Former Los Alamos National Laboratory director Siegfried Hecker assesses North Korea’s claim to have detonated a hydrogen bomb in an underground nuclear test this week. Hecker is one of the world’s top experts on the North Korean nuclear program. He has visited North Korea seven times since 2004, and is the only Western scientist known to have ever been inside a North Korean uranium enrichment facility. He is currently a senior fellow at Stanford’s Center for International Security and Cooperation, and a research professor of Management Science and Engineering.

Do you believe that North Korea actually detonated a hydrogen bomb in its latest nuclear test?

I don’t believe it was a real hydrogen bomb, but my greatest concern is not so much whether or not they actually tested a hydrogen bomb, but rather that they tested at all. Since this test worked, they will have achieved greater sophistication in their bomb design – that is the most worrisome aspect. This is their fourth test – with each test they can learn a lot.

What makes a hydrogen bomb a more threatening weapon than a conventional atomic bomb?

A hydrogen bomb can be a hundred or a thousand-fold more powerful than a fission bomb. Certainly a blast of a megaton will be much more destructive than the Hiroshima bomb, but the more important part is the ability to deliver at long range and to do it accurately. That is what would threaten the United States and its allies most; even with the size of nuclear blasts they have already demonstrated.

White House officials say that initial data from nearby monitoring stations are not consistent with a hydrogen bomb test. How will we know for sure whether it was a hydrogen bomb or not?

The short answer is that we may never know. The telltale signs of a hydrogen bomb are very difficult to pick up in a deeply buried test. Typically hydrogen bombs have greater explosive power or yield. This test is currently believed to have resulted in a seismic tremor of 5.1 on the Richter earthquake scale. That would make it roughly equivalent to the third nuclear test in February 2013. At that time, North Korea claimed it tested a miniaturized atomic bomb – there was no mention of a hydrogen bomb. My estimate of the yield for the 2013 test is roughly 7 to 16 kilotons – which is in the range of the 13-kiloton Hiroshima blast. As far as destructiveness, a Hiroshima-scale explosion is bad enough. Detonated in Manhattan, it may kill as many as a quarter million people. The power of the 2013 and the current explosion is more consistent with fission bombs than hydrogen bombs.

Can you rule out the possibility that it was a hydrogen bomb?

I find it highly unlikely that the North tested a real hydrogen fusion bomb, but we know so little about North Korea’s nuclear weapons design and test results that we cannot completely rule it out. A modern hydrogen bomb is a two-stage device that uses a fission bomb to drive the second stage fusion device. A two-stage device is very difficult to design and construct, and is likely still beyond the reach of North Korea today. However, by comparison, China’s early nuclear weapon program progressed rapidly. It tested its first fission bomb in 1964 and less than three years later demonstrated a hydrogen bomb – and that was 50 years ago. North Korea has now been in the nuclear testing business for almost 10 years, so we can’t rule anything out for certain.

If it wasn’t a hydrogen bomb, what kind of bomb might it have been?

What may be more likely than a two-stage hydrogen bomb is that they took an intermediate step that utilizes hydrogen (actually hydrogen isotopes) fuel to boost the explosive yield of the fission bomb, a sort of turbocharging. Such a device has a fusion or “hydrogen” component, but is not a real hydrogen bomb. It allows miniaturization – that is making the bomb smaller and lighter. Moreover, it would be the first step toward eventually mastering a two-stage hydrogen bomb.

The most important aspect then is to miniaturize, whether it is a fission bomb, a boosted fission bomb, or a hydrogen bomb. The Nagasaki bomb weighed 5,000 kilograms. It was delivered in a specially equipped B-29 bomber. North Korea wants to demonstrate it has a deterrent. To do so, it needs to be able to credibly threaten the U.S. mainland or our overseas assets. For that, you have to make the bomb (more correctly, the warhead) small enough to mount on a missile. The smaller and lighter, the greater the reach. At this point, what makes their nuclear arsenal more dangerous is not so much explosive power of the bomb, but its size, weight and the ability to deliver it with missiles.

How close is North Korea to being able to credibly threaten a nuclear strike against the mainland United States?

North Korea is still a long way off from being able to strike the US mainland. It has only had one successful space launch. It needs a lot more, but it has a large effort in that direction.

Do you think North Korea conducted this test for political or technical reasons?

North Korea had very strong technical and military drivers for this test, as well as follow-on tests. The political environment is mostly what has constrained it from testing earlier and more often. However, this test demonstrates that Pyongyang is willing to weather the political storm this test will bring. It has done so for all previous tests.

What are your current estimates on the size of North Korea's stockpile of nuclear weapons and materials?

Much like in the area of sophistication of the bomb, we have little information of what North Korea actually possesses. The best we can do is to estimate how much bomb fuel, plutonium and highly enriched uranium, they may have produced and estimate how many bombs they can produce from that stockpile. My best estimate at this time is that they may have enough bomb fuel for 18 bombs with a capacity to make 6 to 7 more annually. That, combined with the increased sophistication they surely achieved with this test, paints a troublesome picture.

How should the U.S. respond?

