Climate change threatens Antarctic meteorites

ETH ZURICH

 

IMAGE: 

FIELD GUIDE IN A BLUE ICE AREA DURING A MISSION TO TAKE ICE SAMPLES. PHOTO TAKEN DURING THE 2023-2024 FIELDWORK MISSION OF THE INSTITUTO ANTÁRTICO CHILENO (INACH) TO UNION GLACIER, ELLSWORTH MOUNTAINS, ANTARCTICA.

view more 

CREDIT: VERONICA TOLLENAAR, UNIVERSITÉ LIBRE DE BRUXELLES

Using artificial intelligence, satellite observations, and climate model projections, a team of researchers from Switzerland and Belgium calculate that for every tenth of a degree of increase in global air temperature, an average of nearly 9,000 meteorites disappear from the surface of the ice sheet. This loss has major implications, as meteorites are unique samples of extraterrestrial bodies that provide insights into the origin of life on Earth and the formation of the Moon.

Disappearing at an alarming rate

By 2050, about a quarter of the estimated of 300,000 - 800,000 meteorites in Antarctica will be lost due to glacial melt. By end of the century, researchers anticipate that number could rise approaching a loss of meteorites closer to three-quarters of the meteorites on the continent under a high-warming scenario.

Published in the journal Nature Climate Change, Harry Zekollari co-led the study while working under Professor Daniel Farinotti in the Laboratory of Hydraulics, Hydrology and Glaciology at the Department of Civil, Environmental and Geomatic Engineering at ETH Zurich. Zekollari and co-lead Veronica Tollenaar, Université Libre de Bruxelles, reveal in the study that ongoing warming results in the loss of about 5,000 meteorites a year, outpacing the collection efforts of Antarctic meteorites by a factor five.

Meteorites – time capsules of the universe

Zekollari, now an Associate Professor of Glaciology at Vrije Universiteit Brussel, calls for a major international effort to preserve the scientific value of meteorites, “We need to accelerate and intensify efforts to recover Antarctic meteorites. The loss of Antarctic meteorites is much like the loss of data that scientists glean from ice cores collected from vanishing glaciers – once they disappear, so do some of the secrets of the universe.”

Meteorites are fragments from space that provide unique information about our solar system. Antarctica is the most prolific place to find meteorites, and to date, about 60 percent of all meteorites ever found on Earth have been collected from the surface of the Antarctic ice sheet. The flow of the ice sheet concentrates meteorites in so-called “meteorite stranding zones”, where their dark crust allows them to be easily detected. In addition to intensifying recovery operations, there is potential to increase the efficiency of meteorite recovery missions in the short term. This potential relies mainly on data-driven analysis to identify unexplored meteorite stranding zones and mapping areas exposing blue ice where meteorites are often found.

Extraterrestrial heritage slipping away

Due to their dark colour, meteorites preferentially heat up with respect to the surrounding ice. As this heat transfers from the meteorites to the ice, it can warm up the ice, and eventually cause the ice to locally melt, leading to a sinking of meteorites underneath the surface of the ice sheet. Once the meteorites enter the ice sheet, even at shallow depths, they cannot be detected anymore, and they are thus lost for science.

As atmospheric temperatures increase, so does the surface temperature of the ice, intensifying the loss. "Even when temperatures of the ice are well below zero, the dark meteorites warm-up so much in the sun that they can melt the ice directly beneath the meteorite. Through this process, the warm meteorite creates a local depression in the ice and over time fully disappears under the surface,” says Tollenaar.

Scientists conclude that in the long-term, the only way to preserve most of the remaining unrecovered Antarctic meteorites is to rapidly reduce greenhouse gas emissions.

Ice sampling on a blue ice area in mountainous terrain. Photo taken during the 2023-2024 fieldwork mission of the Instituto Antártico Chileno (INACH) to Union Glacier, Ellsworth Mountains, Antarctica. Credit: Fernando Inostroza Méndez, Center for Antarctic Affairs of the Chilean Army.

