Download or read book Laboratory Simulation of Vapor Space Corrosion in Radioactive Waste Storage Tanks written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laboratory Testing to Simulate Vapor Space Corrosion in Radioactive Waste Storage Tanks written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 70 years at the Hanford nuclear facility. Vapor space corrosion of the tank walls has emerged as an ongoing challenge to overcome in maintaining the structural integrity of these tanks. The interaction between corrosive and inhibitor species in condensates/supernates on the tank wall above the liquid level, and their interaction with vapor phase constituents as the liquid evaporates from the tank wall influences the formation of corrosion products and the corrosion of the carbon steel. An effort is underway to gain an understanding of the mechanism of vapor space corrosion. Localized corrosion, in the form of pitting, is of particular interest in the vapor space. CPP testing was utilized to determine the susceptibility of the steel in a simulated vapor space environment. The tests also investigated the impact of ammonia gas in the vapor space area on the corrosion of the steel. Vapor space coupon tests were also performed to investigate the evolution of the corrosion products during longer term exposures. These tests were also conducted at vapor space ammonia levels of 50 and 550 ppm NH3 (0.005, and 0.055 vol.%) in air. Ammonia was shown to mitigate vapor space corrosion.
Download or read book Vapor Corrosion Response of Low Carbon Steel Exposed to Simulated High Level Radioactive Waste written by B. Wiersma and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A program to resolve the issues associated with potential vapor space corrosion and liquid/air interface corrosion in the Type III high level waste tanks is in place. The objective of the program is to develop understanding of vapor space (VSC) and liquid/air interface (LAIC) corrosion to ensure a defensible technical basis to provide accurate corrosion evaluations with regard to vapor space and liquid/air interface corrosion. The results of the FY05 experiments are presented here. The experiments are an extension of the previous research on the corrosion of tank steel exposed to simple solutions to corrosion of the steel when exposed to complex high level waste simulants. The testing suggested that decanting and the consequent residual species on the tank wall is the predominant source of surface chemistry on the tank wall. The laboratory testing has shown that at the boundary conditions of the chemistry control program for solutions greater than 1M NaNO{sub 3}{sup -}. Minor and isolated pitting is possible within crevices in the vapor space of the tanks that contain stagnant dilute solution for an extended period of time, specifically when residues are left on the tank wall during decanting. Liquid/air interfacial corrosion is possible in dilute stagnant solutions, particularly with high concentrations of chloride. The experimental results indicate that Tank 50 would be most susceptible to the potential for liquid/air interfacial corrosion or vapor space corrosion, with Tank 49 and 41 following, since these tanks are nearest to the chemistry control boundary conditions. The testing continues to show that the combination of well-inhibited solutions and mill-scale sufficiently protect against pitting in the Type III tanks.
Download or read book WVNS Tank Farm Process Support written by Monte R. Elmore and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Species in the Vapor Phase of Hanford Double Shell Tanks written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The presence of corrosive and inhibiting chemicals on the tank walls in the vapor space, arising from the waste supernatant, dictate the type and degree of corrosion that occurs there. An understanding of how waste chemicals are transported to the walls and the affect on vapor species from changing supernatant chemistry (e.g., pH, etc.), are basic to the evaluation of risks and impacts of waste changes on vapor space corrosion (VSC). In order to address these issues the expert panel workshop on double-shell tank (DST) vapor space corrosion testing (RPP-RPT-31129) participants made several recommendations on the future data and modeling needs in the area of DST corrosion. In particular, the drying of vapor phase condensates or supernatants can form salt or other deposits at the carbon steel interface resulting in a chemical composition at the near surface substantially different from that observed directly in the condensates or the supernatants. As a result, over the past three years chemical modeling and experimental studies have been performed on DST supernatants and condensates to predict the changes in chemical composition that might occur as condensates or supernatants equilibrate with the vapor space species and dry at the carbon steel surface. The experimental studies included research on both the chemical changes that occurred as the supernatants dried as well as research on how these chemical changes impact the corrosion of tank steels. The chemical modeling and associated experimental studies were performed at the Pacific Northwest National Laboratory (PNNL) and the research on tank steel corrosion at the Savannah River National Laboratory (SRNL). This report presents a summary of the research conducted at PNNL with special emphasis on the most recent studies conducted in FY10. An overall summary of the project results as well as their broader implications for vapor space corrosion of the DST's is given at the end of this report.