I am concerned about we haven’t done to date. Washington has lost many opportunities we have had since North Korea began its nuclear weapon production in earnest in 2003. One thing that’s clear is that doing what we and the rest of the world have done so far – half-hearted diplomacy, ultimatums, and sanctions – have failed, so these are not the answer. I have previously argued that we should focus on three “No’s” for three “Yes’s” – that is no more bombs, no better bombs (meaning no testing) and no export – in return for addressing the North’s security concerns, its energy shortage and its economic woes. This could have worked when I first proposed it 2008 after one of my seven visits to North Korea. It will be more difficult now.

CISAC and FSI Senior Fellow Siegfried Hecker has been awarded the prestigious Science Diplomacy Award from the American Association for the Advancement of Science for his dedication to building bridges through science.

Hecker, director emeritus of the Los Alamos National Laboratory and CISAC co-director from 2007-2012, was honored at the AAAS’s annual conference in Chicago for his “lifetime commitment to using the tools of science to address the challenges of nuclear proliferation and nuclear terrorism and his dedication to building bridges through science during the period following the end of the Cold War."

In nominating Hecker for the 2013 award, Glenn E. Schweitzer, director of the Office for Central Europe and Eurasia at the National Academies, noted that Hecker has been particularly effective in working with government officials and scientific colleagues in Russia, Kazakhstan and North Korea.

"For over two decades, Dr. Hecker has worked on international nuclear security activities and fostered cooperation with the Russian nuclear laboratories to secure and safeguard the vast stockpile of ex-Soviet fissile materials," said AAAS Chief International Officer Vaughan Turekian.

Schweitzer wrote in his nomination that Hecker's activities can be judged on two outcomes: responsible handling of nuclear materials and prevention of dangerous materials from falling into the wrong hands. "On both counts, he scores very high on anyone's ledger," Schweitzer wrote. "In addition, his openness and respect for the views of others have won important friends for the United States around the world."

More details about the award and Hecker's work can be read here.

Please join CISAC in congratulating Hecker for this honor.

William J. Perry was only 18 when he found himself surrounded by death, a young U.S. Army mapping specialist in Japan during the Army of Occupation. The atomic bombs had been dropped on Hiroshima and Nagasaki and World War II had just come to an end. 

“The vast ruins that once had been the great city of Tokyo – nothing, nothing had prepared me for such utter devastation that was wrought by massive waves of firebombing rained down by American bomber attacks,” said Perry, who was then shipped off to the island of Okinawa in the aftermath of the last great battle of WWII.

More than 200,000 soldiers and civilians had been killed in that closing battle of 1945, codenamed Operation Iceberg. 

“Not a single building was left standing; the island was a moonscape denuded of trees and vegetation,” Perry told a rapt audience during a recent speech. “The smell of death was still lingering.” 

The young man quickly understood the staggering magnitude of difference in the destruction caused by traditional firepower and these new atomic bombs.

 “It had taken multiple strikes by thousands of bombers and tens of thousands of high explosive bombs to lay waste to Tokyo,” he recalls. “The same had been done to Hiroshima and then to Nagasaki with just one plane – and just one bomb. Just one bomb. 

“The unleashing of this colossal force indelibly shaped my life in ways that I have now come to see more clearly,” said Perry, who would go on to become the 19^th secretary of defense. “It was a transforming experience. In many ways – I grew up from it.” 

William J. Perry in 1945 in his U.S. Army Air Corps uniform.

William J. Perry in 1945 in his U.S. Army Air Corps uniform.  Photo Credit: U.S. Army

Now, nearly seven decades later, the 86-year-old Perry has come full circle. His new winter course will take students back to his fateful days in Japan after the United States became the first – and last – nation to use atomic weapons. He’ll go through the Cold War, the arms race and expanding nuclear arsenals, and today’s potential threats of nuclear terrorism and regional wars provoked by North Korea, Iran or South Asia. 

Living at the Nuclear Brink: Yesterday & Today (IPS 249) – to serve as the backdrop for an online course at Stanford next year – concludes with the declaration Perry made in 2007: The world must rid itself entirely of nuclear weapons. And students will get a primer on how to get involved in organizations that are working on just that. 

“They did not live through the Cold War, so they were never exposed to the dangers and therefore it doesn’t exist to them; it’s just not in their world,” Perry said of millennial and younger students. “I want to make them aware of what the dangers were and how those dangers have evolved.”

Perry and former U.S. Sen. Sam Nunn, both Democrats, joined former Republican Secretaries of State George P. Shultz and Henry A. Kissinger in launching a series of OpEds in The Wall Street Journal (the first in 2007) that went viral. Together they outlined how nations could work together toward a world without nuclear weapons.

“I think I have some responsibility since I helped build those weapons – and I think that time is running out,” Perry said in an interview. 

Perry helped shore up the U.S. nuclear arsenal as undersecretary of defense for research and engineering, procuring nuclear weapons delivery systems for the Carter administration. Later, as secretary of defense for President Bill Clinton, his priority became the dismantling of nuclear weapons around the world. 

