On July 28, 1992, the BARSEBACK-2 nuclear power plant loss-of-coolant accident has led to the ECCS failure due to the plugging of its sump screens. To cope with this problem, the international community assessments firstly focused on the BWR units and modifications were implemented till 1996, based on the existing knowledge at that time.
Then, assessments on PWR units have been conducted or are in progress worldwide.
In France, IRSN has performed an experimental program, from 2000 until now, concluding on the potential sump screens plugging for the 58 existing French units. A lot of experimental data have been obtained. At the present time, an agreement exists between the French concerned organizations on the need to consider the problem and to implement improvements on all the French units.
However, IRSN considers that the current knowledge is not enough substantiated on some important topics which have to be considered to precise design requirements to assess globally this issue. The pending problems are related to the debris generation and the water chemical effects on the fiber bed fixed on the filters.
An experimental program is proposed by IRSN to solve these two open questions in a short term. This program as well the knowledge already gained by IRSN could be of interest for a great number of countries.
Therefore, IRSN propose to perform it under the OECD’s Auspice in compliance along the following conditions:
- concerning the debris generation, the proposal consists to realize the experimental program in EREC (RUSSIA), to share the global cost (1,8 MEuros) between the interested partners and to include in this program their specific tests,
- concerning the chemical effects on the fiber bed fixed on the filters, the proposal consists to realize the program in VUEZ (SLOVAKIA) under IRSN funds (0,44 MEuros) and to allow the partners involved in the debris generation program to take benefit of the results and the models. If some partners want to perform focused tests, their cost will be in charge of these partners.
The objectives of the proposed Agreement shall be to conduct an International Investigation Program of Sump Plugging. An outline of the Project, including a provisional description of the Experiments to be carried out, is provided in Appendix A hereto. A financial proposal is provided in Appendix B.