Wanderausstellung der Regionalstelle Hornissenschutz OWL

Ein starkes Hornissenvolk verfüttert pro Tag bis zu 500 g Insekten an seine Brut, z. B. auch wetterbedingt massenhaft auftretende Stechmücken Außerdem sind Hornissen friedliche und ungefährliche Mitgeschöpfe. Die Erhaltung von Hornissen und deren Nester ist aber schwieriger als ihre bedenkenlose Vernichtung. Die Maßnahmen zur Erhaltung erfordern einen hohen Aufwand an Zeit, Geld, Geduld und meistens auch sehr viel Überredungskunst. Und da der Mangel an Informationen über das tatsächliche Verhalten der Hornissen und den besten Umgang mit ihnen das größte Hindernis vor einem wirklich einfachen, friedlichen Miteinander-Leben scheint, entschloss sich der NABU Höxter, sowohl eine Hornissenschutz-Anlaufstelle als auch eine Wanderausstellung zu schaffen

Non-destructive verification of materials in waste packages using QUANTOM®

The nuclear and non-nuclear industry has produced a considerable amount of low and intermediate-level radioactive wastes during the last decades. The material characterization of waste packages recently became more and more important in order to dispose of these waste packages in a final underground repository. Material characterization remains an indispensable criterion to prevent pollution of the groundwater with toxic materials and is usually required by the national licensing and supervisory authorities. Information on the nature of waste materials can be obtained based on existing documentation or, if the documentation is insufficient, on further destructive or non-destructive analysis. Non-destructive methods are to be preferred to minimize radiation exposures of operating personnel as well as costs. Existing non-destructive techniques (Gamma scanning, X-ray, active/passive neutron counting, muon tomography) do not allow the identification of non-radioactive hazardous substances. An innovative non-destructive measurement system called QUANTOM® (QUantitative ANalysis of TOxic and non-toxic Materials) has been developed. It is based on the prompt and delayed gamma neutron activation analysis (P&DGNAA). This technology is able to identify and quantify the elemental composition (Cd, Cu, B, Pb, Hg, Fe, Al, …) in radioactive packages such as 200-l radioactive drums. This information helps waste producers verify the content of their radioactive wastes, especially regarding the presence of hazardous substances. Different reference materials have been analysed by means of the same technology (P&DGNAA) at the research reactor of BUDAPEST. A comparison of those results for five reference materials is presented. The results show a very good agreement between QUANTOM® and standardized reference analyses

The JCPOA - a victory of diplomacy

Ever since the disclosure of undeclared activities within the Iranian nuclear program in 2002, the international community had doubts about its exclusive peaceful direction. Secret procurement of uranium and equipment, and late and bit by bit disclosures lead to missing confidence in the trustworthiness of Iran; intelligence reports even suggest that Iran had launched a structured program and "[...] carried out activities relevant to the development of a nuclear explosive device". Since 2002, the IAEA is in discussions with Iran and the Director General reports quarterly to the Board of Governors on this issue. These reports are timely derestricted and released to the general public and provide a seamless documentation of this case. In a second track, the E3 started in 2002 negotiations with Iran that accumulated in the Geneva interim agreement and ultimately in the Vienna final agreement in July 2015. This talk gives an overview of the provisions of this Joint Comprehensive Plan of Action, combined with an analysis of the IAEA reports

Schneller Nachweis von nuklearen Gefahrstoffen mit modernen tragbaren Messsystemen

Bei Auffinden von nuklearem Material müssen zeitnah verlässliche Messungen inklusive einer Identifikation derim Objekt enthaltenen Nuklide erfolgen, und zwar mit tragbaren Messsystemen für den Einsatz vor Ort. Das Fraunhofer-Institut für Naturwissenschaftlich-Technische Trendanalysen INT hatte am Joint Research Center (JRC) die Gelegenheit, einige solche Messsysteme an realem Spaltmaterial hinsichtlich der Praktikabilität der Analyse zu untersuchen

Untersuchung von ⁶Li basierten Szintillatoren zum Nachweis von Neutronen: Vortrag gehalten auf der 22. Deutschen Physikerinnentagung, 27. bis 30. September 2018, Oldenburg

