Seminar der Abteilung Strahlenschutz und Sicherheit (ASI)

The Seminar series of the PSI Department of Radiation Safety and Security (Abteilung Strahlenschutz und Sicherheit, ASI) introduces new results and developments in radiation protection, dosimetry, radioanalytics and similar topics. For more information and registration, please contact Claudia Nydegger.


10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Helium-beam imaging and secondary-ion tracking with Timepix detectors in ion-beam therapy

Tim Gehrke, German Cancer Research Center (DKFZ)

Abstract: Ion-beam radiotherapy has the potential to provide high conformal doses to the tumor while better sparing healthy tissue in comparison to radiotherapy with photons. On the other hand, ion-beam radiotherapy has a higher sensitivity to treatment uncertainties like anatomical changes or patient-positioning uncertainties. Thus, a precise knowledge of the actual stopping power distribution of the patient's tissue relative to water (RSP) and an online-monitoring of the ion beam inside the patient is of great interest. This talk will introduce two methods towards these purposes that are investigated in the Department of Medical Physics in Radiation Oncology at the German Cancer Research Center (DKFZ). The first method is helium-beam radiography that has the potential to improve the accuracy of the RSP prediction. The second is secondary-ion tracking that could provide an online monitoring of the treatment beam inside the patient. Both approaches are based on the use of silicon pixel detectors. The principles of these type of detectors will be outlined, and the current status of the two methods will be presented.


10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Decommissioning costs reduction due to novel clearance measurement system

Jiri Suran, Czech Metrology Institute, Brno, Czech Republic

Abstract: This presentation addresses the measurement facilities for pre-selection of waste materials prior to measurement for repository acceptance or possible free release (segregation measurement system); and free release (free release measurement system), based on a single standardized concept characterized by unique, patented lead-free shielding. The key objective is to improve the throughput, accuracy, reliability, modularity and mobility of segregation and free-release measurement. This will result in a more reliable decision-making with regard to the safe release and disposal of radioactive wastes into the environment and, resulting in positive economic outcomes. The research was carried out within “Metrology for Decommissioning Nuclear Facilities” (MetroDecom) project.


10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Activation calculations and zoning for Long Shut-down 2 (LS2) related activities

Robert Froeschl, CERN

Abstract: After successfully completing Run 2 in December 2018, the LHC entered a more than 2 yearlong shut-down, denoted as Long Shut-down 2 (LS2). During this period, the whole CERN accelerator complex will undergo a series of upgrades to prepare the machines to be able to fully exploit the potential of the High-Luminosity LHC that will start operating after Long Shut-down 3 (LS3) in 2026. Activation zoning for work-sites plays a crucial role to ensure proper radiation protection, especially in view of the clearance limits in force since 2018. This talk will present the strategies and techniques used for several installations at CERN for LS2 related activities, ranging from civil engineering works to the upgrades of the LHC experiments. The role of Monte Carlo simulations will be discussed together with dedicated benchmark campaigns for their validation.


10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Blended-Learning bei Strahlenschutzkursen: Neue Möglichkeiten für den Präsenzunterricht … und ein anderes Outcome?

Andreas Jagenburg, ccm-Campus GmbH

Abstract: Strahlenschutz ist ein Nebenaspekt bei der Anwendung ionisierender Strahlen - aber kein Randthema. Nicht selten wirken sich die Rahmenbedingungen auf die Motivationslage und den stofflichen Zugang der Lernenden aus. Blended-Learning-Modelle bieten Vorteile. Nicht nur, dass der Content im e-Learning-Teil anders aufbereitet werden, der Teilnehmer intensiver gefordert und er sich individuell vorbereiten kann. In der Folge ergeben sich auch neue Möglichkeiten der Unterrichtsgestaltung in der Präsenzphase. Die Aktivierung der Teilnehmer spielt dabei eine große Rolle.


