Saturday, January 18, 2014

#Fukushima I NPP Reactor 3: Water Leak from MSIV Room Could Be a Huge Problem for Nuclear Reactor Safety

(UPDATE 1/19/2014) New post with nuclide analysis result.


This is a follow-up on yesterday's post.

TEPCO released the video which was being taken by the robot on the first floor of Reactor 3 and which was being monitored by a TEPCO employee who noticed the water.

The flow looks significant and fast.

From TEPCO's photos and video library, 1/18/2014:

Location of the MSIV Room:

Radiation levels on the 1st floor of Reactor 3, from yesterday's post:

The main steam isolation valve (MSIV) is one of the two most important safety systems in a nuclear reactor (the other one being the control rod drive mechanism). It seals off the water/steam from the Pressure Vessel in case of an emergency (like a big earthquake). This MSIV system is not supposed to fail.

If the MSIV of Reactor 3 was damaged during the March 11, 2011 earthquake/tsunami (either one) and the water has been leaking ever since, the safety standard for nuclear reactors around the world may be impacted, says one nuclear researcher that I follow on Twitter.

(Oh wait... Does it mean then that part of the reason why the water (coolant) inside the Reactor 3 Pressure Vessel dried up was because it was leaking through the damaged MSIV?)

To get a feel for the size of the MSIV, here's a photo and a video from one of the top manufacturers, Flowserve:

The 1st floor of Reactor 3 is where the human workers ventured in in June 2011 for the first time since the start of the accident on March 11, 2011 and took the smear samples from the floor. The result of the analysis of the smear samples, if it was ever done, hasn't been released.

The location of the floor drain funnel is near the equipment hatch shield plug that was found slightly open, through which highly radioactive steam/water had been leaking. (TEPCO finally admitted the shield plug had been open on April 19, 2012, more than one full year after the start of the accident.)

Packbot was sent on November 18/19, 2011 to clean the hatch rail with what looked like a white towel. The result of the analysis of what the towel caught, if it was ever done, hasn't been released.

(Now I think about it, the towel Packbot was using was soaking-wet, and even on the next day after the cleaning the guide rails were very wet. I have assumed the water on the guide rails was from inside the Containment Vessel, but is it possible that it has been coming from the MSIV Room?)

From @BB45_Colorado, one of the nuclear researchers that I follow:


If the leak from (or from near) the Main Steam Isolation Valve is from the start of the accident, that means the MSIV couldn't withstand the earthquake and/or internal abnormal pressurization. This is bad in the heart of the BWR safety design. It could affect the safety reviews worldwide.

Browsing the articles by the mainstream media in Japan (eg. Yomiuri, Mainichi/Kyodo) on this incident, it seems to me that they don't know what MSIV is or its importance.


Anonymous said...

Good post. This does look significant coming from the area of Main Steam Isolation Vlv, however if I remember correctly aren't there expansion bellows in the room as well? If TEPCO is working to find the source of the leak I would hold off on further comment and conjecture until that determination. Au_Canary

Anonymous said...


What is the presumed flow path in the TEPvid?

".. there is no leak from the reactor building to outside.
There is no statistically significant change observed at the monitoring posts and in the plant parameters (amount of water injected into the reactors, temperatures .."

arevamirpal::laprimavera said...

Anon at 11:40PM, see the image below the video.

Anonymous said...

Curious looking stainless steel tubes or rods laying there. Wonder where they came from. Pins?

Anonymous said...

From the schematic the piping comes in from the Containment Vessel, so the vessel must be flooded to at least that level. 1st floor so it's not groundwater.

Anonymous said...

In April 2012 they had a camera in the same area, and there was not much water that time

This might indicate that the water leak has started after April 2012. Corrosion caused by seawater?

Unknown said...

Hello your blog is sharing great information.I read your blog. Thanks for share this blog, Belehy providing best كشف الشركة تسرب المياه
in Saudi Arab.

Unknown said...

