Arbeitsgruppe Analytik und kernchemische Grundlagen

Abteilung Nuklearchemie an der Universität zu Köln

Working Group of Analytics and Basic Nuclear Chemistry

Division of Nuclear Chemistry at the University of Cologne

Jahresbericht 2017

Annual Report 2017

April 2014

2

Arbeitsgruppe Analytik und kernchemische Grundlagen

Abteilung Nuklearchemie an der Universität zu Köln

Working Group of Analytics and Basic Nuclear Chemistry

Division of Nuclear Chemistry at the University of Cologne

Jahresbericht 2017

Annual Report 2017

April 2017

Titelbild

Zwei Segmente einer Schwerbetonprobe or der Bestrahlung im Mainzer TRIGA-Reaktor

→S. 8;

Coverpage

Sample segments of heavy concrete before the irradiation at the TRIGA reactor Mainz

→p. 8;

3

Content / Inhaltsverzeichnis

Laufende Arbeiten / Ongoing Works .................................................................................. 4

Nachweis von Po-210 in Zigarettenrauch ........................................................................... 5

Development of a Bi/Tl-separation procedure for application on ultratraces of 205Tl in

bismuth-minerals ............................................................................................................... 6

Separation of 41Ca from activated heavy concrete ............................................................. 7

Profile analysis of fire-gilded silver and copper sheets ....................................................... 8

Measurement of prompt-gamma-neutron-activation with a semiconductor detector ........... 9

Herstellung eines 133Ba-Präparats für die Konversionselektronenspektrometrie ................10

Radiochemical analysis of fertilizer & sewage sludge/ashes .............................................11

ColPuS, a new Multi-Isotope Plutonium Standard for Accelerator Mass Spectrometry ......12

La–Ce isotope measurements by multicollector-ICPMS ....................................................13

Strahlenschutz 2017 ...........................................................................................................14

Publikationen, Vorträge, Poster, abgeschlossene Arbeiten 2017 ...................................15

Publikationen ....................................................................................................................15

Beiträge zu Jahresberichten anderer Institutionen ............................................................15

Vorträge an anderen Institutionen .....................................................................................16

Eingeladene Vorträge Dritter an der Universität zu Köln ...................................................16

Poster ...............................................................................................................................16

Abgeschlossene Arbeiten .................................................................................................17

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Laufende Arbeiten / Ongoing Works

5

Nachweis von Po-210 in Zigarettenrauch

Sebastian von Döllen

Einleitung

Rund 25 % aller Deutschen sind Raucher [1]. Tabakrauch enthält neben diversen schädlichen Verbrennungs-produkten auch Radionuklide wie 210Pb-oder 210Po in nicht vernachlässigbaren Mengen. Diese Radionuklide sind Teil der natürlichen 238U Zerfallsreihe, in deren Verlauf das gasförmige 222Rn gebildet wird, wodurch der Übergang aus dem Boden in die Tabakpflanze erleichtert wird.

Durch Bestimmung der Aktivität des 210Po in Tabakrauch kann die daraus resultierende Belastung für den Menschen abgeschätzt werden. In dieser Arbeit wurde eine Methode für den quantitativen Nachweis von 210Po aus Tabakrauch entwickelt.

Experimentelles

Zum Auswaschen des 210Po aus Rauch wurde eine Apparatur nach Vorbild einer Gaswaschflasche entworfen, die die Grenzfläche zwischen Waschlösung und Rauch maximiert. Als Waschlösung wurden Natronlauge, wie auch Salzsäure verwendet. Nach anschließender elektro-chemischer Autodeposition auf Silber- bzw. Kupferblech wurde die Zählrate des 210Po-

am -Zähler bestimmt.

Ergebnisse

Es wurde gezeigt, dass zur Autodeposition in basischer NaOH-Lösung besser mit Kupferblech gearbeitet wird, wohingegen in salzsaurer Lösung die Autodeposition besser auf Silberblech funktioniert.

