millisieverts radiation, or every one second 172 microsieverts.

Any volunteers? (Dr. Allison of Oxford University, maybe?)

Tweet