Seminar der Abteilung Strahlenschutz und Sicherheit (ASI)


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

Intake of radionuclides: in vivo internal monitoring of exotic radioisotopes

Siria Medici, Institut de radiphysique (IRA), CHUV Lausanne

In this talk I will describe our approach to develop a new in vivo internal monitoring programme for the CERN workers that is compatible with the Swiss regulation. The risk of internal contamination at CERN increased following the commissioning of the CERN-MEDICIS facility, which produces short-lived and exotic radionuclides for medical research that are not considered in the Swiss Personal Dosimetry Ordinance. This talk will present the different topics covered during the PhD project : the development of a computer program allowing to solve the biokinetic models of the considered radionuclides, the description of a pragmatic procedure to assess the suitability of conventional radiation protection instruments to perform in vivo screening measurements (Triagemessungen) and the ability of two portable spectrometers to quantify intakes in different phantoms.


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

Ergebnisse und Herausforderungen bei der Durchführung der internationalen Vergleichsmessung für Neutronendosimeter IC2017n

Sabine Mayer, Abteilung Strahlenschutz und Sicherheit, PSI

EURADOS e.V. (European Radiation Dosimetry Group) ist ein gemeinnütziger Verein, der sich zur Aufgabe gesetzt hat, das wissenschaftliche Verständnis und die technische Entwicklung von Methoden der Dosimetrie ionisierender Strahlung auf den Gebieten Strahlenschutz, Strahlenbiologie, Strahlentherapie und medizinische Diagnostik zu fördern. In Arbeitsgruppen, bestehend aus Mitarbeitern von zumeist europäischen Forschungseinrichtungen, werden Forschungsprojekte koordiniert und durchgeführt. Die ASI arbeitet in verschiedenen Arbeitsgruppen von EURADOS mit. Eine der Arbeitsgruppen hat sich der Planung, Organisation und Durchführung der internationalen Vergleichsmessung für Neutronendosimeter IC2017n gewidmet, wobei die ASI die Koordination übernommen hat.

Ziel der Vergleichsmessung für Neutronendosimeter war es, Neutronendosimeter, die sonst in der Routine in verschiedenen Ländern eingesetzt werden, in verschiedenen Referenzfeldern von akkreditierten Primärlaboren zu testen. Die Energien der dabei eingesetzten Referenzneutronenspektren reichten von thermisch bis zu mehreren MeV, wobei bei den Bestrahlungen unterschiedliche Dosiswerte und Winkel verwendet wurden.

Der Vortrag berichtet über die Ergebnisse der internationalen Vergleichsmessung und die gesammelten Erfahrungen aus Sicht des Koordinators.



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

Using minerals as dosimeters

Georgina King & Lily Bossin, Institute of Earth Surface Dynamics, University of Lausanne

Abstract: Natural minerals like quartz or fluorite behave as natural radiation dosimeters. The radiation dose received by these minerals can be quantified using luminescence methods, allowing questions ranging from retrospective accident dosimetry to the timing of landscape evolution to be addressed. In this seminar, the principles of luminescence dosimetry will be outlined, followed by a discussion of its applications in both personal dosimetry and the Earth sciences.



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

Laser spectroscopy for on-line monitoring of radioactive emissions from nuclear facilities

Guillaume Genoud, MIKES Metrology, VTT Technical Research Centre of Finland Ltd

Abstract: In recent years, laser spectroscopy has emerged as a new alternative for the monitoring of fugitive radioactive emissions from nuclear facilities. The method is particularly suited for the monitoring of gaseous emissions of long-lived radioisotopes, such as radiocarbon and tritium, which are challenging to detect on-site with conventional radiation detectors. Liquid scintillation counting is often used in this context, but it lacks on-line measurement capabilities, requires complex sample preparation and produces additional radioactive waste. High sensitivity can be achieved using advanced spectroscopy techniques, such as cavity ring-down spectroscopy (CRDS). This method is able to provide continuous automated measurements allowing for more efficient environmental monitoring. Examples related to the detection of radiocarbon will be presented, which is measured in the form of carbon dioxide (C-14O2). Challenges and solutions related to the development of sampling techniques in connection with the use of optical detection methods will be considered. We will also present results from a field measurement campaign at a nuclear power plant, where automated C-14 monitoring was demonstrated with hourly measurement points and a detection sensitivity down to 30 Bq/m3



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

Optimierung der Bildgebung mit nichtreinen und hochenergetischen Positronenstrahlern in der Kleintierbildgebung

Sophie Harzmann, Abteilung Strahlenschutz und Sicherheit, PSI

Die Positronenemissionstomograhie (PET) repräsentiert ein funktionelles diagnostisches Untersuchungsverfahren, welches es ermöglicht Stoffwechselvorgänge in vivo zu visualisieren und absolut zu quantifizieren. Die präklinische Bildgebung stellt hierbei besondere Anforderungen an dieses Verfahren, insbesondere an eine hohe Ortsauflösung. Diese wird maßgeblich durch die eingesetzten PET-Detektoren sowie durch die verwendeten Isotope beeinflusst. Hochenergetische und nichtreine Positronenstrahler, wie beispielsweise das Isotop I-124, verschlechtern, bedingt durch eine lange Positronenreichweite, deutlich die Ortsauflösung und erschweren zudem durch die Emission von Kaskadengammalinien die Quantifizierung. Dieser Vortrag zeigt einige Korrekturansätze auf, wie mit diesen Isotopen in der nuklearmedizinischen Diagnostik umgegangen werden kann.