10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Praktische Aspekte des anlagenexternen Notfallschutzes

Horst Miska

Abstract: Neben der „übersichtlichen“ Theorie zum anlagenexternen Notfallschutz wer­den die Probleme der Umsetzung der verschiedenen Empfehlungen in die Pra­xis beleuchtet. Die Lageerfassung nach den Unfällen von Fukushima, die an­fangs zu überhöhten Dosisabschätzungen führte und die daraus resultierenden, überzogenen Schutzmaßnahmen werden analysiert. Auf die Referenzwerte der Dosen im Notfallschutz wird hingewiesen und die Notwendigkeit der Beach­tung der Rechtfertigung von Schutzmaßnahmen wird betont.


10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Increased Uranium concentrations in ground and surface waters of the Swiss Plateau: A result of Uranium accumulation and leaching in the Molasse Basin and (ancient) wetlands?

Anja Pregler, Abteilung Strahlenschutz und Sicherheit, PSI

Abstract: In this presentation I will provide an overview of the research carried out in the last 3 years as part of my PhD work which focused on naturally occurring Uranium (U) series isotope disequilibirum in phreatic water. Exceptionally high natural U concentrations in ground and surface waters were found in the western part of the Swiss Plateau. More than 100 public fountains were analyzed for their radionuclide content, revealing that increased U-238 concentrations frequently occur at the interface between the Lower Freshwater Molasse and the Upper Marine Molasse. Two springs at the northern slope of Mont Vully (20 km northwest of Berne, Switzerland) that originate from this interface exhibit the highest concentrations in U-238 and were thus monitored for almost 2 years in order to screen seasonal variations. In addition, the arable land north of Mont Vully was surveyed by gamma dose rate measurements to locate possible U accumulations underground. In order to verify the assumption that enhanced gamma dose rates are owed to an underground U accumulation, 5 shallow sediment drill cores were taken and analyzed for their U content. In the course of the present study, the origin of U concentration in ground and surface water as well as the U accumulation in soils are investigated and the relationship between the increased values is discussed.


10:30-11:30 Uhr, PSI Bildungszentrum EG6

Radiation protection at the ELI Beamlines facility

Roberto Versaci and Veronika Olšovcová, ELI Beamlines Czech Republic

Abstract: ELI Beamlines, located on the outskirts of Prague, is part of the Extreme Light Infrastructure (ELI) project, a new Research Infrastructure of pan-European interest and part of the European Strategy Forum on Research Infrastructures (ESFRI) Roadmap . ELI is a multi-site Research Infrastructure with complementary facilities located in the Czech Republic, Hungary, and Romania for the investigation of light-matter interactions at the highest intensities and shortest time scales.

ELI Beamlines will be a user facility, however, it will also perform in house research. ELI Beamlines aims at fundamental research, however, investigation of possible application of its cutting edge technologies is also envisioned. The interaction of extremely powerful lasers with matter is capable of producing a large amount of ionizing radiation that will have to be dealt with. The type and scale of the facility and presence of radiation hazard is novel to the laser community. Besides, the field characteristics (extremely short pulsed field of high energy particles) represent a challenge for radiation protection.

We will introduce the project, its scientific goal, and the status of the facility. We will describe the radiation protection preparatory work describing the specific challenges and safety measures taken, the design of the shielding and of the monitoring system, and the interaction with the regulatory authorities. Finally, as the commissioning started in 2018, we will discuss the first operations and the lessons learned.


10:30-11:30 Uhr, PSI Bildungszentrum EG6

Personal Dosimetry Research at the Belgian Nuclear Research Centre SCK•CEN

Filip Vanhavere, Belgian Nuclear Research Center SCK•CEN

Abstract: The Research in Dosimetric Application unit at SCK•CEN is focused on quantification of doses to reduce the risk in the working environment and for the public, and to optimize medical practices for patient and personnel. There is also a focus on the development of dosemeters to improve the monitoring in specific situations. The group is now composed of 8 researchers and 7 phD students. For personal dosimetry, work has been done in neutron dosimetry, eye lens dosimetry and active personal dosemeters. The major project now is focused around the PODIUM project, where PODIUM stands for Personal On-line Dosimetry using Computational Methods. An overview of the recent progress in some of these projects, and mainly PODIUM will be given.