Antarctic meteorite (HUT 18036) partially in the ice, in contrast to most samples that are collected while lying on the surface. Meteorite collected by the Lost Meteorites of Antarctica project.

CREDIT

Katherine Joy, The University of Manchester, The Lost Meteorites of Antarctica project.

JOURNAL

Nature Climate Change

DOI

10.1038/s41558-024-01954-y 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Antarctic meteorite archives threatened by climate warming

ARTICLE PUBLICATION DATE

8-Apr-2024

SPACE

 

How the moon turned itself inside out

University of Arizona scientists combined computer simulations and spacecraft data to solve a long-standing mystery surrounding the moon's "lopsided" geology

UNIVERSITY OF ARIZONA

 

IMAGE: 

SCHEMATIC ILLUSTRATION WITH A GRAVITY GRADIENT MAP (BLUE HEXAGONAL PATTERN) OF THE LUNAR NEARSIDE AND A CROSS-SECTION SHOWING TWO ILMENITE-BEARING CUMULATE DOWNWELLINGS FROM LUNAR MANTLE OVERTURN.

view more 

CREDIT: ADRIEN BROQUET/UNIVERSITY OF ARIZONA & AUDREY LASBORDES

About 4.5 billion years ago, a small planet smashed into the young Earth, flinging molten rock into space. Slowly, the debris coalesced, cooled and solidified, forming our moon. This scenario of how the Earth's moon came to be is the one largely agreed upon by most scientists. But the details of how exactly that happened are "more of a choose-your-own adventure novel," according to researchers in the University of Arizona Lunar and Planetary Laboratory who published a paper in Nature Geoscience. The findings offer important insights into the evolution of the lunar interior, and potentially for planets such as the Earth or Mars.

Most of what is known about the origin of the moon comes from analyses of rock samples, collected by Apollo astronauts more than 50 years ago, combined with theoretical models. The samples of basaltic lava rocks brought back from the moon showed surprisingly high concentrations of titanium. Later satellite observations found that these titanium-rich volcanic rocks are primarily located on the moon's nearside, but how and why they got there has remained a mystery – until now.

Because the moon formed fast and hot, it was likely covered by a global magma ocean. As the molten rock gradually cooled and solidified, it formed the moon's mantle and the bright crust we see when we look up at a full moon at night. But deeper below the surface, the young moon was wildly out of equilibrium. Models suggest that the last dregs of the magma ocean crystallized into dense minerals including ilmenite, a mineral containing titanium and iron.

"Because these heavy minerals are denser than the mantle underneath, it creates a gravitational instability, and you would expect this layer to sink deeper into the moon's interior," said Weigang Liang, who led the research as part of his doctoral work at LPL.

Somehow, in the millennia that followed, that dense material did sink into the interior, mixed with the mantle, melted and returned to the surface as titanium-rich lava flows that we see on the surface today.

"Our moon literally turned itself inside out," said co-author and LPL associate professor Jeff Andrews-Hanna. "But there has been little physical evidence to shed light on the exact sequence of events during this critical phase of lunar history, and there is a lot of disagreement in the details of what went down – literally."

Did this material sink as it formed a little at a time, or all at once after the moon had fully solidified? Did it sink into the interior globally and then rise up on the near side, or did it migrate to the near side and then sink? Did it sink in one big blob, or several smaller blobs?   

"Without evidence, you can pick your favorite model. Each model holds profound implications for the geologic evolution of our moon," said co-lead author Adrien Broquet of the German Aerospace Center in Berlin, who did the work during his time as a postdoctoral research associate at LPL.