Im Rauch von einem Gramm Tabak wurden durchschnittlich ca. 12 mBq 210Po

gefunden (vgl. Abb 1). Die resultierende zusätzliche Strahlenbelastung für durch-schnittliche Raucher liegt demnach bei etwa 200 µSv/Jahr [2], was immerhin rund 10 % der natürlichen Strahlenbelastung durch Ingestion von Radionukliden entspricht [3].

Abbildung 1. -Spektrum der natürlichen Radioaktivität aus Rauch von 5 g Tabak (NaOH-Waschlösung, Abscheidung auf Silber, 210Po: 439 Impulse in 18 Stunden Messzeit).

Referenzen

[1] WHO report on the global tobacco epidemic, (2017) http://www.who.int/tobacco/surveillance/policy/country_profile/deu.pdf [2] H.-G. Vogt, H. Schultz, Grundzüge des praktischen Strahlenschutzes, [3] BMUB „Umwelt-Radioaktivität und Strahlenbelastung im Jahr 2014“, Bundestagsdrucksache 18/9600, (2016) http://dip21.bundestag.de/dip21/btd/18/096/1809600.pdf.

6

Development of a Bi/Tl-separation procedure for

application on ultratraces of 205Tl in bismuth-minerals

Kevin Beu

Introduction

The development of a Bi/Tl separation scheme using carrier free 204Tl for modeling ultra trace levels of stable Tl has been investigated in previous studies [1]-[4]. Since this separation scheme has not yet been applicated on Bi-material, this study deals with first application experiments of the Bi/Tl separation technique on Bi-metal.

Experimental

Bi-metal (0.5-0.6 g) was dissolved in 5 mL HNO3 (5 M) and evaporated to dryness. The remaining colourless solid (Bi(NO3)3) was re-dissolved in 5 mL HBr (4.5 M) and evaporated to dryness. A yellow solid remained (BiBr3, BiOBr) which was re-dissolved quantitatively in a mixture of 5 mL HBr (8.89 M)-HNO3 (0.5 M)-1%Br2 (aq.), spiked with 0.2 mL 204Tl tracer solution and refluxed overnight. After cooling to room temperature, the mixture was stored for at least 1 hour. A column was prepared (2 mL DOWEX® 1X8 100-200 mesh), which was rinsed and equilibrated using 10 mL HCl (0.1 M)/SO2 and 10 mL HBr (8.89 M)-HNO3 (0.5 M)-1%Br2 (aq.). The eluated fractions (7-8 mL) were collected in 10 mL vwr® centrifuge tubes. After loading the sample solution (Fraction 1), the beaker was cleaned out onto the column 2 times using again 10 mL HBr (8.89 M)-HNO3 (0.5 M)-1%Br2 (aq.) each time, while Bi was eluted (fractions 2 & 3). In the following steps Tl was eluted using 10 mL HCl (0.1 M)/SO2 each time (fractions 4-10). The eluted fractions were analyzed for their 204Tl content using a NaI(Tl)-Szintillation Counter (UMes=0.6-0.9 V).

Results and discussion

First experiments showed, that Bi can be dissolved easily using HNO3 (5 M). A challenging aspect is the inclusion of received BiBr3 into the eluent HBr-HNO3-

1% Br2. After elution of 204Tl, no remaining activity was detected on the column. In figure 1, an example for a successful separation of 204Tl from Bi is illustrated.

Fig.1: Counts per second (CPS) values of the Tl content in the eluated fractions.

The main Tl content is located in the 4th and 5th Tl-Fraction, respectively, so the switch of the eluent after the separation of Bi does not result in a direct elution of the main Tl content. The results also show, that an excess of Bi has obviously no influence on the separating capacity. This confirms the results of the previous experiments regarding the separating capacity in the presence of excess amounts of Bi. The recovery rates of the experiments were kept constantly ≥ 9 0 %.

The first application of the separation scheme on Bi-metal was successful. The usage of concentrated HBr during the dissolution process of Bi avoids the formation of poorly soluble BiOBr. Future experiments will deal with dissolution experiments of crystalline bismuthinite samples and the application of the Bi/Tl separation technique on these geological samples.

