WASHINGTON (Reuters) - New commercial satellite imagery indicates North Korea has resumed operation of a reactor at its main nuclear site used to produce plutonium for its nuclear weapons program, a U.S. think tank said on Friday.

North Korea's Yongbyon Nuclear Scientific Research Center is pictured in this January 16, 2017 handout satellite image obtained by Reuters January 27, 2017. Includes material Pleiades CNES 2017 Distribution Airbus DS / Spot Image, all rights reserved. Airbus Defense & Space and 38 North/Handout via REUTERS

Washington’s 38 North North Korea monitoring project said previous analysis from Jan. 18 showed signs that North Korea was preparing to restart the reactor at Yongbyon, having unloaded spent fuel rods for reprocessing to produce additional plutonium for its nuclear weapons stockpile.

“Imagery from January 22 shows a water plume (most probably warm) originating from the cooling water outlet of the reactor, an indication that the reactor is very likely operating,” it said in a report.

It said it was impossible to estimate at what power level the reactor was running, “although it may be considerable.” A 38 North Korea report last week said operations at the reactor had been suspended since late 2015.

North Korea has maintained its nuclear and missile programs in violation of repeated rounds of international sanctions.

News of the apparent reactor restart comes at a time of rising concern about North Korea’s weapons programs, which could present the new administration of U.S. President Donald Trump with its first major crisis.

A report by leading U.S.-based nuclear expert Siegfried Hecker published by 38 North last September estimated North Korea had stockpiles of 32 to 54 kg (70 to 119 pounds) of plutonium, enough for 6 to 8 bombs, and had the capacity to produce 6 kg, or approximately one bomb’s worth, per year.

North Korea also produces highly enriched uranium for atomic bombs and would have sufficient fissile material for approximately 20 bombs by the end of last year, and the capacity to produce seven more a year, that report said.

In a New Year speech, North Korean leader Kim Jong Un said his country was close to test launching an Intercontinental Ballistic Missile (ICBM) and state media has said a launch could come at any time.

Trump’s defense secretary plans to visit Japan and South Korea next week and shared concerns about North Korea are expected to top his agenda.</s>Satellite images indicate that North Korea has resumed operation of a reactor at its main plutonium production plant that could be used to build nuclear weapons, a think tank has said.

The Washington-based 38 North say that images taken on 22 January reveal a water plume shooting out from the reactor. This, the monitoring project say, could be an indication that the reactor at Yongbyon Nuclear Scientific Research Centre was again operating.

In addition to this clue the group say that unloaded spent fuel rods, that may have been in contact with nuclear material, were spotted in other images.

The report from 38 North said: "New commercial satellite imagery indicates that operations at the 5 MWe plutonium production reactor located at North Korea's Yongbyon Nuclear Scientific Research Center has likely resumed.

"Analysis from January 18 showed signs that Pyongyang was preparing to restart the reactor after spent fuel rods had previously been unloaded for a reprocessing campaign that produced additional plutonium for its nuclear weapons stockpile.

"Imagery from January 22 shows a water plume (most probably warm) originating from the cooling water outlet of the reactor, an indication that the reactor is very likely operating."

Although the think tank, based at the US-Korea Institute at John Hopkins University in Maryland, added it was: "Impossible to estimate at what power level the reactor is running, although it may be considerable".

Nuclear production at Yongbyon was shut down in 2007 as part of a disarmament agreement with the US, but in the years since Kim Jong Un's hermit nation has threatened to reopen production there.

In February 2016 former director of US National Intelligence James Clapper said that the Democratic People's Republic of Korea (DPRK) had: "Followed through on its announcement by expanding its Yongbyon enrichment facility and restarting the plutonium production reactor".

Then in September 2016, a report published by Siegfried Hecker, a leading expert on Pyongyang's nuclear programme, who visited Yongbyon in 2010, revealed that the country has ramped up its uranium enrichment facilities. According to Reuters the report said that North Korea will have enough material for about 20 nuclear bombs by the end of 2016.</s>North Korea appears to have restarted plutonium reactor -think tank

WASHINGTON, Jan 27 (Reuters) - New commercial satellite imagery indicates North Korea has resumed operation of a reactor at its main nuclear site used to produce plutonium for its nuclear weapons program, a U.S. think tank said on Friday.

