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Key issues in nuclear reactor safety


Specific Objectives

- To generate a virtual network on Nuclear Reactor Safety Research projects for dissemination and remote training;

- To establish a common approach and understanding in Severe Accident phenomena and related Accident Management Measures;

- To contribute to the development of the next generation thermal-hydraulic safety code and to evaluate the safety problems connected with the potential detonation of hydrogen;

- To perform benchmark-exercises and studies for the harmonisation of safety methodologies and procedures, especially in the field of probabilistic and risk assessment methodologies;

- To compare the safety aspects of new advanced and innovative reactor concepts;

- To support the integration of the CCs and the NIS to a common safety level and safety culture.
Planned Deliverables

Specific deliverables to DGs:

- generally: the activities serve as an input to the harmonisation efforts of DG TREN in their standing committees (NRWG, ENIS-G) and help to enhance the safety level at European and international level;
- Support to the Council Resolutions C128-75 and C172/2-92 and in general to nuclear safety related questions
- Alert function for emerging safety problems especially connected with the enlargement;
- Implementation of the institutional research into the overall European effort;
- Wider dissemination of DG RTD projects through the virtual network.

As a result of the research:

- Virtual network in Nuclear Reactor Safety Research Projects for dissemination and training;

- extend the capability of STRESA (Reactor Safety Analysis DataBase) for remote calculation;

- include all major European thermal-hydraulic test programs

- extend the network to the CCs;

- promote the use of STRESA within OECD/CSNI;

- organise a work-shop on harmonisation of the different European data bases and data banks in this field;

- start benchmark-exercises via internet;

- Dissemination and "lessons learned" from Severe Accident International programs;

- assist in the management of the PHEBUS FP program and run the 3 interpretation networks on the PHEBUS dissemination (together with IPSN) with corresponding documentation;

- contribute to and participate in the OECD Phebus International Standard Problem (ISP-46);

- co-ordinate the European and international opinion on the PHEBUS 2K test program;

- prepare the FPT0 final interpretation report and the FPT1 intermediate interpretation report;

- journal papers on iodine chemistry in the primary circuit of a LWR;

- Advanced Computational Fluid Dynamics in Reactor Safety;

- complete the parallelisation of REACFLOW including automatic grid adaptation and edit a full operational version and related documentation;

- extend the Advanced Two-Phase Flow Modelling Code to full 3D capability and document the modelling and numerical methods;

- journal papers on the scientific/technical achievement;

- Harmonisation in safety assessment methodologies and procedures;

- launch a network on Probabilistic & Risk Assessment methodologies and a related internet based information system;

- write an intermediate report on the comparison of industrial and regulatory approaches on safety critical software within control & protection systems;

- develop harmonised approaches in risk-informed methodologies and their applications;

- participate in the relevant committees of OECD (CSNI, GAMA, WG RISK)
and of IAEA;

- Safety aspects of innovative reactor concepts

- contribute to the "Technical Documentation (TECDOC)" of the INPRO initiative of IAEA and participate in the committees of OECD and in Generation IV of DoE/USA;

- first report on comparison of the main safety features of innovative reactor concepts;

- update version of European Accident Code with Pb/Bi cooling and neutronic studies of reactivity accidents;

- Enlargement specific action (see also PECO project E-94 "Critical Safety Issues in NPPs of Eastern Design");

- increase the participation of CCs in the networks and institutional activities and the numbers of VS and GH

- map all relevant research organisations in CCs and their contribution to nuclear reactor safety.

Summary of 2001 Deliverables: 31/12/2001

Dissemination of experimental programs;
- Transfer of the KROTOS test facility and related knowledge to CEA/Cadarache;
- Thematic network CERTA on basis of the Web-based informatic platform STRESA (open access to all institutions of the EU) meetings;
- Documentation and validation of the COMETA code (melt-water interaction).

