Scroll Top
19th Ave New York, NY 95822, USA
+1 916-85-2235
Join Now
SASPAM-SA
Safety Analysis of SMR with PAssive Mitigation strategies – Severe Accident

How it started

  • Small Modular Reactors (SMR) are one of the key options for the near-term deployment of new nuclear reactors. Currently in Europe there is a growing interest towards the deployment of SMRs, and several activities are underway in many countries preparing for possible licensing needs. 
  • In particular, Integral Pressurized Water Reactor (iPWR) are ready to be licensed as new builds because they start from the well-proven and established large Light Water Reactor (LWR) technology, incorporate their operational plant experience/feedback, and include moderate evolutionary design modifications to increase the inherent safety of the plant. However, despite the reinforcement of the first three levels of the Defence-in-Depth (DiD), e.g., with the adoption of passive safety systems, a sound demonstration of iPWR ability to address Severe Accidents (SA) should be carried out (DiD levels 4-5). 
  • By looking at the current initiatives that are already finished or are on-going in different fora, it appears clear that the iPWRs SA investigation is very limited and iPWRs safety assessment, with best estimate methods, is still not addressed. 
  • Therefore, the systematic analyses of the applicability and transfer of the current available SA experimental database (developed for current large-LWR) for iPWR safety assessment studies, and the analyses of current codes capabilities to simulate SA phenomena in iPWR are novel topics of current high interests for TSOs, regulators, research centres, universities, industries and operators. 
  • Considering these research needs and the synergies with past and ongoing activities in different fora (e.g., SNETP, H2020, IAEA, OECD/NEA, etc.), the Safety Analyses of SMR with Passive Mitigation strategies – Severe Accident (SASPAM-SA) project proposal has been submitted and has been founded in HORIZON-EURATOM-2021-NRT-01-01, “Safety of operating nuclear power plants and research reactors”. In particular:
    • SASPAM-SA ideas born in the framework of the NUGENIA TA2;
    • The first project ideas has been presented at the TA2 General Meeting of the 31/03/2021:
      • The target of this first proposal was to address the main SMR research needs related to DBA, BDBA, SA and EPZ, reliability aspects;
      • The proposal was named Safety Analyses of SMR with Passive Mitigation strategy (SASPAM);
    • During and after the TA2 meeting a great interest for the proposal has been immediately manifested together with the request of a major focus on the SA research needs;
    • SASPAM proposal has been revised and the SASPAM-SA (SASPAM- Severe Accident) proposal has been prepared;
    • 15/06/2021: FIRST SASPAM-SA video meeting with the envisaged Consortium;
    • 27/08/2021:  SASPAM-SA obtained the NUGENIA label that recognizes the excellence of the project proposal;
    • ctober 2021: SASPAM-SA project proposal has been submitted to the HORIZON-EURATOM-2021-NRT-01-01, “Safety of operating nuclear power plants and research reactors”;
    • February 2022: SASPAM-SA proposal has reached the stage of Grant Agreement preparation;
    • October 2022: SASPAM-SA started.

In a nutshelL

 There is growing interest in Europe in the deployment of small modular reactors (SMRs). One type of SMR is the integral pressurised water reactor (iPWR), which is ready to be licensed as a new build. Despite the reinforcement of the first three levels of the Defence-in-Depth (DiD), a sound demonstration of iPWR ability to address Severe Accidents (SA) should be carried out (DiD levels 4-5).

 

In this context, the EU-funded SASPAM-SA project aims to investigate the applicability and transfer of the operating large light-water reactor knowledge and know-how to the iPWR, taking into account European licensing analysis needs for the SA and Emergency Planning Zone.  Project outcomes will help speeding up the licensing and siting process of iPWRs in Europe.

Key Objective of SASPAM-SA:
investigate the applicability and transfer of the operating large-LWR reactor knowledge and know-how to the near-term deployment of integral PWR (iPWR), in the view of Severe Accident (SA) and Emergency Planning Zone (EPZ) European licensing analyses needs. 
Key Outcome of SASPAM-SA :

  • To be supportive for the iPWR licensing process by bringing up key elements of the safety demonstration needed.
  • To speed up the licensing and siting process of iPWRs in Europe.

