Realization of the German Concept for Interim Storage of Spent Nuclear Fuel - Current Situation and Prospects

The German government has determined a phase out of nuclear power. With respect to the management of spent fuel it was decided to terminate transports to reprocessing plants by 2005 and to set up interim storage facilities on power plant sites. This paper gives an overview of the German concept for spent fuel management focused on the new on-site interim storage concept and the applied interim storage facilities. Since the end of the year 1998, the utilities have applied for permission of on-site interim storage in 13 storage facilities and 5 storage areas; one application for the interim storage facility Stade was withdrawn due to the planned final shut down of Stade nuclear power plant in autumn 2003. In 2001 and 2002, 3 on-site storage areas and 2 on-site storage facilities for spent fuel were licensed by the Federal Office for Radiation Protection (BfS). A main task in 2002 and 2003 has been the examination of the safety and security of the planned interim storage facilities and the verification of the licensing prerequisites. In the aftermath of September 11, 2001, BfS has also examined the attack with a big passenger airplane. Up to now, these aircraft crash analyses have been performed for three on-site interim storage facilities; the fundamental results will be presented. It is the objective of BfS to conclude the licensing procedures for the applied on-site interim storage facilities in 2003. With an assumed construction period for the storage buildings of about two years, the on-site interim storage facilities could then be available in the year 2005

Location and chemical bond of radionuclides in neutron-irradiated nuclear graphite

The locations and the chemical forms (chemical bonds) of radionuclides in neutron-irradiated nuclear graphite have been determined in order to develop principal strategies for the management of graphitic nuclear waste. Due to the relatively low concentration of radionuclides in neutron-irradiated nuclear graphite (<1 ppm) direct spectroscopic methods are not applicable to investigate chemical structures. Therefore, methods by analogy have been applied. Such methods are investigations of the chemically detectable precursors of radionuclides in neutron-irradiated nuclear graphite and subjection of irradiated graphite to different chemical reactions followed by measurements of the radionuclide-containing reaction products by sensitive radiochemical methods. The paper discusses the applicability of these methods. The radionuclides investigated in this study can be divided into three parts: tritium, radiocarbon and metallic activation and fission products. Tritium can be bound in neutron-irradiated nuclear graphite as strongly adsorbed tritiated water (HTO), in oxygen-containing functional groups (e.g. C–OT) and as hydrocarbons (C–T). Radiocarbon is covalently bound with the graphite structure. The activity can be described by a homogeneously distributed part and a heterogeneously distributed part (enriched on surfaces or in hotspots). Metallic radionuclides can be bound as ions or covalent metal–carbon compounds. The distribution of all these radionuclides is mainly dependent on the distribution of their inactive precursors

Optimal ion beam, target type and size for accelerator driven systems: Implications to the associated accelerator power

In interactions of different energetic ions with extended targets hydrogen isotopes are the most effective projectiles for the production of spallation neutrons. It is shown that for every target material and incident ion type and energy there is an optimal target size which results in the escape of a maximum number of spallation neutrons from the target. Calculations show that in an ADS, combination of a beam of 1.5 GeV deuteron projectiles and a uranium target results in the highest neutron production rate and therefore highest energy gain. For fast 1.5 GeV d + U-238 ADS with lead or lead-bismuth eutectic moderator, the required ion beam current is only 38% of that for 1 GeV proton projectiles on lead target. It is shown that for a modular ADS with uranium target and output power of 550 MWth, a 1.5 GeV deuteron beam of current 1.8 mA is required, which is easily achievable with today's technology. For an ADS with k(eff)=0.98 and output power of 2.2 GW(th), the required beam currents for (a) 1 GeV p + Pb and (b) 1.5 GeV d + U systems are 18.5 and 7.1 mA, respectively. (C) 2010 Elsevier Ltd. All rights reserved

Dosisleistung von Abfallgebinden Eine Anleitung zur Ermittlung der aus Dosisleistungsbegrenzungen resultierenden Aktivitaet einzelner Radionuklide und Radionuklidgemische in standardisierten Abfallgebinden

Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Dosisleistung von Abfallgebinden Eine Anleitung zur Ermittlung der aus Dosisleistungsbegrenzungen resultierenden Aktivitaet einzelner Radionuklide und Radionuklidgemische in standardisierten Abfallgebinden

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Dosisleistung von Abfallgebinden Eine Anleitung zur Ermittlung der aus Dosisleistungsbegrenzungen resultierenden Aktivitaet einzelner Radionuklide und Radionuklidgemische in standardisierten Abfallgebinden

Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Tiutiunnikov, Spatial distribution of thorium fission rate in a fast spallation and fission neutron field: An experimental and Monte Carlo study

a b s t r a c t The Energy plus Transmutation (EpT) set-up of the Joint Institute for Nuclear Research (JINR), Dubna, Russia is composed of a lead spallation target surrounded by a blanket of natural uranium. The resultant neutron spectrum is a combination of spallation and fission spectra, modified by a reflective external layer of polyethylene and an internal absorbing layer of cadmium. The EpT set-up was irradiated with a beam of 4 GeV deuterons from the Nuclotron Accelerator at JINR. The spatial distribution of thorium fission rate within the assembly was determined experimentally, using a fission track detector technique, and compared with Monte Carlo predictions of the MCNPX code. Contributions of neutrons, protons, deuterons, photons and pions to total fission were taken into account. Close agreement between the experimental and calculated results was found