ASN Report 2018

2.2  ̶  Ionising radiation arising from human activities The human activities involving a risk of exposure to ionising radiation, called nuclear activities, can be grouped into the following categories: ∙ ∙ operation of BNIs; ∙ ∙ transport of radioactive substances; ∙ ∙ small-scale nuclear activities; ∙ ∙ disposal of radioactive waste; ∙ ∙ management of contaminated sites; ∙ ∙ activities enhancing natural ionising radiation. 2.2.1  –  Basic Nuclear Installations Nuclear activities are highly diverse, covering any activity relating to the preparation or utilisation of radioactive substances or ionising radiation. These activities are subject to the general provisions of the Public Health Code and, depending on their nature and the risks that they involve, to a specific legal system. Basic Nuclear Installations (BNIs) are defined in Article L. 593-2 of the Environment Code: 1° Nuclear reactors; 2° Facilities, corresponding to characteristics defined by Decree of the Council of State, for the preparation, enrichment, fabrication, treatment or storage of nuclear fuels, or for the treatment, storage or disposal of radioactive waste; 3° Installations containing radioactive or fissile substances and meeting characteristics defined by Decree of the Council of State; 4° Particle accelerators meeting characteristics defined by Decree of the Council of State; 5° Deep geological repositories for radioactive waste mentioned in Article L. 542-10-1. The installations and facilities are subject to the BNI System, governed by Chapters III and VI of Title IX of Book V of the Environment Code and their implementing texts. The list of BNIs as at 31 December 2018 figures in an appendix to this report. • Accident prevention and nuclear safety The fundamental internationally adopted principle underpinning the specific organisational system and regulations applicable to nuclear safety is that of the responsibility of the licensee (see chapter 2). The public authorities ensure that this responsibility is fully assumed, in compliance with the regulatory requirements. As regards the prevention of risks for workers, BNI licensees are required to implement all necessary means to protect workers against the hazards of ionising radiation. They must more particularly ensure compliance with the general rules applicable to all workers exposed to ionising radiation (work organisation, accident prevention, medical monitoring of workers, including those from outside contractors, etc.). As regards protection of the population and the environment, the BNI licensee must also take all necessary steps to achieve and maintain an optimum level of protection. More particularly, discharges of liquid and gaseous effluents, whether radioactive or not, are strictly limited (see chapter 3). 2.2.2  –  Transport of radioactive substances When transporting radioactive substances, the main risks are those of internal or external exposure, of criticality, and risks of a chemical nature. Safe transport of radioactive substances relies on an approach called defence in depth: ∙ ∙ the robustness of the packaging is the first line of defence. The packaging plays a vital role and must withstand the foreseeable transport conditions; ∙ ∙ the reliability of the transport operations constitutes the second line of defence; ∙ ∙ finally, the third line of defence consists of the means of response implemented in the event of an incident or accident. 2.2.3  –  Small-scale nuclear activities Ionising radiation, whether emitted by radionuclides or generated by electrical equipment, is used in many areas, including medicine (radiology, radiotherapy, nuclear medicine and fluoroscopy-guided interventional practices), biology, research, industry, but also in veterinary applications and the conservation of foodstuffs. The employer is required to take all necessary measures to protect workers against the hazards of ionising radiation. The facility licensee must also implement the provisions of the Public Health Code for the management of the ionising radiation sources in its possession (radioactive sources in particular) and, where applicable, manage the waste produced and limit discharges of liquid and gaseous effluents. In the case of use for medical purposes, patient protection issues are also taken into account. 2.2.4  –  Radioactive waste management Like all industrial activities, nuclear activities can generate waste, some of which is radioactive. The three fundamental principles on which strict radioactive waste management is based are the accountability of the waste producer, the traceability of the waste and public information. The technical management provisions to be implemented must be tailored to the hazard presented by the radioactive waste. This hazard can be assessed primarily through two parameters: the activity level, which contributes to the toxicity of the waste, and the half-life, the time after which the activity level is halved. Finally, management of radioactive waste must be determined prior to any creation of new activities or modification of existing activities in order to: ∙ ∙ ensure the availability of processing channels for the various categories of waste likely to be produced, from the front-end phase (production of waste and packaging) to the back-end phase (storage, transport and disposal); ∙ ∙ optimise the waste disposal routes. 2.2.5  –  Management of contaminated sites Management of sites contaminated by residual radioactivity resulting either from a past nuclear activity or an activity which generated deposits of natural radionuclides warrants specific radiation protection actions, in particular if rehabilitation is envisaged. Depending on the current and future uses of the site, decontamination objectives must be set. The removal of the waste produced during post-operation clean-out of the contaminated premises and remediation of soil must be managed from the site through to storage or disposal. The management of contaminated objects also follows these same principles. 96  ASN report on the state of nuclear safety and radiation protection in France in 2018 01 – NUCLEAR ACTIVITIES: IONISING RADIATION AND HEALTH AND ENVIRONMENTAL RISKS