It’s unclear. But experts say it also doesn’t really matter: it’s unlikely to much affect the North’s nuclear capabilities.
CBS News has reported that Administration Officials have named the Sohae Satellite Launching Ground at Ch'olsan County, North Pyongan province as the site to be destroyed. The site was very important in testing and development of the Hwasong-15 intercontinental ballistic missile. Middlebury researcher Jeff Lewis, quoted below, said of the announcement "I don’t want to be churlish, but this is like the closure of the nuclear test site. It’s showy and an important facility, but in isolation it doesn’t mean much. There are other sites for static engine testing and could be easily rebuilt. It’s a gesture toward the idea of disarmament more than disarmament itself."
Dave Schmerler, a research associate at the James Martin Center for Nonproliferation Studies, also quoted below, said: "Well it is their biggest missile engine test stand. The focal point for their most powerful engine tests to date. Removing it would be a start toward something but it is not a major step. They could always build another one excluding the other test sites across the country. That's if they even do it."
North Korea will destroy an engine-testing site as part of its denuclearization process, U.S. President Donald Trump told reporters Tuesday after his meeting with Kim Jong Un in Singapore. “Chairman Kim has told me that North Korea is already destroying a major missile engine testing site,” Trump said. “We agreed to that after the agreement was signed. That’s a big thing, for the missiles that they were testing. The site is going to be destroyed very soon.”
But Trump didn’t name the “engine test site” and it’s not clear what he was talking about. More importantly, experts say the removal of any one testing site is unlikely to hamper North Korea’s ability to make nuclear weapons.
Perhaps it was the Iha-ri Driver Training and Test Facility, which the North Koreans are already razing. Jenny Town, managing director of the open-source intelligence site 38 North, said Iha-ri Driver was “as educated a guess as any.”
That site helped develop the solid-state rocket engine for the Pukguksong-2 mid-range ballistic missile, but there’s no reason to believe its destruction indicates the abandonment of any future tests or programs, said Dave Schmerler, a research associate at the James Martin Center for Nonproliferation Studies.
“The dismantlement of the Iha-ri ejection test stand seems to reflect the progress made in the Pukguksong-2 program, rather than it being connected to any other notional canister launched missile system. If we see a new test stand appear near a vehicle manufacturing site, it might indicate that the North Koreans are working on a new system, however there is no indication of this at the moment,” he said. (Check out his thread, below.)
On Trump's statement after meeting with KJU: the North offered to destroy a major missile engine test site. But the question now is which one? Here are our options https://t.co/tONYUThI3Z— Dave Schmerler (@DaveSchmerler) June 12, 2018
But Middlebury researcher and arms control watcher Jeffrey Lewis said that site doesn’t really qualify as an engine test site.
“North Korea has multiple engine test stands. The one at Hamhung is a concrete block with a roof over it. It is a good thing if North Korea refrains from static engine tests, but that won't prevent North Korean from producing more missiles. And North Korea could easily resume testing,” Lewis said. Bottom line, he says: “North Korea does not need to conduct further static engine tests to continue to produce existing missile systems."
The Iha-ri facility played an important role in the North’s continued development of solid-state engines. The North Koreans began testing engines there in February 2017.
In his 38 North piece, Joseph S. Bermudez Jr. wrote that the North began to raze the site after Kim announced that his regime would cease all ballistic missile tests. The work began last month and was mostly done by May 19.
How important is the facility? Bermudez described it as useful for testing canister-based solid-state medium-range missiles. Such engines burn potassium nitrate or another solid propellant rather than more finicky liquid fuels such as hydrogen, making them more stable, easier to prepare for launch, and simpler to make. If it hadn’t been razed, the site might have been used, say, to convert North Korea’s liquid-fueled Hwasong-15 ICBM to solid fuel.
Whichever missile it is, Town agreed that the concession is largely moot. “North Korea has also said it is done with the development phase of its nuclear and missile systems, so these measures are still largely symbolic diplomatic gestures and do not affect the core of NK’s nuclear capabilities,” she said.