Download or read book Corrosion of Spent Nuclear Fuel written by and published by . This book was released on 2003 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: The successful disposal of spent nuclear fuel (SNF) is one of the most serious challenges to the successful completion of the nuclear fuel cycle and the future of nuclear power generation. In the United States, 21 percent of the electricity is generated by 107 commercial nuclear power plants (NPP), each of which generates 20 metric tons of spent nuclear fuel annually. In 1996, the total accumulation of spent nuclear fuel was 33,700 metric tons of heavy metal (MTHM) stored at 70 sites around the country. The end-of-life projection for current nuclear power plants (NPP) is approximately 86,000 MTHM. In the proposed nuclear waste repository at Yucca Mountain over 95% of the radioactivity originates from spent nuclear fuel. World-wide in 1998, approximately 130,000 MTHM of SNF have accumulated, most of it located at 236 NPP in 36 countries. Annual production of SNF is approximately 10,000 MTHM, containing about 100 tons of ''reactor grade'' plutonium. Any reasonable increase in the proportion of energy production by NPP, i.e., as a substitute for hydrocarbon-based sources of energy, will significantly increase spent nuclear fuel production. Spent nuclear fuel is essentially UO2 with approximately 4-5 atomic percent actinides and fission product elements. A number of these elements have long half-lives hence, the long-term behavior of the UO2 is an essential concern in the evaluation of the safety and risk of a repository for spent nuclear fuel. One of the unique and scientifically most difficult aspects of the successful disposal of spent nuclear fuel is the extrapolation of short-term laboratory data (hours to years) to the long time periods (103 to 105 years) as required by the performance objectives set in regulations, i.e. 10 CFR 60. The direct verification of these extrapolations or interpolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the public that there is a reasonable basis for accepting the long-term extrapolations of spent fuel behavior. In recent years ''natural analogues'' for both the repository environment (e.g., the Oklo natural reactors) and nuclear waste form behavior (e.g., corrosion and alteration of uraninite, UO{sub 2+x}) have been cited as a fundamental means of achieving confirmation of long-term extrapolations. In particular, considerable effort has already been made to establish that uraninite, UO{sub 2+x}, with its impurities, is a good structural and chemical analogue for the analysis of the long-term behavior of the UO2 in spent nuclear fuel. This proposal is based on the study of uraninite and the naturally occurring alteration products of UO{sub 2+x} under oxidizing and reducing conditions. The UO2 in spent nuclear fuel is not stable under oxidizing conditions. In oxic solutions, uranium has a strong tendency to exist as U{sup 6+} in the uranyl molecule, UO2{sup 2+}. Uranyl ions react with a wide variety of inorganic and organic anions to form complexes. Throughout most of the natural range of pH, U{sup 6+} forms strong complexes with oxygen-bearing ions like CO32−, HCO3−, SO42−, PO43−, and AsO43−, which are present in most oxidized stream and subsurface waters. In arid environments, the U{sup 6+} ion can precipitate as a wide variety of uranyl oxide hydrates, uranyl silicates and uranyl phosphates. This is well demonstrated in experimental work, e.g., in long term drip tests on UO2 and is confirmed by natural occurrences of UO2 in which a wide variety of uranyl phases form as alteration products. The most striking feature of these studies is the very close parallel in the paragenetic sequences (i.e. phase formation sequence) between the very long term (10 year tests) and the young (therefore, low-Pb uraninites) of the Nopal I deposit in Mexico.

Download or read book Safety Related Issues of Spent Nuclear Fuel Storage written by North Atlantic Treaty Organization. Public Diplomacy Division and published by Springer Science & Business Media. This book was released on 2007-05-09 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains papers from a NATO-sponsored workshop in Almaty in September 2005, which discussed safety-related issues of storing spent nuclear fuel. Fifteen papers cover aluminum-clad fuel discharged from research reactors worldwide, while five papers examine stainless steel-clad fuel from fast reactors, and two Zircaloy-clad fuel from commercial light-water reactors.

