Workpackages

The objective of WP2 is to establish a status (achievements, deficiencies) of calculation tools capabilities for simulation of simple passive systems using natural circulation in closed loops. Separate and combined effect tests are studied in this work package (whereas integral effect tests are the subjects of WP3 and WP4). WP2 is composed of several activities from bibliographic research to comparisons between calculations and experiments. The bibliographic research activity will establish the status of code validation for natural circulation systems. This includes models, experimental support, difficulties, and successes encountered in simulations. Results of simulations and comparisons with simple experiments carried out in the PASTELS projects will also be presented. Two different experiments are available: HERO-2 and PERSEO. Synthesis of the results and proposals for additional separate effect tests support the final activity of this work package.

IRSN leads WP2 with key inputs from EDF, ENEA, the University of Stuttgart, and UJV.

WP3 generates experimental data on the performance of a passive secondary-side heat removal system for pressurised water reactor under operational environment conditions and plant accident conditions. The major tasks are:

• Commissioning of the Safety COndenser (SACO) and related systems after the procurement, manufacturing and installation of components (i.e. the SACO and related piping, valves and measurement installations),
• Completion of the parameter studies to characterise SACO behaviour and performance under different operating states,
• Completion of the transient tests to demonstrate the performance of the system in the foreseen operational environment.

Framatome GmbH leads WP3 with key inputs from all partners, especially GRS and CEA.

WP4 performs a series of tests on natural circulation and heat transfer in a low-pressure open loop Containment Wall Cooler system (CWC) with no moving parts. WP4 begins with a detailed definition of a test matrix, which will address the most common concerns related to passive systems in general and naturally circulating loops in particular, taking into account the wide diversity of the operating conditions that are possible on the containment side. The main activity of WP4 is the test campaign itself, but the work package also relies on analytical support in the form of pre-test calculations (helping in test planning) and post-test calculations (helping with test data interpretation). WP4 generates the experimental database in electronic form, and reports detailing the test matrix, PASI system used in the tests, test results, and summary of key findings from the tests.

LUT University leads WP4 with key inputs from all partners, especially EDF as leader of several tasks.

WP5 manages the dissemination of PASTELS results. This WP will deliver key technical reports, which will synthesize the work accomplished by the consortium in terms of:

• Improving the capabilities of European computation tools to simulate innovative passive systems and guidelines to go further in the use of such tools,
• Lessons learned from the evaluation of prototypes of SACO and CWC under representative experimental conditions,
• Reflection on the future work that will be necessary to enable the implementation of such passive systems in European nuclear powerplants.

A large part of the WP5 is also devoted to presenting the relevant results of PASTELS to the academic audience and the industries through various communication in relevant scientific journals, technical reviews and Scientific Conferences.

The University of Stuttgart is leading this WP with the participation of the consortium.