References

[1] K. Beu, Diplomarbeit. [2] K. Beu, Jahresbericht (2014), 9. [3] K. Beu, M. Körbitzer, Jahresbericht (2015), 8. [4] K. Beu Jahresbericht (2016), 10.

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7

Separation of 41Ca from activated heavy concrete

Raphael Margreiter

Introduction:

During the lifetime of a nuclear reactor, the biological shield is exposed to a high neutron flux, resulting in the activation of the material. Therefore, the disposal of the biological shield is subject to regulations concerning the disposal of radioactive waste. Due to the high mass and volume of the biological shield, the most economic approach for its disposal is usually the subdivision of the material with regards to the exceedance of the legal exemption limits.

One of the elements in heavy concrete that has to be considered, is 41Ca, an activation product of Ca contained in the concrete. Although it has a long half live

(9.94 104 a), it is commonly accounted for by theoretical calculations, because it solely decays through electron capture without the emission of γ-radiation, so its detection is not a trivial task. An established method to detect traces of 41Ca is accelerator mass spectrometry (AMS).

AMS requires separation of the calcium from the concrete, therefore, the establishment of a simple separation procedure is needed. A previously reported

technique for the separation of 41Ca from concrete for liquid scintillation counting (LSC) [1] was adapted and modified with the goal of simplification, see figure 1.

Procedures

In [1], it is suggested to perform acid leaching with aqua regia as a less time-consuming alternative to alkali fusion for the first step of the procedure. We chose to stick with the alkali fusion nevertheless to ensure the best possible decomposition of the concrete, and also because the needed sample amount for AMS is much smaller than for LSC.

Further changes are mostly due to the desired product separation. Calciumoxide (CaO) is a possible precursor for the AMS targets, which is easily accessible through calcination of Ca oxalate (CaC2O4). Since CaC2O4 is the only earth alkali oxalate with a solubilty lower than the corresponding sulfate, sulfate-/oxalate-precipitation is a good way of separating Ca the other group 2 elements.

References

[1] X. Hou, Radiochim. Acta 93 (2005).

Fig.1: Ca-separation procedure following [1].

8

Profile analysis of fire gilded silver and copper sheets

Raphael Margreiter

Introduction

Fire gilding is a historic technique for the application of golden layers onto materials such as silver, copper, and brass. During the gilding process, the base material is covered with a gold amalgam and subsequently heated to evaporate excess mercury. This leaves a dull yellow layer containing mainly gold and not evaporated mercury. After polishing, the layer shows the desired golden color and metallic gloss [1].

X-ray fluorescence analysis (XRF) is a useful method to analyze these gold layers since it allows for a destruction-free, qualitative and quantitative analysis of the samples by looking at the emitted characteristic X-rays.

Earlier research by our group suggests [2]

a characteristic Hg distribution in the profile

of silver and copper sheets gilded with the

method of fire-gilding. Therefore, a careful

analysis of these profiles was conducted.

Method

For this purpose, several fire-gilded silver and copper sheets were prepared in the lab, polished and embedded in an epoxy raisin. These samples were later cross-sected and polished at the Bundesanstalt für Materialforschung (BAM).

The samples were analyzed with synchrotron XRF performing line scans on the cross sections using a µm beam spot at the BAMline of BESSY II at the Helmholtz-Zentrum-Berlin.

Results and Discussion

The results of the line scans are given in figure 1 and figure 2, respectively. The data are averaged over ~45 single line scans.

Fig.1: Hg content along the cross section of a fire-gilded silver sheet.

Fig. 2: Hg content along the cross section of a fire-gilded copper sheet.

For the fire gilded silver sheets, the data show clearly an Hg enrichment at the interface of the gold layer and the base material. On the other hand, for the copper sheets the Hg distribution in the layer seems to be generally homogeneous. Further investigations regarding the formation and time development over time of the Hg enriched layer are planned.

