Comprehensive safety analysis code system for nuclear fusion reactors III: Ex-vessel LOCA analyses considering passive safety

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Fusion Technology

OSTI ID:249619

Honda, T; Okazaki, T; Maki, K; Uda, T ^[1]; Seki, Y; Aoki, I; Kunugi, T ^[2]

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1. Hitachi Ltd., Ibaraki (Japan)
2. Japan Atomic Energy Research Inst., Ibaraki (Japan)

Ex-vessel loss-of-coolant accidents (LOCAs) in a fusion reactor have been analyzed to investigate the possibility of passive plasma shutdown. For this purpose, a hybrid code of the plasma dynamics and thermal characteristics of the reactor structures, which has been modified to include the impurity emission from plasma-facing components (PFCs), has been developed. Ex-vessel LOCAs of the cooling system during the ignition operation in the International Thermonuclear Experimental Reactor (ITER), in which graphite PFCs were employed in conceptual design activity, were assumed. When double-ended break occurs at the cold leg of the divertor cooling system, the copper cooling tube begins to melt within 3 s after the LOCA, even though the plasma is passively shut down at nearly 4 s. An active plasma shutdown system will be needed for such rapid transient accidents. On the other hand, when a small (1%) break LOCA occurs there, the plasma is passively shut down at nearly 36 s, which happens before the copper cooling tube begins to melt. When the double-ended break LOCA occurs at the cold leg of the first-wall cooling system, there is enough time (nearly 100 s) to shut down the plasma with a controllable method before the reactor structures are damaged. 21 refs., 8 figs.

• OSTI ID: 249619
• Journal Information: Fusion Technology, Journal Name: Fusion Technology Journal Issue: 1 Vol. 29; ISSN 0748-1896; ISSN FUSTE8
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
99 GENERAL AND MISCELLANEOUS
COMPUTER CODES
COMPUTERIZED SIMULATION
DESIGN
LOSS OF COOLANT
REACTOR ACCIDENTS
REACTOR COOLING SYSTEMS
SAFETY ANALYSIS
THERMONUCLEAR REACTORS