(LCC18)
This report compiles field operating experience and maintenance of some of the following PWRs components: heaters and reheaters, pumps, valves, piping and their supports, heat exchangers and bolted connections.
(ZIRAT27/IZNA22)
The content of the Updated RIA is basically the same as the original report (Nuclear Fuel Behaviour under RIA conditions published within the ZIRAT21/IZNA Programmes), see information below.
The main focus of this report is to give an update on two major subjects: (1) new RIA tests and the interpretation of the results and (2) new RIA related regulations. New RIA tests will complete the existing data base and their potential significance for RIA modelling or for RIA ruling. New acceptance criteria for RIA issued by US NRC are briefly described as well as some national approaches, different from the US NRC
(ZIRAT27/IZNA22)
Pellet-Cladding Interaction (PCI) and Pellet-Cladding Mechanical Interaction (PCMI) remains an important phenomenon in the modern nuclear reactor fuel engineering. This topic was addressed in detail in ZIRAT-11 Special topical report on PCI issued in 2006. Since then, a substantial development has taken place, such as introduction of new cladding materials and additive fuel pellets. In addition to this, flexible power operation is being considered by many utilities worldwide. This introduces new challenges to the safe and reliable operation of the nuclear fuel. The report discusses up-to-date developments in the above mentioned areas and summarizes the main outcomes of the R&D work performed since 2006.
Formation of deposits on Pressurised Water Reactor (PWR) fuel cladding has been an inherent problem in these systems since their inception and remains a problem to-date. The report provides: 1) a brief history of fuel crud in PWR systems, 2) mechanisms for material release, transport and deposition in the core and the influence by material choice, coolant chemistry and core design 3) discussions of what occurs within fuel crud that may affect its deposition rate, its effect on core neutronics and possible impact on clad corrosion leading to failure. Finally, a discussion is given summarizing our current understanding and where future work is required to further this knowledge.
Corrosion and Hydrogen pickup (HPU) mechanisms of Zr alloys remain a top priority of the nuclear industry. Commercial Zr alloys have today adequate in-reactor corrosion properties. However, hydrogen in fuel components limits the fuel performance today during normal operation and accident conditions as well as during transport of spent fuel. Despite more than 50 years research, the corrosion and HPU mechanisms are still not clear. Improved understanding of the in -reactor oxidation and hydrogen pickup mechanisms are thus required. To shed light on theses complicated mechanisms A.N.T. International has published a set of three reports (Vol. I, II and III) with the focus on explaining the very complicated corrosion and hydrogen pickup mechanisms in an understandable manner.
Volume III gives an introduction to the best understood mechanisms of Zr alloys corrosion and HPU mechanisms, with the aim of giving a ”mental image of the phenomena”, more than discussing in detail all the controversial aspects of the current scientific debates.
Corrosion and Hydrogen pickup (HPU) mechanisms of Zr alloys remain a top priority of the nuclear industry. Commercial Zr alloys have today adequate in-reactor corrosion properties. However, hydrogen in fuel components limits the fuel performance today during normal operation and accident conditions as well as during transport of spent fuel. Despite more than 50 years research, the corrosion and HPU mechanisms are still not clear. Improved understanding of the in -reactor oxidation and hydrogen pickup mechanisms are thus required. To shed light on theses complicated mechanisms A.N.T. International has published a set of three reports (Vol. I, II and III) with the focus on explaining the very complicated corrosion and hydrogen pickup mechanisms in an understandable manner.
Volume II gives more detailed information on:
Corrosion and Hydrogen pickup (HPU) mechanisms of Zr alloys remain a top priority of the nuclear industry. Commercial Zr alloys have today adequate in-reactor corrosion properties. However, hydrogen in fuel components limits the fuel performance today during normal operation and accident conditions as well as during transport of spent fuel. Despite more than 50 years research, the corrosion and HPU mechanisms are still not clear. Improved understanding of the in -reactor oxidation and hydrogen pickup mechanisms are thus required. To shed light on theses complicated mechanisms A.N.T. International has published a set of three reports (Vol. I, II and III) with the focus on explaining the very complicated corrosion and hydrogen pickup mechanisms in an understandable manner.
Volume I gives an introduction on the corrosion and hydrogen pickup (HPU) processes in zirconium alloys. The following topics are treated in details:
This report compiles the degradations observed in condensers, either on steam side or raw water side. The oldest condensers were known before the nuclear era, the newest came to the light with the development of nuclear reactors. However, more attention was brought to nuclear plant condensers since while operating with a few leaks was allowed in fossil fired plants, this was strictly forbidden in pressurized water reactors, mainly because of the steam generators susceptibility to pollution.
This report discusses in detail, the steps involved in, generation of corrosion products including colloid formation, activation on fuel, transport through the coolant, deposition on surfaces including zeta potential effects, release from surfaces and removal of activated corrosion products in light water reactors. The report also discusses activity transport that will include basic steps involved and models used.
This updated report reviews, as of 2020, the laboratory and field results of zinc injection technology in PWR plants worldwide. The review covers the range from basic information to current knowledge and understanding of operational behaviour. This information on PWR plants given in this report is also applicable for VVER plants.
