The development of the next generation of Sodium-cooled Fast Reactors (SFRs) needs to integrate innovative options regarding the core design in order to comply with the objectives of the 4th generation reactors in terms of safety, cost and performance. In this framework, the aim to design fast core with economy improvements leads to limit the number of control and shutdown systems and to extend their lifetime. These objectives require choosing absorber material with maximal efficiency in terms of neutronic absorption.

The French concept of absorber pin is based on the use of boron carbide (B₄C) pellets with ¹⁰B various enrichments and the absorber element consists of a vented non-leaktight pin with a permanent sodium bond between the pellet column and the stainless steel clad.

In order to test an innovative concept of absorber pin and with the aim to improve in one hand, the in pile behavior understanding and in the other hand, the absorber rod modelling codes, an experimental program named MACARON is undergone. This program consists in an irradiation test in the BOR-60 reactor following by a complete NDE and PIE program. Two short absorber pins are irradiated currently. This program is performed by both CEA and RIAR teams.

A brief description of the experiment is first provided, in terms of objectives. The main characteristics of absorber pin with the main design criteria are detailed. The manufacturing steps and the characterization of the experimental absorber pins are given with as manufactured results.

The design studies of the Irradiation Rig and the neutronic and thermal hydraulic calculations are described in details. The irradiation test has begun in September 2018 and the first experimental results are provided. The huge program of Non-Destructive and Destructive Examinations is detailed with experimental objectives and methods that will be used.

下一代钠冷快堆（SFR）的开发需要集成有关核心设计的创新选择，以便在安全性，成本和性能方面符合第四代反应堆的目标。在此框架中，旨在设计具有快速经济性的快速核的目的在于限制控制和停机系统的数量，并延长其使用寿命。这些目的要求选择在中子吸收方面具有最大效率的吸收体材料。

法国吸收塔的概念是基于使用碳化硼（B ₄ C）粒料，其中含¹⁰ B各种富集物，吸收塔由一个排气的非渗漏针组成，在粒料塔和不锈钢之间具有永久性的钠键穿的

为了测试减震器销的创新概念，并旨在提高对桩内行为的理解，另一方面，为了改善减震器销的建模代码，进行了名为MACARON的实验程序。该程序包括在BOR-60反应器中进行辐照测试，然后执行完整的NDE和PIE程序。当前正在照射两个短的吸收销。此程序由CEA和RIAR团队执行。

首先根据目标对实验进行了简要说明。详细介绍了吸收销的主要特征以及主要设计准则。作为制造结果给出了实验性吸收销的制造步骤和特性。

详细介绍了辐射钻机的设计研究以及中子和热力水力计算。辐照测试已于2018年9月开始，并提供了第一批实验结果。庞大的非破坏性和破坏性检查程序详细介绍了将要使用的实验目标和方法。