References

[1] Plinius, Historia Naturalis 33, XXXII, 100 [2] Margreiter, Bachelorarbeit, Universität zu Köln, 2016

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9

Measurement of Prompt-Gamma-Neutron-Activation

(PGNAA) with a Semiconductor Detector

Sebastian Weist

Introduction

The goal of this work was to construct a new experiment for the practical lab course, to determine the chloride concentration of a solution by prompt-gamma-neutron-activation-analysis (PGNAA). While first tests with a scintillation detector were generally promising [1], another aim was to improve the results by implementing a Ge detector for the measurements.

Experimental and Results

The Am-Be neutron-source of the division of nuclear chemistry was used to generate (n,γ)-reactions in a sample which were detected using a Ge detector. With the help of reference samples, the concentration of different elements the sample was determined.

First a geometry of the setup was investigated, by variating the distances between neutron source, sample and detector. Also, different sample sizes and sample holders were investigated. Because the neutron source emits not only neutrons but also hard gammas, (> 4 MeV), a lead shielding between the source and the detector was necessary to minimize the dead time of the detector. A lead bar with a thickness of 5 cm was sufficient.

The first approach used big sample sizes (several L of aqueous solutions of HCl) so that the sample was simultaneously used to moderate the neutrons.

Figure 1: Sketch of the used setup (top view). D: detector; P: Sample; yellow: paraffin, grey: lead bars, red: neutron source.

However, further testing with smaller samples (one L), with an additional layer of paraffine (3.6 cm) as a moderator yielded better results. The final setup is displayed in figure 1.

With this setup it was possible to find serval characteristic γ signals for Cl-35 ( 517, 786, 788, 1165, 1951, 1959 keV, see [2]). For the evaluation, the 1165 keV line was chosen. The spectra were analysed using GammaVision. The correlation of the signal strength and the HCl is plotted in figure 2.

Figure 2: caliibration curve for concentration determination

Discussion

The goal to build a PGNAA setup that can be used in the nuclear chemistry practical course for the determination of HCl concentrations was achieved. Further, “unknown” elements like samarium can be identified by this procedure via their characteristic gamma energies.

References

[1] Fabian Hartl, Prompt-Gamma-Neutronenaktivierungsanalyse, Projektarbeit, Universität zu Köln, (2016). [2]https://www.nds.iaea.org/pgaa/databases.htm

10

Herstellung eines 133Ba-Präparats für die

Konversionselektronenspektrometrie

Erik Strub

Ziel

Aus einer 133Ba-Lösung sollte ein Präparat als Kalibrierquelle für die Konversionselektronenspektrometrie präpariert werden. Ausgangspunkt war eine alte (1971) Lösung von BaCl2 in HCl mit einer nominellen Aktivität von 0.89 mCi/mL (Referenzdatum 01.04.1971; Aktivität zum 01.04.2017 demnach ca. 1.58 MBq/mL) und einer Ba-Konzentration von 109 µg/mL (Bild 1). Die Kalibrierquelle sollte eine Aktivität in der Größenordnung von 600-700 kBq besitzen, entsprechend einem Volumen der Ausgangslösung von ca. 500 µL.

Aufarbeiten der 133Ba-Lösung

Zunächst wurden 500 µL (ca. 790 kBq) der Ausgangslösung in ein Eppendorf-Vial pipettiert und vorsichtig (eingestellte

Sandbadtemperatur: 95C) eingedampft. Dabei zeigte sich ein erheblicher Rückstand, der schätzungsweise in der Größenordnung von mg liegt, also deutlich über dem Erwarteten. Vermutlich handelt es sich dabei um Material des Gummistopfens, mit dem die ursprüngliche Lösung verschlossen war.

Das Material wurde daher durch eine Säulentrennung in 10 M HCl über Anionen-austauscher aufgereinigt. Unter diesen Bedingungen wird Ba2+ innerhalb des Totvolumens eluiert, wie aus Abbildung 3 hervorgeht.

