'Fission' scare at wrecked Japan plant

2011-11-02 18:37

Tokyo - The operator of tsunami-hit nuclear power plant in Japan said on Wednesday it had found substances in a reactor which could be a result of nuclear fission, a possible setback in efforts to bring the plant to a safe, cold shutdown.

Analysts said there was unlikely to be any heightened risk of radiation.

The Fukushima Daiichi plant was struck by a devastating earthquake and tsunami in March and has released radiation into the atmosphere ever since in the world's worst nuclear crisis since Chernobyl 25 years ago.

Tokyo Electric Power said that it discovered xenon, a substance produced as a byproduct of fission, in the No 2 reactor, and had poured in a mixture of water and boric acid, an agent that helps prevent nuclear reactions, as a precaution.

"It can be assumed that isolated criticality took place for a short period of time judging from the presence of xenon," Tepco spokesperson Junichi Matsumoto told reporters.

Criticality is a state when controlled nuclear reactions take place. Nuclear power plants harness the resulting heat to produce electricity.

Richard Wakeford at the University of Manchester said his initial response to the Tepco findings was "scepticism".

"Nuclear criticality requires delicate conditions," Wakeford said in an e-mail. "And it seems unlikely that these exist at Fukushima... Also, criticality would be accompanied by a burst of radiation, which I would have expected to be detected."

Paddy Regan, at the department of physics, University of Surrey, said he doubted a major release of radiation.

"But it is worth noting that even if the fuel is cooled, there is still a small amount of residual natural fission of the large amount of uranium fuel in the core... As with other reports, this one does not appear to show any new radiological hazard from the disaster."

Melted down

Tepco, which was widely criticised for its slow release of information in the early days of the disaster, said it was still assessing the find but that it believes any criticality was temporary and finished.

The amount of detected xenon was small and the nuclear fuel in the No 2 reactor was unlikely to have melted down again, Tepco said.

The fuel rods in the No 2 reactor and two other reactors melted down early in the crisis after the tsunami knocked out the plant's cooling system.

"We think there won't be an impact on the surrounding environment even if criticality did take place, given that there is no change to parameters from the plant," said an official at the Nuclear Industrial Safety Agency, Japan's nuclear watchdog.

"The amount of detected xenon is so low to have an effect, although we are still in the process of fully analysing the situation," he said.

Tepco said the temperature and pressure at the No 2 reactor remained stable.

The company has succeeded in bringing down the temperatures at the three damaged reactors from levels considered dangerous and hopes to declare a cold shutdown - when temperatures are stable below boiling point - this year.

Tepco said in October that the amount of radiation being emitted from the complex had halved from a month earlier in the latest sign that efforts to bring the facility under control are progressing.

To show that decontamination efforts were progressing, Japanese cabinet official Yasuhiro Sonoda on Tuesday drank a glass of purified water taken from the Daiichi plant after being challenged by journalists to prove it was safe.

Read more on:    japan  |  nuclear  |  japan earthquake
NEXT ON NEWS24X
SHARE:

Read News24’s Comments Policy

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
0 comments
Add your comment
Comment 0 characters remaining
 

Inside News24

 
/News
 

10 facts about swimming you didn't know

This will make you want to jump right into the pool.

 
 

Where were you when you last felt alive?

Snors with a cause - creating awareness of male health
Inspiring: Rock climbing with just one leg
Watch! Skateboarders racing cyclists
Exciting new zipline for Cape Town!

Jobs in Cape Town [change area]

Property [change area]

Travel - Look, Book, Go!

Magical Massinga

Spend 5 nights at the gorgeous Massinga Beach Lodge in Mozambique and only pay for 4 from R13 220 per person sharing. Includes return flights, accommodation, transfers and romantic turndown. Book now!

Kalahari.com - shop online today

Save up to R2100 on electronics! – As seen in the catalogue

Wishing for tech gadgets this festive? Save up to R2100 on hot tech products at kalahari.com. While stocks last. Shop now!

TV Series – 2 for R299

Loads of hot titles to choose from. Shop now!

Hot offer: Up to 50% off irons

Save up to 50% on all Philips irons. While stocks last. Shop now!

Seen something you like in our catalogue?

Find the perfect gift and save up to R5000 – As seen on the catalogue. Hurry and shop now!

Toys 4 for the price of 3

Buy 4 toys and get the cheapest FREE! Offer valid while stocks last. Shop now!

OLX Free Classifieds [change area]

Samsung Galaxy s4

Mobile, Cell Phones in South Africa, Western Cape, Cape Town. Date October 24

Best bargain in big bay

Real Estate, Houses - Apartments for Sale in South Africa, Western Cape, Cape Town. Date October 25

VW Golf 6, 1.6 Trendline (Excellent condition)

Vehicles, Cars in South Africa, Western Cape, Cape Town. Date October 25

Horoscopes
Aquarius
Aquarius

Life can feel quite full on and overwhelming at the moment as the pressure of expectations and obligations start to pile up. You...read more

There are new stories on the homepage. Click here to see them.
 
English
Afrikaans
isiZulu

Hello 

Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.


Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Settings

Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.








Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.