TITLE:
Radiological Doses and Risk Assessment of NORM Scrap Metal by Using RESRAD-RECYCLE Computer Code
AUTHORS:
Amaal A. Tawfik, Eman M. Ahmed
KEYWORDS:
NORM Scrap Metals; Risk Assessment; Dose Assessment; RESRAD-RECYCLE; Radioactive Waste
JOURNAL NAME:
Open Journal of Modelling and Simulation,
Vol.2 No.2,
March
28,
2014
ABSTRACT: In this work the radiological dose and risks resulting from recycling of radioactive contaminated
NORM scrap metal that produced from one of oil and gas production companies in Egypt, were determined
by using RESRAD-RECYCLE computer code. Two scenarios were used: the first was the
workers’ scenario, while the second was end-use product scenario. Workers’ scenario was used in
this study for evaluating the dose and risk to workers who process recycled materials. This scenario
focused on the transport of radioactive NORM scrap metal from the place of origin to the smelter
(scrap delivery step). Scenarios for six different workers were included under the scrap delivery
step: two workers scrap cutter, two workers scrap loader, and two workers scrap truck driver.
The values for each scenario were specified on the basis of processing 200 tons of NORM scrap
metal. Because these operations occur before melting of the metal, mass and radionuclide partitioning
factors were not applied in the scrap metal delivery step. The radionuclide concentration
of the NORM scrap metal was used directly in the dose calculation. The maximum doses received
from direct external exposure to all radio nuclides during cutter/sorter, scrap truck driver and
unloading of scrap metals were 2.14E-04, 1.4E-06 and 1.86E-05 (mSv) respectively. The excess
cancer risks for all radio nuclides during cutter/sorter of scrap metals reached 1.25E-07. Radiation
exposures incurred by the scrap unloaders and scrap cutters/sorters were greater than those
incurred by the other workers for their closer exposure distances and longer time.