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-06 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Cooling Coil Corrosion in Storage Tanks for Radioactive Waste written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The high frequency of cooling coil leaks observed in high-heat waste storage tanks soon after sludge removal operations is attributed to pitting, according to laboratory corrosion studies. Experiments show that the most likely series of events leading to coil leakage is (1) excessive dilution of basic nitrite in the supernate, (2) initiation of attack in crevices due to oxygen depletion cells, and (3) acceleration of the attack by sulfate dissolved from the sludge. When sludge was slurried with water, the interstitial liquid was diluted. Nitrite, the anodic inhibitor that prevented attack on coils and tanks in normal operation when its concentration was 0.5 to 3.0M, could accelerate attack when diluted to 10−4 to 10−3M. Attack was presumably initiated at oxygen depletion cells. The presence of sulfate, leached from the sludge, produced a conductive solution that could produce high current densities at the corroding steel surface. The proposed series of events leading to coil leakage agrees with the observations previously made on one leaking coil removed from Tank 2F after sludge removal in 1967. Examination revealed pitting that had originated on the outside of the coils. This pitting was attributed to oxygen depletion cells in coil crevices. To prevent recurrence of pitting attack on cooling coils during future sludge removal operations, the sludge should be slurried (1) with waste diluted less than one hundredfold with water, or (2) with a 500-ppm nitrite-H2O solution at pH 12. Either method should preclude pitting damage to the coils.
Download or read book Investigation of the Corrosivity of the Vapor Phase Over High Level Radioactive Waste written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion in the vapor space and at the liquid/air interface of the Department of Energy high level waste tanks have emerged as a potentially aggressive degradation mechanism.
Download or read book CORROSION MONITORING IN HANFORD NUCLEAR WASTE STORAGE TANKS DESIGN AND DATA FROM 241 AN 102 MULTI PROBE CORROSION MONITORING SYSTEM written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2008, a new Multi-Probe Corrosion Monitoring System (MPCMS) was installed in double-shell tank 241-AN-102 on the U.S. Department of Energy's Hanford Site in Washington State. Developmental design work included laboratory testing in simulated tank 241-AN-102 waste to evaluate metal performance for installation on the MPCMS as secondary metal reference electrodes. The MPCMS design includes coupon arrays as well as a wired probe which facilitates measurement of tank potential as well as corrosion rate using electrical resistance (ER) sensors. This paper presents the MPCMS design, field data obtained following installation of the MPCMS in tank 241-AN-102, and a comparison between laboratory potential data obtained using simulated waste and tank potential data obtained following field installation.
Download or read book Waste Tank Corrosion Program at Savannah River Site written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Savannah River Site (SRS) has approximately 30 million gallons of high level radioactive waste stored in 51 underground tanks. SRS has maintained an active corrosion research and corrosion control and monitoring program throughout the operating history of SRS nuclear waste storage tanks. This program is largely responsible for the successful waste storage experience at SRS. The program has consisted of extensive monitoring of the tanks and surrounding environment for evidence of leaks, extensive research to understand the potential corrosion processes, and development and implementation of corrosion chemistry control. Current issues associated with waste tank corrosion are primarily focused on waste processing operations and are being addressed by a number of active programs and initiatives.
Download or read book Mechanistic Modelling of the Corrosion Behaviour of Copper Nuclear Fuel Waste Containers written by Fraser King and published by Pinawa, Man. : Whiteshell Laboratories. This book was released on 1996 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Deployment of Advanced Corrosion Monitoring Systems for High level Waste Tanks written by and published by . This book was released on 2002 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the results of a collaborative technology development program, sponsored by the Tanks Focus Area, to use electrochemical noise (EN) for corrosion monitoring in underground storage tanks. These tanks, made of carbon or stainless steels, contain high-level radioactive liquid waste (HLW) generated by weapons production or radioactive liquid waste from nuclear fuel reprocessing activities at several Department of Energy (DOE) sites. The term EN is used to describe low frequency fluctuations in current and voltage measurements associated with corrosion. In their most basic form, EN-based corrosion monitoring systems measure and record these fluctuations over time from electrodes immersed in the environment of interest - in this case, radioactive tank waste. The resulting EN signals have characteristic patterns for different corrosion mechanisms. In recent years, engineers and scientists from several DOE sites, in collaboration with several private companies, have conducted laboratory studies and field applications to correlate the EN signals with corrosion mechanisms active in the radioactive waste tanks. The participating DOE sites are Hanford, Savannah River, Oak Ridge Reservation and the Idaho National Engineering and Environmental Laboratory. The commercial vendors have included HiLine Engineering and Fabrication, Inc., EIC Laboratories, Inc., and M A Technologies. Successful deployment of the EN technology will yield improved information of waste tank corrosion conditions, better tank management, and lower overall cost.
