ELECTROCHEMICAL CORROSION STUDIES FOR TANK 241-AN-107 CORE 309 SEGMENTS 21R1 & 21R2

Liquid waste in tank 241-AN-107 is below Technical Safety Requirements Administrative Control 5.16 (AC 5.16) limits. Electrochemical corrosion testing was performed on Core 309, Segments 21R1 and 21R2, to provide information on the conductivity and corrosive tendencies of the tank saltcake and interstitial liquid. This report describes data obtained under the execution of RPP-PLAN-29001, 'Electrochemical Corrosion Studies for Tank 241-AN-107 Core 309, Segments 21R1 and 21R2'. Analytical results are presented that show supernatant was within the limits while the interstitial liquid remained below the limits for the analytical cores. Applicable AC 5.16 chemistry control limits for AN-107 are presented

ELECTROCHEMICAL CORROSION REPORT FOR TANKS 241-AW-103 & 241-AZ-102 & 241-AN-106 & 241-AN-107 & 241-AY-101 & 241-AY-102

Corrosion rates using supernatant samples retrieved from near the top of the liquid layer were determined for the tanks. Corrosion rates using settled solids (saltcake) were determined. The supernatant samples were tested as received without argon sparging. The settled solid sample segments were extruded under anaerobic condition and kept under a sweep of humidified argon gas during 'the electrochemical corrosion testing. The class of steel used to construct the tank in question was used, and test coupons were allowed to equilibrate for a minimum of 18 hours before a Tafel scan was initiated. The coupons were scanned from -250 mV to +250 mV from the rest or open circuit potential. The corrosion rate is reported along with the corrosion current measurement, open circuit potential, and a chi-square statistic generated by the instrument controlling and analysis algorithm

ELECTROCHEMICAL CORROSION TEST RESULTS FOR TANK 241-SY-102 SUPERNATE GRAB SAMPLES

This report describes the electrochemical corrosion scans and conditions for testing of SY-102 supernatant samples taken December 2004. The testing was performed because the tank was under a Justification for Continued Operation allowing the supernatant composition to be outside the chemistry limits of Administrative Control 5.16, 'Corrosion Mitigation program'. A new electrochemical working electrode of A516 Grade 60 carbon steel was used for each scan; all scans were measured against a saturated calomel electrode, with carbon counter electrodes, and all scans were carried out at 50 C. The samples were scanned twice, once as received and once sparged with argon to deoxygenate the sample. For those scans conducted after argon purging, the corrosion rates ranged from 0.012 to 0.019 mpy. A test for stress corrosion cracking was carried out on one sample (2SY-04-07) with negative results

EFFICACY OF FILTRATION PROCESSES TO OBTAIN WATER CLARITY AT K EAST SPENT NUCLEAR FUEL (SNF) BASIN

The objective is to provide water clarity to the K East Basin via filtration processes. Several activities are planned that will challenge not only the capacity of the existing ion exchange modules to perform as needed but also the current filtration system to maintain water clarity. Among the planned activities are containerization of sludge, removal of debris, and hydrolasing the basin walls to remove contamination

ELECTROCHEMICAL CORROSION STUDY FOR TANK 241-AY-102 SLUDGE

The report describes the analyses performed on core samples from the sludge region of the waste in Tank 241-AY-102 to determine the electrochemical corrosion potential

Reservation status and priorities for Tasmanian plants I. Angiospermae (Dicotyledonae)

Almost one-fifth of Tasmanian native dicotyledonous angiosperms are not known from any national park or equivalent reserve. Extinct, endangered, vulnerable and unreserved species are "most common among annuals and least common among woody plants. The unreserved species have their distributions concentrated between Launceston and Hobart in the dry, naturally grassy Midlands. A minimum reservation strategy is suggested for those species for which this option still exists

FINAL REPORT FOR THE REDUCTION OF CHROME (VI) TO CHROME (III) IN THE SECONDARY WASTE STREAM OF THE EFFLUENT TREATMENT FACILITY

This report documents the laboratory results of RPP-PLAN-35958, Test Plan for the Effluent Treatment Facility to Reduce Chrome (VI) to Chrome (III) in the Secondary Waste Stream With the exception of the electrochemical corrosion scans, all work was carried out at the Center for Laboratory Science (CLS) located at the Columbia Basin College. This document summarizes the work carried out at CLS and includes the electrochemical scans and associated corrosion rates for 304 and 316L stainless steel

TANK 241-AN-107 CORROSION COUPON LABORATORY ANALYSIS

To support the corrosion study for Tank 241-AN-107, corrosion coupons consisting of C-rings and pins were removed from four detectors of the corrosion probe retrieved from the tank. The detectors were located as follows: one in the sludge layer, one in the liquid layer, one in the lower head space and the last in the upper head space. ASTM Method G-190 was used to determine the amount of corrosion product present

FINAL ANALYTICAL RESULTS FROM THE EXAMINATION OF CORROSION ON SECTIONS OF CORROSION PROBE REMOVED FROM TANK 241-AN-107 ON 08/10/2006

Tank Farms Operations removed an electrochemical noise probe from Tank 241-AN-107. In the field, the probe was cut into four sections, wrapped, and placed in a 55-gallon drum, This drum was delivered to the 222-S Laboratory. The 222 S Laboratory unpackaged the sections of the AN-107 electrochemical noise probe and examined the material for evidence of corrosion. Each of the four sections contained three C-ring and three bullet specimens. The specimens were examined for pitting corrosion, crevice corrosion, and stress corrosion cracking. No evidence of stress corrosion cracking was found in the stressed C-ring specimens. Minor pitting was evident on some surfaces. Crevice corrosion was the dominant type of corrosion observed

ELECTROCHEMICAL CORROSION TESTS FOR TANK 241-AY-101 CORE 325 SEGMENTS 16R1 & 16R2

The interstitial liquid in the double-shell tank 241-AY-101 settled solids layer is below the hydroxide chemistry control limit required by HNF-SD-WM-TSR-006, Tank Farms Technical Safety Requirements, Administrative Control 5.16, 'Corrosion Mitigation Controls'. Operating tanks outside of the specification may increase the propensity corrosion of the carbon steel wall. This report is concerned with generalized electrochemical corrosion mechanism that may occur at specific loci. All cyclic potentiodynamic polarization scans exhibited a negative hysteresis, scan reversing at lower current density, indicating that there was no pitting propensity. The general electrochemical corrosion rates ranged from 4.4E-02 to 1.5E-03 mpy with the first round of coupons, while the second round yielded corrosion rates of 2.5E-03 to 2.9E-02 mpy