Читать книгу Disarmament and Decommissioning in the Nuclear Domain - Jean-Claude Amiard - Страница 32

By having early detection of the theft of nuclear materials or the misuse of nuclear technology, the IAEA can alert the world to a proliferation risk [AMA 16]. Through safeguards, the IAEA provides credible assurance that states only use nuclear material and technology for peaceful purposes in accordance with their international obligations.

In 2015, the IAEA conducted 2,118 field inspections, collected 967 environmental and nuclear material samples, observed 1,416 surveillance cameras and 407 satellite images through a network of 20 certified laboratories and 883 staff. This enabled it to provide safeguards at 1,286 nuclear facilities.

The implementation of the safeguards is carried out in four steps. The first stage is the collection and evaluation of information about a state. The second step is the development of a monitoring methodology specific to that state. The third step is the planning of safeguards to be carried out in both the field and the Agency’s headquarters. The final step is the establishment of a safeguards conclusion for each state [AIE 16a].

A safeguards inspector must perform three types of verification at each nuclear facility. These are to verify the integrity of the reactor seals, to control the correct storage of new and spent fuel and the correct operation of surveillance cameras [HEN 16].

Technicians mainly have five handheld instruments at their disposal to carry out their inspection. An HM-5 (detector of multiple alpha, beta, gamma and neutron radiation) can detect the presence of radioactive materials and the enrichment of uranium. The second is a force sensor that operates in two ranges (up to 5,000 kg and up to 20,000 kg). The third instrument is an electrically cooled germanium gamma radiation detection system; the fourth is an ultrasonic thickness gauge. Finally, there is an attribute tester (gamma ray detector) of irradiated elements for underwater fuel, or a digital device for the observation of the Chernenkov effect, which remains dry and protected from water, associated with a camera that detects ultraviolet radiation emitted by spent fuel assemblies.

In the case of additional protocols, inspections require a special toolkit. The toolkit contains all kinds of instruments to collect information and verify reports: a camera, laser meter, GPS, voice recorder, flashlight, universal radiation meter, such as the HM-5 and an environmental sampling kit [FOU 16a].

The IAEA monitors more than one million sets of encrypted data that are collected by more than 1,400 surveillance cameras and 400 radiation sensors around the world. The containment of materials and equipment is ensured by more than 23,000 seals installed at nuclear facilities.

The IAEA’s Next-Generation Surveillance System (NGSS) uses cameras that are protected by casings designed to reveal any attempt at tampering, and are equipped with long-life batteries that ensure their autonomy in the event of an absence of an external power supply for extended periods of time. Approximately 160 systems, with a total of 700 detectors and sensors, are installed in more than 40 countries.

Different types of automatic systems are used, depending on whether it is an enrichment facility, a reactor, a spent fuel storage site or a reprocessing plant.

The IAEA seals are the best known and most widely used safeguarding equipment. Despite their simplicity, these anti-fraud devices are highly effective in preventing unauthorized access to IAEA safeguarding materials and equipment. The IAEA uses several types of seals depending on the case. Some are designed to be installed underwater, others can withstand extreme conditions. The most common seals are metal seals, as well as Cobra seals, which incorporate a multi-core fiber optic cable whose ends are protected by the seal. There are also electro-optical seal systems and laser systems for containment verification [FOU 16b].

The IAEA’s scientific safeguards depend on the laboratories located in Seibersdorf, Austria. These laboratories include two modern facilities. The Nuclear Materials Laboratory (NML) handles the sampling of nuclear materials and the Environmental Samples Laboratory receives and analyzes all environmental smear samples for traces of nuclear materials [JAW 16].

The analysis of environmental samples taken by smear tests allows the determination of all elements present in a facility, which have been used in the past or recently. This technique was first used in Iraq in 1990 in a nuclear facility, the Osirak or Tammouz reactor, which had been bombed on June 7, 1981.

Once collected, the samples are anonymously labeled and analyzed at the IAEA laboratories near Vienna, as well as in the IAEA’s network of 19 accredited laboratories in many IAEA Member States (Australia, Brazil, France, Germany, Japan, Republic of Korea, Russia, the United Kingdom and the United States). The shipment of samples is also accompanied by “blind samples” for quality control purposes [DIX 16].

Satellite images are used to establish site maps. These provide valuable and accurate information about buildings and structures. For example, satellite imagery helps the IAEA monitor developments in the nuclear program of the Democratic People’s Republic of Korea (DPRK), since the IAEA is not in a position to conduct physical verification activities in that country. In particular, the IAEA is monitoring activities at the Yongbyon site [QUE 16].