Bei der Untersuchung von unbekannten, radioaktiven Materialien spielt der Nachweis von Neutronen eine wichtige Rolle. Da Neutronen keine elektrische Ladung haben, sind sie nicht direkt, sondern nur über einen Zwischenschritt nachzuweisen. Hierzu wird in der Regel das Isotop Helium-3 (³He) verwendet. Durch eine Zunahme des ³He-Bedarfs zur Neutronendetektion, und eine gleichzeitige Reduktion der am freien Markt verfügbaren Menge, sind die Preise für ³He in den letzten Jahren stark angestiegen, wodurch nun vermehrt an Alternativen zum Neutronennachweis durch ³He geforscht wird. Ein Isotop, welches wie ³He für die Neutronendetektion geeignet ist, ist das in fester Form vorkommende Lithium-6 (⁶Li). In diesem Forschungsfeld wurden zwei Detektionsmaterialien auf Basis von ⁶Li untersucht und mit dem herkömmlichen Detektionsmaterial ³He verglichen. Dabei handelt es sich um das Szintillationsmaterial CLYC (Cs₂LiYCl₆:Ce) und das Szintillationsmaterial CLLB (Cs₂LiLaBr₆:Ce). Beide Kristalle ermöglichen zusätzlich zur Neutronendetektion die Detektion von Gamma-Strahlung und erlauben eine Diskriminierung zwischen Neutronen-induziertem und Gamma-induziertem Messsignal. Ergebnisse aus dem Vergleich von ³He und ⁶Li bei der Neutronendetektion und zur gleichzeitigen Detektion von Neutronen und Gamma-Strahlung werden in diesem Vortrag vorgestellt

Simulation of a neutron multiplicity counter and comparison to validation experiments: Paper presented at International Workshop on Numerical Modelling of NDA Instrumentation and Methods for Nuclear Safeguards, 2018, Luxembourg, 16th-17th May 2018, co-hosted during the ESARDA 40th Annual Meeting

Neutron coincident counting is a useful tool, both to determine the nature of a neutron source and to extract parameters like the multiplicity, α-ratio and ultimately the mass. For the latter, well characterized detectors, like the Active Well Coincident Counter (AWCC), enable the measurement of uranium or plutonium content in the order of several grams. The multiplicity analysis also allows determining if an unknown neutron source emits fission neutrons and thus possibly contains special nuclear material. The Ortec Fission Meter is an instrument designed exactly for this purpose. It consists of a highly efficient moderated 3He neutron detector and a Windows Mobile handheld computer with dedicated software. It is powered by batteries and intended for field use. In order to get a deeper understanding of the measured data and to predict the dependence of the analysis on different parameters like additional shielding, Fraunhofer INT performed a Monte-Carlo simulation of the instrument. A MCNP simulation of the source assembly and the instrument results in the arrival times of the neutrons for one single source event. Further software modules allow to generate a pulse train and to perform the same analysis as the Fission Meter hard- and software does. While the count rate of the simulation and a validation experiment were in agreement, the calculated Feynman-Variance showed a significant deviation. The main cause is presumably a small fraction of double pulsing from the discriminator. The inclusion of this effect in the post-processing results in a very good agreement of measured and simulated data

Simulation of a neutron multiplicity counter and comparison to validation experiments: Presentation held at 83. Jahrestagung der DPG und DPG-Frühjahrstagung, Rostock, 10 - 15 March 2019

Neutron coincident counting is a useful tool, both to determine the nature of a neutron source and to extract parameters like the multiplicity, α-ratio and ultimately the mass of uranium or plutonium . For the latter, well-characterized detectors enable the determination in the order of several grams. The multiplicity analysis also allows determining if an unknown neutron source emits fission neutrons and thus possibly contains special nuclear material. The Ortec Fission Meter is an instrument designed for this purpose, equipped with a highly efficient moderated 3He neutron detector. In order to gain deeper understanding of the measured data and to predict the dependence of the analysis on different parameters like additional shielding, Fraunhofer INT performed a Monte-Carlo simulation of the instrument. A MCNP simulation of the source assembly and the instrument results in the arrival times of the neutrons for one single source event. Further software modules allow generating a pulse train and performing data analysis. While the count rate of the simulation and a validation experiment were in agreement, the calculated Feynman-Variance showed a significant deviation. The main cause is presumably a small fraction of double pulsing from the discriminator. The inclusion of this effect in the post-processing results in a substantial improved agreement of measured and simulated data

