NEW cracks have been discovered in one of Scotland’s ageing nuclear reactors, raising radiation safety fears and resulting in a prolonged shutdown, the Sunday Herald can reveal.

Checks have detected fresh cracks in the graphite core of a reactor at Hunterston B in North Ayrshire. The reactor was taken offline on March 9, but is not now due to restart until May 1 at the earliest, more than a month later than originally planned.

The UK Government safety watchdog, the Office for Nuclear Regulation (ONR), is assessing whether the cracks render the reactor too dangerous to fire up. Its operator, EDF Energy, insists it will reopen, but critics say it should stay shut.

The integrity of the thousands of graphite blocks that make up the reactor core is vital to nuclear safety. They ensure that the reactor can be cooled and safely shut down in an emergency.

But bombardment by intense radiation over decades causes the blocks to start cracking. If they fail, experts say, nuclear fuel could overheat, melt down and leak radioactivity in a major accident.

Both the ONR and EDF told the Sunday Herald that new cracks had been found at Hunterston reactor number three during inspections in recent weeks, but they wouldn’t say how many, or how significant they were.

“We are currently assessing the safety case submitted by EDF after a planned outage identified a number of cracks in the graphite blocks that make up reactor three’s core,” said an ONR spokesman.

“Before we grant permission to EDF to restart reactor three we will require that an adequate safety case justifying further operation has been made. ONR has to formally permission the restart of the reactor.”

The ONR’s decision was still “a number of weeks” away, he added. “We will publish the justification behind our decision once it has been made.”

According to EDF’s website, Hunterston reactor three was originally due back online on March 30 after a “graphite inspection outage”. But this has been repeatedly postponed to April 6, April 19, April 24 and now May 1.

The company confirmed that it had “discovered cracks in the inspections during the current outage”. It promised to report the details to the local site stakeholder group after the reactor was restarted.

“As part of the normal ageing process we expect to see defects occurring in some of the graphite blocks that make up the reactor core of our plants,” said an EDF spokeswoman.

“This phenomenon is understood and is recognised in our operational safety cases which are agreed with the nuclear safety regulator. We have prepared well for this; we have a £100 million graphite research programme.”

She added: “Hunterston B remains safe to operate and will be back online once the current outage is completed. We will, as normal, consult with our regulators before returning the reactor to service.”

Hunterston reactor three, which has been running since 1976, is one of the oldest of its kind. It’s where “graphite defects are most advanced” and hence has more inspections than other reactors, said the EDF spokeswoman.

But Pete Roche, a nuclear critic and consultant in Edinburgh, warned that EDF’s optimism that the reactor will restart could be misplaced. “Cracks could prevent control rods from being inserted causing the nuclear fuel to overheat, potentially resulting in a nuclear accident,” he said.

It was “all a bit of a gamble”, he argued. “Hunterston is already 42 years old - when it was only expected to operate for 30 or 35 years. It is clearly time to say goodbye to reactor three.”

Expert nuclear engineer John Large also suggested that the reactor should be closed down. “The core at Hunterston may now be in such a poor structural state that its collapse during a relatively modest earthquake could result in a nuclear fuel meltdown and significant radioactive release,” he said.

“All that EDF can do is permanently shut Hunterston, there being no alternative means to remedy this very serious situation.”

Professor Paul Bowen, a metallurgist from the University of Birmingham who advises the ONR, thought that the body was likely to insist on more frequent inspections rather than reactor closure. “I’m absolutely confident that the regulator will take a very conservative position,” he said.

According to Rita Holmes, a local resident who chairs the Hunterston site stakeholder group, people were worried. “The local communities are unhappy that the reactor has any cracks, and certainly not happy that one with a growing number of cracks could be allowed to continue generation,” she said.

The Scottish Greens MSP for the west of Scotland, Ross Greer, warned that the discovery of new cracks would cause widespread concern. “EDF and the regulator must explain what has been found, and seek the community's views, before putting this reactor back online,” he said. </s> The Fukushima nuclear power plant’s (NPP) operator has detected extremely high radiation levels at a damaged reactor at the Fukushima power plant in Japan.

Radiation levels that are lethal after brief exposure were found inside the second reactor on Thursday

Tokyo Electric Power Company also found a hole which was likely caused by melted nuclear fuel was also discovered at the reactor.

Radiation levels of up to 530 Sieverts per hour were detected inside an inactive Reactor 2 at the Fukushima Daiichi nuclear complex damaged during the 2011 earthquake and tsunami catastrophe, Japanese media reported on Thursday citing the plant operator, Tokyo Electric Power Company (TEPCO).

A dose of about 8 Sieverts is considered incurable and fatal.

