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 Savannah River Site High level Waste Tank Closure written by and published by . This book was released on 2002 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In service Inspection of Radioactive Waste Tanks at the Savannah River Site written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid radioactive wastes from the Savannah River Site (SRS) separation process are stored in large underground carbon steel tanks. The high level wastes are processed in several of the tanks and then transferred by piping to other site facilities for further processing before they are stabilized in a vitrified or grout waste form. Based on waste removal and processing schedules, many of the tanks, will be required to be in service for times exceeding the initial intended life. Until the waste is removed from storage, transferred, and processed, the materials and structures of the tanks must maintain a confinement function by providing a barrier to the environment and by maintaining acceptable structural stability during design basis events, which include loadings from both normal service and abnormal (e.g., earthquake) conditions. A structural integrity program is in place to maintain the structural and leak integrity functions of these waste tanks throughout their intended service life. In-service inspection (ISI) is an essential element of a comprehensive structural integrity program for the waste tanks at the Savannah River Site (SRS). The ISI program was developed to determine the degree of degradation the waste tanks have experienced due to service conditions. As a result of the inspections, an assessment can be made of the effectiveness of corrosion controls for the waste chemistry, which precludes accelerated localized and general corrosion of the waste tanks. Ultrasonic inspections (UT) are performed to detect and quantify the degree of general wall thinning, pitting and cracking as a measure of tank degradation. The results from these inspections through 2013, for the 27 Type III/IIIA tanks, indicate no reportable in-service corrosion degradation in the primary tank (i.e., general, pitting, or cracking). The average wall thickness for all tanks remains above the manufactured nominal thickness minus 0.25 millimeter and the largest pit identified is approximately 1.70 millimeter deep (i.e., less than 10% through-wall). Improvements to the inspection program were recently instituted to provide additional confidence in the degradation rates. Thickness measurements from a single vertical strip along the accessible height of the primary tank have been used as a baseline to compare historical measurements. Changes in wall thickness and pit depths along this vertical strip are utilized to estimate the rate of corrosion degradation. An independent review of the ISI program methodology, results, and path forward was held in August 2009. The review recommended statistical sampling of the tanks to improve the confidence of the single strip inspection program. The statistical sampling plan required that SRS increase the amount of area scanned per tank. Therefore, in addition to the baseline vertical strip that is obtained for historical comparisons, four additional randomly selected vertical strips are inspected. To date, a total of 104 independent vertical strips along the height of the primary tank have been completed. A statistical analysis of the data indicates that at this coverage level there is a 99.5% confidence level that one of the worst 5% of all the vertical strips was inspected. That is, there is a relatively high likelihood that the SRS inspection program has covered one of the most corroded areas of any of the Type III/IIIA waste tanks. These data further support the conclusion that there are no significant indications of wall thinning or pitting. Random sampling will continue to increase the confidence that one of the worst 5% has been inspected. In order to obtain the additional vertical strips, and minimize budget and schedule impacts, data collection speed for the UT system was optimized. Prior to 2009, the system collected data at a rate of 32 square centimeters per minute. The scan rate was increased to 129 - 160 square centimeters per minute by increasing the scanner step and pixel sizes in the data acqui ...

Download or read book Savannah River Plant High Level Waste Waste Form Selection Aiken written by and published by . This book was released on 1982 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vapor Corrosion Program Plan written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive wastes are contained in 48 underground storage tanks at the Savannah River Site (SRS). The materials and structures of the tanks provide a confinement function by maintaining leak integrity and structural stability. It is essential that the potential changes in properties of the structural materials due to service environment be evaluated and that conditions that can cause significant (active) degradation be avoided or mitigated. Aging mechanisms are those which cause changes in the materials including degradation of the materials. Degradation is either a reduction of the mechanical properties (e.g., loss of toughness or ductility), or a loss of net section of materials (e.g., cracking, pitting, thinning), or both which reduces the level of confinement inherent in the original installed condition and could lead to failure of confinement.

