Fukushima Update - Things Not Settled , Not Resolved At All

When is a cold shutdown not cold at all ?

So much for "cold shut down" and "end of the accident". Maybe the reactor didn't like the endoscopy done in January...

From FNN News (2/5/2012):

福島第1原発2号機の原子炉の温度が、2月2日以降、上昇を続けていて、東京電力は5日未明、原子炉への注水量を増やし、温度が低下するか確認することにしている。

Temperature of the Reactor Pressure Vessel of Reactor 2 at Fukushima I Nuclear Power Plant has been rising since February 2. TEPCO will increase the amount of water being injected into the reactor to see if that lowers the temperature.

2号機の原子炉圧力容器下部の温度は、2月2日におよそ52度だったが、その後、上がり続けていて、5日午前5時の時点で67.4度と、およそ15度上昇している。

The temperature at the bottom of the Reactor Pressure Vessel of Reactor 2 was about 52 degrees Celsius on February 2, but it kept rising. As of 5AM on February 5, it was 67.4 degrees Celsius, 15 degrees increase.

これを受けて、東京電力は5日未明、原子炉への注水量を1時間あたり8.6トンから9.6トンに増やし、温度が低下するか監視するとしている。

On February 5 TEPCO increased the amount of water injected into the reactor from 8.6 tonnes/hour to 9.6 tonnes/hour to see if it lowers the temperature.

原因について東京電力は、現時点で明確にはわからないとしているが、「冷温停止状態」の判断には影響はないとしている。

TEPCO says it doesn't know what is causing the temperature to rise, but says it doesn't affect the decision of "cold shutdown state".

According to the latest plant parameter data from TEPCO, the temperature at the bottom of the RPV of Reactor 2 at 11AM is 68.6 degrees Celsius, up over 1 degrees from 5AM.

By the way, the temperature at the CRD Housing Upper Part, which went up to 142 degrees on January 14, and dropped down to -197 degrees on January 19, is now back up at 124.7 degrees Celsius ("instrument failure", according to TEPCO):By the way, the temperature at the CRD Housing Upper Part, which went up to 142 degrees on January 14, and dropped down to -197 degrees on January 19, is now back up at 124.7 degrees Celsius ("instrument failure", according to TEPCO):

Here's what TEPCO said in the handout for the press on February 4, 2012:

【Unit 2】19:20 on February 3: To improve reliability of water injection to the reactors, the injection line connecting to the reactor injection pump on the hill was replaced with polyethylene pipes and we have been changing the route for reactor injection from feed water system to reactor core spray system in a stepwise manner. After completion of adjusting water flow amount as planned on February 2, tendency of temperature rise at the bottom of PCV was observed. Thus, we changed the injection amount into Unit 2 reactor through feed water system from 2.9 m3/h to 4.9 m3/h and changed that though reactor core spray system from 5.8 m3/h to 3.8 m3/h . As for the temperature rise, the temperature at the upper head of the bottom of PCV has risen to approx. 67.2 ℃ at the highest (as of 4 pm on February 4: reference), but currently, it is approx. 65.1℃*1 (as of 5 pm on February 4). The trend of the temperature seems to be going flat and we will monitor it continuously.

The worker who tweets from Fukushima I Nuke Plant is more worried about Reactor 2 than Reactor 4.

and....

Skimmer surge tank level decreasing very rapidly at reactor 4

Posted by Mochizuki on February 4th, 2012 · 3 Comments

Following up this article ..2 Sv/h from leaked water

According to plant parameter data of Tepco, the water level of skimmer surge tank has been decreasing very rapidly since around 1/30/2012.

It has been in the decreasing trend since the beginning of this year for some reason.
It has been slowly decreasing, but it picked up on 1/20/2012.
However again, it started falling off from 1/30/2012.

Tepco asserts it’s because a part of the pool was damaged by frozen water. Whatever the reason is, there is a major damage to reactor 4.