Dedicated actions on Accident Tolerant Fuels (ATF)  and In-Vessel Melt Retention (IVMR).

Key Highlights of SASPAM-SA: 

  • The applicability of large LWR reactor knowledge & know-how to the near-term deployment iPWR, in view of SA and EPZ analyses, will be assessed and consolidated. 
  • The research priorities will be identified in terms of methodology, code development and experimental needs; 
  • The knowledge gained can support Regulators in decision-making as well as Industry and TSOs in assessing the applicability of iPWR safety features. 

Safety Analyses of SMR with Passive Mitigation strategies – Severe Accident (SASPAM-SA) project proposal has been submitted and funded in HORIZON-EURATOM-2021-NRT-01-01, “Safety of operating nuclear power plants and research reactors”. The project is coordinated by ENEA. Twenty-three Organizations from thirdteen Countries are involved: ENEA, CIEMAT, CNRS, EDF, FZJ, GRS, INRNE, IRSN, KIT, KTH, LEI, POLIMI, RATEN, RUB, SINTEC, SSTC-NRS, SURO, TRACTEBEL, TUS, UNIROMA1, VTT, PSI, JRC.

BUDGET:​   Overall Budget: € 4 276 038.85 ​,   EU Contribution: € 2 991 694.00            Technical project leader: Fulvio Mascari (ENEA)​: fulvio.mascari@enea.it

SPECIFIC NEEDS

  • Identification of plausible SA scenarios for iPWR and address potential impact on the environment;
  • Investigation of the applicability and transfer of the operating large-LWR reactor SA knowledge & know-how (codes, experiments, methodologies, etc.) to the near-term deployment iPWR;
  • Identification of SA experimental and code development needs;
  • Test the current best estimate safety analyses methodologies for iPWR SA analyses;
  • Start to address challenges of SA mitigation measures in iPWR including EPZ assessment.

 

GENERIC DESIGNS CONSIDERED

  • To maximize the knowledge transferability and impacts of the project:
    • Two generic design-concepts will be considered;
    • Characterized by different evolutionary innovations in comparison with larger operating reactor.
  • Despite generic, they resemble currently discussed designs and take benefit from available data in the open literature:
    • Design 1: iPWR characterized by a submerged containment and electric power of about 60 MWe;
    • Design 2: iPWR characterized by the use of several passive systems, a dry containment and an electric power of about 300 MWe.
  • The two generic reactor concepts:
    • Include the main iPWR design features, considered in the most promising designs ready to go on the European market;
    • Allow to assess in a wider way the capability of codes (SA and CFD) to simulate the SA phenomena typical of iPWR.
  • This will allow to characterize:
    • Feasibility and efficiency of the different SA mitigation features of the non-European designs, ready to be installed in Europe in the very near term;
    • Feasibility and efficiency of the different SA mitigation features of new European iPWR concepts, already in advanced design status, when the final designs become available.
  • It is not the project’s objective to assess the generic reactor designs selected but, based on the project findings, allow a more general statement on the code’s applicability to currently favored designs under postulated SA condition. 
  • No PSA considerations will be done in the project due to the generic nature of the reactor concept considered, then the scenarios identified will be characterized in terms of severity but not in terms of probability.
iPWR characterized by a submerged containment and electric power of about 60 Mwe
IPWR characterized by the use of several passive systems, a dry containment and an electric power of about 300 MWe

SPECIFIC OBJECTIVES

  • Identification of plausible SA scenarios for iPWR designs; 
  • Identification of the conditions in the vessel and in the containment that characterize iPWR SA scenarios and differ significantly from those in large-LWRs; 
  • Study the applicability of the existing experimental database to iPWR and identify new experimental needs;
  • Assess the capability of internationally recognized European and Non-European computational tools (largely used in Europe) to describe the behaviour of the most promising iPWR designs during SA scenarios and to predict the resulting radiological impact on- and off-site.

