ALWT-2 Remediation Characterization for AECL
Contained representative subsurface sampling, gamma radiochemical characterization and profiling at depth using TruPro® of the Active Liquid Waste Tank 2 (ALWT-2) concrete, sand contents, and the concrete inner walls of the concrete structure without entry through the tank roof hatch was successfully achieved. NMNTI obtained samples from the tank and analyzed these samples in close proximity to sampling operations. The purpose was to provide the necessary physical data and gamma radiochemical fingerprinting to properly identify and quantify the waste radiochemical activities. The field work occurred at the Chalk River Laboratories (CRL) Waste Management Area A (WMA A) located at the Atomic Energy of Canada Limited’s (AECL) Chalk River Laboratories, Chalk River, Ontario, Canada.
NMNTI worked in a very confined area of an active waste tank roof with a working area foot print of less than an 8 foot diameter with operator and equipment and provided materials and labor, obtaining 25 separate discrete incremental samples including powdered tank inner wall concrete, sand, liquid, and liquid level determination from the ALWT-2 subsurface tank structure. Included in this sampling and characterization activity were associated site evaluations, day to day sampling, characterization, and documented reporting. Sampling was in the vertical and diagonal directions (i.e. through the tank roof downwards and at angles to walls and through voids) to obtain samples from inaccessible depths within ALWT-2. All of the retrieved liquid, sand, and powdered concrete inner tank wall samples were measured quantitatively by ISOCS in close proximity to the sampling site for gamma radionuclide activities (Bq/g for sand and concrete and Bq/ml for liquid) of interest, specifically Cs-137 and Am-241 in near real time.