CASP-II: Clearance assesment methodology for Ra-226+ contaminated pipes using MARSAME

During crude oil extraction processes in the Oil&Gas industry, extraction pipes are impacted with Ra-226+ and Ra-228+. For their management in the treating and final disposal integral plant in the United Arab Emirates, clearance is considered as a mean for material revalorization. This is a complex process due to regulatory and technical constraints. Notable constraints are the low specific activity for clearance, difficult detection of isotopes in the natural series, and the uncertainty in the secular equilibrium., as well as the plant design basis that require to perform the clearance process of 3,000 pipes per year with non-destructive techniques.

For this purpose, TECNATOM S.A. developed and licensed an agile methodology for clearing large quantities of pipes using the equipment Clearance Assessment System por Pipes (CASP), designed ad hoc by NUSIM S.A.

As a result of the operating experience and lessons learned, potential areas for improvement were identified, including the enhancement of the dynamic detection capability, reduction of uncertainties, and the MARSAME methodology application.

MARSAME methodology allows the clearance process optimization. In this regard, a MARSSIM-type survey was designed, which requires a limited number of static measurements, so the process is kept agile, but it also offers sufficient guaranties and a higher control and reduction of Type II error rates (clearable pipes that are not cleared).

The improved CASP-II equipment, aligned with the change in the methodology, optimizes detection levels, required measuring times, and survey variability. The equipment is accompanied with an automatized system that allows the operator to perform the clearance process with minimum actions.

The application of the MARSAME methodology and use of the new equipment will continue permitting the quick clearance of pipes by direct gamma readings in less than 1,5 hours per pipe of 9 meters, adjusting the process to the operative requirements of management of thousands of pipes per year and the equivalent tons of carbon steel. Pipes that are recovered, with the subsequent economic and environmental benefit.

Objetivo Cofrentes: cuidado y respeto del entorno a través del PVRA