Neutronics calculation and activation analysis for CFETR magnet system

doi:10.16568/j.0254-6086.201703019

Abstract

Abstract:

The Monte Carlo neutron transport code (MCNPX) is used to carry on the neutronics calculation for CFETR magnet system, and its activation analysis is performed by FISPACT, a European activation calculation code, besides. The calculated results show that the max neutron energy flux is 3.97×10¹⁴MeV•m^–2, which meets the design requirements of the superconducting coil under this condition. The activity of magnet assembly is 3.33×10¹⁰Bq•kg^–1 when reactor is shut down, and after 10-year shut down, the activity reaches 6.14×10⁸Bq•kg^–1, which decreases two order of magnitude. Conclusively, the CFETR 3D model meets the preliminary design requirements and can provide some data support for the construction of CFETR.

Key words: CFETR, Superconducting magnet, Neutron dose rate, Activity

摘要：

用蒙特卡洛中子输运程序(MCNPX)对中国聚变工程实验CFETR超导磁体进行中子学输运计算，利用欧洲活化计算程序FISPACT对其进行活化计算分析，针对计算结果重点分析了磁体系统的中子学剂量分布以及活化情况。计算结果表明，中子能量通量最大处出现在聚变堆内侧线圈处，为3.97×10¹⁴ MeV•m^–2，在该条件下超导线圈可以满足设计要求。停机后磁体组件的活度为3.33×10¹⁰Bq•kg^–1，停机10年后下降2个数量级达到6.14×10⁸Bq•kg^–1。研究结果验证了所使用的CFETR 3维模型满足初步设计条件。

关键词: CFETR, 超导磁体, 中子剂量率, 活度

CLC Number:

TL64

QIAO Shi-ji, JIANG Shuai, CHEN Zhi, XU Xie. Neutronics calculation and activation analysis for CFETR magnet system[J]. NUCLEAR FUSION AND PLASMA PHYSICS, 2017, 37(3): 354-360.

乔世吉，蒋帅，陈志*，徐榭. CFETR磁体系统的中子学计算及活化分析[J]. 核聚变与等离子体物理, 2017, 37(3): 354-360.

References

[1] Song Y T, Wu S T, Li J G, et al. Concept design of CFETR tokamak machine[J]. Plasma Science, 2014, 42(3): 503–509.

[2] Savoldi Richard L, Bonifetto R, Bottero U, et al. Analysis of the effects of the nuclear heat load on the ITER TF magnets temperature margin[J]. Applied Superconductivity, IEEE Transactions on, 2014, 24(3): 1–4.

[3] Nishimura A, Izumi Y, Imaizumi M, et al. Neutron and gamma ray irradiation effects on interlaminar shear strength of insulation materials with cyanate ester-epoxy blended resin[J]. Fusion Engineering and Design, 2011, 86(6): 1558–1561.

[4] Prokopec R, Fischer D X, Weber H W, et al. Suitability of coated conductors for fusion magnets in view of their radiation response[J]. Superconductor Science and Technology, 2015, 28(1): 014005.

[5] Humer K, Bittner-Rohrhofer K, Fillunger H, et al. Radiation effects on the mechanical properties of insulators for fusion magnets[J]. Fusion engineering and design, 2006, 81(20): 2433–2441.

[6] Bittner-Rohrhofer K, Humer K, Fillunger H, et al. Performance of magnet insulation systems at low temperature and after reactor irradiation[C]. Advances in Cryogenic Engineering: Transactions of the International Cryogenic Materials Conference-ICMC. AIP Publishing, 2004, 711(1): 281–288.

[7] Weber H W. Neutron irradiation effects on alloy superconductors[J]. J. Nucl. Mater., 1982, 108: 572–584.

[8] Zheng J, Liu X, Song Y, et al. Concept design of CFETR superconducting magnet system based on different maintenance ports[J]. Fusion Engineering and Design, 2013, 88(11): 2960–2966.

[9] Wu Z, Li J, Huang C, et al. Processing characteristic and radiation resistance of various epoxy insulation materials for superconducting magnets[J]. Fusion Engineering and Design, 2013, 88(11): 3078–3083.