Washington's 38 North North Korea monitoring project said previous analysis from Jan. 18 showed signs that North Korea was preparing to restart the reactor at Yongbyon, having previously unloaded spent fuel rods for reprocessing to produce additional plutonium for its nuclear weapons stockpile.

"Imagery from January 22 shows a water plume (most probably warm) originating from the cooling water outlet of the reactor, an indication that the reactor is very likely operating," it said in a report.

It said it was impossible to estimate at what power level the reactor was running, "although it may be considerable."

North Korea has maintained its nuclear and missile programs in violation of repeated rounds of international sanctions. (Reporting by David Brunnstrom; Editing by James Dalgleish)</s>North Korea appears to have restarted plutonium production for its nuclear weapons program at its main Nyongbyon reactor complex, commercial satellite imagery released by a think tank showed Friday. Imagery from a previous analysis by the North Korean-watching 38 North website on Jan. 18 showed that Pyongyang had been preparing to restart the reactor after spent fuel rods had been unloaded for reprocessing to produce extra plutonium for its weapons program, the report said.

Start the conversation, or Read more at The Japan Times.</s>A U.S. group that monitors North Korean weapons development says the communist country has likely resumed operations at a plutonium reactor at its Yongbyon nuclear facility.

38 North on Friday posted commercial satellite images that it said indicate Pyongyang is preparing to restart the reactor after previously unloading spent fuel rods.

The group said the images show a water plume that it believes is caused by the cooling water outlet of the reactor, an indication the reactor is very likely operating.

The organization says that without further measurements, it is impossible to estimate at what power level the reactor is running, although 38 North says it could be considerable.

North Korea is believed to be able to reprocess plutonium — used in nuclear warheads.

The Yongbyon nuclear complex, which includes a 5-megawatt reactor and other facilities, was shut down under an agreement reached in 2007 involving North Korea and five other countries: the United States, China, Japan, Russia and South Korea. North Korea, however, vowed in 2013 to resume activities at the site, 90 kilometers north of the capital, Pyongyang.

The International Atomic Energy Agency, a U.N. body, said last year that the Yongbyon reactor had been restarted, either for enrichment or reprocessing.

The reported activities by North Korea are the latest in a series of defiant acts amid numerous United Nations sanctions for the North's atomic and ballistic missile development.</s>North Korea appears to have restarted plutonium production for its nuclear weapons program at its main Nyongbyon reactor complex, commercial satellite imagery released by a think tank showed Friday.

Imagery from a previous analysis by the North Korean-watching 38 North website on Jan. 18 showed that Pyongyang had been preparing to restart the reactor after spent fuel rods had been unloaded for reprocessing to produce extra plutonium for its weapons program, the report said.

“Imagery from January 22 shows a water plume (most probably warm) originating from the cooling water outlet of the reactor, an indication that the reactor is very likely operating,” the report said, noting that most of the river remained frozen except where the warm water mixed.

“Currents carry this mix downstream — visible as a plume of ice-free water.”

However, without being able to measure the water’s temperature rise or flow from the reactor, the report said it was impossible to estimate the power level the reactor was running at — “although it may be considerable.”

According to the earlier report by 38 North, operations at the Nyongbyon complex had been halted since late 2015.

Pyongyang has stoked international concern with its atomic saber-rattling. In a his New Year’s address, North Korean leader Kim Jong Un said that the country had “entered the final stage of preparation for the test launch of intercontinental ballistic missile.”

Experts say that the isolated nation is moving closer to making this claim a reality after conducting an unprecedented spate of missile and nuclear tests over the past year — including its most powerful atomic blast to date.