QUANTOM

For the final disposal of radioactive waste, the waste packages have to meet the acceptance requirements defined by national licensing and supervisory authorities. Nondestructive methods are very much preferred over destructive methods for the qualification or re-qualification. Existing nondestructive methods as integral or segmented gamma scanning or neutron counting only determine the isotope specific activity but do not allow quantifying other non-radioactive hazardous substances. These should have been documented during creation, conditioning, and packaging of the waste. But especially for legacy waste, this documentation is often poor or even missing. This gap is to be filled by the QUANTOM® measurement device that will determine the mass fraction of elements within a 200-l-drum using the Prompt- and Delayed- Gamma-Neutron-Activation-Analysis. In order to obtain a spatially resolved characterization, it will employ a segmented scanning approach. For the determination of the absolute mass fractions, the neutron flux inside the drum has to be known accurately. As the waste itself will alter the neutron distribution and flux, it is not possible to calculate the latter a priori from the gamma measurement. Hence the neutron flux has to be measured simultaneously with the gamma radiation. In this presentation, we will introduce the system for measuring the thermal neutron flux surrounding the waste drum from which the flux within the waste package has to be reconstructed. We performed a simulation study to score several possible detector placements for an improved reconstruction performance. We will show the outcome of these calculations and present the final design of the detector arrangement

D3S - results of qualification measurements of a wearable RIID for homeland security: Paper presented at INMM 2019, 60th Annual Meeting Institute of Nuclear Materials Management, July 14-18, 2019, Palm Desert, California, USA

A testing facility for qualification tests of measurement devices for radioactive and nuclear material was established at the Fraunhofer INT. This was done in the framework of the Illicit Trafficking Radiation Detection Assessment Program + 10 (ITRAP+10). The test methods were developed in the program based on ANSI and IEC standards. After the completion of the setup of the facilities, they are now used for the testing of various devices. This paper deals with tests in accordance with the ITRAP test procedures and the corresponding results obtained for the D3S detector from Kromek. The device is designed to be used as radiation isotope identifier (RIID) as well as personal radiation dosimeter (PRD). Therefore tests referring to both test methods were performed. The device contains a cesium iodine gamma as well as a non-helium-3 neutron detector and both kinds of sources were used for the device qualification. The tests are divided in tests of general requirements, radiological tests, and radionuclide identification tests. The tests of general requirements include for example tests of the user interface, battery requirements, documentation or audible and vibrational alarm. The radiological tests comprise tests concerning false identification rate, time to alarm, accuracy tests for photons, over range and gamma response of the neutron detector. The quality of the nuclide identification results is part of the radionuclide tests. Partly the requirements for PRDs and RIIDs are identical, partly not. For example the time to alarm value in which an alarm after the device is exposed to the source shall be created is 2 s for PRDs and 3 s for RIIDs. The D3S passed many tests, but also failed some. The tests also showed the limits of such test procedures. They are standard tests under fixed conditions whereas in reality different situations occur in which the obtained results may not turn out as well as the tests indicate. The paper gives results of the qualification tests done with the D3S as well as a suggestion for an additional close to reality test

Highly efficient on-site detection of neutron sources with the INT measurement car DeGeN

Counter-acting the potential misuse of nuclear and radioactive material has been a subject of tremendous importance for quite a while, and the detection of such material is a key figure to counter-acting measures in that respect. Especially regarding nuclear material, detecting gamma and neutron radiation simultaneously on-site with high efficiency provides a good chance of retrieving such material during transport after it was removed from nuclear facilities, either as a malicious act or simply by chance. The Fraunhofer INT's (Institute for Technological Trend Analysis) measurement car DeGeN (detection of gammas including neutrons) is equipped with highly sensitive 3He neutron detectors and 12 l plastic detectors for gammas. After a reconfiguration of the measurement system, including new gamma detectors, the INT was given the opportunity of verifying the system's detection limits at the premises of WIS (Bundeswehr Research Institute for Protective Technologies and CBRN Protection) in Munster, Germany. Two different neutron sources were used for the experimental determination of the detection limits concerning neutrons. The results were then compared to theoretical detection limits which had been calculated previously. The results proved to be in good agreement overall