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The Forsmark site was recently proposed by the Svensk Kärnbränslehantering AB (SKB) to serve as the potential site for construction of a future geological repository for spent high-level nuclear fuel at about 470 m depth in fractured crystalline rock. The considerations included, among other things, distance from regionally significant deformation zones with highly strained rock, lithological homogeneity, low hydraulic conductivity, groundwater salinity with an acceptable range, and lack of potential mineral resources. This report describes the calculation of transmissivity of deduced deformation zones at Forsmark and the transmissivity model used in the regional groundwater flow modeling carried out in support of the integrated site description. Besides significant decrease with increasing depth (more than four orders of magnitude over a depth of about 1 km), the calculated transmissivity values also reveal considerable spatial variability along the strikes of the zones, i.e. lateral heterogeneity (more than two orders of magnitude). A hydro-mechanical coupling is discussed, based on presented models for the tectonic evolution and the principal stress tensor. Tentatively, laboratory-scale relationships developed from normal stress experiments on a single fracture in crystalline rock can be used to estimate the maximum values of transmissivity of deduced deformation zones at Forsmark. © 2013 Springer-Verlag Berlin Heidelberg. Source

King F.,Integrity Corrosion Consulting | Lilja C.,Swedish Nuclear Fuel and Waste Management Company
Corrosion Engineering Science and Technology

The Swedish Nuclear Fuel and Waste Management Company has developed a method for safely disposing spent nuclear fuel, which involves encapsulation of the waste in copper canisters and burying it deep in the stable crystalline rock of the Fenno-Scandian shield. The design life of the canisters in the so called KBS-3 design is in excess of 100 000 years. These long canister lifetimes are a consequence of a number of factors involving the properties of the material and the nature of the near field environment in the KBS-3 repository. One of these factors, namely the thermodynamic stability of copper in O2 free water in the absence of sulphide, has been questioned. This paper critically reviews the evidence for and against the claim that water oxidises copper, and discusses the implications for canister lifetimes even if the proposed mechanism is correct. Even though the evidence presented in support of the proposed mechanism is not compelling, the Swedish Nuclear Fuel and Waste Management Company is actively engaged in ongoing research and development on the topic. © 2011 Institute of Materials, Minerals and Mining. Source

Munier R.,Swedish Nuclear Fuel and Waste Management Company
Environmental Earth Sciences

Safe, long-term disposal of nuclear wastes requires a thorough analysis of the interactions between all components in the proposed repository system. In their article entitled "Superior techniques for disposal of highly radioactive waste (HLW)", published online in this journal January 26, 2012, the authors Pusch and Weston bring forward severe criticism on the methods our company, SKB, have chosen for disposal of spent nuclear fuel (SKB in Design premises for a KBS-3V repository based on results from the safety assessment SR-Can and some subsequent analyses. SKB TR-09-22, Svensk Kärnbränslehantering AB, Stockholm, Sweden, 2009; SKB in Design and production of the KBS-3 repository. SKB TR-10-12, Svensk Kärnbränslehantering AB, Stockholm, Sweden, 2010a; Thegerström and Olsson in 13th International High-Level Radioactive Waste Management Conference 2011 (IHLRWMC 2011), April 10-14, 2011. Albuquerque, NM Curran Associates, Inc. ISBN: 9781617828508, 2011) and therefore propose an alternative called KBS-3i, claimed to outperform the method favored by SKB, KBS-3V. We here argue that the authors overlook several effects of their proposed modifications of the disposal concept. The purpose of this reply is to clarify some misconceptions, correct factual errors and provide the interested reader a more nuanced description of the complexities involved in nuclear waste disposal. Here, we focus our reply on a few key topics. © 2013 Springer-Verlag Berlin Heidelberg. Source

Berglund S.,HydroResearch AB Stora Marknadsvagen | Bosson E.,Swedish Nuclear Fuel and Waste Management Company | Sassner M.,DHI Water - Environment - Health

This paper presents an analysis of present and future hydrological conditions at the Forsmark site in Sweden, which has been proposed as the site for a geological repository for spent nuclear fuel. Forsmark is a coastal site that changes in response to shoreline displacement. In the considered time frame (until year 10 000 ad), the hydrological system will be affected by landscape succession associated with shoreline displacement and changes in vegetation, regolith stratigraphy, and climate. Based on extensive site investigations and modeling of present hydrological conditions, the effects of different processes on future site hydrology are quantified. As expected, shoreline displacement has a strong effect on local hydrology (e.g., groundwater flow) in areas that change from sea to land. The comparison between present and future land areas emphasizes the importance of climate variables relative to other factors for main hydrological features such as water balances. © 2013 The Author(s). Source

Torudd J.,Facilia AB | Saetre P.,Swedish Nuclear Fuel and Waste Management Company

This study investigates whether non-human biota are protected against harmful effects of ionizing radiation after a possible future release of radioactive matter from a planned repository for spent nuclear fuel. Radiation dose rates to a broad spectrum of organisms were calculated based on data from sampled organisms and modeled activity concentrations. Calculations were performed with the ERICA Tool, a software program which applies a screening dose-rate value of 10 microgray per hour (μGy h-1) for all types of organisms. Dose rates below this value are thought to result in minimal risk to the individual or population. All calculated dose rates were below the screening value and below the lowest relevant band of "derived consideration levels" proposed by the International Commission on Radiological Protection. This provides a sound basis for arguing that no individuals or populations of examined species would be harmfully affected by a possible radioactive release from the repository. © 2013 The Author(s). Source

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