熔盐实验堆备用停堆方案及其可行性分析
|
摘要
反应性控制系统的设计是反应堆物理设计的主要内容之一。熔盐堆采用熔融的氟化盐混合物作为燃料,由于核燃料的特殊性,熔盐堆在反应堆设计方面与传统固体燃料反应堆有着较大区别。本文鉴于熔盐堆的特殊性,针对2 MW液态燃料钍基熔盐堆(Thorium Molten Salt Reactor-Liquid Fuel,TMSR-LF1),提出多种停堆方式,包括排燃料盐、套管中注中子毒物、改变燃料盐成分、改变堆芯石墨栅元数,并进行了计算分析。分析结果表明:往套管中注入中子毒物是在控制棒失效的情况下很好的替换停堆方式;燃料盐成分可调,是熔盐堆本身具有的特点,因此往燃料盐中添加BF_3、LiF-BeF_2-ZrF_4、LiF-ThF_4,是调节堆芯反应性很好的方式;改变石墨栅元数也可以使反应堆停堆。本研究分析可以为熔盐堆停堆方式提供技术储备和理论参考。
[Background] Reactivity control design is one of the main contents of reactor neutronics design. Molten fluoride mixture was used as fuel in molten salt reactor(MSR). Due to the particularity of nuclear fuel, molten salt reactor is different from traditional solid fuel reactor in reactor design. [Purpose] This study aims at feasibility analysis of shutdown modes with emphasis on the standby scheme. [Methods] The shutdown modes includes discharging fuel salt, injecting neutron poison into the core tube, changing the composition of fuel salts, changing the number of graphite cells. The 2 MW thorium molten salt reactor-liquid fuel(TMSR-LF1) model was taken as the reference reactor, and the calculation was completed by using Monte Carlo N particle transport code(MCNP).[Results] The analysis results show that injection of neutron poison into the core tube was a good alternative to shutdown the reactor when the control rod cannot be inserted into the core. The adjustable composition of fuel salts was the characteristic of MSR itself, thus, adding BF_3, LiF-BeF_2-ZrF_4, LiF-ThF_4 to fuel salts was a good way to adjustthe reactivity. Changing the number of graphite cells could also shutdown the reactor. [Conclusion] The analysis of this study can provide technical reserves and theoretical reference for the shutdown modes of molten salt reactor.
[Background] Reactivity control design is one of the main contents of reactor neutronics design. Molten fluoride mixture was used as fuel in molten salt reactor(MSR). Due to the particularity of nuclear fuel, molten salt reactor is different from traditional solid fuel reactor in reactor design. [Purpose] This study aims at feasibility analysis of shutdown modes with emphasis on the standby scheme. [Methods] The shutdown modes includes discharging fuel salt, injecting neutron poison into the core tube, changing the composition of fuel salts, changing the number of graphite cells. The 2 MW thorium molten salt reactor-liquid fuel(TMSR-LF1) model was taken as the reference reactor, and the calculation was completed by using Monte Carlo N particle transport code(MCNP).[Results] The analysis results show that injection of neutron poison into the core tube was a good alternative to shutdown the reactor when the control rod cannot be inserted into the core. The adjustable composition of fuel salts was the characteristic of MSR itself, thus, adding BF_3, LiF-BeF_2-ZrF_4, LiF-ThF_4 to fuel salts was a good way to adjustthe reactivity. Changing the number of graphite cells could also shutdown the reactor. [Conclusion] The analysis of this study can provide technical reserves and theoretical reference for the shutdown modes of molten salt reactor.
引文
1 Bettis E S,Schroeder R W,Cristy G A,et al.The aircraft reactor experiment-design and construction[J].Nuclear Science and Engineering,1957,2:804-825.
2 Haubenreich R C.MSRE design and operations report Part?description of reactor[R].ORNL-TM-728,Tennessee,America:ORNL,1965.
3 Haubenreich P N,Engel J R,Prince B E,et al.MSREdesign and operations report Part III nuclear analisis[R].ORNL-TM-730,Tennessee,America:ORNL,1964.
