MYSTERY OF KOREA H-BOMB TEST

Pariah state boasts of explosion – but experts are dubious

NORTh Korea’s claim to have tested a hydrogen bomb sparked outrage and scepticism yesterday.

The pariah state announced what it said had been a ‘world startling event’ and ‘perfect success’.

But the small scale of the underground blast – 5.1 on the earthquake magnitude scale – put the claim in serious doubt.

‘The seismic data indicates the explosion is probably significantly below what one would expect from an h-bomb test,’ said Crispin Rovere, an Australian-based nuclear policy specialist.

‘It seems to be that they’ve successfully conducted a nuclear test, but unsuccessfully completed the secondstage hydrogen explosion.’

Bruce Bennett, an analyst with the Rand Corporation think-tank, said: ‘The bang they should have got would have been ten times greater.’

North Korea has already tested atomic weapons – in 2006, 2009 and 2013 – in breach of UN resolutions barring it from developing the technology. The possibility of it building hydrogen bombs

‘Underlines a very real threat’

is especially serious because they are many times more destructive.

Philip hammond joined world leaders in condemning North Korea, calling the test a provocation.

The Foreign Secretary, who is on a visit to neighbouring China, said the test ‘underlines the very real threat that North Korea represents to regional and international security’.

There were cheers in the capital Pyongyang as crowds in thick winter coats gathered outside a large video screen near a main railway station to hear the news of the test.

A state television announcer said: ‘With the perfect success of our historic h-bomb, we have joined the ranks of advanced nuclear states.’

No photos were offered as evidence but the blast was strong enough to be felt in Chinese towns over the border. Pupils at one high school were dismissed in the middle of an exam when a crack appeared in the playground.

China, which is one of the communist state’s few allies, said it firmly opposed the nuclear tests.

Russia accused North Korea of a severe violation of international law. The US condemned the test as an ‘unacceptable and irresponsible provocation’.

The White house said its early analysis of underground activity in North Korea was ‘not consistent’ with the claim of a successful hydrogen bomb test.

The UN Security Council said North Korea’s actions were a clear violation of the four previous sanctions resolutions ‘and therefore a clear threat to international peace and security’.

It pledged to take ‘further significant measures’ – UN code for sanctions. hydrogen weapons are not only vastly more powerful than atomic bombs, they are much more difficult to develop.

The latter work through fission – atoms of uranium or plutonium are smashed apart to unleash a huge amount of energy.

hydrogen bombs also start with an atomic explosion. But this is only the trigger for a secondary blast in which hydrogen atoms are fused together, releasing devastating power.

The atomic bomb dropped on hiroshima in 1945 delivered the equivalent of around 15 kilotons of TNT explosive. But the US hydrogen bomb tested at Bikini atoll in 1954 delivered 450 kilotons.

This extra destructive power means they are standard issue in the arsenals of the US, Russia, Britain and France.

The epicentre of yesterday’s blast was Punggye-Ri – a mountainous region where the regime’s three previous atomic bomb tests are thought to have been carried out.

The magnitude of the quake suggests an explosion equal to six to 15 kilotons of TNT – well short of a full hydrogen blast. Nevertheless, it would still be enough to wipe out a city.

One possibility is that yesterKorea day’s test may have used a small amount of hydrogen in a conventional atomic bomb. Joe Cirincione, a nuclear expert at the Ploughshares Fund, a security organisation, said: ‘Because it is, in fact, hydrogen, they could claim it is a hydrogen bomb.’

A further claim made by North was of the bomb being miniaturised. This means it could be carried on a missile that would pose a new threat to the United States and its regional allies. Pyongyang has developed the Taepodong 2 – a long-range missile with an estimated range of around 3,700 miles.

This puts it in striking distance of Japan, Australia and mainland US – albeit only Alaska. Other missiles – based on Soviet Scud technology – can reach neighbours, such as South Korea.

North Korean dictator Kim Jong-un had said in his new year address: ‘Let’s begin the year of 2016 ... with the thrilling sound of our first hydrogen bomb.’

Last night it emerged that Jeremy Corbyn had called for Britain to deal with the North Korean threat by abandoning Trident.

In an article in 2013, the Labour leader said: ‘Peace leads to peace.’

‘Violation of international law’