Abb. 3: Elutionsdiagramm verschiedener Radonuklide in 10 M HCl über Anionenaustauscher Dowex 1-x8 (Quelle: B. Dittmann)

Präparation der Kalibrierquelle

Um den dunklen Niederschlag nicht zu transferieren, wurden nur ca. 28 µL BaCl2-Lösung in zwei Tranchen (20 µL + 8 µL) auf den dafür vorgesehenen Punkt auf dem Probenträger aufgegeben und bei Raumtemperatur eingetrocknet (Abb. 5). Die zweite Tranche wurde nach dem Eintrocknen der vorherigen in die Mitte des eingetrockneten Flecks pipettiert. Die nominelle Aktivität ist demnach etwa

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Abb.2: Der präparierte Fleck für die Konversionselektronenspektrometrie vor dem Abkleben mit Mylarfolie

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11

Radiochemical analysis of fertilizer & sewage sludge/ashes

Fabian Roemer

Introduction and motivation

Phosphorus and Phosphates (P) are an important basic resource for industry and agriculture. However the supply for Europe is actually not secured. While the global demand increases, the quality and quantity of the reserves are decreasing (phosphor reserves for 50 – 100 years). Known deposits are located in countries with enormous political potential of conflict or high self-interest [1]. The gain of P out of secondary sources becomes more interesting. One of these sources is sewage sludge and sewage sludge ashes with up to 1 % P. Advantages of the incineration are the removal of organic pollution (chemical/ pharmacological residues, pathogenic organism), the high reclamation index (possible < 90 % P) and waste-to-energy [2].

Experimental

The sewage sludges are dried for several days by 50 °C until constant weight. For decreasing the homogeneity and the comparability the dried sludge is pestled and incinerated by 850 – 950 °C for 90 min until an orange-white powder remains. The procedure is similar to the technical incineration process for sewage sludge. A higher oven temperature leads to sintering, while a lower temperature causes an enormous smell nuisance.

All samples are measured in a Marinelli-beaker.

Result and Discussion

Using γ-spectrometry, it can be seen that the fertilizers contain K-40 (5400 ± 20 Bq/kg) and the decay products of U-238 (14 ± 2 Bq/kg) and Th-232 (41 ± 3 Bq/kg). Secular equilibria for the U-238- and Th-232 series are intact. Depending on use and producer, the fertilizer and the specific activities vary and so do the specific activities of the samples.

The specific acitivites in the sewage sludge for U and Th are comparable, although the secular equilibrium are interrupted due to the remove of radon gas.

The inceneration of the sewage sludge leads to the accumulation of anorganic components and the actinoides. Therefore the specific activities reach up to 120 ± 3 Bq/kg U-238 and 99 ± 3 Bq/kg for Th-232. The secular equilibria are not intact.

Other peaks with the energy 364 keV & 637 keV (I-131), 477 keV (Be-7), 662 keV (Cs-137) and 1460 keV(K-40) can be detected in the sewage sludge. Be-7 and I-131 are identified with a half-life determination.

I-131

With a half-life of 8,02 d it has been used recently near the sewage plant. The sample contained 23 ± 2 Bq/kg at the sampling date. Regarding to radiation protection the activity is uncritical.

Be-7

It is constantly produced in the upper atmosphere by spallation of oxygen- and nitrogen-nuclei caused by cosmic radiation with a half-life of 53,12 d. It can be found in rain water and it is used in industrial leak tests. Apparently it accumulates in sewage sludges of waste waters containing rainwater. Unless there is no artificial emission, the activity is not ruled by radiation protection ordinance.

Cs-137

The sample contained 4 ± 0,1 Bq/kg. In Europe measurable amounts can be found in nature referable to the nuclear accident in Chernobyl in 1986. Up to 100.000 Bq/m2 were deposited additional to 1000 Bq/m2 of nuclear bomb tests[3].

References

[1] Cordell, D., Drangert, J.-O., White, S. The story of phosphorus: Global food security and food for thought, 2009. [2] Umweltbundesamt, Klärschlamm-entsorgung in der Bundesrepublik Deutschland, 2013.

