People watch a TV screen showing North Korean leader Kim Jong Un during a news program, at Seoul Railway Station in Seoul, South Korea, Tuesday, March 15, 2016.

People watch a TV screen showing North Korean leader Kim Jong Un during a news program, at Seoul Railway Station in Seoul, South Korea, Tuesday, March 15, 2016. AP Photo/Ahn Young-joon

Intelligence Chief: We Don’t Know If North Korea Has a ‘Boosted Bomb’

Pyongyang’s bomb-making capabilities remain opaque even to the nation’s top spy.

“We don’t really know” if North Korea tested a “boosted” nuclear device this year, the U.S. intelligence chief said Monday.

A boosted nuclear weapon is sometimes described as an intermediary point between a fission bomb and a much more destructive hydrogen bomb.

The seismic data from the Jan. 6 underground bomb test, which produced a 5.1-magnitude quake, indicates that the yield was about 6 kilotons (possibly 10), in line with a conventional fission device, not a thermonuclear bomb, which can have a yield between 15,000 and 50,000 kilotons.  

On Monday, Director of National Intelligence James Clapper echoed what most other experts have said: “It was much more modest than they claimed,” he said. “It’s hard to say what they are trying.”

Some have argued that a so-called boosted bomb would represent a significant increase in North Korean capability. In a boosted bomb, fissile material such as plutonium (of which North Korea has a small stockpile) or highly enriched uranium is put into a fissile chain reaction. The reaction fuses deuterium and tritium, two hydrogen isotopes, that have been thrust into the bomb’s core.

“While the fusion reaction does somewhat increase the explosive yield, the main purpose of this reaction is to release lots of neutrons that would then cause many additional fission reactions,” Charles D. Ferguson, the president of the Federation of American Scientists, wrote in January.

Bottom line, it’s not exactly a mega-destructive hydrogen bomb, but it does allow you to get a lot bigger explosion out of much less fissile material. That means you can make smaller bombs that can fly farther atop a given missile.

“A boosted fission bomb alone…would mean that North Korea is well on its way to making nuclear bombs that are small enough and lightweight enough to fit on ballistic missiles,” wrote Ferguson.

That’s far more concerning in the wake of the most recent demonstration of a submarine-launched missile, even though the missile flew only about 19 miles. (A successful test would have flown closer to 200 miles.)

“In the case where North Korea does not need to produce a much bigger explosive yield per bomb, but is content with low to moderate yields, it can make much more efficient use of its available fissile material...and have much lower weight bombs,” Ferguson wrote. He said North Korea probably has enough fissile material to make as many as “a few dozen” bombs. U.S. capabilities for detecting or analysing different tests are limited. Besides seismic tests, the Air Force Technical Applications Center, or AFTAC, at Patrick Air Force Base, Florida, can probe the atmosphere for different isotopes with sensors aboard a Boeing WC-135 Constant Phoenix plane. The presence of tritium would be a more conclusive evidence of a boosted bomb blast. Clapper’s response suggests that AFTAC has yet to detect any telltale tritium.

Other experts were more confident that North Korea had tested a boosted bomb. "Given Kim Jong-un’s desire to claim North Korea had mastered H-bomb technology, North Korea likely did test a boosted weapon in January," Bruce Bennett, a senior defense analyst with the RAND Corporation, told Defense One. "According to the web site 38 North, the fourth nuclear test was buried about twice as deep as the third nuclear test, suggesting that North Korea was seeking a 50 kiloton or so weapon yield.  It got 10 kilotons.  From just measuring the weapon yield, we cannot tell whether any of this explosion was due to fusion—the 'h-bomb' component of the explosion. But if North Korea had gotten 50 kilotons, it would almost certainly be the case that fusion was a part of the explosion. I think Kim wanted that proof, and likely was very unhappy that he did not get it," said Bennett.

If North Korea developed a boosted bomb, how soon could they upgrade to a full hydrogen bomb? Clapper would not say.

“Aspirationally, the current regime in North Korea, which is one guy, is very determined to portray to the world that North Korea is a nuclear power and he wants recognition of that,” the U.S. intelligence chief said. “Despite some of the failure that they’ve recently incurred they will continue to press on to develop nuclear capabilities, which I think, ultimately, aspirationally, would include a hydrogen bomb capability. But I certainly can’t prescribe a timeline,” he said. “if you think about it, the North Koreans have achieved an objective there because they’ve created at least the psychology of deterrence.”

"it has taken the big countries 10 years or less to go from first fission test to first significant (beyond boosted) fusion test. On the other hand, the US and Soviet nuclear programs were massively staffed, and the North Korean program is not as well staff or financed," said Bennett.

“I don't know if it is possible within five years,” Ferguson told Defense One in an email. “It seems reasonably clear that they want such a capability. If they had outside help, they might be able to speed up the development process. Even more advanced states such as India and Pakistan have struggled to develop H-bomb capabilities. There are still some who doubt whether those two countries really have such capability. Recall that the United States, Russia, China, France, and the UK made many tests (in the case of the United States more than 1,000) to develop more advanced nuclear weapons. So, North Korea would not be much different,” he said.

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.