Simulating ice core 10Be on the glacial–interglacial timescale

10Be ice core measurements are an important tool for paleoclimate research, e.g., allowing for the reconstruction of past solar activity or changes in the geomagnetic dipole field. However, especially on multi-millennial timescales, the share of production and climate-induced variations of respective 10Be ice core records is still up for debate. Here we present the first quantitative climatological model of the 10Be ice concentration up to the glacial–interglacial timescale. The model approach is composed of (i) a coarse resolution global atmospheric transport model and (ii) a local 10Be air–firn transfer model. Extensive global-scale observational data of short-lived radionuclides as well as new polar 10Be snow-pit measurements are used for model calibration and validation. Being specifically configured for 10Be in polar ice, this tool thus allows for a straightforward investigation of production- and non-production-related modulation of this nuclide. We find that the polar 10Be ice concentration does not immediately record the globally mixed cosmogenic production signal. Using geomagnetic modulation and revised Greenland snow accumulation rate changes as model input, we simulate the observed Greenland Summit (GRIP and GISP2) 10Be ice core records over the last 75 kyr (on the GICC05modelext timescale). We show that our basic model is capable of reproducing the largest portion of the observed 10Be changes. However, model–measurement differences exhibit multi-millennial trends (differences up to 87% in case of normalized to the Holocene records) which call for closer investigation. Focusing on the (12–37) b2k (before the year AD 2000) period, mean model–measurement differences of 30% cannot be attributed to production changes. However, unconsidered climate-induced changes could likely explain the model–measurement mismatch. In fact, the 10Be ice concentration is very sensitive to snow accumulation changes. Here the reconstructed Greenland Summit (GRIP) snow accumulation rate record would require revision of +28% to solely account for the (12–37) b2k model–measurement differences

Monte-Carlo Simulations of Radiation-Induced Activation in a Fast-Neutron and Gamma- Based Cargo Inspection System

An air cargo inspection system combining two nuclear reaction based techniques, namely Fast-Neutron Resonance Radiography and Dual-Discrete-Energy Gamma Radiography is currently being developed. This system is expected to allow detection of standard and improvised explosives as well as special nuclear materials. An important aspect for the applicability of nuclear techniques in an airport inspection facility is the inventory and lifetimes of radioactive isotopes produced by the neutron and gamma radiation inside the cargo, as well as the dose delivered by these isotopes to people in contact with the cargo during and following the interrogation procedure. Using MCNPX and CINDER90 we have calculated the activation levels for several typical inspection scenarios. One example is the activation of various metal samples embedded in a cotton-filled container. To validate the simulation results, a benchmark experiment was performed, in which metal samples were activated by fast-neutrons in a water-filled glass jar. The induced activity was determined by analyzing the gamma spectra. Based on the calculated radioactive inventory in the container, the dose levels due to the induced gamma radiation were calculated at several distances from the container and in relevant time windows after the irradiation, in order to evaluate the radiation exposure of the cargo handling staff, air crew and passengers during flight. The possibility of remanent long-lived radioactive inventory after cargo is delivered to the client is also of concern and was evaluated.Comment: Proceedings of FNDA 201

The certification of the activity concentration of the radionuclides 137Cs, 90Sr and 40K in wild berries: IRMM-426

This report describes the production of CRM IRMM-426, a dried bilberry material certified for the radionuclide activity concentrations of 137Cs, 90Sr and 40K. The material was produced following ISO Guide 34:2009. Bilberry samples were collected in a woodland region of so-called “strontium hot spots” close to the Chernobyl reactor site. The samples were air-dried at the sampling site before transport to IRMM, where the raw material was oven-dried, cryo-milled, sieved, homogenised and bottled. The bottled material was sterilised by gamma-irradiation. Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The material was characterised by an intercomparison among laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity and instability and to characterisation. The material is intended for the assessment of method performance and quality control. As any reference material, it can also be used for control charts or validation studies. The CRM is available in amber glass jars containing about 100 g of dried bilberry powder. The minimum amount of sample to be used for analysis is 50 g for 90Sr and 18 g for 137Cs and 40K.JRC.D.2-Standards for Innovation and sustainable Developmen

Die Bestimmung von Konzentration und chemischer Form der Iodisotope I-129 und I-127 in der Luft der Umgebung der Wiederaufarbeitungsanlage Karlsruhe

SIGLEAvailable from the library of Bonn Univ. (DE) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Measurement of plutonium isotopes in ground-level air in Northern-Germany - history and recent results

The history of plutonium measurements performed on ground-level aerosols is summarised. Recent results are presented, the activity ratios a((239+240)Pu)/a(137Cs) and a(238Pu)/a((239+240)Pu) measured are discussed and potential sources of 238Pu are considered

An inter-laboratory comparison of low-level measurements in ground-level aerosol monitoring

After the nuclear reactor accident of Chernobyl, the “Integrated Measurement and Information System (IMIS) for Monitoring the Environmental Radioactivity and Detecting Emissions from Nuclear Plants was implemented in Germany. IMIS is a nationwide comprehensive measuring system which permanently monitors the radioactivity in all important environment media in the whole federal territory. At approximately 40 sites, the activity concentration of radioactive substances is measured in air and precipitations. At least 14 of them are responsible for trace monitoring of radionuclides in the air. The legal bases of IMIS prescribe regular inter-laboratory comparison analyses in cooperation with the Physikalisch-Technische Bundesanstalt (PTB), with the use of reference materials prepared by the Federal Coordinating Laboratories. In order to fulfil this requirement in the field of trace survey measurements in ground-level air, the Federal Office for Radiation Protection (“Bundesamt für Strahlenschutz”, BfS) and the PTB have conducted a comparison with real, dust-loaded reference filters in 2005. The comparison was organized within the framework of a cooperation of trace survey stations from Austria, Germany and Switzerland. The paper describes the preparation of the real, dust-loaded reference filters, the procedure for spiking the filters with the activity standard solution containing ²²Na, ⁸⁸Y, ⁸⁹Sr, ⁹⁰Sr, ¹²⁵Sb, ¹³³Ba, ¹³⁴Cs, and ²⁴¹Am. Some results are discussed and conclusions are given