Earlier this month, South Korea’s Yonhap news agency reported that two new missiles had been loaded onto mobile launchers, citing high-level South Korean officials and South Korean and U.S. military sources,

The missiles were thought to be equipped with new engines that Pyongyang tested last April, Yonhap reported. The North said at the time that the new tech would “guarantee” an eventual nuclear strike on the U.S. mainland.

According to Yonhap, the missiles’ existence appeared to have been intentionally leaked by Pyongyang to send a “strategic message” to the administration of new U.S. President Donald Trump.

Trump has said that a launch by the North of a nuclear weapon capable of hitting U.S. shores “won’t happen,” though he has not given specifics as to how he would halt Pyongyang’s progress toward mastering the technology.

On Wednesday, a senior diplomat in Pyongyang reiterated the North’s claims that it is ready to test-fire an ICBM “at any time, at any place.”

Choe Kang Il, deputy director general for North American affairs at the North’s Foreign Ministry, made the threat in an interview with NBC TV, saying such a move would be “defensive in nature.”

The North has been known to conduct weapons tests around key dates, and some experts believe it could test an ICBM to mark late leader Kim Jong Il’s birthday on Feb. 16.

Friday’s revelation of increased activity at the Nyongbyon plant comes on the heels of an announcement that U.S. Defense Secretary James Mattis will visit Japan and South Korea next week. Discussions are expected to focus on bolstering alliances with the two Asian giants amid the North Korean threat.

“The trip will underscore the commitment of the United States to our enduring alliances with Japan and the Republic of Korea, and further strengthen U.S.-Japan-Republic of Korea security cooperation,” the Pentagon said in a statement.</s>The 38 North group, run by Johns Hopkins University's School of Advanced International Studies, said satellite images taken on Oct. 1 show increased activity at the Sohae Satellite Launching Station, including crates on the launch pad and vehicles near the fuel and oxidizer buildings.

But it added that since some of the structures on the launch pad are covered, "it is unclear whether this activity is related to launch preparations or other operations."

North Korea conducted its fifth and biggest nuclear test on Sept. 9 and South Korea has said it believes the north is ready to conduct another nuclear test at any time. There has been speculation that Pyongyang could mark the Oct. 10 anniversary of the founding of its Workers' Party with a sixth detonation.

North Korea has been testing nuclear weapons and ballistic missiles at an unprecedented rate this year under leader Kim Jong Un's direction, including the launch of a satellite in February that was widely seen as a test of long-range ballistic missile technology.

The Sohae centre is the North's newly upgraded rocket station where the February satellite launch and other rocket tests have been conducted.

On Friday, 38 North said an increase in activity at North Korea's Punggye-ri nuclear test site could signal preparations for a new test or a collection of data from its last one.

North Korea conducted its first nuclear test in 2006 and has since defied U.N. sanctions to press ahead with the development of the weapons and missiles to carry them, which it says it needs for defence.

In January, it conducted its fourth nuclear test and the fifth was carried out on the anniversary of the nation's founding.</s>New commercial satellite imagery has appeared to indicate that North Korea has restarted its plutonium reactor at its nuclear weapons site.

The pictures, taken earlier this month, were obtained by Washington-based think tank 38 North Korea who have analysed them an say they indicate plumes of water.

They say the images show signs that Kim Jong Un has started the reactor at Yongbyon, having unloaded spent fuel rods for reprocessing to produce additional plutonium for its nuclear weapons stockpile.

In a report, the think tank said: 'Imagery from January 22 shows a water plume (most probably warm) originating from the cooling water outlet of the reactor, an indication that the reactor is very likely operating.'

They added it is impossible to estimate at what power level the reactor was running, it may be considerable.

It comes after North Korea suspended operations at the reactor in late 2015, but has maintained its nuclear and missiles programmes in spite of repeated rounds of international sanctions.

News of the apparent reactor restart also comes at a time of rising concern about North Korea's weapons programs, which could present the new administration of U.S. President Donald Trump with its first major crisis.

A report by leading U.S.-based nuclear expert Siegfried Hecker published by 38 North last September estimated North Korea had stockpiles of 70 to 119 pounds of plutonium.

