Periodic Reporting for period 1 - AMHYCO (TOWARDS AN ENHANCED ACCIDENT MANAGEMENT OF THE HYDROGEN/CO COMBUSTION RISK)
Reporting period: 2020-10-01 to 2022-03-31
The concept behind AMHYCO is the need for upgrading the current SAMGs applied in the EU reactor fleet with the most updated understanding on combustible gas behaviour, some of which will be generated within the project by articulating in a concerted way the nuclear safety tools used worldwide with the most advanced simulation techniques and specific experimentation on scenarios where analytical methodologies are not reliable enough yet.
Why is it important? Combustible gases generated in the course of a severe accident are among the most serious threats to the containment integrity, i.e. the last barrier. An appropriate management of the associated risk is paramount to avoid the potential release of significant amounts of radioactive material to the environment. Since the Fukushima accident, more measurements to reduce the risk of containment failure have been taken from the European Union (EU) Nuclear Power Plants.
The key strategic objectives of the AMHYCO project are:
• To experimentally investigate phenomena that are difficult to predict theoretically such as H2/CO combustion and PARs (Passive Autocatalytic Recombiners) behaviour under realistic accidental conditions, taking into account their interaction with safety systems.
• To improve the predictability of analysis tools Including Lumped Parameter (LP), 3D and Computational Fluid Dynamic (CFD) codes – used for explosion hazard evaluation inside the reactor containment and providing support to Severe Accident Management Guidelines (SAMGs) design and development.
• To improve the SAMG for both in vessel and ex-vessel phases with respect to combustible gases risk management, using theoretical, simulation and experimental results.
Why is it important? Combustible gases generated in the course of a severe accident are among the most serious threats to the containment integrity, i.e. the last barrier. An appropriate management of the associated risk is paramount to avoid the potential release of significant amounts of radioactive material to the environment. Since the Fukushima accident, more measurements to reduce the risk of containment failure have been taken from the European Union (EU) Nuclear Power Plants.
The key strategic objectives of the AMHYCO project are:
• To experimentally investigate phenomena that are difficult to predict theoretically such as H2/CO combustion and PARs (Passive Autocatalytic Recombiners) behaviour under realistic accidental conditions, taking into account their interaction with safety systems.
• To improve the predictability of analysis tools Including Lumped Parameter (LP), 3D and Computational Fluid Dynamic (CFD) codes – used for explosion hazard evaluation inside the reactor containment and providing support to Severe Accident Management Guidelines (SAMGs) design and development.
• To improve the SAMG for both in vessel and ex-vessel phases with respect to combustible gases risk management, using theoretical, simulation and experimental results.
In WP1 ‘Critical review’, a critical review of the available literature regarding (1) PAR efficiency under ex-vessel conditions, (2) existing PWR SAMGs regarding containment risk management (3) H2/CO combustion and the available engineering correlations for combustion risk estimation, and (4) equipment and instrumentation surveillance under severe accident conditions has been performed. This Work Package has been closed.
In WP2 ‘Selection of severe accident sequences’, the generic containments have been developed and severe accident sequences have been calculated.
In WP3 ‘Experimental investigations’, the first experiments on H2/CO flame acceleration have been performed (no data existed before in the literature). PAR experiments in the REKO facilities have been performed to validate numerical PAR models. Correlations are now being investigated.
The work in WP4 ‘Full containment analysis’ and WP5 ‘Enhancement of severe accident management guidelines’ will start later.
In WP6 ‘Dissemination, communication, education and training’, many activities took place: workshops with PhD students, mobility programme, funding of the PhD thesis, participation at many events and conferences. In total, 5 papers were already presented in this reporting period and several more will be presented in the coming months.
In WP2 ‘Selection of severe accident sequences’, the generic containments have been developed and severe accident sequences have been calculated.
In WP3 ‘Experimental investigations’, the first experiments on H2/CO flame acceleration have been performed (no data existed before in the literature). PAR experiments in the REKO facilities have been performed to validate numerical PAR models. Correlations are now being investigated.
The work in WP4 ‘Full containment analysis’ and WP5 ‘Enhancement of severe accident management guidelines’ will start later.
In WP6 ‘Dissemination, communication, education and training’, many activities took place: workshops with PhD students, mobility programme, funding of the PhD thesis, participation at many events and conferences. In total, 5 papers were already presented in this reporting period and several more will be presented in the coming months.
In the first reporting period, the project has worked on reinforcing the competencies of the younger generation in the nuclear industry and disseminating widely the first results, to both the general public and the scientific community. The project has included several young researchers (PhD students, postdocs) in the teams, which will have a long-term impact on the promotion of nuclear research among young students and reinforcement of skills and competencies of the individuals engaged in the project. The PhD students have started to work on their thesis (partially or totally funded by the project depending on the case). The mobility scheme has equally started. Additionally, several dissemination activities have been developed, including several conference papers (5 presented and others to be presented in the next months), a wide press release, LinkedIn portal, webpage, newsletter, etc.