Tepco Successfully Removes First Nuclear Fuel Rods at Fukushima
Source: Bloomberg
Tokyo Electric Power Co. (9501) successfully removed the first nuclear fuel rods today from a cooling pool at the wrecked Fukushima nuclear plant, an early milestone in decommissioning the facility amid doubts about whether the rods had been damaged and posed a radiation risk.
The first of the fuel-rod assemblies at the plants No. 4 reactor building was transferred from an underwater rack on the fifth floor to a portable cask just before 4 p.m., the utility known as Tepco said in an e-mailed statement.
Tepco planned to remove 22 assemblies from the pool, which contains 1,331 spent fuel assemblies and 202 unused assemblies, by the end of tomorrow, the company said. Crews are beginning with the unused assemblies because they are less fragile, spokesman Yusuke Kunikage said by phone.
The operation is the most significant test to date of Tepcos ability to contain the threat stemming from the worst nuclear disaster since Chernobyl. Were the rods to break or overheat, it could prompt a self-sustained nuclear chain reaction similar to the meltdowns at three Fukushima reactors following the March 2011 earthquake and tsunami.
<snip>
Read more: http://www.bloomberg.com/news/2013-11-18/fukushima-plant-fuel-rod-removals-to-begin-today-tepco-says.html
truthisfreedom
(23,148 posts)Why the hell are they disassembling it now? I'm headed to Japan on Thursday and I'd like to live, please!
Demeter
(85,373 posts)After all, it's been three years already, almost. It's a ticking time bomb.
bananas
(27,509 posts)I assume you're referring the euronews article here: http://www.democraticunderground.com/1014649672
That euronews article was very poorly written and gave the wrong impression.
It mentions two separate delays:
1)
"The operators of the crippled Fukushima nuclear plant have postponed the extremely complicated and difficult task of removing damaged atomic rods."
I think that refers to the two-week delay that just ended - TEPCO was originally going to start moving the fuel two weeks ago, but realized they should do some practice runs first.
2)
"The inital plan called for the clean-up in the affected towns to be finished by March this year but the government now says the work will be delayed by as much as three years."
This 3 year delay is for decontaminating the surrounding towns, not for removing the spent fuel rods.
There's also a lot of other work to be done - for example, there are several more spent fuel pools.
freshwest
(53,661 posts)As reported along Canada's west coast, not far away. A few posters had concerns it was radioactive pollution from Fukushima.
The scuba diver last went in September with a group and they found nothing out of the ordinary. It's hard to tell with some of these stories, but the Canadian report seemed reputable. They didn't attribute it to Fukushima.
Also, if Japan was going to be 'goodbye' as another thread said it would if the clean up fouled up, why send Caroline Kennedy to get a lethal dose.
Still I want this thing gone and nothing like it resurrected in any area on the Rim of Fire.
Bennyboy
(10,440 posts)I confirmed those reports of them starting work this week on Friday....
Katashi_itto
(10,175 posts)bananas
(27,509 posts)yuiyoshida
(41,831 posts)However, there are many, many fuel rods to be removed manually, and lets hope they can keep their record up!
Katashi_itto
(10,175 posts)dixiegrrrrl
(60,010 posts)this photo, which was taken inside of the crippled Unit 4 reactor building,
showing a orange safety cone which has been flipped upside down to direct leaking materials into a hose which has been attached with duct tape.
http://enenews.com/photo-dangling-rolls-of-duct-tape-upside-down-orange-traffic-cone-used-to-manage-leaking-material-at-fukushima-unit-4
Psephos
(8,032 posts)Brother Buzz
(36,444 posts)According to scientists at Lawrence Berkeley National Laboratory, there's one thing duct tape is no good for: taping ducts.
Sealing HVAC Ducts: Use Anything But Duct Tape
August 17, 1998
By Paul Preuss, [email protected]
BERKELEY -- You can keep your trouser cuff out of your bicycle chain with duct tape; if you need a money belt, you can use it to strap your money to your tummy. Some people claim they can cure warts with it. Unfortunately, one of the things you can't do with duct tape is seal ducts.
At least not for long, according to Max Sherman and Iain Walker of the Department of Energy's Lawrence Berkeley National Laboratory. For three months they tested a variety of sealing materials -- many kinds of duct tape, clear plastic tape, foil-backed tape, mastic, and injected aerosol sealant -- under conditions similar to those encountered in real heating, ventilating, and air-conditioning (HVAC) systems.
"We tried as many different kinds of duct sealants as we could get our hands on. Of all the things we tested, only duct tape failed. It failed reliably and often quite catastrophically," says Sherman, who heads the Energy Performance of Buildings Group in Berkeley Lab's Environmental Energy Technologies Division (EETD). "On the other hand, while duct tape may not last long as a sealant, in the short run it is strong, sticky, and fairly easy to use."
During World War II, before it was called duct tape, the U.S. military bought quantities of the cloth-backed, rubber-adhesive tape for making emergency repairs on the battlefield. In the movie business it's called "gaffer's tape," used for everything from bundling cables to holding sets together. Contractors, however, are not supposed to use it for structural purposes, such as suspending ducts -- although this legal stricture may often be honored in the breach.