In a previous study, led by Nan Zhang at Peking University in Beijing, who is also a co-author on the latest paper, models predicted that the dense layer of titanium-rich material beneath the crust first migrated to the near side of the moon, possibly triggered by a giant impact on the far side, and then sunk into the interior in a network of sheetlike slabs, cascading into the lunar interior almost like waterfalls. But when that material sank, it left behind a small remnant in a geometric pattern of intersecting linear bodies of dense titanium-rich material beneath the crust.

"When we saw those model predictions, it was like a lightbulb went on," said Andrews-Hanna, "because we see the exact same pattern when we look at subtle variations in the moon’s gravity field, revealing a network of dense material lurking below the crust."

In the new study, the authors compared simulations of a sinking ilmenite-rich layer to a set of linear gravity anomalies detected by NASA's GRAIL mission, whose two spacecraft orbited the moon between 2011 and 2012, measuring tiny variations in its gravitational pull. These linear anomalies surround a vast dark region of the lunar near side covered by volcanic flows known as mare (Latin for "sea").

The authors found that the gravity signatures measured by the GRAIL mission are consistent with ilmenite layer simulations, and that the gravity field can be used to map out the distribution of the ilmenite remnants left after the sinking of the majority of the dense layer.

"Our analyses show that the models and data are telling one remarkably consistent story," Liang said. "Ilmenite materials migrated to the near side and sunk into the interior in sheetlike cascades, leaving behind a vestige that causes anomalies in the moon's gravity field, as seen by GRAIL."

The team's observations also constrain the timing of this event: The linear gravity anomalies are interrupted by the largest and oldest impact basins on the near side and therefore must have formed earlier. Based on these cross-cutting relationships, the authors suggest that the ilmenite-rich layer sank prior to 4.22 billion years ago, which is consistent with it contributing to later volcanism seen on the lunar surface.

"Analyzing these variations in the moon's gravity field allowed us to peek under the moon's surface and see what lies beneath," said Broquet, who worked with Liang to show that the anomalies in the moon’s gravitational field match what would be expected for the zones of dense titanium-rich material predicted by computer simulation models of lunar overturn.

Three views of the moon's nearside: the familiar sight from Earth (left), regions covered by titanium-rich volcanic flows (center) and polygonal pattern of gravity anomalies

The lunar near side with its dark regions, or “mare,” covered by titanium-rich volcanic flows (center) makes up the moon’s familiar sight from Earth (left). The mare region is surrounded by a polygonal pattern of linear gravity anomalies (blue in image on the right) interpreted to be the vestiges of dense material that sank into the interior. Their presence provides the first physical evidence for the nature of the global mantle overturn more than 4 billion years ago.

CREDIT

Adrien Broquet/University of Arizona

More than 50 years ago, Apollo astronauts brought basaltic lava rocks back from the moon with surprisingly high concentrations of titanium. Later, satellite observations found that these titanium-rich volcanic rocks are primarily located on the moon's nearside - but how and why they got there has remained a mystery – until now.

CREDIT

NASA

Lopsided moon

While the detection of lunar gravity anomalies provides evidence for the sinking of a dense layer in the moon’s interior and allows for a more precise estimate of how and when this event occurred, what we see on the surface of the moon adds even more intrigue to the story, according to the research team.

"The moon is fundamentally lopsided in every respect," Andrews-Hanna said, explaining that the near side facing the Earth, and particularly the dark region known as Oceanus Procellarum region, is lower in elevation, has a thinner crust, is largely covered in lava flows, and has high concentrations of typically rare elements like titanium and thorium. The far side differs in each of these respects. Somehow, the overturn of the lunar mantle is thought to be related to the unique structure and history of the near side Procellarum region. But the details of that overturn have been a matter of considerable debate among scientists.

"Our work connects the dots between the geophysical evidence for the interior structure of the moon and computer models of its evolution," Liang added.

"For the first time we have physical evidence showing us what was happening in the moon’s interior during this critical stage in its evolution, and that's really exciting," Andrews-Hanna said. "It turns out that the moon’s earliest history is written below the surface, and it just took the right combination of models and data to unveil that story."