Download or read book Treatment Tank Corrosion Studies for the Enhanced Chemical Cleaning Process written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than in the PUREX/oxalic acid environment. (3) The corrosion rates for PUREX/8 wt.% oxalic acid were greater than or equal to those observed for the PUREX/2.5 wt.% oxalic acid. No localized corrosion was observed in the tests with the 8 wt.% oxalic acid. Testing with HM/8 wt.% oxalic acid simulant was not performed. Thus, a comparison with the results with 2.5 wt.% oxalic acid, where the corrosion rate was 88 mpy and localized corrosion was observed at 75 C, cannot be made. (4) The corrosion rates in 1 and 2.5 wt.% oxalic acid solutions were temperature dependent: (a) At 50 C, the corrosion rates ranged between 90 to 140 mpy over the 30 day test period. The corrosion rates were higher under stagnant conditions. (b) At 75 C, the initial corrosion rates were as high as 300 mpy during the first day of exposure. The corrosion rates increased with agitation. However, once the passive ferrous oxalate film formed, the corrosion rate decreased dramatically to less than 20 mpy over the 30 day test period. This rate was independent of agitation. (5) Electrochemical testing indicated that for oxalic acid/sludge simulant mixtures the cathodic reaction has transport controlled reaction kinetics. The literature suggests that the dissolution of the sludge produces a di-oxalatoferrate ion that is reduced at the cathodic sites. The cathodic reaction does not appear to involve hydrogen evolution. On the other hand, electrochemical tests demonstrated that the cathodic reaction for corrosion of carbon steel in pure oxalic acid involves hydrogen evolution. (6) Agitation of the oxalic acid/sludge simulant mixtures typically resulted in a higher corrosion rates for both acid concentrations. The transport of the ferrous ion away from the metal surface results in a less protective ferrous oxalate film. (7) A mercury containing species along with aluminum, silicon and iron oxides was observed on the interior of the pits formed in the HM/2.5 wt.% oxalic acid simulant at 75 C. The pitting rates in the agitated and non-agitated solution were 2 mils/day and 1 mil/day, respectively. A mechanism by which the mercury interacts with the aluminum and silicon oxides in this simulant to accelerate corrosion was proposed.

Download or read book Radioactive Waste Management written by and published by . This book was released on 1981 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Six Sigma Evaluation of the High Level Waste Tank Farm Corrosion Control Program at the Savannah River Site written by P. J. Hill and published by . This book was released on 2003 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Six Sigma is a disciplined approach to process improvement based on customer requirements and data. The goal is to develop or improve processes with defects that are measured at only a few parts per million. The process includes five phases: Identify, Measure, Analyze, Improve, and Control. This report describes the application of the Six Sigma process to improving the High Level Waste (HLW) Tank Farm Corrosion Control Program. The report documents the work performed and the tools utilized while applying the Six Sigma process from September 28, 2001 to April 1, 2002. During Fiscal Year 2001, the High Level Waste Division spent $5.9 million to analyze samples from the F and H Tank Farms. The largest portion of these analytical costs was $2.45 million that was spent to analyze samples taken to support the Corrosion Control Program. The objective of the Process Improvement Project (PIP) team was to reduce the number of analytical tasks required to support the Corrosion Control Program by 50 percent. Based on the data collected, the corrosion control decision process flowchart, and the use of the X-Y Matrix tool, the team determined that analyses in excess of the requirements of the corrosion control program were being performed. Only two of the seven analytical tasks currently performed are required for the 40 waste tanks governed by the Corrosion Control Program. Two additional analytical tasks are required for a small subset of the waste tanks resulting in an average of 2.7 tasks per sample compared to the current 7 tasks per sample. Forty HLW tanks are sampled periodically as part of the Corrosion Control Program. For each of these tanks, an analysis was performed to evaluate the stability of the chemistry in the tank and then to determine the statistical capability of the tank to meet minimum corrosion inhibitor limits. The analyses proved that most of the tanks were being sampled too frequently. Based on the results of these analyses and th e use of additional Six Sigma tools, the team identified improvements that allow sampling frequencies to be extended without increasing the overall risk associated with the Corrosion Control Program. Overall, the team identified improvements to the process that would reduce the number of analytical tasks required to support the corrosion control program by approximately 77 percent reducing analytical costs by $1.2 million per year.

