NEWS |
round up
SAFETY & SECURITY TOKYO ELECTRIC POWER Company (Tepco) reported a water leakage at unit 2 of the Fukushima Daiichi NPP. The leak involved an estimated 25 tonnes of water from the used fuel cooling system pump room and the heat exchanger room. Tepco said it had not found any leakage spread to other rooms and would treat the leaked water through its water treatment facilities.
THE SWEDISH RADIATION Safety Authority (SSM) has authorised the European Spallation Source (ESS) in Lund to begin test operation of the entire accelerator. In October 2023, ESS applied for a permit for test operation of the superconducting part of the accelerator. SSM has now concluded that the ESS has met the conditions necessary to start the test operation.
REGULATION US-BASED NAC International has received a US Nuclear Regulatory Commission (NRC) certification for NAC’s highly shielded version of its versatile OPTIMUS (OPTImal Modular Universal Shipping) transport packaging system. The new certificate for OPTIMUS-H follows licensing approvals obtained under Canadian Nuclear Safety Commission certification and associated certification in Australia.
COMPANIES INDIA’S BIGGEST POWER company NTPC (formerly the National Thermal Power Corporation) is planning to establish a subsidiary specifically to pursue nuclear expansion and is already investigating potential sites in several states. NTPC is also exploring small modular reactor (SMR) technology.
US-BASED AALO Atomics has raised $27m in a Series A funding round to support its “mission to make small nuclear reactors in gigafactories”. The investment “will enable predictable low costs and shortened construction times, making clean energy a reality—any place, any time,” Aalo said.
NUCLEAR FUEL US-BASED WESTINGHOUSE Electric Company has received approval from the US Nuclear Regulatory Commission (NRC) for an increase in the burn-up limit for the Westinghouse Encore fuel designs. This is the first-time nuclear fuel batch reloads in the US will be able to exceed a burn-up limit of 62 GWd/MTU, paving the way for a future extension to benefit utilities to operate economically on 24-month fuel cycles.
United States
Westinghouse makes first LEU+ fuel US-based Westinghouse Electric Company has produced new fuel pellets that contain slightly higher enrichment levels than those currently used in commercial reactors. The low enriched uranium plus (LEU+) ADOPT fuel pellets were pressed at Westinghouse’s Springfield fuel manufacturing facility in the UK. The specialised ADOPT fuel pellets were developed as part of the US Department of Energy (DOE) Accident Tolerant Fuel (ATF) programme to improve the performance and safety of nuclear plants. The new fuel will be tested at unit 2 of the Vogtle NPP in Waynesboro, Georgia, in 2025. The pellets were made from a higher enriched uranium oxide power prepared by Idaho National Laboratory. The new LEU+ ADOPT fuel pellets can be enriched up to 8% uranium 235 and also include additives that are expected to improve the safety performance of the fuel and increased power levels. The higher enrichment allows the fuel to operate for longer periods in the reactor, thereby reducing the number of outages needed for refuelling. ADOPT fuel is one of several ATF concepts being supported through the DOE’s programme, which aims to deliver new fuel pellet and cladding designs that could be commercialised before the end of the decade. The pellets will be fabricated into pins and included in four lead test assemblies in the UK before being irradiation testing in the US at the Vogtle NPP.
Russian Federation Construction continues at Brest The third and last tier of the reactor enclosing structure for Russia’s demonstration Brest- OD-300 lead-cooled fast reactor has been installed in the reactor shaft at the construction site in Seversk, Tomsk Region. Its weight, together with rigging equipment, is 164 tonnes. This is an additional protective barrier. The Brest-OD-300 reactor is part of the pilot demonstration power complex (ODEK – Opitno Demonstratsionovo Energo-Kompleksa), which is being developed at SCC in Seversk under the Breakthrough (Proryv) project intended to demonstrate closed fuel cycle technology. Brest (Bistrii Reaktor Estestvennoi-
bezopasnosti co Svinstovim Teplonositelem – Fast Natural-safety Reactor with Lead Coolant) is a Generation IV 300 MWe power unit. It is supported by a module for the production of mixed dense nitride uranium-plutonium (SNUP) fuel, as well as a module for reprocessing irradiated fuel. SNUP fuel is based on two key components – depleted uranium, which is a by-product of uranium enrichment for nuclear reactors, and plutonium, extracted from irradiated nuclear fuel. The reactor housing consists of three mounting blocks installed in the reactor shaft. The total weight of the structure is 429 tonnes and its height is 17 metres. After connecting the third and second tiers of the housing, installers will assemble the pipelines of the cooling
10 | September 2024 |
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system, drying system and intermediate shell. Then the cavity of the housing will be filled with heat-resistant concrete. The structure is the outer part of the reactor
vessel. It ensures the retention of heat- insulating concrete and forms an additional localising barrier of protection that follows the boundary of the coolant circuit. During operation of the reactor, the temperature on its surface will not exceed 60 degrees celcius, and the background radiation will be normal. The start-up of the Brest-OD-300 reactor is planned for 2027, according to SCC Director General Sergey Kotov. He noted that Brest is a pilot project, which is needed to test the technology, but similar larger installations of 1,200 MWe are already being developed for deployment at other sites in Siberia.
United States ORNL creates glass test cell for MSRs Oak Ridge National Laboratory (ORNL) has developed its first-ever custom glass test cell to observe how gases behave inside a molten salt reactor. The test cell will be used to better understand the complex chemistry that can occur in molten salt-fuelled reactors. The data will be used to help verify existing computer codes and modelling software to better predict their overall performance. Molten salt reactors are among several
new systems under development that could be commercialised early next decade. Some designs will operate on liquid fuel, where the fissile materials are dissolved into a molten salt solution that is also used to cool the reactor. Nuclear and chemical reactions from these designs can result in gases that bubble out of the molten salt. These can impact reactor neutronics and thermal hydraulic performance. To investigate this behaviour, ORNL researchers have designed and developed a customised glass test cell at the lab’s glass shop that can hold up to one litre of liquid molten salt. The team then injected small helium and
krypton bubbles into the cell to observe how they moved through the column. The experiment allowed researchers to observe and measure gas bubble velocity, size distribution, and interactions with neighbouring bubbles using high-speed cameras. This provided unique insights to help improve and validate simulation tools for molten-salt-fuelled systems. “Understanding gas generation and transport
in molten salt reactors is essential to optimising their performance and safety,” said Daniel Orea, ORNL’s lead R&D associate. “This unique glass test cell allows us to overcome certain engineering challenges caused by the high temperature and composition of salt and its two-phase liquid glass system.” The research project was supported through
the Department of Energy’s Molten Salt Reactor Programme that works to accelerate the research, development, and deployment of molten salt reactor technologies in the US.
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