Safety analysis of the US dual coolant liquid lead–lithium ITER test blanket module

Abstract

The US is proposing a prototype of a dual coolant liquid lead-lithium DEMO blanket concept for testing in the International Thermonuclear Experimental Reactor (ITER) as an ITER test blanket module (TBM). Because safety considerations are an integral part of the design process to ensure that this TBM does not adversely impact the safety of ITER, a safety assessment has been conducted for this TBM and its ancillary systems as requested by the ITER project. Four events were selected by the ITER international team (IT) to address specific reactor safety concerns, such as vaccum vessel (VV) pressurization, confinement building pressure build-up, TBM decay heat removal capability, tritium and activation products release from the TBM system and hydrogen and heat production from chemical reactions. This paper summarizes the results of this safety assessment conducted with the MELCOR computer code.

Severe accident analysis of the dual-functional lithium-lead test blanket module using ISAA-DFLL code

“…For the dual-function liquid LiPb experimental cladding module scenario, Li et al [5] conducted steady-state and accident analysis using the system program RE-LAP5/MOD3 embedded with a liquid LiPb thermal-hydraulic submodule. In addition, Merrrill et al [6] modeled the DCLL-TBM using the modified severe accident analysis program MELCOR, which to perform accident analysis calculations such as los of coolant accident (LOCA) outside the vacuum chamber and LOCA inside the vacuum chamber. Marshall et al [7] used other programs such as ATHENA-INTRA to perform safety analysis of TBM.…”

Methodology for accident analyses of fusion breeder blankets and its application to helium-cooled pebble bed blanket

“…Though not as extensive as for 1.8.2, MELCOR 1.8.5 has been subject to verification via comparison studies with standard (fission) MELCOR 1.8.5 and pedigreed MELCOR 1.8.2, and has been used in other fusion safety assessments [3,15]. Although the standard version of MELCOR 1.8.6 has advantages over MELCOR 1.8.5 it is judged that the latter will provide an equally valid calculation of the conditions within the HCPB TBM as former.…”

“…Testing the tritium breeding modules (TBM) in ITER [1], and the need to include them in the ITER licensing [2], offers a unique opportunity for further development and validation of the methodology for DEMO breeder blanket (BB) accident analysis [3][4][5][6][7]. The safety approach and accident analysis methodology for ITER is very well defined, as demonstrated by the successful construction licensing [8].…”

“…Some of these codes have been modified, and have additional physical models to treat fusion-relevant phenomena [9][10][11][12][13]. For example, fusion-adapted versions of MELCOR are widely applied for fusion accident analyses [3,12,14,15]. The underlying fission safety codes have undergone development and validation using extensive separate and integral effects experimental databases [16][17][18].…”

Russian concept for a DEMO-S demonstration fusion power reactor

“…The first wall is an irregularly shaped plate with toroidal coolant channels and Be protective coating (like in European, Chinese and US TBMs [22][23][24]). It is supported by stiffening ribs, which provide the required strength under abnormal operating conditions (plasma disruptions, electromagnetic load hikes, loss of coolant accompanied with pressure build-up in the vacuum vessel and a gas-dynamic blow).…”