"The vestiges of early lunar evolution are present below the crust today, which is mesmerizing," Broquet said. "Future missions, such as with a seismic network, would allow a better investigation of the geometry of these structures."

Liang added: "When the Artemis astronauts eventually land on the moon to begin a new era of human exploration, we will have a very different understanding of our neighbor than we did when the Apollo astronauts first set foot on it."

---

JOURNAL

Nature Geoscience

DOI

10.1038/s41561-024-01408-2 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Vestiges of a lunar ilmenite layer following mantle overturn revealed by gravity data

ARTICLE PUBLICATION DATE

8-Apr-2024

​CSIRO telescope detects unprecedented behaviour from nearby magnetar

CSIRO AUSTRALIA

 

VIDEO: 

ARTIST’S IMPRESSION OF A MAGNETAR WITH MAGNETIC FIELD AND POWERFUL JETS. 

view more 

CREDIT: CSIRO

​

Researchers using Murriyang, CSIRO’s Parkes radio telescope, have detected unusual radio pulses from a previously dormant star with a powerful magnetic field. 

​New results published today in Nature Astronomy describe radio signals from magnetar XTE J1810-197 behaving in complex ways.  

​Magnetars are a type of neutron star and the strongest magnets in the Universe. At roughly 8,000 light years away, this magnetar is also the closest known to Earth.  

​Most are known to emit polarised light, though the light this magnetar is emitting is circularly polarised, where the light appears to spiral as it moves through space. 

​Dr Marcus Lower, a postdoctoral fellow at Australia’s national science agency – CSIRO, led the latest research and said the results are unexpected and totally unprecedented. 

​"Unlike the radio signals we've seen from other magnetars, this one is emitting enormous amounts of rapidly changing circular polarisation. We had never seen anything like this before,” Dr Lower said. 

​Dr Manisha Caleb from the University of Sydney and co-author on the study said studying magnetars offers insights into the physics of intense magnetic fields and the environments these create.  

​"The signals emitted from this magnetar imply that interactions at the surface of the star are more complex than previous theoretical explanations.” 

​Detecting radio pulses from magnetars is already extremely rare: XTE J1810-197 is one of only a handful known to produce them.  

​While it’s not certain why this magnetar is behaving so differently, the team has an idea.  

​“Our results suggest there is a superheated plasma above the magnetar's magnetic pole, which is acting like a polarising filter,” Dr Lower said.  

​“How exactly the plasma is doing this is still to be determined.” 

​XTE J1810-197 was first observed to emit radio signals in 2003. Then it went silent for well over a decade. The signals were again detected by the University of Manchester's 76-m Lovell telescope at the Jodrell Bank Observatory in 2018 and quickly followed up by Murriyang, which has been crucial to observing the magnetar’s radio emissions ever since.  

​The 64-m diameter telescope on Wiradjuri Country is equipped with a cutting edge ultra-wide bandwidth receiver. The receiver was designed by CSIRO engineers who are world leaders in developing technologies for radio astronomy applications.  

​The receiver allows for more precise measurements of celestial objects, especially magnetars, as it is highly sensitive to changes in brightness and polarisation across a broad range of radio frequencies. 

​Studies of magnetars such as these provide insights into a range of extreme and unusual phenomena, such as plasma dynamics, bursts of X-rays and gamma-rays, and potentially fast radio bursts.  

​Lower, M. E., et al., Linear to circular conversion in the polarized radio emission of a magnetar, Nature Astronomy, vol. 8 (2024) 

​– ends –  

​CSIRO acknowledges the Wiradjuri People as the traditional custodians of the Parkes Observatory site where Murriyang, our Parkes radio telescope, is located. 

Images and b-roll video are available here.

CAPTION

Murriyang, CSIRO’s Parkes radio telescope beneath the Milky Way.  

