Steve Connor: Contamination of water is the big headache for Tepco

Analysis: Pumping in fresh water has led to further build-ups of contaminated water

When fighting a fire, you don't worry about your water bills. When the Japanese power company Tepco was fighting a potential nuclear meltdown in its stricken reactors at Fukushima, it was not particularly worried about the huge volume of radioactively contaminated water created by the attempts to keep the reactors cool.

The priority in the aftermath of the devastating tsunami, a 14-metre-high wave that washed over the Fukushima site, was to avert a critical nuclear accident involving soaring temperatures within the steel-lined reactor vessels. Although some of the nuclear fuel rods in the three affected reactors have almost certainly melted, they do not seem to have breached the reactors themselves.

Tepco's priority now is to achieve a "cold shutdown", when the temperatures within the reactors are kept below 95C at atmospheric pressure. This prevents the reactors' coolant water from boiling even when the coolant systems are depressurised, a safer condition than an enforced hot shutdown.

Tepco has said that it would take about three months to stabilise the coolant systems of the three overheated Fukushima reactors. At the same time, the company must prevent the spent fuel rods within the four storage ponds from heating up. It would then take another three to six months to achieve cold shutdown.

This would be difficult enough on its own without having to contend with thousands of tonnes of contaminated water that has accumulated on the site. Some of the water used to keep the reactors cool has drained into the underground trenches used for carrying cables and pipes, which were flooded by the tsunami.

Ideally, the cooling water would be pumped around the reactors in a closed circuit but the company has not fixed the coolant systems completely, relying instead on pumping in fresh water, which leads to further build-ups of contaminated water, some of which has been discharged into the sea along with worryingly high levels of radiation.

The ultimate aim is to cool the reactors down, plug any radiation leaks and deal with the contaminated water. Only then can the serious business of decommissioning begin – a job likely to take at least 10 years.

News
newsVideo targets undecided voters
Arts and Entertainment
Singer Pixie Lott will take part in Strictly Come Dancing 2014, the BBC has confirmed
tv
Life and Style
Cooked up: reducing dietary animal fat might not be as healthy as government advice has led millions of people to believe
healthA look at how governments started advising incorrectly on diets
News
Evan Spiegel, the founder of Snapchat, dropped out of Stanford University just before graduation to develop his app
techAnd yes, it is quite a lot
PROMOTED VIDEO
News
ebooksAn evocation of the conflict through the eyes of those who lived through it
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Retail Business Architect

Flexible for the right candidate: Clearwater People Solutions Ltd: I have a fa...

Calypso Developer

£500 - £700 per day: Harrington Starr: Calypso Developer Calypso, J2SE, XML, ...

IT Developer/Analyst

£35000 - £36000 per annum + benefits: Ashdown Group: A market leading financia...

Pricing Manager, Finance, Edinburgh, £250-350p/d

£250 - £350 per annum + competitive: Orgtel: My client, a leading bank, is cur...

Day In a Page

Kate Bush, Hammersmith Apollo music review: A preamble, then a coup de théâtre - and suddenly the long wait felt worth it

Kate Bush shows a voice untroubled by time

A preamble, then a coup de théâtre - and suddenly the long wait felt worth it
Robot sheepdog technology could be used to save people from burning buildings

The science of herding is cracked

Mathematical model would allow robots to be programmed to control crowds and save people from burning buildings
Tyrant: Is the world ready for a Middle Eastern 'Dallas'?

This tyrant doesn’t rule

It’s billed as a Middle Eastern ‘Dallas’, so why does Fox’s new drama have a white British star?
Rachael Lander interview: From strung out to playing strings

From strung out to playing strings

Award-winning cellist Rachael Lander’s career was almost destroyed by the alcohol she drank to fight stage fright. Now she’s playing with Elbow and Ellie Goulding
The science of saturated fat: A big fat surprise about nutrition?

A big fat surprise about nutrition?

The science linking saturated fats to heart disease and other health issues has never been sound. Nina Teicholz looks at how governments started advising incorrectly on diets
Emmys 2014 review: Can they genuinely compete with the Oscars

Can they genuinely compete with the Oscars?

The recent Emmy Awards are certainly glamorous, but they can't beat their movie cousins
On the road to nowhere: A Routemaster trip to remember

On the road to nowhere

A Routemaster trip to remember
Hotel India: Mumbai's Taj Mahal Palace leaves its darker days behind

Hotel India

Mumbai's Taj Mahal Palace leaves its darker days behind
10 best pencil cases

Back to school: 10 best pencil cases

Whether it’s their first day at school, uni or a new project, treat the student in your life to some smart stationery
Arsenal vs Besiktas Champions League qualifier: Gunners know battle with Turks is a season-defining fixture

Arsenal know battle with Besiktas is a season-defining fixture

Arsene Wenger admits his below-strength side will have to improve on last week’s show to pass tough test
Pete Jenson: Athletic Bilbao’s locals-only transfer policy shows success does not need to be bought

Pete Jenson: A Different League

Athletic Bilbao’s locals-only transfer policy shows success does not need to be bought
This guitar riff has been voted greatest of all time

The Greatest Guitar Riff of all time

Whole Lotta Votes from Radio 2 listeners
Britain’s superstar ballerina

Britain’s superstar ballerina

Alicia Markova danced... every night of the week and twice on Saturdays
Berlin's Furrie invasion

Berlin's Furrie invasion

2000 fans attended Eurofeurence
‘It was a tidal wave of terror’

‘It was a tidal wave of terror’

Driven to the edge by postpartum psychosis