Download or read book Electrochemical and modelling studies on simulated spent nuclear fuel corrosion under permanent waste disposal conditions written by Nazhen Liu and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The safety assessment models for the deep geological disposal of spent nuclear fuel require a fundamental understanding of the corrosion of spent fuel in a failed waste container. The overall research goal of this project is to investigate the corrosion of simulated spent fuel under permanent disposal conditions, using both model simulations and experimental investigations. A model for fuel corrosion has been expanded to determine the relative importance of radiolytic hydrogen and hydrogen from corrosion of the steel vessel in suppressing fuel corrosion. It was shown that, for CANDU (CANada Deuterium Uranium) fuel with moderate in-reactor burnup, only micromolar concentrations of hydrogen from steel corrosion are required to completely suppress fuel corrosion. In a partially closed system (i.e., within cracks in the fuel) radiolytic hydrogen alone can suppress corrosion to a negligible level. The model was validated by comparing the calculated corrosion rates with published measurements. Agreement between calculated and measured rates indicated that corrosion is controlled by the rate of radiolytic production of oxidants, in particular hydrogen peroxide, irrespective of the reactivity of the fuel. Experimentally, the influence of rare earth doping on the reactivity of UO2 was investigated. For REIII-doped UO2, the onset of matrix dissolution was accompanied by the enhanced oxidation of the matrix to UIV1{u2212}2xUV2xO2+x. This can be attributed to the onset of tetragonal lattice distortions as oxidation proceeds which leads to the clustering of defects, enhanced diffusion of OI (interstitial oxygen)to deeper locations and destabilization of the fluorite lattice. A further investigation of the doping effect was performed on a series of (U1{u2212}yGdy)O2 materials (y = 0, 0.01, 0.03, 0.05, 0.07 and 0.10). Overall the increase in doping up to 10% does not exert a major influence on reactivity possibly due to the competition between an increase in the number of (Ov)s (oxygen vacancy) and a contraction in the lattice constant.

Download or read book Radiation Induced Corrosion of Spent Nuclear Fuel written by Jessica Higgins and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Corrosion written by Stefan Ritter and published by Woodhead Publishing. This book was released on 2020-08-29 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear Corrosion: Research, Progress and Challenges, part of the "Green Book” series of the EFC, builds upon the foundations of the very first book published in this series in 1989 ("Number 1 - Corrosion in the Nuclear Industry”). This newest volume provides an overview on state-of-the-art research in some of the most important areas of nuclear corrosion. Chapters covered include aging phenomena in light water reactors, reprocessing plants, nuclear waste disposal, and supercritical water and liquid metal systems. This book will be a vital resource for both researchers and engineers working within the nuclear field in both academic and industrial environments. Discusses industry related aspects of materials in nuclear power generation and how these materials react with the environment Provides comprehensive coverage of the topic as written by noted experts in the field Includes coverage of nuclear waste corrosion

Download or read book Spent Nuclear Fuel written by Roy Forsyth and published by . This book was released on 1995 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion of Research Reactor Aluminium Clad Spent Fuel in Water written by International Atomic Energy Agency and published by . This book was released on 2003 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes research performed in ten laboratories within the framework of the IAEA Co-ordinated Research Project on Corrosion of Research Reactor Aluminium Clad Spent Fuel in Water. The project consisted of exposure of standard racks of corrosion coupons in the spent fuel pools of the participating research reactor laboratories and evaluation of the coupons after predetermined exposure times, along with periodic monitoring of the storage water. A group of experts in the field contributed a state of the art review and provided technical supervision of the project. Localized corrosion mechanisms are notoriously difficult to understand, and it was clear from the outset that obtaining consistency in the results and their interpretation from laboratory to laboratory would depend on the development of an excellent set of experimental protocols. These experimental protocols are described in the report, together with guidelines for the maintenance of optimum water chemistry to minimize the corrosion of aluminium clad research reactor fuel in wet storage.

Download or read book Spent Nuclear Fuel and Its Corrosion Products written by and published by . This book was released on 2013 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Corrosion of Aluminum clad Spent Nuclear Fuel in Wet Basin Storage written by and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Dissolved Hydrogen on Spent Nuclear Fuel Corrosion written by Patrik Fors and published by . This book was released on 2009 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion of Spent Nuclear Fuel written by Rodney C. Ewing and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research program is a broadly based effort to understand the long-term behavior of spent nuclear fuel (SNF) and its alteration products in a geologic repository. We have established by experiments and field studies that natural uraninite, UO2+x, and its alteration products are excellent ''natural analogues'' for the study of the corrosion of UO2 in SNF. This on-going research program has addressed the following major issues: (1) What are the long-term corrosion products of natural UO2+x, uraninite, under oxidizing and reducing conditions? (2) What is the paragenesis or the reaction path for the phases that form during alteration? (3) What is the radionuclide content in the corrosion products as compared with the original UO2+x? Do the trace element contents substantiate models developed to predict radionuclide incorporation into the secondary phases? Are the corrosion products accurately predicted from geochemical codes (e.g., EQ3/6 or Geochemist's Workbench) that are used in performance assessments? Can these codes be tested by studies of natural analogue sites (e.g., Oklo, Cigar Lake or Pena Blanca).

