ASNR adapts to innovative SMRs

The SMR projects led by new players not only involve a wide variety of reactor technologies, but also introduce new uses for nuclear energy, such as industrial heat production.

Safety objectives

Whereas siting of a new power generating reactor is one of the aspects of the project which can to a certain extent be a choice, this is not the case for numerous SMR projects.
 
Indeed, in the case of a SMR dedicated to industrial heat production, the site is determined by the location of the customer to whom it will be delivering the energy. Numerous SMR projects are thus aiming for deployment on industrial sites located near to or even within urban areas.
 
This type of siting near to densely populated or industrial areas is being envisaged by the project developers because these reactors are likely to be able to achieve safety levels significantly better than those of today’s large power generating reactors. The low power to be removed in the event of an accident should make it possible to combine passive and active safety systems, leading to increased diversification of the safety provisions, longer grace periods [1] and better protection of the containment barriers. In addition, some of the new technologies proposed have specific characteristics (such as the intrinsic containment performance of the particular fuels of high-temperature reactors), which also make it possible to envisage a significant reduction in radioactive releases in the event of an accident, even the most severe.
 
Even if these reactors can in principle achieve a higher safety level than those of the high-power electricity generating reactors, ASNR considers that the safety objectives to be attained must be defined before envisaging such siting close to population centres.
 
ASNR thus set up a pluralistic working group to consider the reinforced safety objectives to be defined before envisaging such siting choices.

ASNR's view of the strengthened safety objectives
ASNR's view of the strengthened safety objectives

[1]. Time during which safety can be guaranteed with no intervention being required (for example the time for which – in the event of total loss of electrical power – safety can be guaranteed passively, pending the restoration of a back-up power source).

Dialogue and assessment procedures

In order to optimise preparations for any creation authorisation applications for these various innovative reactor projects, and in order to mobilise resources proportionate to the level of development maturity of each project, a four-phase framework of incremental technical exchanges was set up.

The four phases of technical exchanges
The four phases of technical exchanges

Phase 1: Screening phase

During a meeting, the project developer is asked to present the following to ASNR :

  • the main characteristics of its reactor project (technology, power, form of energy output, upstream and downstream of the fuel cycle, … ),
  • the state of progress of the reactor design and its safety demonstration,
  • the project development schedule,
  • the current technical and financial capacity of the company developing the project, along with its growth plan (calls for funds and staffing).

At the end of this prospective contact, the ASNR assesses the maturity of the project as a whole with regard to the following 3 elements:

  1. Minimum maturity of the technical project:
    the project developer has an initial complete conceptual design and stabilized of its project;
  2. Project developer’s capacity to conduct technical exchanges: the project developer has a sufficient in-house technical team  to be able to carry out technical exchanges with ASNR on all the technical issues involved in demonstrating reactor safety;
  3. Minimum financial security of the project developer: the company behind the project has sufficient financial guarantees to ensure its medium-term development.

If the overall maturity of the project does not appear sufficient to initiate a preparatory review, the project owner is invited to continue its development before contacting the ASNR again. 

Phase 2: Project preparatory review

Once the project maturity is considered to be sufficient with respect to the three above-mentioned criteria, a cycle of thematic technical meetings is scheduled.

The aim of this cycle of meetings is to enable the ASNR, through presentations and technical dialogue, to gain an overall view of the project, to understand its design choices, to take stock of the state of knowledge available or to be acquired, and to understand the main safety orientations on which the project leader intends to base his safety demonstration and justification.

A summary seminar may be organized to close this cycle of meetings.

This phase is merely an exchange of information in preparation for future instructions. No opinion or decision is expressed on the project at this stage by the ASNR. 

Phase 3: Pre-licensing of the fundamental safety options of the project

Pursuant to Article R. 593-14 of the Environment Code, before finalising the detailed design of its reactor, the project developer that intends to apply for a creation authorisation procedure can ask ASNR for its opinion on some or all of the fundamental aspects of its project.

With regard to these innovative reactor projects, ASNR recommends that the project developers take advantage of this pre-licensing step. This step enables initial technical assessments to be started and enables the positions of the regulator to be obtained on a jointly agreed list of identified high-stakes subjects highlighted during the preparatory review phase.

Phase 4: assessment of the Creation authorisation application

Finally, once the detailed design of the reactor project is ready, a submission of a creation authorisation application can be envisaged.

This phase represents a new step in the increasing commitment of resources by ASNR. Following the complete technical evaluation of the project, there will also be an evaluation of the characteristics of the planned site and a programme of inspections of the applicant, who acquires the de facto status of licensee, notably with the aim of checking its management system and its ability to manage subcontracting.

Standardisation and international cooperation

Despite the already high level of harmonisation both internationally, with the safety standards from the International Atomic Energy Agency (IAEA), and at the European level, with the safety objectives and reference levels adopted by the Western European Nuclear Regulators’ Association (WENRA), each project to build a reactor model in a new country generally leads to modification of the original design to adapt to the national regulatory context and the requirements of the local licensee.

Although the cost of these adaptations remains acceptable in the case of large nuclear power reactors, this is not necessarily the case for SMRs, for which the business model is based on mass production to reduce costs and achieve the profitability threshold, thus implying that a given model can be authorised by several countries.

In order to remove potential obstacles to the development of these new small reactors, ASNR is participating in several international initiatives (IAEA, NEA, WENRA, etc.).