2022

Ilvonen, Mikko

Small modular reactors (SMRs) have been a ‘hot topic’ of discussion in recent years, as they offer some potential advantages, like improved safety features and reduced capital costs per unit. A central questions in SMR deployment is the emergency planning zone (EPZ), whose size determines, to a large extent, where such plants can be located. This is important particularly for heat applications, as heat should not be transferred over long distances.<br/>This work considers licensing issues of SMR plants through current international (IAEA, national regulators) developments in appropriate EPR (emergency preparedness and response) for SMRs. It is also proposed to study the problem numerically by a possibly definitive, but laborious &amp; ‘brute-force’ approach by full-scope PSA to produce the basis (level 3: offsite consequences, like dose vs. distance) for choosing justified sizes of EPZ zones.<br/>This review report contains a general literature survey on the SMR EPZ problem, but is also based on the author’s work (2016- 2018) in the GENXFIN project (in SAFIR2018) and in the IAEA CRP (coordinated research project) I31029 ‘Determining the technical basis for EPZ for SMR deployment’ (2018-2021). Some information / insight also comes from participation in various IAEA Technical Meetings (TM), particularly the Feb 2017 TM on NGR EPZs, and the Sep 2020 TM on NGR and EPR (NGR = next generation reactor). Other relevant meetings were the Apr 2019 TM on Advances in EPR arrangements, and the Dec 2019 Regional workshop on EPR for SMRs.<br/>In Finland, a MEAE-set working group gave their final report 27 Aug 2020 on the coming reform of nuclear regulation. Earlier in 2020 STUK gave out an overview report on Preconditions for the safe use of SMRs. For assessing the possibility of SMRs in Finland, the licensing process, licensing requirements and related safety issues should be studied in more detail. In the author’s (of this work) view this includes particularly passive safety systems and further evaluation of possible offsite consequences, down to doses and health effects.