12

ColPuS, a new Multi-Isotope Plutonium Standard for

Accelerator Mass Spectrometry†

Björn-Alexander Dittmann, Raffaele Buompane, Elena Chamizo, Marcus Christl, Alfred

Dewald, Tibor Dunai, Claus Feuerstein, Keith Fifield, Michaela Fröhlich, Stefan Heinze,

Fabio Marzaioli, Carsten Münker, Antonio Petraglia, Carmina Sirignano, Erik Strub, Hans-

Arno Synal, Filippo Terrasi, Stephen Tims, Anton Wallner

Abstract

A new multi-isotope plutonium standard for isotopic ratio measurements with Accelerator Mass Spectrometry (AMS) was created by gravimetric mixing of different single-isotope standards provided by IRMM (Pu-239, Pu-240, Pu-242, Pu-244). This standard material has been measured at the AMS facilities at Canberra (Australia), Cologne (Germany), Caserta(Italy), Sevilla (Spain) and Zurich (Switzerland).

Additionally, the material was characterized using a Neptune MC-ICPMS (multi-collector inductively coupled plasma mass spectrometry) at the joint Cologne-Bonn isotope facility. The results of this laboratory intercomparison are presented and consensus values for the isotope compositions of the standard material are proposed.

Reference

Ditmann et al., Nuclear Instruments and Methods B 2018 DOI: 10.2016/j.nimb.2018.04.032

† This is the abstract of a paper appearing in Nuclear Instruments and Methods B, see reference

13

La–Ce isotope measurements by multicollector-ICPMS‡ Christiane Schnabel, Carsten Münker and Erik Strub

Abstract

The 138La-138Ce decay system (half-life 1.02x1011 years1) is a potentially highly useful tool to unravel information about the timing of geological processes and about the interaction of geological reservoirs on Earth, complementing information from the more popular 147Sm-143Nd and 176Lu-176Hf isotope systems. Previously published analytical protocols were limited to TIMS. Here we present for the first time an analytical protocol that employs MC-ICPMS, with an improved precision and sensitivity. To perform sufficiently accurate La-Ce measurements, an efficient ion-chromatographic procedure is required to separate Ce from the other rare earth elements (REE) and Ba quantitatively. This study presents an improved ion-chromatographic procedure that separates La and Ce from rock samples using a three-step column separation. After REE separation by cation exchange, Ce is separated employing an Ln Spec column and selective oxidation. In the last step, a cation clean-up chemistry is performed to remove all remaining interferences. Our MC-ICPMS measurement protocol includes all stable Ce isotopes (136Ce, 138Ce, 140Ce and 142Ce), by employing a 1010 Ohm amplifier for the most abundant isotope 140Ce. An external reproducibility of ±0.25 -units (2 r.s.d) has been routinely achieved for 138Ce measurements for as little as 150-600 ng Ce, depending on the sample-skimmer cone combinations being used. Because the traditionally used JMC-304 Ce reference material is not commercially available anymore, a new reference material was prepared from AMES laboratory Ce metal (Cologne-AMES). In order to compare the new material with previously reported isotopic composition of AMES material prepared at Mainz (Mainz-AMES2), Cologne-AMES and JMC-304 were measured relative to each other in the same analytical session, demonstrating isotope heterogeneity between the two AMES and different JMC-

‡ This is the abstract of a paper in the Journal of Analytical Atomic Spectrometry, see reference

304 batches used in the literature. To enable sufficiently precise age correction of radiogenic 138Ce and to perform isochron dating, a protocol was developed where La and Ce concentrations are determined by isotope dilution (ID), using an isotope tracer enriched in 138La and 142Ce. The new protocols were applied to determine the variations of Ce isotope compositions and La-Ce concentrations of certified geochemical reference materials (CRMs): BCR-2, BCR-1, BHVO-2, JR-1, JA-2, JB-3, JG-1, JR-1, JB-1b, AGV-1 and one in-house La Palma standard.