This would be enough for six to eight bombs, and the report added North Korea had the capacity to produce six kilos of plutonium, or approximately one bomb's worth, per year.

North Korea also produces highly enriched uranium for atomic bombs and would have sufficient fissile material for approximately 20 bombs by the end of last year, and the capacity to produce seven more a year, that report said.

In a New Year speech, North Korean leader Kim Jong Un said his country was close to test launching an Intercontinental Ballistic Missile (ICBM) and state media has said a launch could come at any time.

Trump's defense secretary plans to visit Japan and South Korea next week and shared concerns about North Korea are expected to top his agenda.

Assessments of the North's plutonium stockpile are generally consistent and believed to be accurate because experts and governments can estimate plutonium production levels from telltale signs of reactor operation in satellite imagery.

The known history of the uranium enrichment project dates to 2003, when the North was confronted by the United States with evidence of a clandestine programme to build a facility to enrich uranium with the help of Pakistan.</s>North Korea set off its most powerful nuclear blast to date on Friday, saying it had mastered the ability to mount a warhead on a ballistic missile and ratcheting up a threat that its rivals and the United Nations have been powerless to contain.

"Assessment by South Korean and U.S. intelligence is that the North is always ready for an additional nuclear test in the Punggye-ri area," the site of all five nuclear explosions, South Korean Defence Ministry spokesman Moon Sang-gyun told a news briefing.

"North Korea has a tunnel where it can conduct an additional nuclear test," Moon said.

On Monday, Siegfried Hecker, a former director of the Los Alamos National Laboratory in the United States and a leading expert on North Korea's nuclear program, said Pyongyang's claims that it had standardized a nuclear warhead for mounting on ballistic missiles and could produce as many bombs as it wanted had to be taken seriously.

Writing on the 38 North website which monitors North Korea, Hecker estimated the country had stockpiled sufficient plutonium and highly enriched uranium for approximately 20 bombs by the end of the year and had the capacity to add about seven more a year.

"Its ability to field an ICBM fitted with a nuclear warhead capable of reaching the United States is still a long way off - perhaps 5 to 10 years - but likely doable if the program is unconstrained," Hecker added.

The United States and South Korea are pushing for more sanctions against Pyongyang to close loopholes left in a United Nations Security Council resolution adopted in March.

U.S. Treasury Secretary Jack Lew said on Monday the United States would do all it could to oppose North Korea's nuclear weapons policy with financial tools as coordinated economic sanctions had been shown to work.

"North Korea is an enormous challenge and we will do everything we can to keep the pressure on them. We will continue to sharpen financial tools as we can," he said, while adding that China's participation was very important.

Both China and Russia backed sanctions imposed in March following North Korea's January nuclear test, but their apparent ambivalence about fresh sanctions has cast doubt on the Security Council's ability to quickly form a consensus.

"We expect that China, as one of the Security Council member states, should take this issue seriously and play a very constructive role to come up with a very effective and strong sanctions resolution," a South Korean foreign ministry official said.

The Security Council has denounced the latest test and said it would begin work immediately on a resolution. The United States, Britain and France - three of the five veto-wielding permanent members - have pushed for the 15-member body to impose new sanctions.

However, China's foreign ministry spokeswoman Hua Chunying said sanctions alone could not solve the North Korean nuclear issue. The crux of the issue lay with the United States, not China, she added, in an apparent reference to Washington's refusal to resume negotiations with North Korea until it commits to de-nuclearization.

On Saturday, Russian Foreign Minister Sergei Lavrov said a "creative" response was needed.

Speaking to Lavrov on Monday, Chinese Foreign Minister Wang Yi said China "strongly urged North Korea and other relevant parties to remain calm and exercise restraint, and not take any new steps to intensify tensions", China's Foreign Ministry said.

Russia said Lavrov and Wang condemned North Korea's latest nuclear test in a phone conversation on Monday. Russia and China are the other veto powers on the Security Council.

