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Japan Earthquake: nuclear plants

 
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Jun3-13, 07:36 PM   #14009
 

Japan Earthquake: nuclear plants


Quote by zapperzero View Post
I'm not part of that consensus. Water is supposed to be self shielding and so only gamma radiolysis yields are taken into account; no-one has seriously addressed the possibility of localized boiling on the surface of fuel elements which would have increased H2 production as lots of beta radiolysis would also take place.
Betas do not penetrate fuel cladding.
Jun4-13, 01:23 AM   #14010
 
Quote by nikkkom View Post
Betas do not penetrate fuel cladding.
So, in your considered opinion spent fuel rods do not give off beta?
Jun4-13, 04:34 AM   #14011
 
Quote by zapperzero View Post
So, in your considered opinion spent fuel rods do not give off beta?
Spent fuel rods certainly emit beta particles.
Even my desk emits beta particles.
I probably need to run away in terror?
Jun4-13, 06:45 AM   #14012
 
Quote by nikkkom View Post
Spent fuel rods certainly emit beta particles.
Even my desk emits beta particles.
I probably need to run away in terror?
You probably need to educate yourself a bit (just how many beta particles? what yields?) and maybe just maybe consider a change of tonality. This one is rather grating.
Jun4-13, 08:57 AM   #14013
I_P
 
Thanks for that translation Tustsuji, I hope they make some progress with their inquiry and are able to resolve some of those outstanding questions - or at least shed some additional light.

Regarding the earthquake damage - I recall reading that there were radiation alarms set off before the tsunami arrived and as the "remaining questions" list shows the state of the cooling apparatus immediately following the earthquake remains in doubt.

Clearly also there are unresolved issues about the source of hydrogen that fueled the explosion at unit 4.
Jun4-13, 08:57 AM   #14014
I_P
 
dbl post again - must remember to explicitly log in before trying to post a reply. Any help on guidelines/tips for posting images to the thread would be appreciated.
Jun4-13, 02:15 PM   #14015

Nuclear Engineering 2012
 
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http://www3.nhk.or.jp/news/genpatsu-..._chikasui.html Heeding to a remark by a Nuclear Regulaton Agency officer, Tepco performed a more precise measurement of the groundwater intended for release into the sea. In the past, Tepco said that the cesium 137 concentration was lower than the detection threshold. Now Tepco is providing a measurement of 0.39 Bq/l . This is lower than Tepco's internal standard of 1 Bq/l and lower than the legal requirement of 90 Bq/l. There is no prospect of starting the releases as the local fishermen have been resisting. Tepco said "we are going to politely explain to the local inhabitants that this is lower than our internal standard".

Any help on guidelines/tips for posting images to the thread would be appreciated.
What do you want to know ? If the picture is on your computer, you may use the "manage attachments" button below the edit box. If the picture is online you may type the image URL and insert it between [ I M G] [/ I M G] tags (or click on the icon above the edit box).
Jun4-13, 09:05 PM   #14016
I_P
 
This is the image I tried to post on the previous page showing the spike in emissions after march 20th:
Attached Thumbnails
Ibaraki_rad.jpg  
Jun4-13, 09:07 PM   #14017
I_P
 
"manage attachments" worked. I tried the url and [ I M G ] tags last time and it didn't seem to work for me. Thank you Tsutsuji
Jun5-13, 10:10 AM   #14018

Nuclear Engineering 2012
 
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Quote by tsutsuji View Post
http://www3.nhk.or.jp/news/genpatsu-..._kiseicho.html The NRA is starting an inspection on 30 May to investigate accident causes. They will go to unit 1 and check the circumstances of a water leak that had been reported by an employee before the tsunami struck, and whose cause remains unknown. Because of radiations, the inspection on unit 1's 4th floor, to be performed by 5 Nuclear Regulation Agency employees on 31 May will be limited to about 10 minutes. On May 1st they held their first meeting and discussed the possibility that earthquake damage took place in a unit 1 cooling system. The purpose of the inspection is to check the validity of the explanation that water from the pool flowed into the air conditioning system, by looking for equipment damage. The second meeting will be held in the beginning of June.
http://www.asahi.com/national/update...306040838.html The NRA released two pictures of the inspection on unit 1's 4th floor.

http://www3.nhk.or.jp/news/genpatsu-...10_koukai.html They took hundreds of pictures and a 40 minute long video. Maximum exposure was 4.8 mSv. Results of this inspection will be announced at the second study group meeting.

http://www3.nhk.or.jp/news/genpatsu-...10_koukai.html A patrol found a leak from an above-ground tank at 00:15 PM today. The rate was about one drop every 3 or 4 seconds. The leak was stopped about 4 hours later as a result of tightening bolts and transferring part of the water to another tank. The total amount is about 1 l.

http://www.tepco.co.jp/nu/fukushima-...30605_08-j.pdf Leakage from flange of G6 area tank (cylindrical metallic tank)
Jun5-13, 04:35 PM   #14019
 
Quote by tsutsuji View Post
The NRA released two pictures of the inspection on unit 1's 4th floor. [...]They took hundreds of pictures and a 40 minute long video. Maximum exposure was 4.8 mSv. Results of this inspection will be announced at the second study group meeting.
Wooo. Yet another visit and video of unit one's 4th floor. I still don't know what they were looking for during the last two visits but I find them fascinating.
Jun5-13, 05:27 PM   #14020
 
During the May inspection, the investigators were able to remain on the fourth floor of the building--where the condensers were installed--for only 15 minutes due to high levels of radiation, which were measured at 20-30 millisieverts per hour.
http://ajw.asahi.com/article/0311dis...AJ201306050085
What can you learn in 15 minutes.?

Sorry, but this is ridiculous.
No one checked the availability of water in the tanks themselves, checked only tool the water.

In addition, it is clear that the valve (outside) need to be opened by hand, very quickly.
03.11.2011. Just 1.5 hours was in stock.
then on top of the reactor accumulated non-condensable gases and end all.
the condenser air pocket, it does not work.............
.
Jun6-13, 08:59 AM   #14021
I_P
 
What can you learn in 15 minutes.?

Sorry, but this is ridiculous.
I think the idea was to photograph and record video of relevant areas and to analyze the pictures after the fact. They had specific questions so the photography should have been well targeted.

We will see what they come up with.
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