A hole of no less than one square meter in size has also been discovered beneath the reactor’s pressure vessel, TEPCO said. According to researchers, the apparent opening in the metal grating of one of three reactors that had melted down in 2011, is believed to be have been caused by melted nuclear fuel that fell through the vessel.

The iron scaffolding has a melting point of 1500 degrees, TEPCO said, explaining that there is a possibility the fuel debris has fallen onto it and burnt the hole. Such fuel debris have been discovered on equipment at the bottom of the pressure vessel just above the hole, it added.

The latest findings were released after a recent camera probe inside the reactor, TEPCO said. Using a remote-controlled camera fitted on a long pipe, scientists managed to get images of hard-to-reach places where residual nuclear material remained. The substance there is so toxic that even specially-made robots designed to probe the underwater depths beneath the power plant have previously crumbled and shut down.

However, TEPCO still plans to launch further more detailed assessments at the damaged nuclear facility with the help of self-propelled robots.

Earlier this week, hopes for a more efficient cleanup at Fukushima were high, as the plant operator announced a portion of nuclear fuel debris responsible for a lot of the lingering contamination from six years ago may have finally been found. </s> An area of the Fukushima Daiichi nuclear plant is showing record levels of radiation, the highest since the complex suffered a nuclear meltdown initiated by a tsunami in 2011. The plant operator Tokyo Electric Power Company (Tepco) announced that the containment vessel of the No 2 reactor showed radiation levels of up to 530 sieverts per hour, which can kill a human in under a minute.

Previous analysis of the area back in 2012 showed records of 73 sieverts per hour in the same area. The new discovery, which was made on 30 January, is based on images captured by three manned cameras which were mounted on a robot to gather information about the state of the reactor.

Images also indicated a hole below the pressure vessel, Nekkei Asian Review reported. According to Tepco, the hole may have been the result of nuclear fuel that entered the vessel as it overheated. Loss of reactor cooling functions in the days following the tsunami could have led to the melting of the walkway.

"It may have been caused by nuclear fuel that would have melted and made a hole in the vessel, but it is only a hypothesis at this stage," Tepco spokesman Tatsuhiro Yamagishi told AFP on 3 February.

"We believe the captured images offer very useful information, but we still need to investigate given that it is very difficult to assume the actual condition inside."

The radiation levels could effectively shut down TEPCO's robots that are being used for the investigation in under two hours, AFP reported. However, the operators plan to extend the probe and check conditions by sending a robot to the bottom of the reactor containment vessel.

The Fukushima plant suffered three meltdowns as a result of the tsunami on 11 March, 2011 which destroyed the emergency generators which provided power to cool the reactors. The accident led to one of the worst nuclear disasters since Chernobyl in 1986, and last year, researchers were able to detect radiation from the site all the way in Oregon, USA. </s> A fire caused an explosion at the Flamanville nuclear power plant in northwest France on Thursday, leading the operator EDF to take a reactor offline, but there was no risk to the reactor, EDF and a local official said on Thursday. FILE PHOTO A general view shows France's oldest Electricite de France nuclear power station, outside the eastern French village of Fessenheim, near Colmar, France, September 5, 2012.

Start the conversation, or Read more at Channelnewsasia.com. </s> Leaked fuel in a reactor containment vessel is believed to be releasing deadly radiation within the Fukushima Daiichi Nuclear Power Plant, the Nikkei Asian Review reported Friday.

The discovery was made in January when plant operator Tokyo Electric Power Company (Tepco) conducted an inspection of the containment vessel in the No. 2 reactor, Nikkei added. A camera used in the inspection captured images of a 1-square meter hole melted into a walkway below the pressure vessel.

The Fukushima Daiichi plant was badly damaged after a massive quake struck the north-eastern coast of Japan in March, 2011, knocking out its cooling systems and causing a meltdown. However, a recent study showed that radiation levels at the plant were lower than previously expected and plenty continue to live in close proximity to the disaster site. </s> An explosion at a nuclear power plant in northern France on Thursday caused minor injuries but took place outside the plant's nuclear zone and posed no risk of contamination, the authorities said.

"It is a significant technical event but it is not a nuclear accident," senior local official Olivier Marmion told AFP following the blast at the Flamanville plant 25 kilometres (15 miles) west of Cherbourg.

The cause of the explosion at the power station, which has been in operation since the 1980s, was not immediately known.

Marmion said five people had reported feeling unwell but that there were no serious injuries, adding that rescue services were at the site.

One of the plant's two reactors was shut down after the explosion and the incident was declared over at 1100 GMT, the authorities said. </s> PARIS (Reuters) - A fire caused an explosion at the Flamanville nuclear power plant in northwest France on Thursday, leading the operator EDF to take a reactor offline, but there was no risk to the reactor, EDF and a local official said on Thursday.

