Steady and Transient Thermodynamic Performance Analysis of UN-FeCrAl Fuel Element under High Burnup
-
摘要: UN-FeCrAl燃料元件作为耐事故燃料高燃耗应用的主要方案之一,需要评价其在高燃耗下的热力学性能。本研究基于FUPAC软件对UN-FeCrAl燃料元件在燃耗68000 MW·d·t−1(U)下的稳态和瞬态热力学性能进行了预测。分析结果表明,稳态工况下UN-FeCrAl燃料元件热力学性能表现良好;瞬态下UN燃料的芯块中心温度最高仅为862℃,可满足芯块温度设计要求,但FeCrAl包壳的瞬态应力最大将达到459 MPa,且瞬态应变量相比于稳态应变量最大增加了0.23%,这可能会使FeCrAl包壳面临瞬态应力和瞬态应变准则超限的风险。因此后续研究应重点关注FeCrAl包壳的瞬态应力和瞬态应变性能。Abstract: The UN-FeCrAl fuel element is one of the main schemes for high burnup application of accident tolerant fuel, and the thermodynamic property of the fuel element under high burnup needs to be evaluated. The steady and transient thermodynamic property of UN-FeCrAl fuel element under 68000 MW·d·t−1(U) was predicted by FUPAC software, and the analysis results showed there is a good thermodynamic property of UN-FeCrAl fuel element under steady condition. Under transient conditions, the maximum pellet center temperature of UN fuel is only 862℃, which can meet the requirements of pellet temperature design, but the maximum transient stress of FeCrAl cladding will reach 459 MPa, and the transient strain will increase by 0.23% compared with steady-state strain, which may make FeCrAl cladding face the risk of transient stress and transient strain criterion exceeding the limit. Therefore, the subsequent research shall focus on the transient stress and transient strain of FeCrAl cladding.
-
Key words:
- Accident tolerant fuel /
- UN fuel /
- FeCrAl cladding /
- Thermodynamic property
-
表 1 燃料元件主要参数
Table 1. Main Parameters of Fuel Element
参数 数值 包壳外径/mm 9.5 包壳内径/mm 8.8 包壳厚度/mm 0.35 芯块直径/mm 8.632 气腔长度/mm 180.9 活性段长度/mm 3657.6 初始气体压力/MPa 2.1 初始气体温度/℃ 20 表 2 瞬态性能对比
Table 2. Comparison of Transient Property
参数名 参数值 线功率密度为
24.46 kW/m线功率密度为
33.34 kW/m燃耗/[MW·d·t−1(U)] 68000 经历循环数 4 3 燃料瞬态温度/℃ 862 989 燃料元件内压/MPa 8.7 9.2 包壳瞬态应力/MPa 459 478 包壳瞬态应变变化量/% 0.23 0.29 -
[1] 涂腾,李文杰,李伟,等. UN燃料性能数值分析[J]. 核动力工程,2017, 38(6): 185-188. doi: 10.13832/j.jnpe.2017.06.0185 [2] SWEET R T, GEORGE N M, MALDONADO G I, et al. Fuel performance simulation of iron-chrome-aluminum (FeCrAl) cladding during steady-state LWR operation[J]. Nuclear Engineering and Design, 2018, 328: 10-26. [3] 邢硕,张坤,陈平,等. 燃料棒性能分析程序FUPAC V2.0的研发与验证[J]. 原子能科学技术,2021, 55(11): 2048-2053. doi: 10.7538/yzk.2020.youxian.0925 [4] HAYES S L, THOMAS J K, PEDDICORD K L. Material property correlations for uranium mononitride: III. Transport properties[J]. Journal of Nuclear Materials, 1990, 171(2-3): 289-299. doi: 10.1016/0022-3115(90)90376-X [5] STORMS E K. An equation which describes fission gas release from UN reactor fuel[J]. Journal of Nuclear Materials, 1988, 158: 119-129. doi: 10.1016/0022-3115(88)90161-4 [6] ROSS S B, EL-GENK M S, MATTHEWS R B. Uranium nitride fuel swelling correlations[J]. Journal of Nuclear Materials, 1990, 170(2): 169-177. [7] SWEET R, GEORGE N M, TERRANI K A, et al. BISON fuel performance analysis of FeCrAl cladding with updated properties: TM-2016/475[R]. Oak Ridge: Oak Ridge National Laboratory, 2016. [8] HAYES S L, THOMAS J K, PEDDICORD K L. Material property correlations for uranium mononitride: I. Physical properties[J]. Journal of Nuclear Materials, 1990, 171(2-3): 262-270. doi: 10.1016/0022-3115(90)90374-V [9] HAYES S L, THOMAS J K, PEDDICORD K L. Material property correlations for uranium mononitride: II. Mechanical properties[J]. Journal of Nuclear Materials, 1990, 171(2-3): 271-288. doi: 10.1016/0022-3115(90)90375-W [10] HAYES S L, THOMAS J K, PEDDICORD K L. Material property correlations for uranium mononitride: IV. Thermodynamic properties[J]. Journal of Nuclear Materials, 1990, 171(2-3): 300-318. doi: 10.1016/0022-3115(90)90377-Y [11] WU X, KOZLOWSKI T, HALES J D. Neutronics and fuel performance evaluation of accident tolerant FeCrAl cladding under normal operation conditions[J]. Annals of Nuclear Energy, 2015, 85: 763-775. doi: 10.1016/j.anucene.2015.06.032 [12] 雷阳,张海生,毛建军,等. 中子辐照对耐事故燃料FeCrAl合金力学性能的影响研究[J]. 核动力工程,2022, 43(1): 97-101.