Latest news with #ILRT
The Citizen
5 days ago
- Business
- The Citizen
Eskom: Koeberg repairs won't worsen load-shedding this winter
Eskom has announced that Koeberg Unit 1 will now return to service by the end of August, instead of this month, due to additional steam generator maintenance. The unit was initially expected back online in July, but Eskom said the revised timeline reflects its commitment to thorough inspections and the highest quality standards at South Africa's only nuclear power station. 'During scheduled detailed eddy current inspections – a non-destructive testing method used to detect cracks, corrosion or wear in the metal tubes of steam generators – defects were identified on four tubes, among several thousand inspected, across two of the newly installed generators,' the power utility explained. Specialised international and local teams immediately carried out advanced automated repairs on the four tubes. Eskom confirmed these repairs have been successfully completed to uphold stringent safety standards. Major maintenance completed Eskom said major maintenance work, including the legally required 10-year Integrated Leak Rate Test (ILRT), had been successfully completed. The ILRT pressurised the reactor building over 72 hours to confirm its structural integrity and leak-tightness in line with international standards. Eskom group executive for generation Bheki Nxumalo emphasised: 'The safety of employees, the public and the environment remains our top priority. Carrying out these additional inspections and repairs to world-class standards is an investment in the long-term reliability of Koeberg and South Africa's energy future.' No increased load-shedding risk Eskom reassured that the delay will not increase the risk of load-shedding. Since mid-May, there has been no load-shedding, with only 26 hours of outages recorded between April 1 and Thursday. 'The winter outlook released on May 5 remains valid. Importantly, the planned return of 2 500MW this winter does not rely on Unit 1,' Eskom said. Unit 2 remains fully operational, generating up to 946MW with a year-to-date Energy Availability Factor of 99.38% at the end of June. – Read original story on At Caxton, we employ humans to generate daily fresh news, not AI intervention. Happy reading!
IOL News
5 days ago
- Business
- IOL News
Koeberg Nuclear Power Station's Unit 1 return postponed: what it means for South Africa's energy
Eskom said the return to service of Unit 1 at the Koeberg Nuclear Power plant has been moved to August, after initially scheduled to return to service in July after planned maintenance. Image: Supplied Eskom announced that Unit 1 at the Koeberg Nuclear Power Station, South Africa's only nuclear facility located in Cape Town, that is supposed to return to service this month, has been pushed back to the end of next month. Currently offline for the second phase of its long-term operational maintenance programme, Unit 1 was initially expected to return to service by July 2025. Eskom said this adjustment reflects their "unwavering commitment to thorough inspections and maintaining the highest quality standards to ensure the safety and reliability of the facility". As part of the scheduled maintenance, detailed eddy current inspections — an essential non-destructive testing method—revealed defects in four tubes across two of the newly installed steam generators. Eskom said it acted promptly, deploying an advanced automated process to rectify the identified issues, with specialised international teams working in tandem with local experts to ensure the repairs met global safety and quality standards. "The successful completion of these critical repairs marks a significant milestone in reinforcing the safety framework at Koeberg." In addition to the tube repairs, the maintenance activities included the legally mandated 10-year Integrated Leak Rate Test (ILRT). "During this rigorous test, the reactor building was pressurised over a continuous 72-hour period, carefully monitoring its leak rate and structural integrity. The results from the ILRT confirmed the robustness of Unit 1's containment structure, thereby aligning with international safety protocols." Bheki Nxumalo, Eskom's Group Executive for Generation, emphasized the importance of prioritising safety at Koeberg. 'Our top priority is always the safety of our employees, the public and the environment. Carrying out these additional inspections and repairs to world-class standards, we are investing in the long-term reliability of Koeberg and South Africa's energy future,' he said. Nxumalo reiterated that the maintenance of Unit 1 is vital for delivering decades of affordable, low-carbon power, advocating how nuclear energy contributes to economic growth and environmental sustainability. Eskom is concurrently progressing on other generation projects, including the recently synchronised 800MW Kusile Unit 6, which is expected to enter commercial operation by September 2025. "This year has already seen the reconnection of Kusile Units 1, 2, and 3 to the repaired west stack, as well as the return to service of Medupi Unit 4 after a prolonged outage. Together, these initiatives are aimed at bolstering generation capacity and securing a stable electricity supply." Eskom said the revised return date for Koeberg Unit 1 is not anticipated to increase the risk of loadshedding. "The latest Winter Outlook released in May remains valid, indicating that the planned return of 2,500MW this winter is unaffected by the status of Unit 1. The report shows that loadshedding will not be necessary as long as unplanned outages stay below 13,000MW. Even with potential increases in outages, Eskom has projected a maximum of 21 days of loadshedding during the winter season, capped at Stage 2. As the winter season progresses, Eskom continues to encourage energy efficiency among customers while assuring them of the national power system's stability. Unit 2 of Koeberg remains operational, currently contributing up to 946MW and recording an impressive Energy Availability Factor (EAF) of 99.98% as of the end of June 2023. Once all maintenance work is completed, Unit 1's reactor core will undergo refuelling, testing, and will be synchronised back to the national grid. Eskom said it meticulously plans these outages to ensure that both Koeberg units are not offline simultaneously, maintaining an essential power supply for the country.
