Large volume Ge detectors require efficient methods of background reduction if radionuclide analyses at very low-levels are
planned. It is advisable therefore to carry out simulations of background characteristics of Ge detectors in advance of installations
of low-level Ge-spectrometers either in surface or underground laboratories. We present results of Monte Carlo simulations
of background characteristics of Ge detectors in surface laboratories with various lead shielding without and with anticosmic
shielding, as well as in underground laboratories operating at different depths.
The past quarter of a century has seen considerable improvement in time resolution for pulse radiolysis and laser photolysis experiments, made possible by advanced excitation sources. To document the present status, three installations for pulse radiolysis are discussed: a picosecond linac (Tokyo), a nanosecond Van de Graaff (Delft), and a high current accelerator (ód). Also indicated are future experimental possibilities, in particular the use of a high current photoemission electron gun. Available lasers for excitation with nanosecond pulses are summarized and a picosecond facility which permits optical and conductivity observations with subnanosecond time resolution is described.
Authors:R. Dewberry, D. Williams, R. Lee, D. Roberts, L. Arrigo, and S. Salaymeh
In this paper, the setup, calibration, and testing of the F-Area Analytical Labs active well neutron coincidence counter (HV-221000-NDA-X-1-DK-AWCC-1)
in SRNL are described for use in the Savannah River Site (SRS) transuranium metal production facility to enable assay of mixed
uranium/plutonium metal product. The instrument was required within a three-month window for availability upon receipt of
LANL uranium oxide samples into the SRS facility. Calibration of the instrument in the SRNL nuclear nondestructive assay facility
in the range 10–400 g HEU is described. We also report qualification and installation of the instrument for assay of the initial
suite of product samples.
Authors:K. Szabó, L. Nagy, G. Török, D. Hegedüs, and G. Fóti
A control system for monitoring the radioactive concentration in aqueous wastes of nuclear installations was elaborated. The
mobile station developed for in situ control enables simultaneous measurement of gamma radiation in the energy range of 0.15–2.0
MeV and that of beta radiation in the energy range of 0.3–2.0 MeV by means of a combined scintillation detector. Disturbing
effects of accompanying and secundary radiations on the determination of the counting efficiency vs. radiation energy functions
used in calculation of the radioactive concentration limits as well as some experiences during a long time of operation of
the system have been discussed.
The Pacific Northwest National Laboratory is working with US Customs and Border Protection to assist in the installation of
radiation portal monitors. Our challenge was to provide radioactive sources—both gamma and neutron emitting, to a number of
ports of entry where radiation portal monitors are being installed and calibrated. A portable shipping case has been designed
such that it meets the DOT requirements for a “limited quantity” shipment. Over three hundred shipments, both domestic and
international, were made in FY2008 using this type of shipping case.
A complete series of measurements have been performed in the thermal neutron beam at the Budapest Research Reactor to determine the prompt k0 factors for every stable element. After the installation of the cold neutron source, the flux of the beam increased by more than an order of magnitude, which made possible to determine the k0 and cross-section values having low cross-sections with a better accuracy. The paper presents the new data for the first set of low-cross-section elements and they are compared to the best literature data.
Nowadays natural disasters phenomena as hurricanes, volcanic eruptions, tsunamis or earthquakes, are still difficult to prevent. Based on signaling of the phenomenon imminent appearance in the destructive area, important limitations in human losses and material damages will be carried out. For that reason, WARNING turned into a key objective, both in theoretical and practical research. For the earthquakes, warning intervals are nevertheless very short - seconds to maximum one minute (Mexico City case). Even if the time window is reduced, automated decision measures are possible to establish in case of an well organized system, mainly for: protection of dangerous chemical units and oil installations; shutdown valves of the natural gas pipelines to prevent fire hazard; protection of nuclear power plants and other high-risk nuclear objectives; electrical insulating of the power distribution network systems; alerting of emergency services, alerting of civil protection, and particularly of civil population; protection of railway transportation systems etc. In Romania, the major seismic risk zone is located in Vrancea region. The earthquakes occurring in this area are the main sources of the seismic hazard on the Romania territory. Seismotectonic characteristics of the Vrancea region offered the opportunity to create and develop a rapid seismic warning system. This system is simple, reasonably low-priced and robust and allows warning in an approximately 25 seconds time window for Bucharest. Warning signal obtained will be issued at the responsible factors and specific users in order to control automated blocking of the installations and to carry out the required protection actions.
The essay describes two copies of documents from the hand of Staatskanzler Wenzel Anton Kaunitz-Rietberg sent to the Swiss engraver and art dealer Christian von Mechel. The letters were written at the time when Mechel was involved with the installation of paintings from the Imperial collection in the Belvedere palace, Vienna. The first letter is dated June 14th, 1779, and tells of several paintings that Mechel had suggested the Austrian court; one being identified as “Decent from the Cross” by Sandrart, which was included in Mechel's Belvedere hanging, and is now to be found in Cluj/Klausenburg. The document also refers to four paintings by Teniers in Nymphenburg offered by Kurfürst Karl Theodore von Pfalz-Sulzbach, (from 1777 onwards also Kurfürst von Bayern), who had retained Mechel as his agent in this affair. These four works, showing the interior of Archduke Leopold Wilhelm's paintings gallery, could very well be the set of paintings now in the Bayrische Gemäldesammlung in Munich. This would suggest that the transfer to the Austrian court must have failed to happen for reasons not yet known. The second letter is dated July 28th, 1790 and reveals an increasing of impatience towards Mechel, who Kaunitz implys is causing delays in the completion of the gallery installation. Kaunitz further makes reference to a large painting by Frans Floris, which could correspond to “The Last Judgement” (ill. 4).
Authors:P. Sawant, S. Prabhu, P. Kalsi, and K. Pendharkar
Individual monitoring of radiation workers handling Pu in various nuclear installations requires the detection of trace levels
of plutonium in bioassay samples. It is necessary to develop methods that can detect urinary excretion of Pu in fraction of
mBq range. Therefore, a sensitive method such as fission track analysis has been developed for the measurement of trace levels
of Pu in bioassay samples. In this technique, chemically separated plutonium from the sample and a Pu standard were electrodeposited
on planchettes and covered with Lexan solid state nuclear track detector (SSNTD) and irradiated with thermal neutrons in APSARA
reactor of Bhabha Atomic Research Centre, India. The fission track densities in the Lexan films of the sample and the standard
were used to calculate the amount of Pu in the sample. The minimum amount of Pu that can be analyzed by this method using
doubly distilled electronic grade (E. G.) reagents is about 12 μBq/L.
This paper focuses on Vasily Shukshin’s “working records” dated from 1966. It is established that a lot of contexts and names are important for the interpretation of these records: from the antique myths to Russian literature. In the paper, it is proved that the motive of the waterway of a ship appears in Shukshin’s texts as the concentrated symbol of spiritual aspirations, warm rushes, as the allegory of movement towards the aim and the overcoming of obstacles. At the same time, it is also a symbol of moral ascension, which is shown by the reflections about intelligence as the aim of the artist. The conclusion drawn is that the poetics of Vasily Shukshin’s texts represents a very open and dialogical structure with wide referential installations.