Download or read book Corrosion and Failure Processes in High level Waste Tanks written by and published by . This book was released on 1992 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large amount of radioactive waste has been stored safely at the Savannah River and Hanford sites over the past 46 years. The aim of this report is to review the experimental corrosion studies at Savannah River and Hanford with the intention of identifying the types and rates of corrosion encountered and indicate how these data contribute to tank failure predictions. The compositions of the High-Level Wastes, mild steels used in the construction of the waste tanks and degradation-modes particularly stress corrosion cracking and pitting are discussed. Current concerns at the Hanford Site are highlighted.

Download or read book A Corrosion Monitoring and Chemical Species Probe for the Savannah River Site written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A corrosion monitoring and chemical species probe for the Savannah River Site (SRS) has been developed for remotely monitoring the corrosion of the high level waste tanks and for measuring the concentration of waste constituents. The probe incorporates two technologies, Raman spectroscopy (RS) for chemical analysis and electrochemical noise (EN) for corrosion monitoring. The RS technology was optimized to measure the primary waste constituents, specifically nitrate, nitrite and hydroxide. EN monitoring measures the instantaneous current and potential difference fluctuations that occur between three identical electrodes which are similar to the tank wall. An acceptance test, which was not performed under radiological conditions, was designed to verify the operation the RS, EN, the probe deployment reel and system control station. For RS, good measurements were made over the following concentration ranges; 0.1 to 10 molar for hydroxide, 0.1 to 5.0 molar for nitrate and 0.1 to 3.0 molar for nitrite. When the probe body was unperturbed, the EN signal displayed low amplitude and frequency waveforms that are typical for general corrosion.

Download or read book Corrosion Study for Waste Tanks to High and Salt Concentration Conditions written by and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book STATUS OF CHEMICAL CLEANING OF WASTE TANKS AT THE SAVANNAH RIVER SITE F TANK FARM CLOSURE PROJECT 9114 written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical Cleaning is currently in progress for Tanks 5 and 6 at the Savannah River Site. The Chemical Cleaning process is being utilized to remove the residual waste heel remaining after completion of Mechanical Sludge Removal. This work is required to prepare the tanks for closure. Tanks 5 and 6 are 1950s vintage carbon steel waste tanks that do not meet current containment standards. These tanks are 22.9 meters (75 feet) in diameter, 7.5 meters (24.5 feet) in height, and have a capacity of 2.84E+6 liters (750,000 gallons). Chemical Cleaning adds 8 wt % oxalic acid to the carbon steel tank to dissolve the remaining sludge heel. The resulting acidic waste solution is transferred to Tank 7 where it is pH adjusted to minimize corrosion of the carbon steel tank. The Chemical Cleaning flowsheet includes multiple strikes of acid in each tank. Acid is delivered by tanker truck and is added to the tanks through a hose assembly connected to a pipe penetration through the tank top. The flowsheet also includes spray washing with acid and water. This paper includes an overview of the configuration required for Chemical Cleaning, the planned flowsheet, and an overview of technical concerns associated with the process. In addition, the current status of the Chemical Cleaning process in Tanks 5 and 6, lessons learned from the execution of the process, and the path forward for completion of cleaning in Tanks 5 and 6 will also be discussed.

Download or read book The Office of Environmental Management Technical Reports written by and published by . This book was released on 1997 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tank Waste Retrieval Processing and On site Disposal at Three Department of Energy Sites written by National Research Council and published by National Academies Press. This book was released on 2006-09-12 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: DOE Tank Waste: How clean is clean enough? The U.S. Congress asked the National Academies to evaluate the Department of Energy's (DOE's) plans for cleaning up defense-related radioactive wastes stored in underground tanks at three sites: the Hanford Site in Washington State, the Savannah River Site in South Carolina, and the Idaho National Laboratory. DOE plans to remove the waste from the tanks, separate out high-level radioactive waste to be shipped to an off-site geological repository, and dispose of the remaining lower-activity waste onsite. The report concludes that DOE's overall plan is workable, but some important challenges must be overcomeâ€"including the removal of residual waste from some tanks, especially at Hanford and Savannah River. The report recommends that DOE pursue a more risk-informed, consistent, participatory, and transparent for making decisions about how much waste to retrieve from tanks and how much to dispose of onsite. The report offers several other detailed recommendations to improve the technical soundness of DOE's tank cleanup plans.

Download or read book Energy and Water Development Appropriations for 2007 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2006 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Savannah River Site Waste Management Facilities Aiken County Allendale County Barnwell County written by and published by . This book was released on 1995 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: