Download or read book Corrosion of Aluminum Clad Spent Nuclear Fuel in the 70 Ton Cask During Transfer from L Area to H Canyon written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33 % was found after 1 year in the cask with a maximum temperature of 260 °C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 °C. These losses are not expected to impact the overall confinement function of the aluminum cladding.
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 Criteria for Corrosion Protection of Aluminum Clad Spent Nuclear Fuel in Interim Wet Storage written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Storage of aluminum-clad spent nuclear fuel at the Savannah River Site (SRS) and other locations in the U.S. and around the world has been a concern over the past decade because of the long time interim storage requirements in water. Pitting corrosion of production aluminum-clad fuel in the early 1990''s at SRS was attributed to less than optimum quality water and corrective action taken has resulted in no new pitting since 1994. The knowledge gained from the corrosion surveillance testing and other investigations at SRS over the past 8 years has provided an insight into factors affecting the corrosion of aluminum in relatively high purity water. This paper reviews some of the early corrosion issues related to aluminum-clad spent fuel at SRS, including fundamentals for corrosion of aluminum alloys. It updates and summarizes the corrosion surveillance activities supporting the future storage of over 15,000 research reactor fuel assemblies from countries over the world during the next 15-20 years. Criteria are presented for providing corrosion protection for aluminum-clad spent fuel in interim storage during the next few decades while plans are developed for a more permanent disposition.
Download or read book Corrosion Surveillance of Aluminum Alloys In a Spent Fuel Storage Basinfinal written by and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spent nuclear fuels from foreign and domestic research and test reactors are being returned to the Savannah River Site for storage with other nuclear materials in the L-Basin. Recent efforts have consolidated the fuel storage systems and L-Basin has become the SRS site for wet storage of spent nuclear fuels. Corrosion surveillance of coupons in this basin is being performed to provide assurance of safe storage of spent fuel. This paper describes the highlights of recent studies on these aluminum coupons after immersion for more than 7 years in L-Basin. Selected coupons were metallurgically characterized to establish the existence of general corrosion and pitting. Minor pitting corrosion was observed on the intentionally galvanically coupled samples and creviced coupons, thus demonstrating that localized concentration cells were formed during the exposure period. In these cases, the susceptibility to pitting was not attributed to aggressive basin water chemistry but to localized conditions--crevices and galvanic coupling--that allowed the development of oxygen and/or metal ion concentration cells that produced locally aggressive waters. General corrosion was also observed on some of the coupons. None of the coupons were pre-oxidized to form a protective oxide as compared to the spent fuel which was oxidized during reactor operations. This enables the coupons to react to basin water chemistry in a relatively short period of time whereas spent fuel is protected against such reactions. The coupon observations demonstrate that, even when the basin water chemistry is rigorously controlled, localized aggressive conditions can develop, emphasizing the importance of a routine surveillance program.
Download or read book Experiments for Evaluation of Corrosion to Develop Storage Criteria for Interim Dry Storage of Aluminum alloy Clad Spent Nuclear Fuel written by and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aqueous Corrosion of Aluminum based Nuclear Fuel written by and published by . This book was released on 2003 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the U.S. National Spent Nuclear Fuel Program, aluminide fuels (UAl(subscript x)) are being tested under conditions that might exist in the proposed repository at Yucca Mountain, Nevada. Intermittent drip tests at 90 C were completed for up to 183 days on partially declad, unirradiated, low-enriched UAl(subscript x) samples. Through 183 days of exposure to modified water from the J-13 well at 90 C, the fuel coupon remained in good mechanical condition. Only a tarnishing of the surface was observed and no spalled products were found in the fuel holder. The mechanism for alteration is consistent with that observed from dry oxidation experiments on UAl(subscript x) (for the initial corrosion) and humid UO2 oxidation (for the subsequent paragenesis). Specifically, solid-state conversion of UAl(subscript x) into UO2 and oxidized Al is followed by further oxidation, dissolution of the uranium, and reprecipitation as uranyl oxyhydroxides. The release rate of uranium varied from 0.23 to 2.9 mg/m2/day (avg. = 0.97 mg U/m2/day) depending on the specimen and test interval, but was similar in magnitude to that observed in earlier flow-through and drip tests with irradiated UAl(subscript x) and UO2. Most (mean=87%) of the released uranium sorbed to the vessel walls. Colloids were detected in the leachate samples, and dynamic light scattering of aliquots from most sampling periods favored a polydisperse distribution typical of environmental samples. In addition, the light scattering intensities measured in these tests were much higher than any measured from UO2 fuel tests in our laboratory. Electron microscopy of the colloids indicated that the colloids were individual and agglomerated silicates and aluminosilicates. No distinct uranium-rich colloids were found, although dissolved uranium would be expected to sorb to aluminosilicate colloids. In conclusion, the UAl(subscript x) corroded slowly, releasing uranium at a rate comparable to UO2 fuels. Colloid production, however, was quite high with light scattering intensities that were much higher than any measured in previous tests with spent fuels in our laboratory.
Download or read book Corrosion of Breached Aluminide Fuel Under Potential Repository Conditions written by and published by . This book was released on 2000 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Permanent disposal of spent nuclear fuel is proposed in a repository located in the volcanic tuff beds near Yucca Mountain, Nevada, and it is the responsibility of the National Spent Nuclear Fuel Program (NSNFP) to provide the Yucca Mountain Project (YMP) with information related to the release of fission products from the DOE-owned SNF resulting from SNF corrosion. Hydrologically unsaturated spent fuel tests (''drip'' tests) are designed to simulate and monitor the release of radionuclides from the spent fuel under potential exposure conditions in the repository. Of the priority fuels being tested under the NSNFP, the aluminum-based fuels are included because of their high relative volume and uranium enrichment. The Al fuel structure is composed of fissile and aluminum powders pressed and annealed between Al plates to form thin metallic plates. The most widely used fissile powder was the intermetallic compound aluminide UAl(subscript x) (where x=2,3,4). As part of this testing program, preliminary corrosion tests using unirradiated UAl(subscript x) were initiated to address experimental design, sampling, and analysis issues prior to conducting tests with spent fuels. However, during this program the decision was made by U.S. DOE to convert the aluminum-based fuels to safer enrichment levels by using the melt-dilute process at Savannah River. Nonetheless, the product ingot of the melt-dilute process resembles low enriched UAl(subscript x) fuel and corrosion of the fuel is expected to be similar. This paper summarizes the preliminary testing results for the first year of the program and compares them to other corrosion testing results on aluminum fuels as well as other DOE fuel types.
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 Corrosion of Spent Nuclear Fuel written by and published by . This book was released on 2002 with total page 5 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 success of the nuclear fuel cycle and the future of nuclear power generation. 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 (239Pu: 24,100 years; 237Np: 2 million years; 129I: 16 million years; 79Se: 1.1 million years; 99Tc 200,000 years); hence, the long-term behavior of the UO2 is an essential concern in the evaluation of the safety 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). 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, UO2+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, UO2+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 research program is based on the study of uraninite and the naturally occurring alteration products of UO2+x under oxidizing and reducing conditions. We address the following issues: (1) What are the long-term corrosion products of natural UO2+x under reducing and oxidizing conditions? (2) What is the paragenesis or the reaction path of the phases that form during alteration? How is the paragenetic sequence of formation related to the structures and compositions of the phases? (3) What is the trace element content in the corrosion products (as compared with the original UO2), and does the trace element content substantiate models developed to predict radionuclide incorporation? (4) Are the corrosion products the phases that are predicted from reaction path models (e.g., EQ3/6) that are used in performance assessments? (5) How persistent over time are the metastable phase assemblages that form? Will these phases serve as barriers to radionuclide release? (6) Based on the structures of these phases (mostly sheet structures) can the thermodynamic stabilities of these phases be estimated, or at least bounded, in such a way as to provide for a convincing and substantive performance assessment?
Download or read book Temperature and Humidity Effects on the Corrosion of Aluminum base Reactor Fuel Cladding Materials During Dry Storage written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Corrosion of Aluminum cald Spent in Reactor Basin Water Storage written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Corrosion of Aluminum Alloys in a Reactor Disassembly Basin written by and published by . This book was released on 1992 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document discusses storage of aluminum clad fuel and target tubes of the Mark 22 assembly takes place in the concrete-lined, light-water-filled, disassembly basins located within each reactor area at the Savannah River Site (SRS). A corrosion test program has been conducted in the K-Reactor disassembly basin to assess the storage performance of the assemblies and other aluminum clad components in the current basin environment. Aluminum clad alloys cut from the ends of actual fuel and target tubes were originally placed in the disassembly water basin in December 1991. After time intervals varying from 45--182 days, the components were removed from the basin, photographed, and evaluated metallographically for corrosion performance. Results indicated that pitting of the 8001 aluminum fuel clad alloy exceeded the 30-mil (0.076 cm) cladding thickness within the 45-day exposure period. Pitting of the 1100 aluminum target clad alloy exceeded the 30-mil (0.076 cm) clad thickness in 107--182 days exposure. The existing basin water chemistry is within limits established during early site operations. Impurities such as Cl[sup [minus]], NO[sub 3][sup [minus]] and SO[sub 4][sup [minus]] are controlled to the parts per million level and basin water conductivity is currently 170--190 [mu]mho/cm. The test program has demonstrated that the basin water is aggressive to the aluminum components at these levels. Other storage basins at SRS and around the US have successfully stored aluminum components for greater than ten years without pitting corrosion. These basins have impurity levels controlled to the parts per billion level (1000X lower) and conductivity less than 1.0 [mu]mho/cm.
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 209 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cartas y mensajes written by Francisco de Paula Santander and published by . This book was released on 1955 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 The Radiological Accident in the Reprocessing Plant at Tomsk written by International Atomic Energy Agency and published by . This book was released on 1998 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: On 6 April 1993 a major radiological accident occurred at a plutonium extraction facility at a location then known as Tomsk-7, Russian Federation. The accident blew the concrete cover off the reaction vessel and led to widespread contamination of the site and the surrounding area up to a distance of 28 km. The report describes the events leading up to the accident and the radiological consequences. It provides a detailed description of the decontamination and recovery operations and gives an analysis of their effectiveness.
Download or read book Corrosion of Spent Advanced Test Reactor Fuel written by and published by . This book was released on 1994 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a study of the condition of spent nuclear fuel elements from the Advanced Test Reactor (ATR) currently being stored underwater at the Idaho National Engineering Laboratory (INEL) are presented. This study was motivated by a need to estimate the corrosion behavior of dried, spent ATR fuel elements during dry storage for periods up to 50 years. The study indicated that the condition of spent ATR fuel elements currently stored underwater at the INEL is not very well known. Based on the limited data and observed corrosion behavior in the reactor and in underwater storage, it was concluded that many of the fuel elements currently stored under water in the facility called ICPP-603 FSF are in a degraded condition, and it is probable that many have breached cladding. The anticipated dehydration behavior of corroded spent ATR fuel elements was also studied, and a list of issues to be addressed by fuel element characterization before and after forced drying of the fuel elements and during dry storage is presented.