Download or read book The Corrosion of Uranium Implications for Stabilizing Spent Nuclear Fuel written by S. C. Ashworth and published by . This book was released on 1995 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion Surveillance for Research Reactor Spent Nuclear Fuel in Wet Basin Storage written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Foreign and domestic test and research reactor fuel is currently being shipped from locations over the world for storage in water filled basins at the Savannah River Site (SRS). The fuel was provided to many of the foreign countries as a part of the "Atoms for Peace" program in the early 1950's. In support of the wet storage of this fuel at the research reactor sites and at SRS, corrosion surveillance programs have been initiated. The International Atomic Energy Agency (IAEA) established a Coordinated Research Program (CRP) in 1996 on "Corrosion of Research Reactor Aluminum-Clad Spent Fuel in Water" and scientists from ten countries worldwide were invited to participate. This paper presents a detailed discussion of the IAEA sponsored CRP and provides the updated results from corrosion surveillance activities at SRS. In May 1998, a number of news articles around the world reported stories that microbiologically influenced corrosion (MIC) was active on the aluminum-clad spent fuel stored in the RBOF basin at SRS. This assessment was found to be in error with details presented in this paper. A biofilm was found on aluminum coupons, but resulted in no corrosion. Cracks seen on the surface were not caused by corrosion, but by stresses from the volume expansion of the oxide formed during pre-conditioning autoclaving. There has been no pitting caused by MIC or any other corrosion mechanism seen in the RBOF basin since initiation of the SRS Corrosion Surveillance Program in 1993.

Download or read book Spent Nuclear Fuel Project Recommended Reaction Rate Constants for Corrosion of N Reactor Fuel written by and published by . This book was released on 1998 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The US Department of Energy (DOE) established the Spent Nuclear Fuel Project (SNF Project) to address safety and environmental concerns associated with deteriorating spent nuclear fuel presently stored in the Hanford Site's K Basins. The SNF Project has been tasked by the DOE with moving the spent N-Reactor fuel from wet storage to contained dry storage in order to reduce operating costs and environmental hazards. The chemical reactivity of the fuel must be understood at each process step and during long-term dry storage. Normally, the first step would be to measure the N-fuel reactivity before attempting thermal-hydraulic transfer calculations; however, because of the accelerated project schedule, the initial modeling was performed using literature values for uranium reactivity. These literature values were typically found for unirradiated, uncorroded metal. It was fully recognized from the beginning that irradiation and corrosion effects could cause N-fuel to exhibit quite different reactivities than those commonly found in the literature. Even for unirradiated, uncorroded uranium metal, many independent variables affect uranium metal reactivity resulting in a wide scatter of data. Despite this wide reactivity range, it is necessary to choose a defensible model and estimate the reactivity range of the N-fuel until actual reactivity can be established by characterization activities. McGillivray, Ritchie, and Condon developed data and/or models that apply for certain samples over limited temperature ranges and/or reaction conditions (McGillivray 1994, Ritchie 1981 and 1986, and Condon 1983). These models are based upon small data sets and have relatively large correlation coefficients.

Download or read book Corrosion Experiments on Stainless Steels Used in Dry Storage Canisters of Spent Nuclear Fuel written by and published by . This book was released on 1996 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonradioactive (cold) experiments have been set up in the Idaho Chemical Processing Plant (ICPP)-1634, and radioactive (hot) experiments have been set up in the Irradiated Fuel Storage Facility (IFSF) at ICPP. The objective of these experiments is to provide information on the interactions (corrosion) between the spent nuclear fuel currently stored at the ICPP and the dry storage canisters and containment materials in which this spent fuel will be stored for the next several decades. This information will be used to help select canister materials that will retain structural integrity over this period within economic, criticality, and other constraints. The two purposes for Dual Purpose Canisters (DPCs) are for interim storage of spent nuclear fuel and for shipment to a final geological repository. Information on how corrosion products, sediments, and degraded spent nuclear fuel may corrode DPCs will be required before the DPCs will be allowed to be shipped out of the State of Idaho. The information will also be required by the Nuclear Regulatory Commission (NRC) to support the licensing of DPCs. Stainless steels 304L and 316L are the most likely materials for dry interim storage canisters. Welded stainless steel coupons are used to represent the canisters in both hot and cold experiments.

Download or read book Spent Nuclear Fuel Corrosion written by Ronald Stewart Forsyth and published by . This book was released on 1994 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SPENT NUCLEAR FUEL STORAGE BASIN WATER CHEMISTRY written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The factors affecting the optimal water chemistry of the Savannah River Site spent fuel storage basin must be determines in order to optimize facility efficiency, minimize fuel corrosion, and reduce overall environmental impact from long term spent nuclear fuel storage at the Savannah River Site. The Savannah River National Laboratory is using statistically designed experiments to study the effects of NO3−, SO42−, and Cl− concentrations on alloys commonly used not only as fuel cladding, but also as rack construction materials The results of cyclic polarization pitting and corrosion experiments on samples of Al 6061 and 1100 alloys will be used to construct a predictive model of the basin corrosion and its dependence on the species in the basin. The basin chemistry model and corrosion will be discussed in terms of optimized water chemistry envelope and minimization of cladding corrosion.