Fuel Handling Machine potentially opening the door of SFP3 to the reactor vessel

On 3/26/2015, Tepco announced they found FHM (Fuel Handling Machine) dropped into SFP3 (Spent Fuel Pool of Reactor 3) in 311 and it’s “touching” the door to PCV (Primary Containment Vessel).

Tepco is planning to remove the fuel assemblies from SFP in the first half year of 2015. Is it reported that the pool stores 514 spent fuel assemblies and 52 new assemblies.

 

This April, Tepco is supposed to remove one of the major debris, FHM. In the precedent inspection, they found the dropped FHM is possibly deforming the part called “gate”, which separates SFP3 and PCV.

The gate is designed to seal SFP water by 44t of pressure. However in the process of removing FHM, it can lose the sealing function to leak water.

Tepco comments they still have no alternative way when the gate loses the water sealing function.

 

http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/d150326_10-j.pdf

https://www.pref.fukushima.lg.jp/sec/16025c/genan10.html

 

 

_____

Français :

Réacteur 3 : la machine à manipuler les combustibles peut casser la porte entre la SFP3 et l’enceinte du réacteur

 

Le 26 mars 2015, Tepco déclare qu’ils ont découvert qu’en mars 2011 la FHM (Fuel Handling Machine = machine de manipulation des combustibles) était tombée dans la SFP3 (Spent Fuel Pool of Reactor 3 = Piscine à combustibles usagés du réacteur 3) et qu’elle “s’appuie” sur la porte de la PCV (Primary Containment Vessel = Enceinte de confinement primaire).
Tepco prévoit de retirer les assemblages de combustible de la SFP3 au cours du premier semestre de 2015.

Il est rapporté que cette piscine contient 514 assemblages de combustible usagé et 52 assemblages neufs.

Tepco est supposé retirer un des plus grands gravas, la FHM, en avril prochain. Lors de l’inspection précédente, ils avaient découvert qu’elle avait probablement déformé ce qu’ils appellent la “porte” séparant la SFP3 de la PCV.
Cette porte est conçue pour bloquer de façon étanche, jusqu’à 44 tonnes de pression, l’eau de la SFP3. Cependant, au cours de l’opération de retrait de la FHM, cette étanchéité pourrait être compromise et la piscine se vider alors dans l’enceinte du réacteur.
Tepco déclare qu’ils n’ont aucune solution de secours si cette porte perdait son étanchéité.

http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/d150326_10-j.pdf
https://www.pref.fukushima.lg.jp/sec/16025c/genan10.html

About this site

This website updates the latest news about the Fukushima nuclear plant and also archives the past news from 2011. Because it's always updated and added live, articles, categories and the tags are not necessarily fitted in the latest format.
I am the writer of this website. About page remains in 2014. This is because my memory about 311 was clearer than now, 2023, and I think it can have a historical value. Now I'm living in Romania with 3 cats as an independent data scientist.
Actually, nothing has progressed in the plant since 2011. We still don't even know what is going on inside. They must keep cooling the crippled reactors by water, but additionally groundwater keeps flowing into the reactor buildings from the broken parts. This is why highly contaminated water is always produced more than it can circulate. Tepco is planning to officially discharge this water to the Pacific but Tritium is still remaining in it. They dilute this with seawater so that it is legally safe, but scientifically the same amount of radioactive tritium is contained. They say it is safe to discharge, but none of them have drunk it.

Categories

March 2015
M T W T F S S
 1
2345678
9101112131415
16171819202122
23242526272829
3031