Project Presentation: WP6
WP6: RECOMMENDATIONS FOR STANDARDIZATION (VCE, ENEA, AREVA NP SAS, SCK•CEN, FIP INDUSTRIALE, MAURER-SOEHNE, EC-JRC, SINTEC, KTH, BOA-BKT, IPUL, NUMERIA, CEA, NUVIA)The WP6 is organized in three tasks.
Task 6.1. Isolated systems economics
It is performed a cost benefit analysis elaborating the differences between the conventional approach and the innovative isolated solution. With the increased demand from the seismic input side isolation becomes a considerably interesting solution. It is to be demonstrated that economic savings do not sacrifice safety; rather a win/win situation exists under the changed conditions of a considerably increased hazard.
Task 6.2. Guidelines
The task is devoted to outline recommendation for mitigating seismic risks in next generation nuclear plants.
Most of the partners will contribute to implement the guidelines document.
Design suggestions for a pool type LFR to reduce risks and uncertainty related to sloshing and void entrapment into coolant in a seismic event for isolated and non-isolated systems are proposed. Aapplicable nuclear codes and regulations for the design of pipes and pipe expansion joints and outlining standard procedures for pipes and pipe expansion joints testing are identified.
Procedures for the design, manufacturing, qualification and installation of seismic isolators and joints covers are edited. Reference will be made to the European Norm EN 15129, approved by CEN in November 2009. This Norm, which will became effective and mandatory on August 1st, 2011, is not specifically addressed to nuclear plants, and thus the guidelines document will suggest extensions and additional clauses for NPPs to be included during its revision process.
Pprocedures for the replacement of the isolators and their in-service inspection and maintenance are set up.
A plan for the monitoring of the isolation system is implemented.
Tthe present situation in electromagnetic pump stability under seismic events is evaluated and rules of optimal positioning of pumps in reactors are evaluated, as well as construction safety parameters of electromagnetic pumps (with windings) and on permanent magnets.
Tthe applicability of the guidelines to real case nuclear power plants is evaluated.
Task 6.3: Knowledge transfer to Gen III LWR systems and other Gen IV systems
The possibility to transfer to GEN III LWR the seismic risk mitigation techniques developed in this project for GEN IV fast reactor, is investigated. In particular, the main differences in the dynamic behaviour of LWRs and LMRs (in particular LFR and SFR) are identified, outlining the boundary conditions for the knowledge transfer.
The reliability of the seismic isolation for reducing earthquakes risks is assessed for GEN III reactors and the isolation technologies developed in the project transferred to LWRs.