Development of Approaches, Methodologies and Criteria for Determining the Technical Basis for Emergency Planning Zone for Small Modular Reactor Deployment

Closed for Proposals

Project Type

Coordinated Research Project

Project Code

I31029

CRP

2222

Approved Date

19/05/2017

Project Status

Closed

Start Date

09/02/2018

Expected End Date

08/08/2021

Completed Date

26/11/2025

Participating Countries

Argentina, Canada, China, Finland, United Kingdom of Great Britain and Northern Ireland, Indonesia, Israel, Japan, Republic of Korea, Kingdom of the Netherlands, Pakistan, Saudi Arabia, Tunisia, United States of America

Description

Small Modular Reactors (SMRs), with electrical power up to 300 MW per module, have?specific design, safety and siting features as well as applications?that should be properly assessed to formulate and plan for adequate Emergency Preparedness and Response (EPR) arrangements, in particular the size of Emergency Planning Zones (EPZs). EPR is one of the elements in the development of a national infrastructure for nuclear power, while EPZ is one of?the specific regulatory aspects to enable SMR deployment in diverse siting niches. The CRP has the key objective to develop approaches and methodologies which enable relating design and safety features of SMRs with the extent of offsite arrangements needed, focusing on the size of EPZ, by comparing design- and site-specific technical basis to be provided by SMR developers, nuclear regulators, emergency planners and users/utilities;?Notes: An EPZ consists of?the precautionary action zone (PAZ) and the urgent protective actions planning zone (UPZ) where arrangements have been made to take precautionary and urgent protective actions in the event of a nuclear or radiological emergency to avoid or minimize severe deterministic effects off the site and to avert doses off the site in accordance with international safety standards.

Objectives

The??main goal of the CRP is to develop approaches, methodologies and?criteria for determining the technical basis for EPR arrangements, focusing on the size of EPZ for SMR deployments based on international safety standards.

Specific Objectives

Formulate criteria on the events and technical aspects to be considered for defining EPR arrangements for SMR, focusing on EPZ sizing. This should be based on the results of the research and the implementation of defence-in-depth in the design of SMRs, including small power, smaller source term, increased safety margin, enhanced engineered safety system, smaller and slower fission product release, and consequent reduced potential for radiation exposure to population in the vicinity of the plant;

Develop approaches and methodologies which enable relating safety features of SMRs with the extent of offsite arrangements needed, particularly the size of EPZ, by comparing design- and site-specific technical basis to be provided by SMR developers, nuclear regulators, emergency planners and users/utilities;

Provide suitable technical basis, as an input into the development of IAEA additional technical guidance (EPR series report) on EPR arrangements for SMRs. Also additional input into new guidance regarding source term definition and assessment could be derived on that basis, as appropriate.

Impact

The completion of the CRP and upcoming publication are expected to give positive impact to the development and deployment of SMRs. Regardless of the methodology used, all EPZ sizes estimated by institutes in the CRP are below the 15–30 km size currently suggested in the IAEA guidance for establishing a UPZ for an LWR with a nominal thermal power higher than or equal to 100 MW(th) [11]. Most EPZ sizes estimated as part of the CRP are smaller than 15 km. The smallest estimates were a few hundred metres around the reactor, which was within what the participants reported as the site boundary. Participants concluded that an EPZ was, therefore, not necessary in such cases. However, these conclusions were not obviously based on a complete hazard assessment and prior determination of an EPC. As per IAEA definitions, EPZs (including PAZs and UPZs) are inherently defined outside the site boundary, and determination of an EPZ distance presumes EPC I or EPC II.

Relevance

The CRP is strongly relevant to global activities and projects on SMR development and deployment in Member States.