Community Research and Development Information Service - CORDIS

Periodic Report Summary 2 - ALISA (Access to Large Infrastructures for Severe Accidents)

Project Context and Objectives:
Enhanced transnational access to large research infrastructures in Europe and in China is offered to allow the optimal use of the resources in the extremely complex field of severe accident analysis for the existing power plants. This research involves very substantial human and financial resources and, in general, the research field is too wide to allow investigation of all phenomena by any national program. To optimize the use of the resources, the collaboration between nuclear utilities, industry groups, research centers and safety authorities, at both European and Chinese levels is very important. This is precisely the main objective of the ALISA project, which aims to provide these resources and to facilitate this collaboration by providing large-scale experimental platforms in Europe and in China for transnational access.

Large-scale facilities of the ALISA project are designed to resolve the most important remaining severe accident safety issues, ranked with high or medium priority by the SARP group for SARNET NoE. These issues are coolability of a degraded core, corium coolability in the RPV, possible melt dispersion to the reactor cavity, molten corium concrete interaction and hydrogen mixing and combustion in the containment. The major aspect is to understand how these events affect the safety of existing reactors and how to deduce soundly-based accident management procedures. The aim is not only to understand the physical background of severe accidents but to provide the essential knowledge that can help to reduce the severity of the consequences. It is crucially important to understand the whole core melt sequences and identify opportunities to lower the risk, which can be done by e.g.:
- altering the timing or magnitude of reflooding the degraded core,
- in-vessel melt retention in the lower plenum of the reactor pressure vessel,
- ensuring the upper bound of system pressure at vessel failure by dedicated depressurisation valves,
- installation of devices or implementing accident management procedures to mitigate melt dispersion into the containment,
- delaying basement penetration or even by regaining melt cooling before containment failure or basement penetration occur,
- implementing hydrogen mitigation measures in the containment (ignitors, recombiners etc.).

Activities within the ALISA project are focused on the large scale experiments under prototypical conditions addressing the remaining R&D issues on severe accident management in light water reactors. These will help the understanding of core degradation, melt formation and relocation as well as core coolability in real reactors in two ways – firstly by scaling-up and secondly by providing data for the improvement and validation of computer codes applied for safety assessment and planning of accident mitigation concepts, such as ASTEC. ALISA offers a unique opportunity for all parties to get involved in the networks and activities supporting safety of existing and advanced reactors and it allows European and Chinese researches to work together as equal partners so as to arrive at a wider common safety culture.

The importance of the ALISA project for the European and Chinese severe accident research is reflected in three aspects:
1) The access to large scale experimental facilities is proposed to investigate all important processes from the early core degradation to late in-vessel phase pool formation in the lower head, continuation to ex-vessel melt situations and to the hydrogen behaviour in the containment. Therefore four high priority issues identified by the SARP group will be addressed in the project.

2) The results of the project will be applicable both to the European and Chinese reactor fleet taking into account the main light water reactors.

3) The project offers a unique opportunity for Chinese experts to get an access to large scale facilities in Western research organization and vice versa, to improve understanding of material properties and core behaviour under severe accident conditions, and to become familiar with the high level safety concepts in nuclear power plants.

Project Results:
During the second period of the project (months 13-30) the following tasks were performed:

1. ALISA review meetings.
The first ALISA review meeting was organised on 29-30 September 2015 in Cadarache. Two EU partners (KIT and CEA) and five Chinese partners (CNPRI, SNPSDC, XJTU, SJTU, Hongkong City University) have attend the meeting. Colleagues from SJTU attended the meeting per video conference. The purpose of the meeting was on one hand to present and to discuss the proposals submitted during the first call between facility operators and the potential users, on the other hand was to prepare the second call for proposals.

The second review meeting was organised on 27-28 October 2016 in Hong Kong City University. Besides the EU partners (KIT and CEA) and five Chinese partners (CNPRI, SNPSDC, XJTU, SJTU, Hong Kong City University) participating in the meeting, a new Chinese partner: Nuclear Power Institute of China (NPIC), has joined the meeting. IRSN was invited to the meeting after the morning section on 27 October to present the main objectives of the IVMR project. The main purpose of the meeting was to present the status and the progress of experiments proposed and selected after the second call for proposals, define the time schedule for the experiment performance, discuss alternatives and solutions of emerged technical and financial difficulties. In addition, the meeting has adopted two new facilities in China at NPIC in the ALISA project.

2. Preparation of the detailed technical description of second call.
Together with the preparation of the first call for proposals, the updated technical description of the available test facilities in EU and in China for the second call was prepared. This information is also a part of the rules of access to ALISA facilities. Potential users can make precise and realistic proposals only if they have detailed knowledge about the technical capabilities of a particular facility. The contact person for each facility was identified to further facilitate the communication between the users and facility operators.