Yahoo
27-03-2025
- Science
- Yahoo
Strange red nova deaths of shrouded stars investigated by 'stellar Sherlocks'
When you buy through links on our articles, Future and its syndication partners may earn a commission. The name "Intermediate Luminosity Red Transients" or "ILRTs" might not be an astronomical term you are familiar with, but these rare, brightness-shifting stars have been quite the mystery in astronomical terms. Now, a team of cosmic detectives, who have dubbed their work "A Study in Scarlett" after the Arthur Conan Doyle novel that first introduced the world to Sherlock Holmes, may have finally cracked the case. The stellar Sherlocks from across the globe suggest that ILRTs are stars that don't just erupt when they reach the end of their lives but experience "truly terminal" and destructive supernova explosions. "Following the discovery of three new ILRTs in 2019, we seized the opportunity to study and better understand these phenomena," team leader and National Institute for Astrophysics (INAF) researcher Giorgio Valerin said in a statement. "We have, therefore, collected data for years through telescopes scattered around the world and even several telescopes in orbit. "We have also resumed the observation campaign of NGC 300 OT, the closest ILRT ever observed, at 'just' six and a half million light-years from us." The ground-based instruments used included La Palma, La Silla, Las Campanas, and Asiago, while data was also collected from space-based telescopes, including the James Webb Space Telescope (JWST), the Neil Gehrels Swift Observatory (SWIFT), and the Spitzer space telescope. ILRTs have been somewhat confusing because their brightness is between that of novas, stellar explosions that stars survive, and "classical" supernovas in which a massive star is destroyed, leaving behind a neutron star or a black hole. The team reached their findings by observing the evolution of four ILRTs. They hoped that this would help them determine whether the star survives these explosions or is completely wiped out. The key to solving this mystery was observing ILRTs like NGC 300 OT over long periods of time. "The first images of NGC 300 OT date back to 2008, and in this work, we have observed it again to study its evolution after more than ten years," Valerin said. "The analysis of the images and spectra collected during these observing campaigns has allowed us to monitor the evolution over time of our targets, obtaining information such as the brightness, temperature, chemical composition, and gas velocities associated with each ILRT we have studied." The Spitzer observations of NGC 300 OT showed this ILRT dimming to a tenth of the brightness of the progenitor star that created this eruption over the course of seven years. Spitzer's images of NGC 300 OT ended when they faded below the detection threshold of this NASA space telescope, which retired in 2020. Just as Holmes made his name investigating many cases, the team had another set of ILRT data to peruse. Analyzing JWST observations of the ILRT AT 2019abn located in the nearby galaxy Messier 51 (M51), they found that this transient is declining in brightness in such a way that it is likely to meet the same fate as NGC 300 OT by becoming fainter than its progenitor star. From this information, the team concluded that ILRTs are explosions that see the total destruction of a star. That is despite the fact that ILRTs appear to be significantly weaker than "classical" core-collapse supernovas. The question is, how do they remain fainter than similar supernova events? The team of cosmic detectives suggests that a defining factor in the make-up of ILTRs could be a dense shroud of gas and dust that surrounds the progenitor stars. This cocoon is heated to temperatures as great as around 10,300 degrees Fahrenheit (5,700 degrees Celsius) over just a few days. The peak in temperature corresponds with a peak in brightness for the ILRT. As this happens, the gas in this stellar shroud accelerates to speeds as great as 1.6 million miles per hour (700 kilometers per second), which is around 1,000 times as fast as the top speed of a Lockheed Martin F-16 jet fighter. "This speed is decidedly lower than that of an exploding supernova, which often reaches 10,000 kilometers per second [22 million mph],' team member and INAF researcher Leonardo Tartaglia said. "Yet, we believe that the star may have really exploded, throwing material at thousands of kilometers per second in every direction, but that this explosion was partially suffocated by the dense blanket of gas and dust around the star, which heats up as a consequence of the violent impact." Thus, the launch of material from around the stellar progenitors of ILRTs can explain how they decrease in brightness over long periods of time. The team termed this phenomenon an "electron capture supernova" a type of stellar explosion that has been long theorized but had not been believed to have been observed. Electron-capture supernovas have been of great interest to astronomers because they seem to mark a boundary between stars of around 10 solar masses and more that explode in supernovas to leave behind black holes and neutron stars, and stars with masses more like the sun that don't "go nova" but fade away as white dwarf stellar remnants. Related Stories: — Dead stars within supernova explosions could solve the dark matter mystery in 10 seconds — Could a supernova ever destroy Earth? — Hubble Telescope sees rare supernova explosion as a violent 'pale blue dot' (image) "We are finally seeing the events that separate stars destined to explode as classical supernovas from stars that will slowly fade away as white dwarfs," Valerin said. Perhaps the team would agree with Holmes' words from The Sign of the Four: "When you have eliminated the impossible, whatever remains, however improbable, must be the truth!"The team's research was published across two papers on March 7 in the journal Astronomy & Astrophysics.