The state-owned firm said a fire in the turbine hall caused the explosion in a “non-nuclear” part of the power station.

The fire was brought under control, and reactor number 1 was disconnected from the grid, EDF said, adding that although there were no injuries, five people had been affected by fumes.

The Flamanville 1 and 2 reactors, which each have a electricity generating capacity of 1,300 megawatts, were built in the 1980s.

CONTROVERSY

Industry experts said fires of this nature happened fairly frequently and that there was unlikely to have been any release of radiation, but Flamanville is at the centre of a deep controversy in France over the future of its nuclear industry and the degree to which its engineering can be trusted.

Atomic power accounted for over 70 percent of the country’s power generation in 2015, and reactors made by another state-controlled firm, Areva, have been installed around the world.

Areva and EDF are building the prototype for a new generation of reactor at the Flamanville site on the Normandy coast in the hope it can be the first of many and extricate them from financial difficulty.

Areva is close to bankruptcy due to a lack of orders, disputes with existing customers, and an investigation into document falsification and is undergoing a restructuring that involves EDF buying a part of the business. </s> A fire caused an explosion at EDF's Flamanville nuclear power plant in northern France on Thursday, leading the utility to take a reactor offline, but there was no associated nuclear risk, EDF and a local government official said on Thursday.

State-owned EDF said in a statement a fire in a machine room caused the explosion in a "non-nuclear" part of the power station.

It added that the fire had been brought under control by its team there and that reactor number 1 had been disconnected from the grid.

It said there were no injuries but five people had been affected by fumes.

The Flamanville 1 and 2 reactors, which each have a electricity generating capacity of 1,300 megawatts, were built in the 1980s. A new reactor is being built at the site but the explosion was not there, a spokeswoman said.

The nuclear safety authority ASN said it had no information and could not immediately comment. </s> Swiss voters are deciding on Sunday whether to close the country’s five nuclear power plants after 45 years in operation. The outcome is too close to call, according to the latest opinion poll.

The Green Party initiative argues the safety of old reactors operating since the early 1970s can no longer be guaranteed. Instead, they are calling for more energy efficiency and renewable energy resources.

“An orderly phase out creates more safety and protects our country,” according to the campaign slogan of the initiative committee.

If approved, three plants would have to be shut down as early as next year and Switzerland would phase out nuclear energy production by 2029.

The proposal is backed by an alliance of leftwing parties, trade unions and environmental organisations.

Most of the Swiss nuclear reactors have unlimited operating licences, which are subject to approval by the regulator.

Opponents, including the main centrist and rightwing parties in parliament as well as the business community, have dismissed the proposal as risky and too hasty.

They say it creates more uncertainty, danger and chaos for electricity supplies in Switzerland, and argue the country would have to increase energy imports from abroad, notably from coal-fired power stations in Germany and nuclear reactors in France.

In the run-up to the November 27 vote, opponents warned that the proposed phase out could lead to blackouts and trigger considerable compensation claims from the operators of the power plants.

Switzerland has five nuclear power reactors, generating about 34.5% of its electricity. It uses nuclear energy to produce electricity, in research and medicine. Worldwide there are 447 nuclear power plants in 31 countries, according to the International Atomic Energy Agency (IAEA). An experimental power reactor at Lucens was written off in 1969 following a core melt. Two reactors, Beznau 1 and Leibstadt, are currently off grid due to repairs. The Mühleberg plant will be closed down in 2019 according to the power station operators. Plans to build two power plants were abandoned in the 1980s following anti-nuclear protests.

Following the nuclear disaster in Fukushima, the Swiss government in 2011 decided in principle to opt out of nuclear power production by 2034. In its energy policy, the government recommended decommissioning all nuclear reactors and to promote hydroelectric power, renewable energy and combined gas plants.

Last September, parliament approved an energy strategy, ending more than two years of debate. The programme foresees boosting renewable energy resources and outlaws the construction of nuclear power plants. However, it sets no deadline for the existing reactors to be shut down.

Unhappy with the Energy Strategy 2050, the rightwing Swiss People’s Party is challenging the law to a referendum, criticising planned government subsidies for renewable energy resources.

The latest opinion poll published last week found supporters just a few percentage points ahead of opponents of the initiative with 6% of respondents still undecided.

Based on the considerable drop in support among citizens over the preceding weeks, experts of the leading GfS Bern research and polling institute give an advantage to the opponents.

The vote needs a majority of cantons and the popular vote to win. It is believed that the results from six of the country’s 26 cantons could be a decisive factor, including Bern and Vaud.

Turnout on November 27 is expected to be above average, around 51%.
Cracks are discovered in the core of Hunterston B nuclear power station in North Ayrshire, Scotland. The Office for Nuclear Regulation is investigating to determine if the reactor is now too dangerous to restart.