South Korea's President Park Geun-hye said North Korea's nuclear weapons and missiles posed an "imminent threat."

"As North Korea has publicly said nuclear warheads have been standardized and customized to mount on ballistic missiles, we should keep in mind that North Korea's nuclear missiles are a realistic, imminent threat targeting us, not a simple threat for negotiations," Park told a meeting with major political party leaders.

Pyongyang's assertions that it is able to miniaturize a nuclear warhead have never been independently verified.

North Korean Foreign Minister Ri Yong Ho, formerly the country's chief nuclear negotiator, arrived in Beijing on Monday and was seen entering the country's embassy, Japan's Kyodo news agency reported.

Ri left Pyongyang on Monday to attend a meeting of the Non-Aligned Movement countries in Venezuela and later the U.N. General Assembly, North Korea's official KCNA news agency said.

A U.S. special envoy for North Korea, Sung Kim, met Japanese officials on Sunday and said the United States may launch unilateral sanctions against North Korea, echoing comments by U.S. President Barack Obama on Friday in the wake of the test.

South Korea's Yonhap news agency reported that bad weather had delayed the flight of a U.S. B-1B bomber to the Korean peninsula, a show of strength and solidarity with ally Seoul, scheduled for Monday.

The flight from the U.S. base in Guam would now take place on Tuesday, a U.S. Forces in Korea official told Reuters, declining to identify the type of aircraft involved.

A group of 31 conservative lawmakers in South Korea said the country should have nuclear weapons, either by acquiring its own arms, or asking the United States to redeploy tactical nuclear weapons withdrawn under a 1991 pact for denuclearization of the Korean peninsula.

"We should discuss every plan including an independent nuclear armament program at the level of self-defense to safeguard peace," Won Yoo-chul, a senior lawmaker for the ruling Saenuri Party, said in a statement.

South Korea's Defence Ministry said there was no change in its policy barring nuclear weapons.</s>The 38 North group, run by Johns Hopkins University's School of Advanced International Studies, said satellite images showed activity at all three tunnel complexes at the Punggye-ri nuclear test site involving a large vehicle and personnel.

"One possible reason for this activity is to collect data on the Sept. 9 test, although other purposes cannot be ruled out, such as sealing the portal or other preparations related to a new test," the group said.

North Korea conducted its fifth and biggest nuclear test on Sept. 9 and South Korea has said it believes the north is ready to conduct another nuclear test at any time. There has been speculation that Pyongyang could mark the Oct. 10 anniversary of the founding of its Workers' Party with a sixth detonation.

A study published on Friday by a U.S.-based North Korea research project said North Korean missile and nuclear tests, and other major "provocations", had clustered increasingly closer to U.S. elections.

The study from Washington's Center for Strategic and International Studies said the pattern based on looking at 30 U.S. elections since 1956 suggested a North Korean action as early as a month before the Nov. 8 U.S. presidential election.

This could mean a test coinciding with the Oct.10 anniversary. The trend also suggested the possibility of an act during the December transition period for the next U.S. administration.

North Korea conducted its first nuclear test in 2006 and has since defied U.N. sanctions to press ahead with the development of the weapons and missiles to carry them, which it says it needs for defence.

In January, it conducted its fourth nuclear test and the fifth was carried out on the anniversary of the nation's founding.

South Korea's Unification Ministry spokesman Jeong Joon-hee told a briefing there were no particular indications of a plan for a nuclear test on Oct. 10.

However, South Korea's Yonhap news agency cited an unidentified government official as saying that activity at North Korea's rocket launch station near the west coast could be preparations for a long-range missile launch.

Japan said the possibility of further "provocative action" by North Korea could not be ruled out.

"The government is taking all possible measures in gathering information, exercising vigilance and taking surveillance activities to be able to respond to any situations," Japan's Chief Cabinet Secretary Yoshihide Suga told a news conference.
New satellite imagery released by think tank 38 North indicates North Korea has resumed operations at its Yongbyon Nuclear Scientific Research Center in North Pyongan Province.