SPECIFIC MAJOR IMPACTS

  • Identification of plausible SA scenarios for iPWR to be used for further analyses:
    • In the envisaged European licensing processes (e.g. from TSO, Regulators) or 
    • For the design of the European iPWRs (e.g. from industries).
  • Assessment of the available experimental database to iPWR and identification of exp. needs;
  • Build expertise of code users for SA in iPWR and training of new code users (e.g. youngest generations);
  • Applicability of the built knowledge on ATF for iPWR and large-LWR;
  • Applicability of assessed code guidelines and best practices for the simulation of iPWR;
  • Applicability of the assessed state-of-art methodologies to carry out iPWR SA det. safety analysis;
  • Build the know-how for the demonstration of the ultimate confinement function of the iPWR containment in SA conditions along an independent safety review process;
  • Development of SAMG to prevent accidents or mitigate their consequences avoiding rad. releases; 
  • Applicability of tools and methods for EPZ iPWR analysis. 

SPECIFIC OUTCOMES

  • Assessment and development of generic but representative iPWR SA codes input-decks:
    • Analyses of the iPWR behaviour under hypothetical postulated BDBA conditions; 
    • Plausible SA scenarios in iPWR will be identified.
  • Development of know-how in relation to the use of ATF in iPWR:
    • Enhances ATF application in iPWR;
    • Develop code capability to simulate it.
  • Study the applicability of the existing experimental database to iPWR and identify new exp. needs.
  • Study IVMR strategy in postulated SA scenarios in iPWR:
    • Assess the capability of the codes to simulate the main phenomena characterizing the IVMR in iPWR; 
    • Characterize IVMR feasibility in iPWR.
  • Study containment behaviour in postulated SA scenarios in iPWR:
    • Assess the capability of the codes to simulate the main phenomena characterizing the containment behaviour;
    • Characterize the efficiency of existing and innovative passive measures.

Provide evaluations of size and extension of EPZ for postulated SA scenarios coupling the results of best estimate ST codes to radiological consequences tools.

COMPUTATIONAL TOOLS USED

  • In SASPAM-SA several state-of-art computational tools will be adopted, both European and
    non-European largely used in Europe.
  • For integral SA codes:ASTEC (European code developed by IRSN),AC2 (European code developed by GRS),MAAP-EDF (non-European code developed by EPRI embedding EDF code changes),MAAP (non-European code developed by EPRI)MELCOR (non-European code developed by Sandia National Laboratories for the USNRC).
  • For CFD codes:ContainmentFOAM (European code developed by FZJ)ANSYS CFX (non-European code developed by Ansys Inc.).
  • For atmospheric dispersion codes:ARANO (European code developed by VTT),JRODOS (European code developed by KIT),MACCS (non-European code developed by Sandia National Laboratories for the USNRC).
  • For iodine chemistry:IMPAIR (European code, developed as a European collaboration)

Work packages

To address the ambitions of the project, it will be structured in 5 technical Work packages (WPs) (from WP2 to WP6), plus one for the coordination (WP1) and one for the dissemination (WP7).

WP1

This WP deals with the general coordination of the consortium, i.e. the management of legal, financial and administrative aspects, to guarantee the coherence between the different WPs in order to respect the project’s objectives, the time schedule, to issue timely the deliverables with related quality control and periodic reporting to the European Commission (EC)

WP2

The objective of the WP2 is the development of generic but representative iPWR SA code input-decks and the analysis of the iPWR behavior under hypothetical postulated SA-conditions. Two generic designs concepts, characterized by different evolutionary innovations, will be considered. In order to fulfil the goals, the following tasks will be addressed:

  • Development of plant models using different SA codes for iPWR Designs 1 and 2, including the estimation of the nuclide inventory for plausible radiological ST prediction;
  • Identification of plausible SA sequences for the iPWR Designs 1 and 2;
  • Simulation of selected SA-sequences for iPWR Designs 1 and 2 using different SA-codes, covering the in-vessel, the ex-vessel (if any), and the containment phenomena.
  • The capability of the codes to model ATFs will be investigated with the support of code developers. The effect of the employment of the ATFs on the progress of the analyzed SA scenarios (RPV failure, hydrogen production, ST, etc.) in the iPWR designs will be investigated. The data available from the QUENCH ATF-related experiments performed at KIT will be employed for the assessment of the results of the integral SA analysis codes.
WP3

The main objectives of the WP are to study the relevance and applicability of the existing experimental database to iPWR, to develop methods to extend the applicability of existing data, and to identify the need for new experiments.

