Design of separated first wall for fusion experimental reactor

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:196940

Koizumi, K; Shibui, M; Nakahira, M ^[1]

---

1. JAERI, Ibaraki-ken (Japan); and others

First wall of tokamak fusion experimental reactors has a high possibility of damage caused by high surface heat flux and particle loads during normal and off-normal operation. Also, it is subjected to large electromagnetic loads due to plasma disruption. Because of theses high potential risks, the first wall needs to be replaced in case of failure, though the blanket is expected to survive anticipated design load conditions under the operation environments through its lifetime and classified into {open_quotes}semi-permanent components{close_quotes}. The first wall mechanically separated from the massive blanket structure has been proposed as a promising concept with the following advantageous features; - easy handling during assembly/disassembly due to light weight (-500 kg) - short down-time for maintenance operation - minimized amount of radwaste - reduced thermal stresses of massive blanket structure separated from high heat flux component - possible higher temperature operation of the first wall than the blanket structure. From these points of view, a separate first wall, which has a reliable double-walled thin shell structure with mesh insert for fail-safe feature, has been proposed for the first wall of fusion experimental reactors to improve its reliability, maintainability and inspectability. The quilting structure of austenitic stainless steel (SS316) cooled by low to medium pressure water is employed to accommodate high temperature operation of more than 300{degrees}C with reduced thermal stresses under high surface heat flux of more than 0.3 MW/m{sup 2} and nuclear heating. This structure is effective to obtain electrical connection between adjacent blanket modules and also workable as bumper limiters, start-up limiters and ripple-loss protectors with adequate armors or coating.

• OSTI ID: 196940
• Report Number(s): CONF-940664--
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DESIGN
FIRST WALL
REACTOR MAINTENANCE
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TUBES