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.

28 March 2018 10:30-11:30 Uhr, OFLG/402 (Coffee with speaker from 10:00-10:30)

What does it mean to be a radiometrologist at a university hospital?
Claude Bailat, PhD, Institute of radiation physics, University Hospital (CHUV), Lausanne

Abstract: Radiometrology is performed in various institutions, such as PSI. In a clinical context, radiometrology can be seen as an extension of national metrology institutes or designated institutes. At IRA, radiometrology is performed at a primary and secondary level. It supports nuclear medicine as well as radiotherapy activities and developments. I propose for this talk to give you an overview of the duties of the group of radiometrology. We will detail two or three research projects to show practically what is expected of radiometrologists in a clinical environment.
29 May 2018 10:30-11:30 Uhr, OFLG/402 (Coffee with speaker from 10:00-10:30)

Radiation protection at SwissFEL: Latest experimental results to benchmark the shielding structure and the Dose Rate Protection System assumptions
Marco Tisi, Abteilung Strahlenschutz und Sicherheit, PSI

Abstract: SwissFEL, the new FEL facility, is now under commissioning at PSI. From a radiation protection point of view, SwissFEL operation requires a permanent monitoring of the radiation level in the surroundings of the facility. This task is performed by the lately installed Dose Rate Protection System (DRPS). With the increase of the electron beam energy to 2.5 GeV, measurement campaigns have been performed in order to verify the compliance with the guidance values imposed by law in the adjacent premises to the facility and benchmark DRPS model assumptions and calibration parameters, previously derived by calculations and Monte Carlo simulations.
18 June 2018 10:30-11:30 Uhr, OFLG/402 (Coffee with speaker from 10:00-10:30)

Emergency OSL/TL Dosimetry with Components of Mobile Phones and Other Personal Items
Stephen W. S. McKeever, Oklahoma State University

Abstract: Community response to large-scale radiological incidents, such as nuclear power plant accidents or terrorist attacks, requires the ability to determine the doses potentially received by individual members of the public. Normally, such individuals do not carry personal radiation dosimeters (such as TLDs, RPLDs, etc.) and therefore alternative radiation dosimetry methods need to be developed for eventual deployment following such major events. Two types of dosimetry are currently under investigation for this purpose, namely biological dosimetry (using specific biological markers for the absorption of radiation) and physical dosimetry (using radiation-induced physical markers in objects located on or near the individual). This talk will discuss the development of physical dosimetry methods, focusing primarily on luminescence (thermoluminescence (TL) and optically stimulated luminescence (OSL)) and electron paramagnetic resonance (EPR) of materials found in personal electronic devices, such as smart phones. The state-of-the-art of these research developments will be described along with projections for their potential utility.
17 July 2018 10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Characterization of neutron stray fields around high-energy accelerators using spectrometric and Monte Carlo methods
Roman Galeev, Abteilung Strahlenschutz und Sicherheit, PSI

Abstract: Many tasks associated with radiation protection, waste management and research are strongly dependent on assumptions and modeling. It is desirable to benchmark and optimize these assumptions with measurements of the neutron spectrum. A device suitable for this task is multisphere spectrometer. Such a system is currently under commissioning at PSI.This talk gives the overview of the system calibration and results of first measurements in workplace fields with high energy neutron component available at PSI.
21 August 2018 10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

Erfahrungen im Projekt "Beton-Schredder in der Kernanlage SAPHIR";
Robert Maag, Sektion Rückbau und Entsorgung, PSI

Abstract: Ursprünglich wurde vorgesehen, die leicht aktivierten Betonstrukturen, die aus dem Abbruch der Poolabschirmung stammen, für 30 Jahre zum Abklingen einzulagern. Mit Einführung der revidierten Strahlenschutzverordnung per 1.1.2018 und den damit verbundenen neuen nuklidspezifischen Befreiungsgrenzen, wäre eine Abklinglagerung nicht mehr zielführend gewesen. Aus diesem Grund wurde das Projekt "Beton-Schredder"; initialisiert, um für eine möglichst grosse Menge an Betonmaterial den Nachweis der Unterschreitung der noch gültigen Freigabewerte zu erwirken. Der Vortrag erklärt die Vorgehensweise und die Erfahrungen in diesem zeitlich knapp begrenzten Projekt, das erfolgreich abgeschlossen wurde. Abstract
20 November 2018 10:30-11:30 Uhr, PSI Bildungszentrum EG6 (Coffee with speaker from 10:00-10:30)

The Potential of Terbium-161 for Targeted Radionuclide Therapy: Combining β¯- Particles and Auger Electrons for More Efficient Cancer Therapy
Cristina Müller, Center for Radiopharmaceutical Sciences, BIO, PSI und Nicholas P. van der Meulen, Laboratory for Radiochemistry, NES, PSI

Abstract: Tb-161 is of great interest to be used for therapeutic purposes in nuclear medicine. It provides similar decay properties as the routinely-used Lu-177 but, in addition, it emits substantial number Auger electrons. It is believed that the Auger electrons can efficiently kill small metastases or even single cancer cells. The emission of g-rays allows using the radionuclide for Single Photon Emission Computed Tomography (SPECT) which is useful for therapy monitoring and dosimetry calculations. The production and preclinical evaluation of Tb-161 have been developed at PSI. Optimization of the production process and more detailed investigation in terms of biological effectiveness are on-going. It is the aim to translate Tb-161 in clinical practice within the next few years.

-- Main.VeronikaHeber - 21 Mar 2019