Based on the plant SA scenario identified and investigated in the WP2, the main boundary conditions of iPWR and the specific features will be determined. This allows to identify the conditions in the RPV and in the containment during SA that characterize iPWR SA scenarios and that might differ considerably from large-LWRs. The relevant phenomena will be identified and the review of the current experimental database will be done considering the following phenomena:

a) In-vessel degradation and coolability;

b) Containment;

c) ST;

d) Ex-vessel coolability (If any ex-vessel phenomenology will be identified along the WP2).

WP4

Based on the Designs 1 and 2 input-decks and SA scenarios developed in WP2, the objective of this WP is to investigate IVMR strategy in a postulated SA scenario in iPWR, assess the capability to simulate the main phenomena characterizing the IVMR in iPWR, and characterize its feasibility by guided calculations. The main sources of uncertainty will be investigated together with a limited study of the effect of different claddings (e.g. ATF). The WP4 objectives will be addressed by:

  • Analysing the processes leading to the formation of a molten pool in the lower plenum and the possible oxide/metal stratification (impact of cladding material will be analysed at this stage);
  • Identifying/Implementing modifications to the models used for operating PWR in SA codes;
  • Evaluating the safety margin for a few iPWR designs and the degree of confidence. BEPU analysis for characterizing the different sources of uncertainty.
WP5

The objective of this WP is to study the containment behaviour during a SA in an iPWR. The work will be based on the Design 1 and 2 input-decks and SA scenarios prepared in WP2. Similarly to WP4, guided calculations will be carried out with the European reference codes ASTEC and AC² and the US codes MELCOR and the EDF-MAAP version. Complementary analyses will be done by CFD codes (CFX, containmentFOAM) for specific thermal-hydraulic phenomena. The work aims towards the assessment of the codes to simulate the main phenomena characterizing the containments behaviour (thermal hydraulics and fission product and aerosol behaviour) and characterize the efficiency of existing and innovative passive measures in terms of accident mitigation and ST. The ST estimation will be provided to WP6.

WP6

The objective of this WP is to provide evaluations of size and extension of EPZ for selected SA scenarios coupling the results of best estimate ST codes to radiological consequences tools. One of the most important features of iPWRs is the possibility of their siting near densely populated areas thanks to the low impact and possibly reduced size of the affected region and the increased inherent safety. The need to demonstrate this feature using quantitative results is addressed by this WP which will provide scientifically sound basis for the assessment of EPZ. WP6 will produce recommendations on rigorous and justified methodology for iPWR EPZ right-sized determination.

WP7

Informing society and technical community about the project and its results, going beyond the project’s own group, is one of the key element of SASPAM-SA project. In order to demonstrate and maximize the societal and technical impact of the project and show its benefit a detail communication dissemination and exploitation action plan will be developed.

The communication and dissemination of project and results will be oriented towards the widest audience, so the results will be made accessible to the general public and technical community in the respect of the intellectual property. In this sense the main stakeholders that can benefit of the project results will be regulators, industries, research institutions, universities, and policy makers.