Reference

C. Schnabel et al. J. Anal. At. Spectrom. 32 (2017) 2360

14

Strahlenschutz 2017

Björn Dittmann, Uwe Otto, Erik Strub

Beruflich strahlenexponierte Personen

Im Jahr 2017 waren 7 Personen als strahlenexponierte Personen erfasst, davon 5 Personen ganzjährig.

Amtliche Dosen

In Tabelle 1 sind die Ergebnisse der Personendosisüberwachung dargestellt. Insgesamt wurden im Jahr 2017 72 Filmdosimeter und 4 Albedodosimeter ausgewertet. Alle amtlichen Werte lagen unter der Nachweisschwelle.

Monat N n1 KD [mSv]

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Tab.1.: Ergebnisse der amtlichen Personendosisüberwachung (Filmdosimeter). n: Anzahl ausgewerteter Dosimeter *Albedodosimeter n1: Dosimeter mit Dosis über KD: Kollektivdosis (Summe der Messwerte) in Personen-mSv

Nicht-amtliche Dosimeter

Studierende im Praktikum erhalten elektronische (nichtamtliche) Dosimeter, um die Einhaltung des Grenzwertes für beruflich nicht strahlenexponierte Personen von 1 mSv/a zu dokumentieren.

Abgabe radioaktiver Stoffe

Eine Abgabe radioaktiver Stoffe mit Abwasser oder Abluft fand nicht statt (eine solche Abgabe ist in der gültigen Umgangsgenehmigung nicht vorgesehen). Anfallende radioaktive Reststoffe wurden über die Landessammelstelle entsorgt.

Messstelle

Die Abteilung Nuklearchemie ist die offizielle Dichtigkeitsprüfstelle für um-schlossene radioaktive Präparate der Universität zu Köln.

Auch im Jahr 2017 wurden die an verschiedenen Instituten der Universität befindlichen Strahler der gesetzlich vorgeschriebenen Dichtigkeitsprüfung unterzogen. Die Dichtigkeit aller Präparate wurde nachgewiesen.

Umweltmessungen

Im Rahmen diverser Projektarbeiten wurden umfangreiche Vorversuche zum Nachweis von 137Cs in Umweltproben durchgeführt.

15

Publikationen, Vorträge, Poster, abgeschlossene Arbeiten

2017

Publikationen

1. La-Ce isotope measurements by Multicollector-ICPMS C. Schnabel, C. Münker, E. Strub Journal of Analytical Atomic Spectrometry 32 (2017) 2360

2. Radiochemical Determination of Long-lived Radionuclides in Proton-Irradiated Heavy Metal Targets: Part I-Tantalum Z. Talip, R. Dressler, J.C. David, C. Vockenhuber, E. Müller Gubler, A. Vögele, E. Strub, P. Vontobel, D. Schumann Analytical Chemistry 89 (2017) 13541

3. Beiträge zu den Notizen aus der Chemie Erik Strub Nachrichten aus der Chemie (2017) Reaktivität von Actinium-227 Januar Laserspektroskopie an einzelnen Nobelium-Atomen Februar Stabilität von UV unter Endlagerbedingungen März 18F aus der Forschung in die Klinik Mai Kupfer intrinsisch gekoppelt Juni Spaltspuranalyse Modernisiert Juli/August Photolumineszentes Uranyl September Stickstoffreduktion an Urannitridkomplexen Oktober Um die Gadoliniumecke gebracht November

4. Draft report of the IAEA FaSa project https://www-ns.iaea.org/downloads/rw/waste-safety/FaSa-main-project-report.pdf Annex 1 – The Nuclear Power Plant Test Case https://www-ns.iaea.org/downloads/rw/waste-safety/FaSa-annex%201.pdf Annex 2 – The Research Reactor Test Case https://www-ns.iaea.org/downloads/rw/waste-safety/FaSa-annex%202.pdf Annex 3 – The Fuel Fabrication Facility Test Case https://www-ns.iaea.org/downloads/rw/waste-safety/FaSa-annex%203.pdf Annex 4 – The Mining and Milling Processing Facility Test Case https://www-ns.iaea.org/downloads/rw/waste-safety/FaSa-annex%204.pdf

