What Kind of Little Nuke Are You?

October 17, 2006 Topic: Nuclear Proliferation

What Kind of Little Nuke Are You?

The difference between a uranium and plutonium bomb is of considerable geopolitical, and just plain political, significance. Which was it, Mr. President, uranium or plutonium?


Editor's note: The New York Times reported today that U.S. intelligence agencies have concluded that, according to atmospheric sampling, North Korea's test explosion was in fact powered by plutonium
. That NYT article fails to explain the overriding significance of the plutonium finding. The piece below (published the same day as the NYT article) clearly describes what the implications of such a finding are for the foreign policy record of the current president and his predecessor.

A critical question, easily answered by President Bush, is this: was the nuke that North Korea just tested a Uranium-235 or Plutonium-239 device? That difference, though seemingly technical, is of considerable geopolitical (and just plain political) significance. The answer would indicate whether Bush's decision to pull out of the Clinton-era Agreed Framework directly resulted in North Korea producing nukes from its plutonium assets "frozen" under that framework or if North Korea indeed did have the uranium-enrichment, bomb-making capabilities that Bush has been claiming-a less likely scenario for all such a program would entail.


As of this writing, we don't know what kind of bomb was tested, but Bush does because the at-least partially successful nuke blast was not completely contained. The office of the National Intelligence Director John Negroponte said yesterday that analysis of air samples gathered last week detected radioactive debris that confirms North Korea conducted an underground nuclear explosion. A radiochemical analysis of that debris can quickly and accurately determine the type of nuke and its fission yield.

In the past few months there has been both good news and bad news for Bush. North Korea conducted a test of not only a nuclear weapon, but also ballistic missiles that could reach our West Coast. The good news for Bush is that the tests will help him justify the zillion-dollar ballistic-missile defense boondoggle being constructed in Alaska. The bad news depends on whether North Korea tested a uranium nuke or a plutonium nuke; and whether the media elite chooses to explain the implications of the difference to the voters.

Flashback to 1994

First, let's briefly look at some recent history.

In 1992, because of a dispute with the International Atomic Energy Agency over the analysis of certain materials and activities they were subject to under an IAEA Safeguards Agreement-as required by the Treaty on Non-Proliferation of Nuclear Weapons-the North Koreans threatened to withdraw from the NPT.

In 1994 President Clinton had persuaded North Korea to sign the Agreed Framework, under which North Korea agreed not only to remain a signatory to the Treaty on Non-Proliferation of Nuclear Weapons but also to shut down its 5-MW, Plutonium-239-producing reactor; close its spent-fuel reprocessing facilities; and place all its existing nuclear materials-including (you guessed it) the Plutonium-239 contained in spent fuel elements-under lock and seal of the International Atomic Energy Agency; and to abandon construction of its 50-MW and 200-MW, Plutonium-239-producing reactors.

At the time, the NPT had to be extended every 5 years, and Clinton was hell-bent on getting the NPT extended indefinitely and to get all countries-especially Israel, India and Pakistan-to become NPT signatories, and to sign and ratify the Comprehensive Test Ban Treaty. For Clinton, the Agreed Framework's principal benefit was North Korea's promise to remain a NPT signatory.

What did the Koreans get in return? Well, Clinton promised to facilitate the replacement of their graphite-moderated Plutonium-239 producing reactors with conventional nuclear power plants and promised to provide millions of tons of fuel oil to tide them over until the plants came on line.

But the principal benefit the Koreans got under the Agreed Framework was a promise by the president of the United States to never use or threaten to use nuclear weapons against them. And as denizens of the Hermit Kingdom well know, over the years several American presidents had threatened them with nukes.

Bush Was Aggrieved by the Agreement

Well, you can imagine how constraining Bush the Younger considered the Agreed Framework to be. He couldn't even threaten to nuke Kim Jong-il. Worse, President Clinton promised when getting the NPT extended indefinitely-and again at the 2000 NPT Review Conference-to never use or threaten to use nukes against any NPT signatory-including Iran.

North Korea was on Bush's Axis of Evil because it had already supplied Iran ballistic missiles capable of reaching Israel and was developing ballistic missiles that might one day be capable of reaching our West Coast and carry warheads weighing perhaps several hundred pounds.

So, Bush apparently saw the Agreed Framework as constricting and welcomed a North Korean (and Iraqi and Iranian) withdrawal from the NPT. Although it has not been discussed much, Bush requested a National Intelligence Estimate in 2002 not just for Iraq but also for North Korea-and it was also highly controversial in the intelligence community. That document alleged that Pakistan's A.Q. Khan had provided North Korea (circa 1997) a dozen or so gas-centrifuges similar to those someone (A.Q. Khan, perhaps?) provided Iran at about the same time. The document also alleged that the Pakistanis trained North Korean engineers on how to operate them. The North Koreans were "assessed" to have produced a substantial amount of weapons-grade uranium. 

In September 2002 U.S. officials privately confronted the North Koreas of having a secret Uranium-235 nuke program, which the North Koreans then vehemently denied publicly, and have continued to deny to this day.

The president-citing the Uranium-235 nuke "intelligence"-stopped the fuel oil shipments to North Korea in November 2002, thereby abrogating the Agreed Framework. As Bush may have intended, the North Koreans almost immediately announced they were withdrawing from the NPT. 

Hence, in January 2003, on the eve of Bush's invasion of Iraq, North Korea ejected the IAEA inspectors, restarted their Plutonium-239 producing reactor, and began recovering Plutonium-239 from their spent fuel, which had been under IAEA lock and seal since the Agreed Framework was established in 1994.  By most estimates they now have enough Plutonium-239 to make 6-10 nukes and are busy producing more.

So What Was It?

So the question remains: Was that tested nuke Plutonium-239 or Uranium-235? If the nuke was a plutonium bomb, then Bush can put a nuke-armed North Korea on his list of foreign-policy achievements. If it was a uranium bomb, then the 2002 NIE on North Korea was correct.

Uranium or plutonium? America needs to know.

James Gordon Prather's long association with U.S. nuclear weapons programs includes active duty with the Armed Forces Special Weapons Project, participation in nuclear weapons tests as a diagnostic physicist at Lawrence Livermore Laboratory and as a technical director at Sandia National Laboratory. He was chief scientist for the Army under the Reagan Administration. Dr. Prather has been actively involved since 1991 in the Nunn-Lugar-Domenici Nuclear Threat Reduction programs.