Page 90 - ILLS Annual Report 2018

PROJECTS AND TECHNIQUES DIVISION ACTIVITIES
Projects and calculations service
Y. Calzavara (ILL)
The Bureau des Projets et Calculs (BPC) supports all the ILL’s divisions through its twofold objective: carrying out engineering calculations and managing projects.
Thus, as well as offering technical
expertise throughout the ILL, the BPC manages instrument projects (within the
ILL modernisation programmes) and safety projects for the Reactor division (DRe). Today, our engineers are in charge of several instrument projects, such as WASP, XTremeD, LADI-B, IN20 and NeXT, and have responsibility for several DRe projects.
Overcoming all the challenges of its groundbreaking design, the WASP spin-echo instrument started its final commissioning phase with neutrons on 3 October 2018. From an engineering point of view, WASP (see figure 1) is definitively one of the most complex instruments ever made at the ILL. In an amagnetic environment, a huge system of coils was built in order to achieve the very high level of precision required to operate the instrument. Many severe constraints had to be worked around, such as the 16 tonne magnetic pressure and high expectations concerning the planarity of the large coils. Innovative designs were developed to address these challenges, leading to new engineering concepts such as the Flight Box and the He Fan. The commissioning of WASP and its optimisation will without doubt require several cycles; because of their complexity, many components still need
to be improved to achieve ultimate precision.
The BPC was also involved to a large extent in some of the STR projects. Running parallel to these, the project to convert highly enriched uranium into low enriched uranium (LEU) as
a fuel element is now up and running. LEU configurations are intended to limit performance losses to as low as 10 %, taking into account both cycle length and flux. Partially funded by
the EU, two series of comprehension irradiations were carried out in 2018 but with unfortunately limited success so far. A back-up solution is being explored with an alternative LEU
fuel technology. However, the road to conversion remains challenging; it will require a whole fuel qualification process, which means several irradiations of test plates and prototypes.
Last but not least, the BPC has been heavily involved in the cleaning up of the D-level contamination. The project was delayed because of difficulties encountered by our subcontractor but was eventually completed before the end of 2018.
ANNUAL REPORT 2018
Figure 1
The WASP instrument.