DS500 - Application of the Concept of Clearance

Status: GSG-18

Veröffentlichung  2023

Revision von RS-G-1.7

Beteiligte IAEO-Komitees: WASSC, RASSC, TRANSSC

Specific Safety Guide

Document Preparation Profile "DPP"

Weitere Informationen: s. WASSC Members Area

Zurück zu „IAEO Safety Standards Series“ (Übersicht aller derzeit gültigen Sicherheitsstandards)

Background Information

The objective of the Safety Guide is to provide detailed guidance on the application of the concept of clearance for materials and buildings that are to be released from regulatory control. The safety guide will cover similar subject matter to that in RS-G-1.7, but use the newer concepts and definitions, such as exposure situations given in GSR Part 3. The document will be of particular value for regulatory bodies in Member States to assist them the applying the GSR Part 3 requirements on the clearance of materials and objects from regulatory control.

The scope of this new Safety Guide is to describe the process of clearance from regulatory control. It will include the following aspects:

• Clarification on the use of terminology, especially the use of terms clearance and release
• Responsibilities of the licensee and the regulatory body
• All relevant steps of the clearance process including characterization, determination of the nuclide vector, measurement techniques, sampling, management of the clearance process
• Mass specific and surface specific clearance criteria for unconditional clearance
• Examples of derivation of mass specific and surface specific clearance criteria for conditional clearance (actual values would depend on specific conditions applied, so no universal set of values could be proposed)
• Case by case approach which can be used for small quantities of material, or for other situations where the assumptions for the generic derivation of clearance levels do not apply (e.g. where the water pathway is not relevant), or for radionuclides for which clearance values have not been given in GSR Part 3, or e.g. for cases where it is proposed that the rounding procedure or other features from the model in Safety Report 44 are not applied or are modified
• Clearance in an area affected by consequences of a nuclear or radiological accident
• Considerations of clearance of liquids
• Consideration of clearance of gases
• Additional requirements for building materials containing naturally occurring radionuclides
• Considerations of averaging masses and averaging areas
• Discussion of the degree of homogeneity that was assumed in the calculation of the clearance levels and the implications for application of the clearance levels to non-homogenous material
• Involvement of interested parties

The new Safety Guide will address the transport of conditionally cleared material (material released with restrictions on its future use).

The guidance will be especially applicable during decommissioning to assist in the minimization of waste that will require disposal as radioactive waste. However, the guidance will also be applicable for releasing material for unconditional reuse or for non-radiological disposal during the normal operation of a facility, and may be applicable to other situations.

The information presented in this new Safety Guide is applicable to facilities that use, manufacture, process or store radioactive material.

The types of facilities that may be included under this category are nuclear power plants, research reactors, other nuclear fuel cycle facilities, industrial plants, medical facilities, research facilities and accelerators.

It also applies to industries processing naturally occurring radioactive material (NORM).

The aspects of exemption are outside the scope of this Safety Guide, as they will be addressed in the Safety Guide DS499.

The issue of exclusion will be addressed in the introductory sections of the proposed new safety guide using text that will be duplicated in the new safety guide on exemption.

The aspects related to the control of contaminated non-food commodities that can be traded freely are outside the scope of this Safety Guide, and will be addressed in a separate publication.

The aspects related to release of sites from regulatory control are outside the scope of this Safety Guide, as they are addressed in the Safety Guide WS-G-5.1.