CREDIT

Alex Cherney/CSIRO

Murriyang, CSIRO’s Parkes radio telescope in the field with wild kangaroos. 

CREDIT

CSIRO

Artist’s impression of a magnetar. 

CREDIT

Carl Knox, OzGrav/Swinburne University of Technology

Artist’s impression of a magnetar with magnetic field and powerful jets. 

CREDIT

CSIRO

JOURNAL

Nature Astronomy

DOI

10.1038/s41550-024-02225-8 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Linear to circular conversion in the polarized radio emission of a magnetar

ARTICLE PUBLICATION DATE

8-Apr-2024

Scientists make largest and most precise 3D map of expanding universe


Ellie Crabbe

THE ARGUS
Sun, 7 April 2024 

Graphic by Lawrence Berkeley National Laboratory of the largest 3D map of our universe to date (Image: Lawrence Berkeley National Laboratory/PA)

Scientists have made the largest 3D map of the universe, measuring how fast it has expanded over billions of years by using the most precise measurements to date.

An international team, including researchers from Sussex university, used an instrument known as the Dark Energy Spectroscopic Instrument (Desi) to create the map.

Their aim was to measure the effects of dark energy, a mysterious force that is believed to be making the universe expand faster and faster.


The scientists said they were able to measure the expansion history of the universe spanning 11 billion years with a precision better than one per cent.

The map, comprising more than six million galaxies, is the largest 3D map of the cosmos constructed.

Dr Eva-Maria Mueller, Ernest Rutherford Fellow at the University of Sussex, who led part of the cosmological interpretation of the Desi data, said she could not initially believe the “fascinating” results.

READ MORE: Sussex university asking people to join its bee experiment

Dr Mueller said: “It was a moment I’d been eagerly anticipating since the start of my PhD.

“The findings were not just interesting – they were captivating, sparking fresh insights into the fundamental nature of our universe.

“It’s moments like these that remind me why I’m passionate about cosmology.”

The Desi instrument uses 5,000 tiny robots within a mountaintop telescope near Tucson, Arizona.

Scientists were able to map the cosmos as it was billions of years ago and traced its growth to what it is today, using light from distant objects in space which are only now reaching Desi.

Professor Carlos Frenk, of Durham University’s department of physics and a member of the Desi team, described the findings as “hugely exciting”.

He said: “Never before has mankind measured the basic properties of our universe with such precision.”

At present, Lambda CDM, a cosmological model that describes the structure and evolution of the universe, is seen by scientists as the leading framework determining how the universe is evolving.

It includes both a weakly interacting type of matter, known as cold dark matter (CDM), and dark energy – also referred to as Lambda.

According to the model, both matter and dark matter slow down the universe’s expansion, while dark energy speeds it up.

Starwatch: exploding nova promises rare sight in coming months


Stuart Clark
Sun, 7 April 2024 
Interactive

Get ready for a “new” star to appear in the night sky. Not really new of course, but a star that is now below the naked-eye visibility limit is gearing up for an outburst that will bring it within sight of the unaided eye for the first time since the 1940s.

Such a star is called a nova, Latin for “new”. The star, T Coronae Borealis, is actually composed of two stars: a red giant and a white dwarf. The white dwarf is a dense stellar core about the size of the Earth and its gravity is pulling gas off the red giant. This gas accumulates on the white dwarf’s surface before detonating in a thermonuclear explosion, causing the star to temporarily brighten. Eventually, it returns to normal and the cycle repeats.

In the case of T Coronae Borealis, historical observations show that it explodes approximately every 80 years. Astronomers expect it to blow any time between now and September. The chart shows the view looking east from London at about 22.00 BST this week, and marks the location to keep an eye on. When it erupts, the star is expected to reach the same brightness as Alphecca, the brightest star in its home constellation.

