Iodio 131 scoperto anche in Inghilterra. Dopo Cina, Thailandia, Canada, Usa, Francia e Italia, ora anche Gb

Iodio 131 in Inghilterra. Rilevato nell’Oxfordshire e a Glasgow. Quantità non preoccupanti per la salute umana, dice l’HPA (Health Protection Agency).

E così dopo Cina, Thailandia, Canada, Stati Uniti, Francia e Itakia ora si aggiu ge l’Inghilterra.

L’articolo dell’Independent del 29.3.2011, a seguire l’articolo del Guardian su Fukushima dove la partita sembra quasi persa.

Japan radioactivity found in UK

PA

Tuesday, 29 March 2011

Extremely low levels of radioactive iodine from the tsunami-hit Japanese nuclear plant have been detected in parts of the UK, the Health Protection Agency said today.

A statement from the HPA said the “minutest traces of iodine” were being seen in the UK, with low levels detected at monitoring stations in Oxfordshire and Glasgow.

The agency said there was no public health risk posed by the iodine, as the radiation dose received from inhaling air with the levels recorded in the past few days would be minuscule and much less than the annual background dose.

And while levels may rise in the coming days and weeks, they will be “significantly below any level which could cause harm to public health”, the HPA said.

The statement comes after the Scottish Environment Protection Agency (Sepa) said an air sampler in Glasgow had picked up iodine particles which they believe could be from the Fukushima nuclear plant in Japan.

The HPA said that trace levels of the radioactive chemical iodine-131 had been detected by measurements taken at a monitoring station in Oxfordshire yesterday.

The measurements followed reports of iodine at monitoring stations in Glasgow and Oxfordshire.

Dr James Gemmill, Sepa’s radioactive substances manager, said: “The concentration of iodine detected is extremely low and is not of concern for the public or the environment.

“The fact that such a low concentration of this radionuclide was detected demonstrates how effective the surveillance programme for radioactive substances is in the UK.

“Sepa has an ongoing comprehensive monitoring programme for radioactivity in Scotland and has increased the level of scrutiny to provide ongoing public assurance during this period.”

Engineers have been struggling to bring the Fukushima plant under control since it was hit by the earthquake and tsunami which devastated north east Japan more than two weeks ago.

In the latest problems to hit the plant, which has suffered explosions, fires, radiation leaks and fears of a partial meltdown, radioactive water was found to be leaking from the site, while plutonium has been found in the soil.

Environment charity WWF Scotland’s Dr Richard Dixon said: “The detection of small amounts of radioactivity which may have come from a damaged reactor on the other side of the planet should act as a reminder to all of the folly of nuclear power.

“We know that the majority of the public in Scotland support clean, safe renewable energy over polluting nuclear power.

“Political parties seeking votes this May should now spell out if they would oppose the building of new nuclear power stations in Scotland.”

Prof Neil Hyatt, professor of nuclear materials chemistry at the University of Sheffield, said the iodine was a volatile element that only lasted for a short amount of time, so it was certain to have been produced at Fukushima and transported through the atmosphere to the UK.

“Iodine-131 has also been detected in China, Canada and elsewhere,” he said.

“The Health Protection Agency equipment is extremely sensitive, so they are able to detect very small quantities of radioactivity in very large volumes of air.

“At the level detected, this quantity of iodine does not present any hazard to human health.”

The chief inspector of nuclear installations Mike Weightman, who has been asked by Energy Secretary Chris Huhne to report on the implications of the Fukushima crisis for the UK nuclear industry, today set out what his inquiry will look at.

He said he would examine what had happened in Japan, looking at the power station at Fukushima and its design provisions for resilience to natural hazards, the events that occurred after the earthquake and tsunami and the actions that were taken by the operators and emergency response provisions.

He will compare UK nuclear power station designs with those at Fukushima, examine the potential threats, including natural disasters, to facilities here and any lessons that can be learnt, making any recommendations on the implications for UK nuclear power of the disaster in Japan.

But he said neither the interim or the final report will address nuclear or energy policy issues, as these are outside the role of the nuclear regulator.

The events in Japan have prompted questions over the future of new nuclear build in the UK, which ministers have said is necessary as part of efforts to ensure secure energy supplies and cut carbon emissions to tackle climate change.

Japan may have lost race to save nuclear reactor

Fukushima meltdown fears rise after radioactive core melts through vessel – but ‘no danger of Chernobyl-style catastrophe’

The radioactive core in a reactor at the crippled Fukushima nuclear power plant appears to have melted through the bottom of its containment vessel and on to a concrete floor, experts say, raising fears of a major release of radiation at the site.

The warning follows an analysis by a leading US expert of radiation levels at the plant. Readings from reactor two at the site have been made public by the Japanese authorities and Tepco, the utility that operates it.

Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian workers at the site appeared to have “lost the race” to save the reactor, but said there was no danger of a Chernobyl-style catastrophe.

Workers have been pumping water into three reactors at the stricken plant in a desperate bid to keep the fuel rods from melting down, but the fuel is at least partially exposed in all the reactors.

At least part of the molten core, which includes melted fuel rods and zirconium alloy cladding, seemed to have sunk through the steel “lower head” of the pressure vessel around reactor two, Lahey said.

“The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the drywell,” Lahey said. “I hope I am wrong, but that is certainly what the evidence is pointing towards.”

The major concern when molten fuel breaches a containment vessel is that it reacts with the concrete floor of the drywell underneath, releasing radioactive gases into the surrounding area. At Fukushima, the drywell has been flooded with seawater, which will cool any molten fuel that escapes from the reactor and reduce the amount of radioactive gas released.

Lahey said: “It won’t come out as one big glob; it’ll come out like lava, and that is good because it’s easier to cool.”

The drywell is surrounded by a secondary steel-and-concrete structure designed to keep radioactive material from escaping into the environment. But an earlier hydrogen explosion at the reactor may have damaged this.

“The reason we are concerned is that they are detecting water outside the containment area that is highly radioactive and it can only have come from the reactor core,” Lahey added. “It’s not going to be anything like Chernobyl, where it went up with a big fire and steam explosion, but it’s not going to be good news for the environment.”

The radiation level at a pool of water in the turbine room of reactor two was measured recently at 1,000 millisieverts per hour. At that level, workers could remain in the area for just 15 minutes, under current exposure guidelines.

A less serious core meltdown happened at the Three Mile Island nuclear plant in Pennsylvania in 1979. During that incident, engineers managed to cool the molten fuel before it penetrated the steel pressure vessel. The task is a race against time, because as the fuel melts it forms a blob that becomes increasingly difficult to cool.

In the light of the Fukushima crisis, Lahey said all countries with nuclear power stations should have “Swat teams” of nuclear reactor safety experts on standby to give swift advice to the authorities in times of emergency, with international groups co-ordinated by the International Atomic Energy Authority.

The warning came as the Japanese authorities were being urged to give clearer advice to the public about the safety of food and drinking water contaminated with radioactive substances from Fukushima.

Robert Peter Gale, a US medical researcher who was brought in by Soviet authorities after the Chernobyl disaster, in 1986, has met Japanese cabinet ministers to discuss establishing an independent committee charged with taking radiation data from the site and translating it into clear public health advice.

“What is fundamentally disturbing the public is reports of drinking water one day being above some limit, and then a day or two later it’s suddenly safe to drink. People don’t know if the first instance was alarmist or whether the second one was untrue,” said Gale.

“My recommendation is they should consider establishing a small commission to independently convert the data into comprehensible units of risk for the public so people know what they are dealing with and can take sensible decisions,” he added.