Today, he works on the Nuclear Security Project along with Shultz, Kissinger and Nunn. Former New York Times correspondent Philip Taubman documents their bipartisan alliance in the book, “The Partnership: Five Cold Warriors and Their Quest to Ban the Bomb.” That fifth cold warrior is Sidney Drell, the renowned Stanford physicist and co-founder of CISAC. 

Taubman, a consulting professor at CISAC, will guest lecturer in Perry’s class, along with CISAC’s Siegfried Hecker, David Holloway, Martha Crenshaw and Scott Sagan. Other speakers are expected to include Shultz, a distinguished fellow at Stanford’s Hoover Institution; Andrei Kokoshin, deputy of the Russian State Duma; Ashton B. Carter, who just stepped down as deputy secretary of defense; Joseph Martz of the Los Alamos National Laboratory; and Joeseph Cirincione, president of the Ploughshares Fund.

The world is far from banning the bomb. According to the Ploughshares Fund, an estimated 17,300 nuclear weapons remain in the global stockpile, the majority of which are in Russia and the United States.

                                                                                                CyperusMedia.com

President Barack Obama declared shortly after taking office in his first foreign policy speech in Prague that because the United States was the only country to have used nuclear weapons, Washington “has a moral responsibility to act.” 

“So today, I state clearly and with conviction, America’s commitment to seek the peace

and security of a world without nuclear weapons,” Obama said back in May 2009. 

Perry – a senior fellow at CISAC who received his BS and MS from Stanford and a PhD from Pennsylvania State University, all in mathematics – laments the regression of the movement to dismantle the nuclear legacy of the Cold War. 

Obama has so far not acted on his pledge in his contentious second term, as China and Russia expand their stockpiles. North Korea and Iran are attempting to build nuclear weapons and India and Pakistan are building more fissile material. The U.S. Senate still has not ratified the Comprehensive Test Ban Treaty and the U.S. and Russia have not moved forward on a follow-up to the New START Treaty. 

Perry recognizes that the issue is slipping from the public conscience, particularly among young people. So he’s putting his name and experience behind a Stanford Online course slated to go live next year. It will correspond with the release of his memoir, “My Journey at the Nuclear Brink” and will take a more documentary approach, weaving together key moments in Perry’s career with lectures, archival footage and interviews and conversations between Perry and his colleagues and counterparts. 

"Bill Perry has had a remarkable career and this project draws on his unparalleled experience over a pivotal period in history," said John Mitchell, vice provost for online learning. "We hope his brilliant reflections will be useful to everyone with an interest in the topic, and to teachers and students everywhere." 

At the heart of his winter course, online class and memoir are what Perry calls the five great lessons he learned in the nuclear age. The first four are grim remnants of what he witnessed over the years: the destructive nature of the atomic bombs on Japan; his mathematical calculations about the number of deaths from nuclear warfare; his work for the CIA during the Cuban Missile Crisis; and one pre-dawn call in 1978 from the North American Aerospace Defense Command saying there were 200 missiles headed toward the United States from the Soviet Union. That turned out to be a false, but terrifying alarm. 

His fifth final lesson is hopeful, if not cautionary. It goes like this: 

As secretary of defense from 1994 to 1997, Perry oversaw the dismantling of 8,000 nuclear weapons in the former Soviet Union and the United States and helped the former Soviet states of Ukraine, Kazakhstan and Belarus to go entirely non-nuclear. In that mission, he often visited Pervomaysk in the Ukraine, which was once the Soviet Union’s largest ICBM site, with 700 nuclear warheads all aimed at targets in the United States. 

On his final trip to Pervomaysk in 1996, he joined the Russian and Ukrainian defense ministers to plant sunflowers where those missiles had once stood. 

“So reducing the danger of nuclear weapons is not a fantasy; it has been done,” Perry said. “I will not accept that it cannot be done. I shall do everything I can to ensure nuclear weapons will never again be used – because I believe time is not on our side.”

Siegfried Hecker, a senior fellow at CISAC, writes in this commentary for the Bulletin of the Atomic Scientists that North Korea's decision to restart its 5-megawatt nuclear reactor is a big step back for denuclearization.

"The most likely technical scenario is that the North Koreans will operate the restarted 5-megawatt reactor for two years with a full load of 8,000 fuel rods, cool this spent fuel and extract roughly 10 to 12 kilograms of plutnoium within three years," he writes.

Therefore, he expects Pyongyang to gain one bomb's worth of plutonium a year.

CISAC's Nick Hansen and Jeffrey Lewis have revealed new satellite imagery that indicates North Korea is likely restarting is nuclear reactor at Yongbyon. Pyongyang committed to shut down the nuclear site in 2007.

Hansen and Lewis concluded in a story on the popular blog about North Korea, Jeff Lewis on BBC: North Korea's Yongbyon reactor 'nearing operation', that white steam seen from an electrical power building on Aug. 31 indicates that the electrical system is about to come online. Energy is generated from the heat released by the nuclear reactor, which uses steam to power turbines. 

Lewis spoke with the BBC, commenting that: "The reactor looks like it either is or will within a matter of days be fully operational, and as soon as that happens, it will start producing plutonium." He also added that this development could increase North Korea's bargaining power in negotiations, and add a sense of urgency to issues on the Korean peninsula.