Expert: North’s test not a surprise, more to come

Sigfried Hecker

American nuclear expert Sigfried Hecker believes North Korea is “improving its nuclear weapons capabilities, not giving them up,” following its recent nuclear test.

In an e-mail interview, Hecker, co-director of the Center for International Security and Cooperation at Stanford University, also said North Korea could go ahead with another nuclear and missile test.

“They stated that they would test an ICBM [intercontinental ballistic missile], so they likely will test again,” Hecker said. “As for another nuclear test, they are limited by their small plutonium inventory, but one more test is possible.”

Hecker, who is also a research professor in the Department of Management Science and Engineering at Stanford, has visited North Korea six times since 2005; his most recent trip there was last February. He has previously noted that North Korea has given him “remarkable access to its Yongbyon nuclear facilities and its technical specialists.”

“They told me that it was useful to reduce the ambiguities about the North Korean nuclear program,” Hecker said. “To some extent the access to Yongbyon has allowed me to do that.”

What it has also allowed him to do was gather information on the state of the nuclear program there. Hecker noted that North Korea possesses enough plutonium for a third nuclear test.

“[North Korea] likely used only a small portion of the 26 kilograms it had on hand, perhaps as much as 6 kilograms,” Hecker said. “Since it is now reprocessing another 8 kilograms from the spent fuel, it can replace whatever it used during this test.”

The expert also thought highly of the skill level of North Korean nuclear scientists.

“North Korean scientists and engineers have mastered the plutonium fuel cycle,” he said. “That is, they have demonstrated all the capabilities to make fuel, construct and operate a reactor, and extract plutonium in a reprocessing facility.”

Hecker estimated the latest nuclear yield to be in the range of 2 to 4 kilotons and if a device with this power were detonated above a major city, “it could cause tens of thousands of deaths.”

“I believed that North Korea planned to do a test once it decided to reprocess the 8,000 fuel rods [in mid-April],” he said. “I did not believe it had to finish before it tested because it could use its previously reprocessed plutonium for the test and replace it once the new plutonium is reprocessed. So, I am not surprised they tested early. This test had been in the planning stage for a long time.”

By Kim Su-jeong, Yoo Jee-ho [jeeho@joongang.co.kr]