The ITER Organisation is preparing a new timeline for construction of the International Thermonuclear Experimental Reactor (ITER) being built at Cadarache in France. As part of work underway to update the ITER Project Baseline, a group of experts met in February to evaluate the new blueprint for achieving ITER's research goals.

ITER is a first-of-a-kind global collaboration with construction funded mainly by the European Union (45.6%) with the remainder shared equally by China, India, Japan, Korea, Russia and the USA (9.1% each). However, in practice, the members deliver little monetary contribution to the project, instead providing ‘in-kind’ contributions of components, systems or buildings. The goal of ITER is to operate at 500 MW (for at least 400 seconds continuously) with 50 MW of plasma heating power input. It is not intended to generate electricity.

The ITER Council’s Science & Technology Advisory Committee (STAC) in September 2023 reviewed new plans that had been elaborated in part to minimise the impact of the repairs of the vacuum vessel and thermal shields. In November 2022, defects were identified in the two key tokamak components during assembly. ITER Director General Pietro Barabaschi had indicated that the problems would result in more delays to the project, already affected by the COVID-19 pandemic. Negotiations with the French nuclear safety authority, (ASN - Autorité de Sûreté Nucléaire) to develop a strategy to address ITER's first-of-a-kind regulatory needs and a revised path to nuclear licensing has also caused delays. ITER's previous target was to create first plasma by 2025 but Barabaschi said this would have to be postponed.

The ITER Organisation said it will submit a new project baseline to the ITER Council for consideration in June 2024. Alberto Loarte, head of the ITER Organisation’s Science Division noted: “Taking into consideration past delays incurred due to the Covid-19 pandemic, repairs to key components and other technical challenges with first-of-a-kind components, and a revised path to nuclear licensing, the new baseline proposes an optimised path to achieving the project's goals.”

The new baseline includes modifications to the configuration of the ITER device and its ancillaries such as change from beryllium to tungsten as first wall material and modifications to the heating and current drive mix. The new baseline also includes additional testing of components such as toroidal field coils. It also includes phased installation, starting with an inertially cooled first wall and later installing the final actively water-cooled components to minimise operational risks.

In this new approach, scientific exploitation is divided into three main phases: Augmented First Plasma, DT-1 and DT-2 plus the associated integrated commissioning phases. In its September 2023 meeting, STAC said it found the plan compelling and recommended that it should be adopted for the further articulation of the new ITER Research Plan to be elaborated by the ITER Organisation and member experts.

In late 2023, each ITER member nominated five experts, with a preference for younger contributors “who will have a greater opportunity to be involved in ITER's scientific exploitation”. Following some preparatory teleconference meetings in 2023 and early 2024, the first new ITER Research Plan development workshop took place at ITER headquarters from 13 to 15 February.

The meeting began with presentations by ITER staff describing the details of the new ITER Baseline and ITER Research Plan, followed by joint analysis of the main objectives of the various Research Plan phases, the suitability of the configuration of the ITER device and its ancillaries to achieve these objectives, and the expected operational time for each phase. “Detailed evaluations were carried out by five working groups jointly led by staff from ITER and member experts over three intense days, concluding with a final session during which all the groups reported their findings,” Loarte noted.

Overall, the analyses of the working groups found that the main elements of the outline Research Plan submitted for review to STAC in September 2023 were appropriate. “However, the groups identified specific aspects of the outline plan which require further review and optimisation.”

This new ITER Research Plan development workshop will be followed by further analysis of the issues and optimisation possibilities identified. This work will be performed via email and videoconference by the same groups in the coming weeks in preparation of a second, probably virtual, workshop to be held in late March. This will allow the details of the new ITER Research Plan to be finalised in time for submission for endorsement to the STAC in May.

Dialogue has also been under way with the French nuclear safety authority, Autorité de Sûreté Nucléaire, to create a strategy to address ITER's first-of-a-kind regulatory needs and a revised path to nuclear licensing.

Image: ITER Organization staff and member experts discuss the details of the new ITER Research Plan (courtesy of ITER)

Date: Friday, 23 February 2024
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