ABSTRACT Boiler feedwater pH in high-purity steam-water cycles is not freely adjustable when ammonia is used as the alkalizing agent but becomes the thermodynamic consequence of the coupled ammonia-carbon dioxide (NH3-CO2) system under deaerator conditions. While dissolved oxygen is readily removed, CO2 can be stripped only in its molecular form, CO2(aq), whose fraction decreases sharply […]
ABSTRACT The hot functional test (HFT) represents the first exposure of primary circuit materials to near operational coolant conditions and play a key role in subsequent corrosion product release and radiation field development. This paper evaluates primary circuit passivation during a HFT at the nuclear power plant (NPP) Mochovce Unit 4 (a water-water energetic reactor […]
Between June 29th and July 3rd, 141 scientists, engineers, and guests representing 19 countries met at The Bristol Hotel Conference Centre in Bristol, United Kingdom, for the annual meetings of the IAPWS Executive Committee and Working Groups. This series of meetings began in 1929 in London, UK, with the purpose to connect scientists and researchers […]
ABSTRACT Inductively coupled plasma-mass spectrometry (ICP‑MS) has become a key analytical technique for trace and ultra‑trace elemental analysis in nuclear power plant chemistry since its introduction in the early 1980s. Following a VGB research initiative in 1994, the first such system in a German nuclear power plant was installed at the pressurized water reactor Philippsburg […]
ABSTRACT We previously reported observing oxalate (C2O42–) along with phosphate (PO43–) almost exclusively in the low-pressure (LP) saturated steam of a combined cycle power plant at a time when an atypically high amount of the phosphonate (PN)-based antiscalant was being dosed into the reverse osmosis (RO) feedwater. The coincidence of these events would point to […]
ABSTRACT Reliable makeup water treatment is essential for maintaining the integrity and performance of industrial steam generators, even though these units typically operate under less stringent conditions than high-pressure power plant boilers. This article emphasizes that even minor deviations in water quality can lead to scale formation, heat transfer inefficiencies, tube overheating, and ultimately equipment […]
ABSTRACT For the first time, the PPCHEM Seminar "Monitoring and Avoidance of Chemical Issues in Water-Steam Cycles" took place in Germany. This PPCHEM seminar series addresses important questions about the significance of water-steam chemistry, which parameters need to be measured, and how to effectively interpret and use the resulting data. It also highlights the risks […]
The German-Swiss Association for the Properties of Water and Steam (GSAPWS) e.V. held its annual general meeting and conference on March 5 and 6, 2026. This year, the events took place at Helmut Schmidt University in Hamburg, Germany.
ABSTRACT This article examines the spread of technical misconceptions on platforms such as LinkedIn regarding water-steam cycle chemistry in high-pressure utility systems. It focuses on the incorrect claim that alkalizing amines can replace ammonia for feedwater pH control, supported by a practical case history. While alkalizing amines have valid applications, their use as a direct […]
ABSTRACT Flow-accelerated corrosion (FAC) has been identified as the main cause of damage, failures, and unavailability in heat-recovery steam generators (HRSGs), leading to multimillion-dollar losses from repairs and lost revenue. Across utilities worldwide, FAC is the most frequently cited HRSG tube-damage mechanism (≈ 13 %), exceeding pitting and hydrogen damage. During recent plant outages at the Genelba […]
