Cold neutron source at KAERI, Korea

The HANARO (High-flux Advance Neutron Application ReactOr), an open tank in a pool type multi-purpose research reactor, generating a high neutron flux (fast: 2.1 × 1014 n/cm2/s, thermal flux: 5 × 1014 n/cm2/s) has been operating at 30 MWth since its first criticality in February 1995. The HANARO provides neutrons to various utilization and research groups for global competition. Based on the world-wide trend for an availability of cold neutrons and the national demand for taking full advantage of such a strong neutron source, Korean government decided to commence with the cold neutron source (CNS) project at the HANARO on 2003. The HANARO will be equipped with a vertical liquid hydrogen-moderated CNS within the next 3 years. A moderator cell, made of 1 mm thickness of aluminium 6061-T6, whose shape is a double cylinder type and is connected to a heat exchanger, establishing two phase flow by a natural convection. These components are contained in the vacuum chamber. The cold neutron flux will be 3.9 × 109 n/cm2/s at the reactor face and approximately 8.4 × 108 n/cm2/s at the location of the instruments. This paper presents the current status and future prospect of the CNS project driven by KAERI, Korea.