في شركة شركة عزل فوم بالدمام نعمل قدر الامكان علي حل المشكلة واعطاء العميل فكرة كاملة عن الوضع وكذلك التكاليف المفترض دفعها مع العمل علي اصلاح وصيانة مكان التسرب فقط وليس البدء من الصفر داخل الحمامات او المطابخ كما نقدم في شركة شركة عزل فوم بالقصيم كافة خدمات الصيانة بعد الكشف ويشمل ذلك ( تكسير – اصلاح – ترميم ) كل ذلك بخدمات مميزة وفنيين علي كفائة عالية جدا ومعدات حديثة تضمن صحة النتائج لذلك تعد ركن نجد افضل شركة تسليك مجارى بالرياض
للمزيد يمكن زيارة
شركة تسليك مجارى بالخبر
شركة كشف تسربات المياه بالخبر
شركة كشف تسربات المياه بجدة

لمار للتسويق الالكتروني said...

من أكثر المشاكل التي تؤرق جميع ربات البيوت هي عملية تنظيف المطبخ لكثرة الاستخدام اليومي و المتكرر له بشكل مستمر فقد تتكاثر الدهون والمواد الزيتية على نقدم نصائح مميزة لخدمات التنظيف وخدمات مكافحة الحشرات للمحافظة على المنازل من تلك الأضرار الكبيرة الجدران والحوائط و الأرضيات مما يجعل عملية التنظيف صعبة جدا ، فنحن نوفر لجميع عملائنا من هم أهلشركة مكافحة حشرات بمحايل عسير
شركة مكافحة حشرات ببيشة
شركة تنظيف منازل بسراة عبيدة
شركة مكافحة حشرات بسراة عبيدة
شركة تنظيف بجازان

شركة مكافحة حشرات بجازان
شركة تنظيف خزانات بجازان <br

لمار للتسويق الالكتروني said...

شركة الأمواجد للخدمات المنزلية هي من أحسن وأفضل شركات التنظيف والمكافحة في المملكة العربية السعودية تواصل معنا الأن
شركة تنظيف فلل بابها

شركة تنظيف منازل بابها
شركة عزل اسطح بابها
شركة تنظيف شقق بخميس مشيط
شركة مكافحة حشرات بخميس مشيط
شركة تنظيف منازل بخميس مشيط
شركة رش مبيدات بخميس مشيط
شركة تنظيف خزانات بخميس مشيط
شركة تنظيف سجاد بخميس مشيط
شركة مكافحة حشرات بابها

لمار للتسويق الالكتروني said...

Al-Tamayoz Al-Janoubi Company for Home Services Cleanliness is one of the most important things that a person must pay attention to in order to protect the public health from the diseases that may affect the person because of the presence of piles of garbage, which may be close to the place of residence. The external environment is polluted and filled with very harmful microbes. The cleaning world is better than the treatment, and we in our company provide all our customers unlimited services, cleaning world, whether cleaning apartments, villas, houses, mosques, public institutions, government, companies, offices, Whatever you want to clean, we provide you with the fullest We have the best trained workers who do all types of cleaning.
شركة تنظيف منازل بخميس مشيط
شركة مكافحة حشرات بخميس مشيط
شركة تنظيف بابها
شركة تنظيف فلل بابها
شركة تنظيف منازل بابها
شركة مكافحة حشرات بابها

rukn eltatwer said...

A cleaning company in Al-Ahsa Corner of Development grants a public cleaning benefit in response to the will of the large number of customers, it is known that there are a large number of housewives who do not have the ability to sterilize their house or any place they own themselves, just as the female who do the cleaning do not get the required result in Cleanliness at the hands of classic methods, that is why we facilitate all this and provide a comprehensive cleaning manufacturer by our company Al-Ahsa Cleaning Company at the earliest time, with the smallest burden and the lowest price.
شركة تنظيف بالرياض
شركة مكافحة حشرات بالرياض
شركة تسليك مجاري بالرياض
شركة تنظيف مكيفات بالرياض
شركة تنظيف بالاحساء
شركة تنظيف مكيفات بالاحساء
شركة تسليك مجاري بالاحساء
شركة مكافحة حشرات بالاحساء

Anonymous said...

comprare patente
acheter permis de conduire en France
Comprar carta de conduçao
köpa körkort
kupiti vozačku dozvolu
Koupit řidičský průkaz
comprar carnet de conducir

Anonymous said...

Führerschein kaufen
comprar carta
acheter un permis de conduire
Führerschein kaufen
comprar carta de conduçao verdadeira
comprare patente b
rijbewijs kopen

Post a Comment