Download or read book Predicting the Effects of Microbial Activity on the Corrosion of Copper Nuclear Fuel Waste Disposal Containers electronic Resource written by Stroes-Gascoyne, Simcha and published by Pinawa, Man. : Whiteshell Laboratories. This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book VAPOR SPACE AND LIQUID AIR INTERFACE CORROSION OF LOW CARBON STEEL IN COMPLEX HIGH LEVEL RADIOACTIVE WASTE SOLUTION written by KARTHIK. SUBRAMANIAN and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Second Generation Hanford Tank Corrosion Monitoring System written by and published by . This book was released on 1998 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hanford Site has 177 underground waste tanks that store approximately 253 million liters of radioactive waste from 50 years of plutonium production. Twenty-eight tanks have a double shell and are constructed of welded ASTM A537-Class 1 (UNS K02400), ASTM A515-Grade 60 (UNS K02401), or ASTM A516-Grade 60 (UNS K02100) material. The inner tanks of the double-shell tanks (DSTS) were stress relieved following fabrication. One hundred and forty-nine tanks have a single shell, also constructed of welded mild steel, but not stress relieved following fabrication. Tank waste is in liquid, solid, and sludge forms. Tanks also contain a vapor space above the solid and liquid waste regions. The composition of the waste varies from tank to tank but generally has a high pH (>12) and contains sodium nitrate, sodium hydroxide, sodium nitrite, and other minor radioactive constituents resulting from plutonium separation processes. Leaks began to appear in the single-shell tanks shortly after the introduction of nitrate-based wastes in the 1950s. Leaks are now confirmed or suspected to be present in a significant number of single-shell tanks. The probable modes of corrosion failures are reported as nitrate stress corrosion cracking (SCC) and pitting. Previous efforts to monitor internal corrosion of waste tank systems have included linear polarization resistance (LPR) and electrical resistance techniques. These techniques are most effective for monitoring uniform corrosion, but are not well suited for detection of localized corrosion (pitting and SCC). The Savannah River Site (SRS) investigated the characterization of electrochemical noise (EN) for monitoring waste tank corrosion in 1993, but the tests were not conclusive. The SRS effort has recently been revived and additional testing is underway. For many years, EN has been observed during corrosion and other electrochemical reactions, and the phenomenon is well established. Typically, EN consists of low frequency (
Download or read book VAPOR SPACE AND LIQUID written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenomena of vapor space corrosion and liquid/air interface corrosion of carbon steel in simulated liquid waste environments have been investigated. Initial experiments have explored the hypothesis that vapor space corrosion may be accelerated by the formation of a corrosive electrolyte on the tank wall by a process of evaporation of relatively warmer waste and condensation of the vapor on the relatively cooler tank wall. Results from initial testing do not support the hypothesis of electrolyte transport by evaporation and condensation. The analysis of the condensate collected by a steel specimen suspended over a 40 C simulated waste solution showed no measurable concentrations of the constituents of the simulated solution and a decrease in pH from 14 in the simulant to 5.3 in the condensate. Liquid/air interface corrosion was studied as a galvanic corrosion system, where steel at the interface undergoes accelerated corrosion while steel in contact with bulk waste is protected. The zero-resistance-ammeter technique was used to measure the current flow between steel specimens immersed in solutions simulating (1) the high-pH bulk liquid waste and (2) the expected low-pH meniscus liquid at the liquid/air interface. Open-circuit potential measurements of the steel specimens were not significantly different in the two solutions, with the result that (1) no consistent galvanic current flow occurred and (2) both the meniscus specimen and bulk specimen were subject to pitting corrosion.
