Have a look into our Projects!
The following overview provides a broad idea what NES research is about. More
detailed information can be found on the respective laboratory pages
GaBE Comprehensive
Assessment of Energy Systems: Life Cycle Analysis and Evaluation, Stakeholders
Involvement
Nuclear energy is a
socio-politically controversial technology. NES and ENE researchers together,
therefore, as ‘honest brokers’ provide reliable
comprehensive information about advantages and disadvantages not only of nuclear
energy, but
also all other energy sources for decision makers and the society. As all other
energy sources, fossil as well as renewable, nuclear energy must be set in
a broad technical context, be compared against alternatives with consistent
methods
and be assessed from several viewpoints (safety, economics, environmental compliance,
social acceptance etc). to be revised
HRA Human
Reliability Analysis
To manage the safety of complex systems such
as nuclear power plants, operating organizations and regulators need to understand
the risks. Probabilistic Safety
Assessment (PSA) is the discipline of predicting accident scenarios, calculating
their probabilities, and analyzing the overall risk. Within PSA, Human Reliability
Analysis (HRA) combines human factors and ergonomics, psychology, and cognitive
science to derive the probabilities for human actions and errors. PSI’s
HRA research focuses on decision-related errors and their quantification.
STARS
Safety Research related to Transient analysis of the Reactors in Switzerland
[ Top ]
NES
maintains and further develops a comprehensive best-estimate safety analysis
methodology at state-of-the-art - including criticality safety – for
reactor states ranging from normal operation to beyond design conditions
(before core
melt). The necessary tools are integrated into a consistent system for the
application to the Swiss light water reactors.
Severe
Accidents Research Characterization and understanding of aerosol and iodine
behaviour during severe accidents [ Top ]
To
better understand the evolution of hypothetical severe accidents in nuclear
power plants, NES tries to identify weak points of components which,
in case
of failure, could lead to radioactivity releases into the environment.
The project supports industry and regulators with safety assessment of
power
plants. Related
experiments provide data on aerosol transport and retention and on iodine
chemical behaviour aim at reducing the potential for release of the highly
radiotoxic
iodine to the environment. Possible releases of radioactivity are quantified
and mitigating countermeasures proposed.
INTEGER
Safety of nuclear power plant components, identification of corrosion and
ageing mechanisms, damage characterisation and monitoring (diagnostics)
[ Top ]
In
the context of components safety NES investigates the effect of material
ageing and degradation mechanisms on the structural integrity of Light
Water Reactors in view of extending their safety and lifetime. The project
covers
the characterization, detection and prediction of thermo-mechanical fatigue,
thermal shock and environmentally-assisted cracking phenomena in safety-relevant
primary pressure boundary components of Light Water Reactors.
Core
Materials Behaviour High burn-up behaviour of fuel cladding and explanation
of failure causes [ Top ]
The goal of this project is to improve the quantitative understanding
of Core Materials Behaviour. NES does research on cladding corrosion, hydride
reorientation
and mechanical properties of the cladding, as well as on the high burn-up
structure in the fuel. Post irradiation examinations on fuel rods and related
analytical
investigations are performed for external costumers on a scientific level.
LWR-PROTEUS Experimental
reactor physics with modern core loadings and high burn-up fuels with development
and validation of codes to optimize fuel utilisation
This experimental reactor physics research programme serves to precisely
determine the physics parameters in advanced light water reactor fuel.
NES measures pin
power distributions and investigates their corresponding computer code
validation, related to power up-rates in boiling water reactors. In view
of cost optimization
also fuel reactivity loss with burn-up in pressurised water reactors
is investigated, by using fresh, commercial fuel assemblies and individual
high-burn-up fuel
rod segments.
Waste Management Geochemistry
of repository systems, transport phenomena for substances from a final repository,
contributions to safety assessments
NES
aims at better understanding the mechanisms which are relevant for the
assessment of the long-term safety of a final repository. On the one
hand,
one models the migration of radionuclides escaping from a repository
after the failure of the engineered barriers to determine the amount of radioactivity
that reaches the biosphere. These models are validated against characteristic
data obtained in experiments at PSI and in the rock laboratory of the
Mont
Terri. The validated models are used subsequently in the framework of
integral safety studies for the characterisation of repositories.
HT-Materials Characterisation of materials for applications in very high-temperature
reactors, development of models for their behaviour
Very
high temperature reactors are considered as advanced nuclear plants for cogeneration
of electric energy and process heat (e.g. hydrogen production).
Materials are exposed for about 500’000 hours to temperatures of
1000 C, irradiation and impure helium causing different types of damage.
Based
on experimental damage analyses (mechanical properties, microstructure)
the development
of damage shall be modelled covering a wide range of scales (length,
time). Materials of interest are dispersion strengthened steels (ODS),
intermetallics
and SiC-type compounds.
FAST Code system development for safety analyses of fast-spectrum
reactors
[ Top ]
FAST aims at an active involvement in the
safety design project of gas- sodium- and lead
cooled fast reactors to be used in the future
for power production
and the minimization
of nuclear waste. The project carries out code development and validation
against international experiments and the analysis of the Generation
IV reactor concepts.
For reactor safety thermal-hydraulics phenomena play an important
role. NES develops and analyzes advanced experiments in the large-scale
facility PANDA
(tests related to integral containment system behaviour, containment thermal-hydraulics
and/or primary system/components) and in medium-scale separate-effects
test facilities (e.g. bubble plume investigations in LINX). Subsequently NES
validates,
applies and further develops system, containment and CFD computer codes,
in particular related to three dimensional phenomena and two-phase model
development.
Nuclear Energy and Safety Research Department