Source Term and integral aspects
- Phebus steering committee and Phebus working group and interpretation networks meetings (each 2x);
- Review and quality assurance of Phebus test reports (issued by IPSN);
- Definition of test objectives, preparation of data releases, contribution to test preparation;
- state-of-the-art report on iodine chemistry and related mitigation mechanisms in the containment (EUR);
- meeting reports, technical notes, publications in journals, presentations at conferences;
3-Dimensional Fluid Dynamics;
- Interim version of REACFLOW for parallel computing;
- State-of-the-art report on Nuclear Thermal-Hydraulics.

Harmonisation of safety methodologies and procedures
- Final documentation of the Benchmark Exercise on Expert Judgement techniques in PSA level 2;
- Start with benchmark-exercise on safety critical software within control & protection systems;
- Workshop (DG RTD) on Research for VVER Safety and on Dissemination and Exploitation of RTD results;
- Participation and contribution to the NRWG and ENIS-G of DG TREN (including technical support, advise and review of studies), to OECD/CSNI meetings and their working groups, to IAEA and ESREDA.

New innovative reactor concepts
- Participation in international conferences, in IAEA workshops (INPRO), in Generation IV of DoE/USA, in the HTR-TN network;
- Invited GLOBAL2001 paper on beam shut-off (ADS) and presentations in OECD conference;
- Specific safety evaluations on Reactor Vessel Air Cooling (ADS) and ADS-specific accidents.

- 2 VS; negotiations with EDF and IPSN to enable Phebus participation; 2 study contracts; bilateral meetings.

Output Indicators and Impact

- Technical publications and invited presentations, major network reports, journal & conference publications;

- Increased involvement of CCs, 2-3 VS, 2 GH, 2 study contracts, 2 work-shops;

- Implementation of major SCA output into STRESA (web) and increased participation of CCs organisations (3) in the virtual network CERTA;

- First combined network on data bases and data bank in nuclear reactor safety research;


- 1 Third Party Contract with CEA, 1 contract DG ENV/TREN (TSO study);

- 1 patent, 1 software registration;

- Transfer of JRC STRESA to OECD/NEA, to FZK, to ENEA, CERTA-partners, CEA-Cadarache & Grenoble

- Contribution to papers from OECD, IAEA.
Summary of the project

The project concentrates on key items of nuclear safety connected with a high risk potential and high consequences for the public and the ecosystem, having a strong orientation towards the enlargement related safety questions.

The different tasks within this project deal with:
1) Dissemination of the results of the experimental programs (FARO/KROTOS, LOBI) and generation of a virtual network on Nuclear Reactor Safety Research projects;
2) Investigations on the source term and the integral aspects of severe accidents together with technical and analytical support to the integral in-pile test facility PHEBUS at Cadarache, especially leading the European networks for interpretation on bundle behaviour and fission product release, circuit and containment aerosol behaviour, and chemical/radiochemical effects;
3) Development of advanced computational fluid dynamics methodologies for accident analysis, particularly for the combustion and possible explosion of hydrogen;
4) Harmonisation of safety aspects, for the advice of Commission Services on critical safety issues;
5) Safety aspects of innovative new reactor concepts.

See also the related EU enlargement process pre-accession (pa) project.


Nuclear incidents or accidents could potentially lead to serious consequences for the plants concerned - or worse, for the public and the environment. An impact on the further security of energy supply from nuclear sources cannot be excluded with economic and competitive consequences. The enlargement of the EU, where a number of nuclear plants with different and sometimes less effective safety features enter into the EU, poses a great challenge. For these plants the key questions related to the "defence-in-depth" concept of nuclear safety have to be compared and the integration of the Candidate Countries into a common safety level and safety culture has to be promoted. More generally a need for harmonisation of safety exist (Council resolution C128-75 and C172/2-92). International discussion increased recently on the next generation of nuclear reactors, which should have enhanced performance and safety features.

Funding Scheme

JRC - Joint Research Centre research


Institute for Energy