29th Symposium on Fusion Technology (SOFT 2016)

P4.148 The coolant purification system in DEMO: candidate technologies, requirements and interfaces

8 Sep 2016, 14:20

1h 40m

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

Board: 148

Poster H. Fuel Cycle and Breeding Blankets P4 Poster session

Speaker

Alessia Santucci (ENEA)

Description

The blanket concepts investigated under the EUROfusion program rely on water or helium as the primary coolant medium; the main duty of the coolant is to recover the thermal power from the first wall and the blanket units and drive it into the Primary Heat Transfer System (PHTS). The coolant path goes through three different systems: the breeder, the tritium plant and the PHTS. In the breeding region, due to the high temperature and the reduced thickness of the coolant pipes, some of the produced tritium can permeate into the coolant loop; therefore the main duties of the Coolant Purification System (CPS), located inside the tritium plant, are the extraction of tritium and the control of the coolant chemistry. There are several reasons why it is important to remove tritium from the coolant: 1) to avoid the release of tritium via permeation and/or coolant leakages into the working environment, 2) to keep the release of tritium into the environment lower than the allowable limit (tritium present in the primary coolant can permeate into the secondary coolant and thus reach the environment), 3) to control the tritium balance that is essential for monitoring the blanket performance during the different operational phases. The paper provides a description of the principal candidate technologies to be used inside the CPS both in case of helium and water by considering the very challenging CPS scenario characterized by a low tritium amount diluted in a huge flow of coolant. It also identifies the main requirements (i.e. fraction of coolant inside the CPS, tritium concentration in the coolant, CPS efficiency, etc.) and interfaces of the CPS.