The IAEA Safety Requirements for Disposal of Radioactive Waste
Phil Metcalf
Head Radioactive Waste and Spent Fuel Management Unit
Department of Nuclear safety and Security
IAEA
Abstract

Considerable progress has been made in the development of safety standards for the disposal ofradioactive waste in recent years. In 2008 work was completed on the development of a revisedclassification scheme for radioactive waste, which is both comprehensive; including all types ofradioactive waste, and provides a clear linkage between different waste types and disposal options.
This development assisted greatly with the agreement on a suite of safety standards for disposal
headed by a new safety requirements standard for all classes of radioactive waste and complemented
by a number of safety guides which provide recommendations and guidance to meet the requirements
for the different waste disposal options. The Safety Requirements standard for disposal uses the newformat for standards, with a discrete set of clearly defined, precise requirements.
The supporting safety guide documents are being developed to illustrate how the various safetyfunctions are to be provided by the different disposal options together with the extent and depth ofprovision of the different safety functions needed by the different disposal types to meet the safety
requirements. Supporting these guidance document are a number of Safety Guide documents thataddress the demonstration and assurance of safety for disposal. These are made up of a guide on thesafety case and supporting assessment, management systems and surveillance and monitoring.
In the past year the Safety Requirements document has been approved by the Waste Safety Standards
Committee (WASSC) and the Safety Standards Commission (CSS) and significant progress has been
made on the supporting guide documents; with the guidance on geological disposal also having been
approved by WASSC. The outstanding guides are those on near surface disposal, mining waste
disposal, the safety case and monitoring and surveillance.
The new Safety Requirements combined former standards on near surface and geological disposal
making use of the latter quite recent standard as a model for the structure of the document. Thisdevelopment has required the similarities and differences between near surface and deeper disposal tobe highlighted and caused considerable international debate on a number of issues in particular thestatus of a near surface facility in the longer term, that is beyond the envisaged period of operation, a
few decades and beyond the envisaged period of institutional control, a few centuries.
International consensus was reached on this rather complex issue and it is believed the document will
be of considerable assistance in the future licensing decisions on both the operation and closure ofsuch facilities. For all disposal types the emphasis given to the “safety case“ concept has also evolved
and again international consensus is emerging on this matter, which should again assist the licensing
process commencing in a number of countries in respect of geological disposal.

Page 2The new Safety Requirement sets down the safety objective; to site, design, construct, operate andclose a disposal facility so that protection after its closure is optimized, social and economic factors
being taken into account. A reasonable assurance also has to be provided that doses and risks tomembers of the public in the long term will not exceed the dose constraints or risk constraints thatwere used as design criteria. It provides safety criteria for the post closure period for the normal
evolution of the facility and for possible disruptive events, both naturally induced and those caused byhumans.
The actual requirements are presented in three sections covering; planning for disposal facilities, thedevelopment operation and closure of facilities, assurance of safety and existing facilities. The section
on planning addresses the governmental, legal and regulatory framework, the safety approach to beadopted i.e. the importance of safety in decisions on facility development, the need for passive safety
features and the need to understand the phenomena affecting safety, and the design concepts to beadopted i.e. multiple safety functions, containment, isolation and assurance of the passive safetyfunctions.
The requirements for development , operation and closure of facilities covers the need for step by stepdevelopment of facilities, the safety case and all the steps in the development of the facility e.g. sitecharacterization, design, operation etc. The section on assurance of safety covers waste acceptancecriteria, institutional control, safeguards, security and management systems. The final section deals
with existing facilities developed prior to current standards being in place.
The presentation will provide a background to the disposal standards, discuss the safety criteria forpost closure and then discuss the various requirements related to each of these sections. The newer
aspects introduced into the document will be highlighted, in particular those related to the post closure
phase of near surface disposal facilities and the issues of human intrusion and institutional control.
There are three discrete requirements dealing with the safety case and supporting assessment and thesewill also be discussed. The safety guide on the safety case and supporting assessment currently underdevelopment will be summarized and discussed.