Beiträge zu Jahresberichten anderer Institutionen

1. Production Cross Sections of Long-Lived Lanthanides in Proton-Irradiated Heavy Metal Targets: Lead & Tantalum Z.Talip, R. Dressler, D. Schumann, J. C. David, E. Strub PSI Jahresbericht 2017

2. Production Cross Sections of 36Cl in Proton-Irradiated Tantalum

Z. Talip, R. Dressler, D. Schumann, C. Vockenhuber, J. C. David, E. Strub PSI Jahresbericht 2017

3. Separation of Long-Lived Radionuclides from Proton-Irradiated Tungsten

Targets Z. Talip, B. Schacher, A. Vögele, D. Schumann, E. Strub PSI Jahresbericht 2017

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Vorträge an anderen Institutionen

1. Untersuchungen feuervergoldeter Proben mit Synchrotron-XRF und NAA

E. Strub Jahrestagung der Fachgruppe Nuklearchemie der GDCh Berlin, 12. September 2017

Eingeladene Vorträge Dritter an der Universität zu Köln

1. New Developments New Developments of X-Ray Analytics in the Laboratory - BLiX at a Glance Ioanna Mantouvalou, TU Berlin

5. Carnival Conference Session 2017 Köln, 22. Februar 2017

2. Aktuelle geowissenschaftliche Fragestellungen bei der Endlagerung hochradioaktive Abfälle in Deutschland Holger Seher, GRS Köln

Kolloquium des Instituts für Geologie und Mineralogie Köln, 30. Mai 2017 Poster

1. Cerium Isotope Measurements by MC-ICPMS C. Schnabel, C. Münker, E.Strub GSGS Research Conference 2017 Köln, 29. Januar 2017

2. Defining a New Cerium Reference Material

C. Schnabel, C. Münker, E.Strub 5. Carnival Conference Session 2017 Köln, 22. Februar 2017

3. First step towards the direct proof for the α-decay of 209Bi K. Beu, E. Strub 5. Carnival Conference Session 2017 Köln, 22. Februar 2017

4. Untersuchungen feuervergoldeter Proben mit Synchrotron-XRF und NAA R. Margreiter, E. Strub 5. Carnival Conference Session 2017 Köln, 22. Februar 2017

5. Defining a New Cerium Reference Material

C. Schnabel, C. Münker, E.Strub Goldschmidt 2017 Paris, Frankreich, 14.-18. August 2017

6. Lab Intercomparison for the Establishment of a New Multi-Isotope Plutonium Standard for Accelerator Mass Spectrometry Björn-Alexander Dittmann, Raffaele Buompane, Elena Chamizo, Marcus Christl, Alfred Dewald, Tibor Dunai, Claus Feuerstein, Keith Fifield, Michaela Fröhlich, Stefan Heinze, Fabio Marzaioli, Carsten Münker, Antonio Petraglia, Carmina Sirignano, Erik

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Strub, Hans-Arno Synal, Filippo Terrasi, Stephen Tims, Anton Wallner AMS-14 Ottawa, Kanada, 14.-18. August 2017

7. First step towards the direct proof for the α-decay of 209Bi

K. Beu, E. Strub Jahrestagung der Fachgruppe Nuklearchemie der GDCh Berlin, 12. September 2017

Abgeschlossene Arbeiten

1. Herstellung und Charakterisierung von 53Mn- und 239,24xPu-Standards zur Anwendung in der Beschleuniger-Massenspektrometrie B. Dittmann Dissertation

2. Nachweis von Po-210 in Zigarettenrauch S. von Döllen Bachelorarbeit)

3. Messung von Prompt-Gamma-Neutronenaktivierung mit einem Halbleiterdetektor S. Weist Bachelorarbeit