Assessment of radiation dose rate in main building area of A-FNS facility

• Published in: Fusion engineering and design 2024-04, Vol.201, p.114274, Article 114274
• Main Authors: Kwon, Saerom, Ohta, Masayuki, Ochiai, Kentaro, Sakamoto, Ryota, Sato, Satoshi
• Format: Article
• Language: English
• Subjects: A-FNS; ADVANTG; IFMIF; MCNP; Radiation dose; Shielding measures
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2024.114274

Fusion neutron source facilities intended for material irradiation are characterized by their high-intensity neutron generation, underscoring the paramount significance of dose assessment in facility design. As one of radiation shielding analyses taking into account the facility building, the radiation dose rate in the A-FNS has been calculated by Monte Carlo simulation. The calculation model was created based on the 3D CAD drawings of A-FNS main building. Detailed dose distribution using the variance reduction method with MCNP6.2 and ADVANTG codes were calculated. In the reference design of A-FNS so far, which has no beam duct for the application usage, the neutron dose equivalent rate in the experimental application cell is below 10−2 mSv/h. However, the dose rate increases by eight orders of magnitude to a few Sv/h for the design with the duct of 10 cm in diameter. As a point of view of radiation zoning for A-FNS facility, the experimental application cell should be “yellow” which means that allows restricted access under 2 mSv/h dose rate. We focused on assessing impacts of the radiation dose rates and proposing necessary measures by accurately calculating the radiation dose at normal beam operation, particularly dividing areas with anticipated high radiation in the A-FNS facility.