<more>
http://www.lbl.gov/Science-Articles/Archive/duct-tape-HVAC.html
tomm2thumbs
(13,297 posts)dixiegrrrrl
(60,010 posts)bananas
(27,509 posts)NHK: Fuel removal at Unit 4 underway BBC: Concern casks not watertight, rods would contact air WSJ: Exposure to air can cause sustained nuclear reaction AFP: Tokyo evacuations if uncontrolled nuclear conflagration? AP: Rods contain plutonium, experts concerned quake to hit during process
Published: November 18th, 2013 at 3:40 am ET
By ENENews
12 comments
NHK, Nov. 18, 2013: The operator of the Fukushima Daiichi nuclear power plant has begun removing nuclear fuel from a storage pool at a damaged reactor building. Workers placed a special fuel transport container in the storage pool ... At around 3PM on Monday, the workers started to hoist the unused fuel units into the steel container ... debris in the pool of the Number 4 reactor building could obstruct the work. ... The removal work requires extreme caution, as any damage to the units could release high-level radiation.
WSJ, Nov. 18, 2013: We plan to begin the removal process from around 3 pm today, and work until around 7 pm, said Tepco spokesman Tsuyoshi Numajiri. ... The units are kept in a pool of cool water to prevent exposure to air, which can cause the radioactive material to heat up and could trigger a sustained nuclear reaction.
BBC, Nov. 18, 2013: (It's a critical issue) whether the casks remain watertight so the rods have no contact with air.
AFP, Nov. 18, 2013: Each rod contains uranium and a small amount of plutonium. If they are exposed to the air ... they would start to heat up, a process that, left unchecked, could lead to a self-sustaining nuclear reaction known as criticality. ... Sceptics say with so many unknowables in an operation that has never been attempted under these conditions, there is potential for a catastrophe. Government modelling in the immediate aftermath of the Fukushima disaster ... suggested that an uncontrolled nuclear conflagration at Fukushima could start a chain reaction in other nearby nuclear plants. That worst-case scenario said a huge evacuation area could encompass a large part of greater Tokyo ...
AP, Nov.18, 2013: ... (Experts) raised concern about a major earthquake hitting during the removal work. Japanese nuclear engineers were on Monday preparing to move uranium and plutonium fuel rods at Fukushima ... Experts have warned that slip-ups could quickly cause the situation to deteriorate. ...
Kyodo News, Nov. 18, 2013: Nuclear Regulation Authority Chairman Shunichi Tanaka has said the work requires great prudence because the pools are strewn with small pieces of rubble ... The fuel has to be handled very carefully. There is a need to make sure that a fuel assembly is not pulled out (from the fuel rack) by force when it gets stuck because of the rubble, he said.
Watch NHKs broadcast here
AtheistCrusader
(33,982 posts)"If they are exposed to the air ... they would start to heat up, a process that, left unchecked, could lead to a self-sustaining nuclear reaction known as criticality."
A single rod cannot reach criticality. This is total FUD. If you get the Zircalloy cladding hot enough (uncooled by water) in atmosphere, it can catch fire. Uranium also is pyrophoric, and will burn in atmosphere at low temps. If it burns, it will spread contamination, aerosolized in the soot. THAT is the risk, not criticality. The fuel rods are intentionally built to keep the uranium mass low enough, and the geometric configuration such that criticality cannot happen without other rods in a precise geometric configuration, with a neutron moderator in place.
The full quote from the BBC has it precisely right:
"Experts say it is vital that the casks are watertight so the rods have no contact with air - which risks overheating and possible contamination."
A single rod by itself cannot go critical.
A pile of fuel material in the pool, from broken rods, is potentially a different matter, because you increase the mass of uranium, and change the geometric configuration of it.
As for the plutonium, big whoop. ALL used fuel rods have plutonium. (reactor three was the only one deployed with MOX however, so the plutonium is pretty much a boogie-man. Reactor 4 has a payload of UO2) That's why the MIC loves uranium reactors so much; they produce Plutonium which is excellent for reprocessing into bombs.
Edit: I think that is highly disingenuous to 'quote' the BBC and inject a period there, when that was NOT the end of the sentence.
magical thyme
(14,881 posts)Fingers and toes crossed here. This will be a long, terrifying process.
flamingdem
(39,313 posts)to get their acts together!
Let's hope their luck continues
dixiegrrrrl
(60,010 posts)I am always looking for well written info on Fukisshima.
magical thyme
(14,881 posts)'Trivial in light of other problems at Fukushima, water situation could culminate in the chain reaction scenario'
At Fukushima, they are dealing with massive amounts of groundwater that flow through the property, and the endless pouring that must be kept up 24/7/365 to keep things from getting worse. Recently there appears to be subsidence issues and liquefaction under the plant.
TEPCO has decided to pump the water out of these buildings. However, pumping water out of the buildings is only going to increase the flow rate and create more of these ground issues around the reactors.
An enormous undertaking - but one that needs to be considered for long-term preservation of the integrity of the site - is channelling the water away, like a drain tile installed around the perimeter of a house with a leaky basement, but on an epic scale.
Without this effort, the soils will further deteriorate, structural shift will occur, and subsequently the contents of the pools will shift too.
Edited to add that I don't know what her information sources are. She's not a nuclear scientist or geologist. She's a medical doctor, opthalmologist I think...
dixiegrrrrl
(60,010 posts)What I know after these past few years is "official" reports from Tepco, Japan, and US interests are not reliable,
but there are a few folks around the web who have been quite accurate in identifying current/ongoing problems which
Tepco later is forced to admit are true.
proverbialwisdom
(4,959 posts)freshwest
(53,661 posts)Dopers_Greed
(2,640 posts)I wouldn't be surprised if the fuel rod removal actually failed and Japan is underwater now.
The Stranger
(11,297 posts)Can't they have teams working on this around the clock?
Or should we wait until another earthquake hits?
Bennyboy
(10,440 posts)about them completing today's removal process.
This thread has been crossposted here: http://www.democraticunderground.com/?com=view_post&forum=1002&pid=4054679 And you can see there are no other stories today about this...yet......