Activity determination and nuclear decay data of 113mCd

The radionuclide 113mCd was extracted from a Cd component, which has been irradiated in a research reactor during its routine operation. A validated separation procedure was then used to obtain a 113mCd solution of high radiochemical purity. The solution was measured by means of liquid scintillation counting for activity determination. To this end, the CIEMAT/NIST efficiency tracing method as well as the triple-to-double coincidence (TDCR) counting technique were used. Measurements in a low-background gamma-ray spectrometer were applied to identify any potential photon-emitting impurities and to measure the 263.7 keV photons from the isomer transition. A gamma emission probability of 0.01839(29)% was determined for this line. The liquid scintillation measurements were also used to evaluate the half-life of 113mCd. The decay was followed for about 11 months and a half-life T1/2=13.97(13) years was obtained

Radionuclides in ground-level air in Braunschweig Report of the PTB trace survey station for 1995, 1996 and 1997

Die Aktivitaetskonzentrationen der Spaltprodukte "1"3"4Cs und "1"3"7Cs sowie einiger natuerlicher Radionuklide ("7Be, "2"2Na, "4"0K, und "2"1"0Pb) in der bodennahen Luft Braunschweigs wurden #gamma#-spektrometrisch bestimmt. Wochenmittelwerte wurden gemessen, Monatsmittelwerte und Jahresmittelwerte wurden berechnet. Die langjaehrigen Schwankungen der mittleren Aktivitaetskonzentrationen werden in Diagrammen gezeigt. Die mittlere Jahresaktivitaetskonzentration des "1"3"7Cs, hervorgerufen durch resuspendierten Bodenstaub, war etwa so gross wie in den Jahren 1993 und 1994. 1997 lag sie bei 0,03% des Jahresmittelwertes von 1986 und 38% ueber dem Jahresmittelwert von 1985. 1995, 1996 und 1997 wurden sporadisch Spuren frischer Spalt- oder Aktivierungsprodukte in der bodennahen Luft nachgewiesen. Eine tabellarische Uebersicht ueber die nachgewiesenen Radionuklide und die moeglichen Emissionsquellen wird gezeigt. Aktivitaetskonzentrationen von Plutoniumisotopen in Luftstaub-Ascheproben aus Braunschweig wurden nach radiochemischer Abtrennung und Reinigung #alpha#-spektrometrisch bestimmt. Die mittleren Aktivitaetskonzentrationen der Plutoniumisotope "2"3"8Pu und "("2"3"9"+"2"4"0")Pu in der bodennahen Luft wurden in Quartalsmischproben aus den Jahren 1995, 1996 und 1997 gemessen und die entsprechenden Jahresmittelwerte berechnet. In Zusammenhang mit dem Institut fuer atomosphaerische Radioaktivitaet des Bundesamtes fuer Strahlenschutz (BfS/IAR) wurden die mittleren woechentlichen Aktivitaetskonzentrationen der Edelgasisotope "8"5Kr und "1"3"3Xe fuer die drei Berichtsjahre ermittelt. Eine Grafik zeigt in der Uebersicht die gesamte Edelgas-Messreihe von Braunschweig, die 1987 beginnt. (orig.)The activity concentrations of the fission products "1"3"4Cs and "1"3"7Cs and of some natural radionuclides ("7Be, "2"2Na, "4"0K, and "2"1"0Pb) contained in Braunschweig's ground-level air were determined by #gamma#-ray spectrometry. Mean weekly activity concentrations were measured, mean monthly and mean annual activity concentrations were calculated. Long-term fluctuations of the mean activity concentrations are shown in figures. The mean annual "1"3"7Cs activity concentration due to resuspended soil dust was on a level comparable to that of 1993 and 1994. In 1997 it was less than 0.03% of the annual mean of 1986 but still 38% higher than in 1985. In 1995, 1996 and 1997 some traces of fresh fission products and activation products were occasionally detected in ground-level air dust. A table gives an overview of the radionuclides detected and the possible sources of release. Activity concentrations of plutonium isotopes in air-dust ashes in Braunschweig were determined by #alpha#-spectrometric measurements after a radiochemical separation and purification procedure. Mean quarterly activity concentrations of plutonium isotopes in air were measured in 1995, 1996 and 1997 and the mean annual activity concentrations were calculated. In co-operation with the Institute for Atmospheric Radioactivity, which is a department of the Federal Office for Radiological Protection (BfS/IARI) the mean weekly activity concentrations of the noble gas isotopes "8"5Kr and "1"3"3Xe were measured and compiled for the three years covered by this report. A diagram gives an overview on the measurement series which was started in Braunschweig in 1987. (orig.)Summary in GermanSIGLEAvailable from TIB Hannover: RA 3143(41) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Hitzeassoziierte Gesundheitsprobleme – relevant für die Gesundheitsversorgung?

Schoierer J, Mertens H, Boese-O'Reilly S, Tolks D, Wershofen B. Hitzeassoziierte Gesundheitsprobleme – relevant für die Gesundheitsversorgung? Das Gesundheitswesen. 2017;79(04):299-374