29th Symposium on Fusion Technology (SOFT 2016)

P3.139 FFMECA and recovery strategies for ex-vessel remote maintenance systems in DEMO

7 Sep 2016, 11:00

1h 20m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 139

Poster G. Vessel/In-Vessel Engineering and Remote Handling P3 Poster session

Speaker

Alberto Vale (Instituto de Plasmas e Fusao Nuclear)

Description

In DEMO, the ex-vessel Remote Maintenance Systems (RMS) are responsible for the replacement and transportation of the plasma facing components. The ex-vessel operations of transportation are performed by cranes or by means of cask transfer systems (CTS) moved by trolleys. The main loads of transportation are the blankets and divertors. The blankets are extracted and transported vertically by cranes along galleries from the reactor to the storage or maintenance areas. An alternative is the transportation in horizontal configuration by means of CTS system along the galleries. The divertors are transported by means of trolleys. A failure may occur in any situation, interrupting the current nominal operation. The work identifies a functional breakdown structure for the ex-vessel RMS operations and develops a Functional Failure Modes, Effects and Criticality Analysis (FFMECA). The results of the different FFMECA studies lead to the conclusions in terms of the most critical failure scenarios and the pros and cons of the horizontal versus the vertical transportation of blankets. In case of failure, a recovery procedure shall be triggered. A recovery strategy is presented according to the following priorities: i) resuming the current nominal operation, ii) perform a different nominal operation and iii) perform a rescue operation. For radiation protection aspects, the recovery strategy is divided in two parts: with activated components (when transporting or in the proximity of activated components) and without activated components (free of load or transporting non activated components). The results will help the design process to improve and thus reduce the criticality index of the identified failures. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.