The devil is in the nucleus

Ensuring the safety of nuclear installations and preventing misuse of radioactive material is vital

By Morand Fachot

Monitoring radiation levels is paramount to ensuring protection against nuclear risks. IEC Technical Committee (TC) 45 is the only worldwide body developing international instrumentation and control standards for the nuclear and nuclear power industries and for other industries using nuclear measuring techniques. Its work is also absolutely essential to detect illegal activities and smuggling of radioactive material.

A billet of highly-enriched uranium recovered from scrap processed at the Y-12 National Security Complex Plant (US)

Growing global concern

Nowadays protection from nuclear risks is a global concern. Accidents in nuclear power plants resulting from natural disasters, technical faults or human errors have heightened public concern about the nuclear industry.

Authorities everywhere try to protect people and environment from careless handling and storage of radioactive waste material. Governments also see possible criminal or terrorist misuse of smuggled nuclear waste or spent fuel as representing very serious national security risks.

The IEC makes a major contribution to the safety of nuclear installations, to the safe handling and storage of fissile material and to the fight against nuclear smuggling through the work of its TC 45 and its Subcommittees (SCs), which prepare International Standards relating to electrical and electronic equipment and systems for instrumentation specific to nuclear applications.

Minimizing risks in power plants

The nuclear power industry has been facing important challenges in recent years following the March 2011 nuclear accident at Fukushima, Japan, and the wider availability of additional fuel sources, mainly natural gas, resulting from new drilling techniques.

These factors have led a number of countries to turn away or to cut their level of dependence on nuclear power in favour of renewable sources or cheaper fossil fuels to generate electricity.

The building of new nuclear installations, the refurbishment of older installations and the dismantling of decommissioned reactors are submitted to tighter reviews and regulations where safety plays a major role and where standards for instrumentation are essential.

TC 45, which had published 35 International Standards as of March 2015, and its SCs develop International Standards for the design, construction, performance, testing and calibration of radiation detection instrumentation for all applications.

IEC SC 45A prepares standards applicable to the electronic and electrical functions and associated systems and equipment used in nuclear energy generation facilities (nuclear power plants, fuel handling and processing plants, interim and final repositories for spent fuel and nuclear waste). The aim is to improve the efficiency and safety of nuclear energy generation.

The core domain of SC 45A is instrumentation and control systems important to safety in nuclear energy generation facilities. As of March 2015, SC 45A had issued some 74 publications.

Nuclear power plants are amongst the most rigorously monitored installations and IEC International Standards play a central role for this.

Preventing accidental or criminal storage and transport of radioactive material

In 1995 the International Atomic Energy Agency (IAEA), the UN agency that seeks to promote the peaceful use of nuclear energy, set up a database system, now called the Incident and Trafficking Database (ITDB), to record and analyse incidents of illicit trafficking in nuclear and other radioactive material.

As of 31 December 2013, the ITDB contained a total of 2 477 confirmed incidents reported by participating states. Of these confirmed incidents, 424 involved unauthorized possession and related criminal activities, 664 involved reported theft or loss and 1 337 incidents involved other unauthorized activities and events. It reported that the majority of unauthorized activities fell into one of three categories: the unauthorized disposal (e.g. radioactive sources entering the scrap metal industry), unauthorized shipment (e.g. scrap metals contaminated with radioactive material being shipped across international borders) or the discovery of radioactive material (e.g. uncontrolled radioactive sources).

Radioactive material crossing borders or being moved within countries may not necessarily be there for criminal purposes, but its presence may also result from improper handling of scrapped equipment, therefore monitoring of many installations, such as scrap metal facilities is important.

Places where it is vitally important to detect the presence of radioactive material are harbours and border crossings.

Ports infrastructure central to prevent illegal entry

More than 90% of world trade is transported by sea, with the majority of goods shipped in containers, with the obvious exception of gas and oil, and dry bulk (minerals, foodstuff, etc.). The sheer volume of twenty-foot equivalent unit (TEU) containers leaving and entering world harbours is staggering with 20 harbours shifting more than six million TEUs each in 2011.

Therefore, preventing the illegal transfer of radioactive material across borders is best ensured by controlling goods as they are entering port loading and unloading areas. This is a hugely difficult task as potentially dangerous quantities of radioactive material are not necessary voluminous and can be hidden in tiny spaces.

