Article 20 of the above-mentioned order of 31 December 1999 states:

"The operator drafts a study on the management of its waste, known as the "waste study", indicating its objectives concerning reduction of the volume and the chemical, biological and radiological toxicity of the waste produced in its installations, and optimisation of its management with emphasis on reuse and treatment for final disposal in an ultimate waste repository. It defines the steps it employs in order to achieve these objectives."

Articles 20 to 27 of the order of 31 December 1999 give the regulatory procedures linked to the waste studies and waste management.

These articles were the subject of two instruction notes from the ASN: SD3-D-01 (Guide for the production of nuclear waste studies) and SD3-D-02 (Specifications for the annual nuclear installation waste balances), available on the ASN's website, which were designed to constitute specifications to which the nuclear operators would refer when drafting their waste studies and their annual waste balances.

The waste studies for the nuclear sites are one aspect of the drive for progress designed to promote improved management of the waste produced on the sites. In particular, the operator of a nuclear site must control its waste inventory, minimise waste production, recycle and reuse the waste produced, insofar as this is technically and economically possible, and package the residual waste in the form of ultimate waste for disposal. These studies must lead to definition of a waste reference framework which can act as a reference for the statutory inspection.

The problem of waste management is described in greater detail in Chapter 16.

Detecting and processing significant events play a key role in nuclear safety. As soon as an event occurs, the necessary countermeasures must be put in place along with appropriate experience feedback to prevent it from happening again. This first of all implies the existence of a reliable system for detecting events and distributing the relevant information. For some years now, the number of fields in which events must be declared has risen, particularly in the environmental field in accordance with the discharge orders or the order of 31 December 1999.

During the course of 2005, the ASN produced a guide for declaring significant events affecting all fields of activity in the nuclear industry (BNIs, Transports) (see point 1.2.1 of chapter 4). This will come into use on 1 January 2006. In this document, significant environmental events are dealt with in the same way as those affecting installation safety, transport of nuclear materials or radiation protection. Nine declaration criteria were identified: releases of unauthorised chemical, radioactive or bacteriological substances inducing an impact, non-compliance with a technical or organisational requirement which could have had an impact, malicious or attempted malicious act, discovery of a polluted site, non-compliance with the waste study, etc.

This harmonisation of criteria should in particular help achieve uniform declaration conditions and ensure that all the available lessons are learned.

In 2005, 52 environmental events were declared by the operators, as shown in the breakdown given in the previous graphs.