TEPCO Update 3/22

TEPCO has released a statement on water spraying operations — apparently they are using a cement spraying pumping truck.  I had no idea such a thing existed.

TEPCO Earthquake Information Update on March 22: Fukushima-Daiichi Status

Dear Friends,

Please see updates at Fukushima-Daiichi NPS.

(1) Atmospheric Radioactivity in Fukushima-Diichi site area
(2) Result of additional radioactive material survey in the seawater around Fukushima-Daiichi NPS
(3) Off-Site Power restoration status: Unit 3 main control room light recovered.
(4) Water spray to 1F-4 spent fuel pool using a large concrete pumping vehicle.

Contacts:

TEPCO Washington Office
Kenji Matsuo, Director and General Manager
Yuichi Nagano, Deputy General Manager,
Masayuki Yamamoto, Manager, Nuclear Power Programs

(1) Atmospheric Radioactivity in Fukushima-Diichi site area

TEPCO has reported NISA and Fukushima prefecture on detection of atmospheric radioactivity in Fukushima-Daiichi NPS. TEPCO sampled air on March 19, 20 and 21, then identified radioactivity exceeded the limit for radioactive workers (Japanese law stipulates limit of atmospheric radioactivity concentration for three months average not exceeding 50 mSv even if workers breath this air one year)

Iodine-131 concentration was relatively high, 2.30 times of the limit for March 20 sample and 1.52 times for March 21.

Normal radioactive plume discharge concentration is 5 x 10E -6 Bq/cm3 for Iodine-131. (this value is equivalent to 1mSv if breath the air one year.)

We believe this level of radioactive concentration is not an immediate danger, but we will continue to monitor atmospheric radioactivity and workers have already equipped with charcoal mask.

(2) Result of additional radioactive material survey in the seawater around Fukushima-Daiichi NPS

On March 21st 2011, radioactive materials were detected from the seawater around the discharge canal (south) of Fukushima Daiichi Nuclear Power Station.

TEPCO had conducted re-sampling survey in the wide range of area to examine the effect of radioactive materials in the seawater. Details are as follows;

(3) Off-Site Power restoration status as of 11:00pm March 22nd

The power restoration work was started around 8:00 am. All the cable installment tasks have been completed by the morning of March 22nd (between 8:00 am and 10:30 am). The soundness test is still under progress. It is difficult for us at this moment to clearly decide when the work will be completed.

Current status:

(Unit 1/2)

Reestablishment of power cable to the existing receiving equipment in Unit 2 building has been completed. Soundness test of the equipment and facilities inside Unit 2 building is under progress. As such, the main control room and other equipment inside have not yet been energized.

(Unit 3/4)

“Connection” of power cable to the temporary receiving equipment on the site has been completed.

At 10:35 am, tests to energize between the temporary receiving equipment and the existing receiving equipment in Unit 4 have been completed. Currently the test has been conducted for the equipment at load side.

Unit 3 main control room recovered power for lighting at 10:43 pm on March 22. The power has not been supplied to equipment in the building.

(Unit 5/6)

Reestablishment of power to the existing receiving equipment in Unit 5 and 6 buildings has been completed. The central control center and Residual Heat Removal system which is necessary to cool the reactor are being energized.

(4)Water spray to 1F-4 spent fuel pool using concrete pumping vehicle.

A concrete pumping vehicle sprayed 150ton seawater to spent fuel pool at unit 4, from 5:17 pm to 8:30 pm on March 22. TEPCO has decided to use this concrete pump for spent fuel cooling on March 18, since then we trained workers for the operation as well as to bring the vehicle to the power station under the severe road conditions due to the quake.

The radiation level around the site was 3.0 – 10.0 mSv/hr.

Though we think the concrete pumping vehicle is very effective, we will continue to take all measures to conduct the restoration work with the cooperation of organizations involved.

A camera was set at the end of the water spray arm. We will assess the status of the pool after the spray this time when we retrieve the camera.

 

This vehicle is designed to inject concrete at high elevation.

– Width of the vehicle: approximately 2.5m
– Length of the vehicle: approximately 15m
– Weight of the vehicle: approximately 55 tons
– Length of the arm: approximately 58m
– Discharge rate: approximately 0 to 160 tons per hour
– Manufacturer: Putzmeister (Germany)