 

Nuclear projects receive UK space funding boost

08 April 2024

Two projects featuring nuclear energy are among 11 international space projects selected to received funding from the UK Space Agency. Rolls-Royce's collaboration with BWXT receives GBP1.18 million (USD1.5 million) to further its work on fission nuclear systems for space power missions, while an international project led by the University of Leicester receives GBP800,000.

A Rolls-Royce Micro-Reactor could provide power for a lunar base (Image: Rolls-Royce)

A total of GBP13 million of funding, the second phase of investment awarded through the Agency's GBP20 million International Bilateral Fund (IBF), is being announced today at the 39th Space Symposium in Colorado Springs, USA, the UK Space Agency said. This follows a first phase announced last year, which provided funds of up to GBP75,000 each for 32 projects which then entered into a competitive process to receive Phase 2 funding.

The funding to Rolls-Royce Submarines and BWXT Advanced Technologies LLC is for a project to "identify the optimum technologies for a fission nuclear system which balances flexibility to a range of space power missions and maximises performance whilst minimising programme and technical risk."

The second nuclear project to receive Phase 2 funding is a collaboration between the University of Leicester and partners from the UK, USA and Japan who will work together to identify a range of mission opportunities for UK space nuclear power technologies. The collaboration also includes the development of hybrid power systems with existing US conversion technologies.

"We want to draw on the best global talent to push the boundaries of new technology such as AI and space nuclear power, enhance our homegrown space capabilities and catalyse investment into the UK economy," Chief Executive of the UK Space Agency Paul Bate said. "The projects supported by our International Bilateral Fund champion the best of British innovation, while strengthening our ties with the wider space community."

UK-US collaboration

All space missions depend on a power source to support systems for communications, life-support and science experiments. Nuclear power has the potential to dramatically increase the duration of future space missions and their scientific value. Space micro-reactors are a solution to meet these requirements in a sustainable and resilient way, Rolls-Royce said.

This latest investment follows GBP2.9 million awarded to Rolls-Royce from the UK Space Agency under the Lunar Surface Nuclear Power Contract and Phase 1 of the IBF in 2023, which culminated in an initial demonstration of a UK lunar modular nuclear reactor. Rolls-Royce unveiled its Space Micro-Reactor Concept Model to show how nuclear power could be used to support a future Moon base for astronauts last December.

The new funding award is part of a larger teaming agreement between Rolls-Royce and BWXT Advanced Technologies LLC which facilitates business collaboration and joint developments of new and novel nuclear applications in terrestrial, space and commercial maritime domains using the core nuclear design and manufacturing strengths of both companies. It will benefit both UK and US space nuclear development programmes for a range of space power missions, the companies said, and further strengthens UK and US collaboration on first-of-a-kind space technology innovation set out under the Atlantic Declaration commitment by UK Prime Minister Rishi Sunak and US President Joe Biden last year, in which both countries pledged to study "opportunities for co-operation on space nuclear power and propulsion."

"This exciting research by Rolls-Royce to develop space nuclear power is an opportunity to showcase the UK as a spacefaring nation," Anu Ojha, director of Championing Space at the UK Space Agency, said. "Innovative technologies such as this one could pave the way for continuous human presence on the Moon, whilst enhancing the wider UK space sector, creating jobs and generating further investment."

Researched and written by World Nuclear News

PSEG to apply for second licence renewals for New Jersey plants

08 April 2024

PSEG Nuclear LLC has notified US regulators of its intent to seek subsequent licence renewal for the Salem and Hope Creek nuclear power plants, which together produce nearly half of New Jersey’s electricity and 85% of the state’s carbon-free generation.

PSEG's three New Jersey units: Hope Creek and Salem units 1 and 2 (Image: Peretz Partensky)

It formally informed the US Nuclear Regulatory Commission (NRC) on 28 March that it expects to submit the application in the second quarter of 2027. This would mark the start of a comprehensive NRC review and approval process taking about two years to complete. If approved, the licences for Salem unit 1 and unit 2 would be extended from 2036 and 2040 to 2056 and 2060, respectively, while the single-unit Hope Creek's licence would be extended from its current 2046 expiration to 2066.