[10] Duchateau J L, Hertout P, Saoutic B, et al. Conceptual integrated approach for the magnet system of a tokamak reactor[J]. Fusion Engineering and Design, 2014, 89(11): 2606–2620.

[11] Tomi Y, Mishima F, Akiyama Y, et al. Study of Irradiation effect on electrical insulation material for superconducting magnet of nuclear fusion reactor[J]. Applied Superconductivity, IEEE Transactions on, 2012, 22(3): 7701104–7701104.

[12] 陈志, 冯开明, 张国书, 等. ITER 试验包层模块活化计算与环境安全分析[J]. 核聚变与等离子体物理, 2005, 25(3): 183-188.

[13] 宋欢, 陈志, 雷洁瑛, 等. CFETR 堆体活化计算与分析[J]. 核聚变与等离子体物理, 2014, 34(3): 235–239.

[14] Liu S, Li J, Zheng S, et al. Neutronics analysis of inboard shielding capability for a DEMO fusion reactor CFETR[J]. Fusion Engineering and Design, 2013, 88(9): 2404–2407.

[15] Waters L S. MCNPX user’s manual[J]. Los Alamos National Laboratory, 2002.

[16] Forrest R A. FISPACT-2007: User manual[M]. EURATOM/UKAEA Fusion Association, 2007.

[17] Sartori E. Standard energy group structures of cross section libraries for reactor shielding, reactor cell and fusion neutronics applications: VITAMIN-J, ECCO-33, ECCO-2000 and XMAS[J]. JEF/DOC-315, Revision, 1990, 3.

[18] Youssef M Z, Feder R, Davis I M. Neutronics analysis of the international thermonuclear experimental reactor (ITER) MCNP “Benchmark CAD Model” with the ATTILA discrete ordinance code[J]. Fusion Engineering and Design, 2008, 83(10): 1661–1668.

[19] Liu S, Pu Y, Cheng X, et al. Conceptual design of a water cooled breeder blanket for CFETR[J]. Fusion Engineering and Design, 2014, 89(7): 1380–1385.

[20] Tronza V I, Lelekhov S A, Patrikeev V M, et al. Investigation of ITER TF Conductor Hydraulic Resistance[J]. Applied Superconductivity, IEEE Transactions on, 2015, 25(3): 1–4.

[21] Zhu Y F, Song Y T, Chen Y H. Conceptual design and finite element analysis of STR-3 feeder for ITER[J]. Journal of Fusion Energy, 2014, 33(6): 775–783.

[22] Kim Y, Hong B G, Kim C H. A neutronic investigation of He-cooled liquid Li-breeder blankets for fusion power reactor[J]. Fusion Engineering and Design, 2005, 75: 1067–1070.

[23] Santoro R T. Radiation shielding for fusion reactors[J]. Journal of Nuclear Science and Technology, 2000, 37(sup1): 11–18.

[24] Prokopec R, Fischer D X, Weber H W, et al. Suitability of coated conductors for fusion magnets in view of their radiation response[J]. Superconductor Science and Technology, 2015, 28(1): 014005.

[25] Cullen G W, Novak R L. Effect of Neutron-induced defects on the current-carrying behavior of vapor deposited niobium stannide[J]. J. Appl. Phys., 1966, 37(9): 3348–3352.

[26] Bode H J, Wohlleben K. Enhancement of super- conducting critical current density in Nb₃Sn diffusion layers produced by irradiation with protons[J]. Phys. Lett. A, 1967, 24(1): 25–27.

[27] McEvoy Jr J P, Decell R F, Novak R L. Effect of neutron irradiation on critical currents in hard superconductors (Nb₃Sn and NbZr)[J]. Appl. Phys. Lett., 1964, 4: 147.

[28] Cullen G W, Novak R L. Effect of fast-neutron-included defects on the current-carrying behavior of super- conducting Nb3Sn[J]. Appl. Phys. Lett., 1964, 4: 43.

[29] Coffey H T. Distribution of magnetic fields and currents in type II superconductors[J]. Cryogenics, 1967, 7(1): 73–77.

[30] 国家环境保护局. 放射性废物分类标准GB 9133-88[S].

[31] 冯开明. 聚变实验增殖堆 FEB-E 放射性废物处置指标的计算[J]. 核聚变与等离子体物理, 2000, 20(1): 13–20.