Core design of long‐cycle small modular lead‐cooled fast reactor. (29th October 2018)

• Record Type: Journal Article
• Authors: Nguyen, Tung Dong Cao; Choe, Jiwon; Ebiwonjumi, Bamidele; Lemaire, Matthieu; Lee, Deokjung
• Is Part Of: International journal of energy research. Volume 43:Number 1(2019)
• Page Start: 254
• Page End: 273
• Publication Date: 2018-10-29
• Subjects: core design -- icebreaker -- liquid‐metal fast reactor -- long cycle -- small modular reactor; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.4258
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: A core design of small modular liquid‐metal fast reactor (SMLFR) cooled by lead‐bismuth eutectic (LBE) was developed for power reactors. The main design constraint on this reactor is a size constraint: The core needs to be small enough so that (1) it can be transported in a spent nuclear fuel (SNF) cask to meet the electricity demands in remote areas and off‐grid locations or so that (2) it can be used as a power source on board of nuclear icebreaker ships. To satisfy this design requirement, the active core of the reactor is 1 m in height and 1.45 m in diameter. The reactor is fueled with natural and 13.86% low‐enriched uranium nitride (UN), as determined through an optimization study. The reactor was designed to achieve a thermal power of 37.5 MW with an assumption of 40% thermal efficiency by employing an advanced energy conversion system based on supercritical carbon dioxide (S‐CO2 ) as working fluid, in which the Brayton cycle can achieve higher conversion efficiencies and lower costs compared to the Rankine cycle. The outer region of the core with low‐enriched uranium (LEU) performs the function of core ignition. The center region plays the role of a breeding blanket to increase the core lifetime for long cycle operation. The core working fluid inlet and outlet temperatures are 300°C and 422°C, respectively. The primary coolant circulation is driven by an electromagnetic pump. Core performance characteristics were analyzed for isotopic inventory, criticality, radial and axial power profiles, shutdown margins (SDM), reactivity feedback coefficients, and integral reactivity parameters of the quasi‐static reactivity balance. It is confirmed through depletion calculations with the fast reactor analysis code system Argonne Reactor Computation (ARC) that the designed reactor can be operated for 30 years without refueling. Preliminary thermal‐hydraulic analysis at normal operation is also performed and confirms that the fuel and cladding temperatures are within normal operation range. The safety analysis performed with the ARC code system and the UNIST Monte Carlo code MCS shows that the conceptual core is favorable in terms of self‐controllability, which is the first step towards inherent safety. Abstract : A core design of small modular liquid‐metal fast reactor cooled by lead‐bismuth eutectic is developed with a thermal power of 37.5MW, a cycle length up to 30 years and small size (1m active height for 1.45m active radius) so that it can be transported in a fuel transport cask or used as a power source in an icebreaker ship. The significant neutronics, thermal hydraulics and safety parameters are analyzed, showing that the innovative core design can satisfy advanced requirements of GEN‐IV reactors such as simplicity in design, reliability for long operation time and prolifration resistance.