PAST Events

  • Kick-off meeting of the SASPAM-SA project 12-13th October 2022, Centro Congressi 7Gold – Easy Academy Via Dell’Arcoveggio n. 49/5 – 40129 Bologna
  • WP2 Kick-off meeting, 12 December 2022 – video meeting-
  • WP3 Kick-off meeting, 13 March 2023 – video meeting-
  • Our Coordinator, Fulvio Mascari (ENEA), invited to participate at the  Coordinators’ hub Day, 14 March 2023 contributing to a  panel discussion with others Coordinators giving a feedback from Euratom R&I projects based on SASPAM-SA experience.
  • WP6  Kick-off meeting, 30 March 2023 – video meeting-
  • WP4  Kick-off meeting, 26 of May 2023 – video meeting-
  • TANDEM/SASPAM presentation at the SNETP Forum 2023 Gotherburg, Sweden, May 16, 2023
  • Presentation of SASPAM-SA at: New Trends of Nuclear Reactors: Small Modular Reactors. Experience of Leading Countries and Developers”, 15 June, Vilnius, Lithuania.
  • Presentation of SASPAM-SA at: IPRESCA meeting, 5-6 July 2023, Frankfurt, Germany
  • Presentation of SASPAM-SA at: R2CA SUMMER SCHOOL, 4-6 July, Bologna, Italy
  • Presentation of SASPAM-SA at the panel session “Beyond Design Basis Accidents in Advanced Reactors: Opportunity and Challenges”, 20th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-20), August 20–25, 2023, Washington, USA
  • Presentation of SASPAM-SA at: WGAMA,  September 11-13, 2023, Paris, France
  • SASPAM-SA SECOND ANNUAL MEETING,  October 10-12, 2023, Bologna, Italy
  • WP5  Kick-off meeting, 12 October 2023 in-person meeting along Second SASPAM-SA annual meeting
  • FIRST PASTELS/SASPAM-SA MEETING, 15 November, 2023 (video meeting)
  • Presentation of SASPAM-SA at Enlit Europe | 28-30 November 2023 | Paris, France Enlit Europe
  • Presentation of SASPAM-SA at 5TH meeting of IAEA CRP I31033 “ADVANCING THE STATE-OF- PRACTICE IN UNCERTAINTY AND SENSITIVITY METHODOLOGIES FOR SEVERE ACCIDENT ANALYSIS IN WATER COOLED REACTORS”.
  • U.S.NRC topics of interest for experimental research for Water Cooled reactors, Euratom Research funded projects focusing on LW-SMRs safety. 20th December 2023 (video meeting)

NEWS AND EVENTS

First SASPAM-SA Open Workshop

SASPAM-SA is pleased to invite you at the First SASPAM-SA Open Workshop scheduled to take place the 17-18 October 2024.   MARK YOUR CALENDAR!

SASPAM-SA open workshop aims to create a platform to discuss about the safety of SMR in the view of a sustainable short-term deployment.

Key highlights of the workshop:
o  Provide an overview of the progress made in the framework of SASPAM-SA;
o  Bring together EU-projects dealing with the safety of Light Water SMR;
o  Bring together the main activities related to the safety of the SMR at international level;
o  Discuss safety issues inherent to SMRs, including coupling with industrial facilities, and how to address them;
o  Identify potential remaining safety issues to be investigated;
o  Foster coordination among International Organizations.

Venue: IRSN Headquarter, 31 av. De la Division Leclerc, Fontenay – aux – Roses, France.

Important date to remember:
Extended abstract to be submitted by the 31 of May, 2024.

More details will follow.

PARTNERS

BELGIUM: EC-JRC, TRACTEBEL-ENGIE
BULGARIA: INRNE, TUS
CZECH REPUBLIC: SURO
FINLAND: VTT
FRANCE: CNRS, EDF, IRSN
GERMANY: KIT, FZJ, GRS, RUB
ITALY: ENEA, UNIROMA1, POLIMI, SINTEC
LITHUANIA: LEI
ROMANIA: RATEN
SWEDEN: KTH
SWIZERLAND: PSI
SPAIN: CIEMAT
UKRAINE: SSTC-NRS

 

23 PARTNERS FROM 13 EUROPEAN COUNTRIES,
COMPOSED OF: UNIVERSITIES, RESEARCH INSTITUTES,
TSO, INDUSTRIAL AND ENGINEERING ORGANIZATIONS

SASPAM-SA HORIZON EURATOM PROJECT

TO HAVE MORE INFORMATION

EU – SEDIA                     SNETP                     ETSON News                     ZENODO

 

 

Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or European Commission-Euratom.

Neither the European Union nor the granting authority can be held responsible for them.