Test Blanket Module Concept Research Articles

Design development and analytical assessment of LLCB TBM in Russian Federation during 2012–2013

The activity on the design, analysis, and R&D for the test blanket module (TBM) with lead–lithium (LL) eutectic coolant and ceramic breeder (CB) was performed in the Russian Federation (RF) according to the technical program of cooperation between the leading research institutes of India (“leader” of the LLCB TBM concept) and RF (“partner”). During the period of 2012–2013, the joint efforts of the RF and Indian specialists were focused on the development of the TBM's basic design with an optimal set of parameters (in particular for testing on both H-H and H-D operation phases of International Thermonuclear Experimental Reactor (ITER) machine). This article briefly describes the results of the TBM design and analysis that have been obtained by the RF specialists (“NIKIET” and D.V. Efremov Institute) in support of the LLCB concept (both DEMO blanket and TBM itself). The main directions of this activity in RF institutes were as follows:–development of the TBM design taking into account the ability to manufacture the TBM elements (load-bearing casing, tritium-breeding zone, and attachment system);–thermal analysis (in both stationary and transient approaches) of TBM design options (four variations of helium and eutectic flowing directions);–structural analysis of TBM design elements for Inductive I operation mode; and–recommendations (based upon the results of comparative analysis) on the reference design to be used on further stages of concept development.The critical issues and further plans on the development of LLCB TBM and corresponding DEMO blanket in the RF are also presented in this article.

Overview of Russian Federation activity on the LLCB TBM design and analysis

According to the Technical program of cooperation between the leading research institutes of India and Russian Federation the joint development of lead-lithium ceramic breeder (LLCB) test blanket module (TBM) is one of preferential directions in this program. The concept of LLCB TBM and corresponding DEMO blanket has been proposed by Indian TBM Team and India is a “Leader” in this concept. Russian Federation takes part in the design, analysis and R&D activities on LLCB TBM concept on the rights of “Partner”. In particular the joint efforts are focused now on the development of LLCB TBM in the electromagnetic option (so-called EM-TBM).In the framework of the design and analysis for LLCB TBM several design options have been considered by RF specialists during 2010–2011 period. The main directions of design and analysis works are as follows:-the designing of TBM load-bearing casing including the reliable cooling layout;-the development of tritium breeding zone (TBZ) basing upon the minimizing of MHD-pressure drops for liquid metal circulation, increasing of eutectic outlet temperature (up to 500°C) and tritium production rate;-to create the TBM attachment system that will be able to withstand the loads for all the ITER operation modes;-thermal hydraulic analyses for TBM helium cooling system and eutectic circuit (taking into account the magnetic field conditions);Brief results of this activity and consequent proposals on the design improvements are presented in this paper.The critical issues and further plans on the development of LLCB TBM in Russian Federation are also discussed and analyzed in this article.

The design decisions of breeding zone sub-module for testing in ITER in order to validate the CHC TBM concept

Russian Federation has adopted the strategy to participate in the TBM Program on the rights of “Partner” in the development of ceramic helium-cooled (CHC) test blanket module (TBM) concept. In this connection one of the possible collaboration scenarios is to integrate the characteristic design element of RF concept in the structure of “Leader's” TBM and to test it in ITER environment. According to the collaboration in the framework of Test Blanket Working Group (TBWG) the “Leader” and “Partner” should develop together the selected (DEMO-relevant) TBM concept which will not disturb the ITER operation. Because of the analogue in the design principles, testing objectives and parameters of the EU CHC TBM concept (“Leader”) and of the RF one, the RF specialists have developed the design options of breeding zone sub-module (BZSM) to be integrated in one of the EU TBM cells for further testing in ITER. There are four BZSM design options (according to four types of TBM to be tested) have been developed. Brief explanation of RF strategy in the partnership for the development of CHC blanket concept is presented in this paper. This paper also contains the description of all the four BZSM designs and some technological features.

A Preliminary Assessment of the Occupational Radiation Exposure from Maintaining the US ITER DCLL TBM

This paper details an Occupational Radiation Exposure (ORE) analysis performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This ORE analysis was performed with the QADMOD dose code for maintenance activities anticipated for the US DCLL TBM concept and its ancillary systems. Identification of the maintenance tasks that will have to be performed and estimates of the time required to perform these tasks were developed based on either expert opinion or on industrial maintenance experience for similar technologies. This paper details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.

Development of low activation ferritic/martensitic steel welding technology for the fabrication of KO HCSB TBM

The conceptual design of the Korean helium cooled solid breeder test blanket module has been performed and the fabrication feasibility of the test blanket module concept has been investigated. It is necessary to develop fabrication technology, such as joining technologies of structural material, because low activation ferritic/martensitic steel has been considered for the structural material of the Korean helium cooled solid breeder test blanket module. Several types of the low activation ferritic/martensitic steel have been proposed, but their welding characteristics are still under investigation. In this paper, electron beam welding technologies for the low activation ferritic/martensitic steel were investigated in detail. Tensile, hardness, impact, and microstructure characteristics of the welded specimens before and after post-welded heat treatment have been investigated, and the results show that welding quality and the process applied in this study were found to be reasonable.

Helium-cooled pebble bed test blanket module: Alternative design and fabrication routes

This paper describes two design options of the EU-helium-cooled pebble bed (HCPB)-test blanket module (TBM) and indicates the main differences between the two designs with regard to fabrication routes and general features. The TBM reference design (TBM Ref.) was developed in 2006 and is mainly based on the assumption that fabrication of the cooling channels inside the TBM sub-components (e.g. first wall (FW), caps, stiffening grid (SG)) is based on diffusion-welding processes (DWP). In contrast to that proposal another TBM concept (TBM alt) was developed in 2007 in parallel, where DWP alone was taken into account only for fabrication of the cooling channel structure inside of the TBM FW, where DWP is mandatory with regard to the TBM requirement that plasma-facing surfaces must not include welding seams. The other TBM sub-components equipped with cooling channels were designed to be manufactured by technologies that are already state-of-the-art (e.g. combination of electron beam (EB) welding and spark erosion (SE)). Additionally the design of the manifold system for coolant distribution inside of the TBM is different for both design options.

Preliminary design for a China ITER test blanket module

Preliminary design and analysis for China helium-cooled solid breeder (CH HC-SB) test blanket module (TBM) for testing in ITER device have been carried out recently. In this paper, the design description, the performance analysis and the related ancillary systems for CH TBM are given. The key features of the design are based upon the breeder-outside-tube (BOT) concept, on the use of solid breeder ceramic material, of helium as coolant and tritium purge gas, of ferrite–martensite steel as structural material and of beryllium as neutron multiplier. Results show that the proposed TBM concept has the advantages of higher tritium breeding ratio (TBR), simple structure design and engineering feasibility.