engleski

Scientific Study on External Ionising Radiation Exposure during Cargo Vehicle Radiographic Inspections

http://docslide.us/documents/scientific-study-on-external-ionising-radiation-exposure-during-cargo-vehicle.html Introduction Effective customs, border, port and other inspection authorities increasingly use gamma and x-ray non-destructive (non-intrusive) inspection technology (NDT) in order to produce high-quality interior images of commercial vehicles with or without cargo inside. Ionising radiation easily penetrates cargo and closed containers. The purpose of this scanning is to fight theft, reveal contraband and other types of illegal trade including illicit trafficking of people - illegal immigrants - stowaways, weapons and dangerous goods, nuclear devices and bio-threats. Following the September 11, 2001 attacks in the USA and subsequent terrorist acts, the number of commercial vehicles being scanned has dramatically increased. Therefore, inspection authorities consider scanning tools as an efficient complement to their cumbersome work of manual inspections. This means that standard customs scanning has been widely broadened to encompass modern day security issues. In fact heavy commercial vehicles may be scanned several times a day on the same route and during the same trip. This has led to considerable concern from the transport industry as relatively often no preventive measures are available to protect the drivers, as well as no easily accessible information on control procedures and the possible risks and impacts that ionising radiation inspections have on the health of drivers. Study objective and approach The objective of the scientific study is to investigate the hazards and risk associated with transport activities which are unavoidably connected with the possible exposure of employees to ionising radiation while undergoing the cargo/vehicle scanning process. Over few months the specialist investigated x-ray scanning practices, procedures and levels of radiation exposure at selected borders crossings and undertook measurements of the radiation exposure and residual radiation in the vehicle, using professional radiation detection equipment and personal dosemeters, including active electronic dosemeter (AED). In addition to the quantitative radiation exposure level measurements, the Consultant observed and recorded all practices and procedures related to x-ray scanning at the selected border crossings and compared them to recognized international standards such as IEC1 62523 “Radiation protection instrumentation – cargo/vehicle radiographic inspection system” for production and NCRP2 Furthermore the study initiates discussions on whether truck drivers are exposed to an occupational risk, as trucks are scanned while the driver is performing his professional duties, or should the driver be treated as a member of the general public as they are not exposed to primary radiation and do not work in defined radiation protection control areas. Commentary No. 20 “Radiation Protection and Measurement issues related to Cargo Scanning with Accelerator-Produced High-Energy X Rays” for use and protection. In this respect the study refers to the International Labour Organization (ILO) definition of a work place for which a high possibility of being inadvertently exposed to ionising radiation used to scan the cargo/vehicle exists. The workers – drivers are defined according to the EU basic safety standards Directive3 1 International Electrotechnical Commission (Council Directive 96/29/ Euratom, laying down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiation (Official Journal, L-159 29.06.1996, ) and the Draft of Euratom Basic Safety Standards Directive ; Version 24 February 2010 (Final) laying down 2 National Council on Radiation Protection 3 Exposed workers: persons, either self-employed or working for an employer, subject to an exposure incurred at work from practices covered by this Directive and liable to result in doses exceeding one or other of the dose levels equal to the dose limits for members of the public.Basic Safety Standards for Protection against the Dangers Arising from Exposure to Ionising Radiation. The possible existence of radiation exposure area inside the truck cabin is discussed. It is important to note that the study is not addressing the drivers who drive transports of nuclear and radioactive material because their occupational risk and transport technology are covered by numerous specialised international and national regulations. Furthermore, the study did not look specifically, into the special NORM (Naturally Occurring Radioactive Material) transport control procedures but recognises that radioactive residues can occur during measurements because the NORM was transported in the respective container before. Lastly, any other non-authorised person incidentally scanned whilst inside the truck is also not addressed in this study.

external exposure ; x-ray ; cargo inspection ; LINAC ; NDT ; dosimetry ; ALARA AED

Contract: The International Road Transport Union (IRU)under United Nations, Geneve, 2012, Ivica Prlić - (IMROH, Zagreb)