This report is the first volume out of two focusing on BWR chemistry. A review and discussion of the BWR chemistry fundamentals that are necessary to understand and describe the requirements of the BWR water specifications is provided in this volume. This discussion includes the basics of water radiolysis, the dynamic process that establishes the concentration of oxygen and hydrogen gas in the reactor water, the consequences of tramp uranium and leaking fuel rods on chemistry and other relevant topics.
This report is the second volume out of two focusing on BWR chemistry. This volume II takes a closer look at corrosion of structural materials covering the following topics:
- Corrosion Considerations
- Stress Corrosion Cracking Mitigation
- Start-up IGSCC Mitigation
- Shutdown Dose Rate Minimization
- Reactor Water Purity Transients
- Surveillance Programs
This Report gives a comprehensive understanding of the zinc chemistry mechanism and information on how Zinc Chemistry in BWR and PWR plants was introduced in the plants and explains the results achieved. This information is useful not only for utilities that are intending to apply Zinc Chemistry in the near future in their plants and for selecting strategies for adding zinc; but also for those utilities that are already applying Zinc Chemistry in order to optimize their strategy based on international experience. It will also be useful for Manufacturers and Regulators.
The objective of this report is to provide members with the basic understanding of the mechanisms involved and their relationship to material performance and activity buildup. Content of the report is outlined below.
- Fuel cladding failures due to accelerated corrosion
- Axial Offset Anomaly (AOA)
- Pressure drop problems especially in CANDU-plants and VVER units
- Build-up of out-of-core radiation fields
- Shutdown extensions due to high activity releases (Coolant clean-up)
- Increased generation of radioactive waste
- Interference with inspection necessities
Operational Issues, Practices and Remedies are important issues for plant personnel and designers. This report combines the following subjects of limited extent but potentially important consequences:
- Degradation of the primary coolant barrier together with mechanical remedies.
- The potential benefits of Enriched Boric Acid (EBA).
- Primary coolant (Co-58, colloids) inventory.
- Degradation of concrete structures in NPPs.
- Colloids, Zeta Potential and Activity Transport.
- Electrochemical Corrosion Potential (ECP) measurements.
- Key points, ”lessons learned” and ”best practices” of several recent conferences.
The intent of this Report is to provide a state-of-the-art knowledge of the mechanisms of the various forms of Zr-alloy corrosion and hydrogen pickup (HPU) and how water chemistry impacts fuel performance, including corrosion and HPU. This knowledge will help implement actions to reduce Zr alloy corrosion and hydrogen pickup.
This Report furnished in the LCC10 Programme cover the key information presented at the Nuclear Power Chemistry Conference, in October 2014. The Report not only summarise but also analyse the results to assess in which specific situation the results are applicable.
The objective of this Report is to provide a comprehensive understanding of radiochemistry in Nuclear Power Plants which has a large impact on dose rates, operational exposures, maintenance activities, shutdown process, safety issues, environmental constraints and control of proper plant operation.
Start-Up and Shutdown Practices in BWRs as well as in Primary and Secondary Circuits of PWRs, VVERs and CANDUs
The objective of this Report is to provide a good understanding of the special problems and appropriate good practices during shutdown as well as during startup of LWRs. The Report provides a worldwide review of Startup and Shutdown Procedures both in the Primary and in the Secondary Circuit of PWRs, CANDUs and VVERs, and in the reactor coolant and main steam containing systems of BWRs.
The 20th Nuclear Plant Chemistry (NPC) International Conference, which started in Bournemouth (UK) and held every other year, was held in Brighton (UK) in October 2016. It is the most important conference related to chemistry in Nuclear Power Plants, and covers many new results in this area. The key information presented at this Conference is covered in two separate LCC12 Reports.
This Report summarizes the BWR related papers from the conference and is designed to provide updated information with the author’s critique and analysis for the benefit of the ANT International/LCC customers. The Report is expected to be a comprehensive document summarising the latest information on BWR water chemistry that would benefit the BWR operators and regulators.
The second report covers PWRs, VVERs, CANDUs, PHWRs and auxiliary systems issues.