3. Publication of the rules of access to ALISA facilities and initiation of the second call for proposals.
The second call for proposals together with the rules of access to ALISA facilities for the second call were widely announced on the 11th January 2016 among different EU organizations. In parallel, the same action was undertaken by the Chinese ALISA partners to disseminate the information about the ALISA project between the Chinese organisations. The call for proposals was also announced on the ALISA website and the information about the call for proposals was distributed at international conferences. In the call for proposals the project management process, technical description of facilities description and the Proposal Submission Form were provided.

4. Exchange of technical details about ALISA facilities during the second call between the facility operators and potential users.
After the publication of the call for proposals there was an extensive exchange of information between European and Chinese partners about the technical details of the facilities and other relevant issues related to the call for proposals. The feasibility, the significance and the potential use of the results of proposed experiments were also discussed.

5. Preparation and submission of experimental proposals.
As a result of the second call for proposals, four proposals were submitted by EU organizations for the experiments in Chinese facilities, of which 2 addressed the COTHYD facility, and one proposal for each of the IVR3D and WAFT. Two European facilities (VITI and DISCO) have received 4 proposals submitted from Chinese organisations, of which 3 for VITI and one for the DISCO facility.

6. Evaluation and selection of the proposals.
Proposals for the EU facilities during the second call period have been evaluated and selected during the European User Selection Panel meeting hold on June 08, 2016 in Aix-en-Provence, France. At the same time, Chinese partners have organized a meeting for the evaluation of the proposals submitted by European partners. The Chinese evaluation results have been acknowledged during the second ALISA review meeting.

7. Regulation of the travel costs.
According to the original ALISA Agreement, the travel costs of European users should be covered by Chinese partners and vice versa. The Chinese partners have expressed their organizational difficulty to take over the travel cost for European users. Upon the approval of European Commission, travel cost regulation has been revised in a way, that user users visiting the facility, and not the facility operator, will cover their cost by their own organisation. No additional costs, compared to the original planning of the travel budget, will arise for the project partners.

8. Preparation of deliverables.
Three deliverables have been prepared during the reporting period:
D2.5 The first project periodic report (Month 1-12), submitted on 06/08/2015
D2.6 Evaluations of the proposals by the User Selection Panel and Selection of projects during the second call, submitted on 30/08/2016
D2.7 Periodic Report (months 13-30), scheduled delivery date is 31 January 2017 (this report).

9. Preparation, performance and reporting of the experiments.
The experiments selected in the first call have been intensively prepared both in China and in EU organsations. Two experiments in Europe organisations and one experiment in China were successfully prepared and carried out. These are HYKA at KIT and KROTOS at CEA, and HYMIT at SJTU. The users of these experiments are informed of the detailed reporting issue and are engaged in the process of producing the technical reports. Other experiments planned in the project are undergoing intensive preparation. Most of the test are scheduled for 2017. The rest of the experiments are foreseen in 2018.

Potential Impact:
At present, knowledge of various core melt sequences and the consequences of possible operator actions are not yet sufficient as they are too dependent on specific characteristics of the power plant under consideration. ALISA project aims to provide the resources for a better understanding of possible scenarios of core quenching, different core melt sequences and hydrogen behaviour for different reactor designs by offering state-of-the-art experimental facilities for the transnational access.

The experiments that are being performed amd planned in the ALISA project in both European and Chinese facilities address important issues of early in-vessel core degradation for various accident scenarios, the detailed study of the in-vessel melt pool behaviour, the cooling strategy of the ex-vessel cooling, thermochemical interactions of the corium and its influence on the fuel coolant reaction and the study of the hydrogen behaviour in the containment. The topics address not only the safety issues ranked with high and medium priority by the SARP group for SARNET NoE, but also reflect a high interest in the safety management in the current and future nuclear power plants in both China and in Europe.

The knowledge obtained in the project shall lead to improved severe accident management measures, which are essential for reactor safety and in addition offer competitive advantages for the nuclear industry. The experimental results will be used for the development of models and their implementation in the severe accident codes such as ASTEC. This helps to capitalise the knowledge obtained in the field of severe accident research in the severe accident codes and scientific databases, thus preserving and diffusing this knowledge to a large number of current and future end-users both in Europe and in China.

Due to strong links to other European activities like NUGENIA association and SAFEST and IVMR projects, ALISA offers a unique opportunity for all parties to get involved in the networks and activities supporting safety of existing and advanced reactors and to get access to large-scale experimental facilities in Europe and in China to enhance understanding of material properties as well as reactor core behaviour under severe accident conditions. The ALISA project allows European and Chinese researches to work together as equal partners so as to arrive at a wider common safety culture. By doing this, the project will also help to diffuse the European culture of research and innovation as a support to regulatory and industrial decision making both in Europe and in China.

EU organizations will take advantage in their own research field by using the unique facilities in the Chinese research institutes. ALISA project also provides a platform for the exchange of experience in the experimental techniques and the philosophies between the EU and Chinese partners. The expertise of EU facility operator can be better understood, appreciated and in demand in the course of rapid development of Chinese nuclear safety research.

List of Websites:

Reported by

Karlsruher Institut fuer Technologie


Nuclear Fission
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