With such volumes it is impossible to physically inspect each container. Special instrumentation is needed for this purpose, it must be very sensitive and meet strict specifications to ensure it can identify small quantities of harmful products and operate reliably. This type of equipment is widely used for security purposes at nuclear facilities, border control posts and international seaports.

To ensure that measurements made at different locations and with different instruments of the same type are consistent, radiation instrumentation must be designed to uniform rigorous specifications based upon performance requirements stated in international standards.

SC 45B: Radiation protection instrumentation, prepares, among others, international standards for instrumentation used for: illicit trafficking detection and identification of radionuclides; radiation-based security screening. As of March 2015 SC 45B had issued 55 publications, six of these for illicit trafficking detection, of which three concern equipment of particular relevance to detection at international seaports. These standards relate to both large systems and portable ones.

Reliable radiation detection relies on IEC International Standards

IEC SC 45B prepared, among others, IEC 62244:2006, Radiation protection instrumentation - Installed radiation monitors for the detection of radioactive and special nuclear materials at national borders. This International Standard, which does not apply to hand-held devices, defines "the performance of installed monitors used for the detection of gamma and neutron radiation emitters contained in objects/containers or vehicles, general characteristics, mechanical characteristics, environmental requirements, test procedures and documentation." These systems "are used to monitor vehicles, cargo containers, people, or packages and are typically located at national and international borders."

IEC SC 45B also developed an International Standard for portal monitors, IEC 62484:2010, Radiation protection instrumentation - Spectroscopy-based portal monitors used for the detection and identification of illicit trafficking of radioactive material.

One factor to take into account is that radioactive materials are transported in shielded containers. But even after shielding, some quantity of radiation can be detected and the instruments that meet IEC SC 45B Standards try to do so. It is to be noted that these standards specify the minimum requirements - such as identification of a single radionuclide divided into three categories: unshielded, shielded by 3 mm of steel, shielded by 5 mm of steel - but equipment often exceed such minimal requirements.

Protecting staff with ongoing work

Most officers carrying out the inspection of cargo using hand-held detection instruments are not radiation experts. Therefore, these instruments must be user-friendly as regards their design and operation, and must also have a high degree of inherent safety. To develop such devices, IEC SC 45B prepared IEC 62327:2006, Hand-held instruments for the detection and identification of radionuclides and for the indication of ambient dose equivalent rate from photon radiation.

This Standard "provides guidelines for selecting suitable radionuclide libraries covering radioactive materials that have been most frequently detected at border crossings."

SC 45B published two more international standards for hand-held instruments for the detection of radioactive material.

SC 45B also developed IEC 62401:2007, Alarming personal radiation devices (PRD) for detection of illicit trafficking of radioactive material. PRDs are pocket-sized devices carried on the body that "alert the user to the presence of a source of radiation that is distinctly above the measured average local background radiation level. They are not intended to provide a measurement of dose equivalent rate." IEC SC 45B published another Standard for a spectroscopy-based alarming PRD in February 2013. Work is ongoing to develop new International Standards in the field. One such standard concerning backpack radiation detector for detection of illicit trafficking of radioactive material, IEC 62694:2014, was published in March 2014.

These detection devices and others are not just used to detect illegal activities, but in all sectors dealing with radioactive material.

International recognition

The effectiveness of the radioactive material detection equipment that is designed and built according to IEC SC 45B International Standards is confirmed by the following information published in the IAEA ITDB 2014 Fact Sheet: "The reporting of these incidents, especially ‘unauthorised disposal’ and ‘unauthorised movement’ has risen steadily since 2003. There is evidence that this rise is related to the increased number of radiation portal monitoring systems that have been deployed at national borders and scrap metal facilities."

However, relying blindly on equipment alone is not sufficient to safeguard against the illegal and potentially dangerous entry of radioactive material in any country. The human factor, in the form of properly trained and dedicated staff, remains essential. Port and border authorities should ensure that both technical means and human resources are kept at their best possible levels to prevent illegal entry of nuclear or radioactive material.

CPB-handheld US CBP Officer using a hand-held device to detect radioactive material in a container (Photo: US Customs & Border Protection)
HEUranium A billet of highly-enriched uranium recovered from scrap processed at the Y-12 National Security Complex Plant (US)
Kozloduy plant Control room at Kozloduy nuclear power plant (Bulgaria)