The two pressurised water reactors at Salem began commercial operation in 1976 (unit 1) and 1980 (unit 2), and the boiling water reactor at Hope Creek in 1986. The stations obtained their first 20-year operating licence renewals from the NRC in 2011. The units had all been under threat of premature closure before New Jersey passed the Zero Emissions Certificate Law in 2018, enabling the state to recognise and compensate eligible nuclear power plants for their zero-carbon attributes and contribution to fuel diversity.

"For more than five decades, the nuclear generating stations in South Jersey have safely generated reliable, always-on carbon-free energy," said PSEG Nuclear President and Chief Nuclear Officer Charles McFeaters. "Seeking to renew our licences signifies our commitment to continuing to contribute to New Jersey’s clean energy future and serving as a vital economic engine for the local community."

"I'd like to recognise Congressman Bill Pascrell, the author of the federal nuclear production tax credit legislation in Congress, without which we would not be considering these investments in the site," he added.

The nuclear production tax credit, created in the federal Inflation Reduction Act, will provide nuclear generators with nine years of financial support until 2032. The pricing visibility it has provided "drove PSEG's decision to retain and grow our nuclear fleet via prudent capital investments and will keep our state’s carbon-free nuclear fleet viable for the long-term," the company said.

Over USD100 million in nuclear capital investment projects have already been approved and are in progress, including plant upgrades and a transition to a two-year operating cycle at Hope Creek. PSEG Nuclear is also developing detailed plans to implement power uprates for both Salem units and to upgrade and optimise the nuclear fleet’s turbine generator trains.

The units also deliver positive local economic impacts, the company added, directly employing some 1600 people with additional contract workers supporting refuelling outages and major project work each year and fostering an extensive indirect workforce throughout the community.

Salem is 57% owned by PSEG, with Constellation Energy owning the remaining 43%.

Fourth Korean APR-1400 begins commercial operation

08 April 2024

Unit 2 of the Shin Hanul nuclear power plant in South Korea has entered commercial operation, Korea Hydro & Nuclear Power (KHNP) announced. The unit is the second of two APR-1400 reactors at the site, with a further two planned.

Shin Hanul units 1 and 2 (Image: KHNP)

Shin Hanul 2 received an operating licence from the Nuclear Safety and Security Commission on 7 September last year, after which it completed a preliminary inspection by the regulator. The loading of 241 fuel assemblies into the reactor's core was carried out between 11 and 18 September. High-temperature functional tests were subsequently conducted.

The 1350 MWe pressurised water reactor reached first criticality - a sustained chain reaction - on 6 December and it was connected to the grid on 21 December.

Following seven months of commissioning tests, which included step-by-step power increase tests and performance tests of the reactor and turbine generator, Shin Hanul 2 was declared to be in commercial operation on 5 April.

Ground breaking for the first two units at the Shin Hanul (formerly Shin Ulchin) site took place in May 2012. First concrete for unit 1 was poured two months later, with that for unit 2 following in June 2013. Shin Hanul 1 achieved first criticality on 22 May 2022 and was connected to the grid on 9 June last year.

"With the commercial operation of Shin Hanul unit 2, Korea's 28th nuclear power unit, the total number of nuclear power units operating in Korea has increased to 26 (including Kori unit 2, which is being prepared for continued operation)," KHNP noted.

Shin Hanul 2 is South Korea's fourth operational APR1400 - after Saeul units 1 and 2 (formerly Shin Kori 3 and 4) and Shin Hanul unit 1. Two further APR1400s are under construction as Saeul units 3 and 4, with two more units planned as Shin Hanul units 3 and 4.

Four APR1400 units have been built at the Barakah nuclear power plant in the UAE, which are all now in operation.

Researched and written by World Nuclear News