4江绵恒,徐洪杰,戴志敏.未来先进核裂变能--TMSR核能系统[J].中国科学院院刊,2012,27(3):366-374.JIANG Mianheng,XU Hongjie,DAI Zhimin.The future of advanced nuclear fission energy-TMSR nuclear energy systems[J].Bulletin of Chinese Academy of Sciences,2012,27(3):366-374.
5蔡翔舟,戴志敏,徐洪杰.钍基熔盐堆核能系统[J].物理,2016,45(9):578-590.DOI:10.7693/wl20160904.CAI Xiangzhou,DAI Zhimin,XU Hongjie.Thorium molten salt reactor nuclear energy system[J].Physics,2016,45(9):578-590.DOI:10.7693/wl20160904.
6 Pelowitz D B.MCNP6TM user's manual[R].Los Alamos,NM,USA:Los Alamos National Laboratory,LA-CP-13-00634,2013.
7于世和,刘亚芬,杨璞,等.熔盐实验堆堆芯结构变化对反应性的影响分析[J].核技术,2019,42(2):020603.DOI:10.11889/j.0253-3219.2019.hjs.42.020603.YU Shihe,LIU Yafen,YANG Pu,et al.Effect analysis of core structure changes on reactivity in molten salt experimental reactor[J].Nuclear Techniques,2019,42(2):020603.DOI:10.11889/j.0253-3219.2019.hjs.42.020603.
8 Yan R,Yu S H,Zou Y,et al.Study on neutronics design of ordered-pebble-bed fluoride-salt-cooled hightemperature experimental reactor[J].Nuclear Science and Techniques,2018,29(6):81.DOI:10.1007/s41365-018-0414-0.
9 Boustani E,Hassanzadeh M.Neutronic design investigation of a liquid injection-based second shutdown system for a typical research reactor using MCNPX[J].Nuclear Science and Techniques,2018,29(3):33.DOI:10.1007/s41365-018-0372-6.
10 Koger J W.Corrosion and mass transfer characteristics of NaBF4-NaF(92~0.8 mol%)in hastelloy n[R].ORNL-TM-3866,Tennessee,America:ORNL,1972.
11 Shaffer J H,Grimes W R,Watson G M.Boron trifluoride as a soluble poison in molten salt reactor fuels[J].Nuclear Science and Engineering,2017,12:337-340.
2 Haubenreich R C.MSRE design and operations report Part?description of reactor[R].ORNL-TM-728,Tennessee,America:ORNL,1965.
3 Haubenreich P N,Engel J R,Prince B E,et al.MSREdesign and operations report Part III nuclear analisis[R].ORNL-TM-730,Tennessee,America:ORNL,1964.
4江绵恒,徐洪杰,戴志敏.未来先进核裂变能--TMSR核能系统[J].中国科学院院刊,2012,27(3):366-374.JIANG Mianheng,XU Hongjie,DAI Zhimin.The future of advanced nuclear fission energy-TMSR nuclear energy systems[J].Bulletin of Chinese Academy of Sciences,2012,27(3):366-374.
5蔡翔舟,戴志敏,徐洪杰.钍基熔盐堆核能系统[J].物理,2016,45(9):578-590.DOI:10.7693/wl20160904.CAI Xiangzhou,DAI Zhimin,XU Hongjie.Thorium molten salt reactor nuclear energy system[J].Physics,2016,45(9):578-590.DOI:10.7693/wl20160904.
6 Pelowitz D B.MCNP6TM user's manual[R].Los Alamos,NM,USA:Los Alamos National Laboratory,LA-CP-13-00634,2013.
7于世和,刘亚芬,杨璞,等.熔盐实验堆堆芯结构变化对反应性的影响分析[J].核技术,2019,42(2):020603.DOI:10.11889/j.0253-3219.2019.hjs.42.020603.YU Shihe,LIU Yafen,YANG Pu,et al.Effect analysis of core structure changes on reactivity in molten salt experimental reactor[J].Nuclear Techniques,2019,42(2):020603.DOI:10.11889/j.0253-3219.2019.hjs.42.020603.
8 Yan R,Yu S H,Zou Y,et al.Study on neutronics design of ordered-pebble-bed fluoride-salt-cooled hightemperature experimental reactor[J].Nuclear Science and Techniques,2018,29(6):81.DOI:10.1007/s41365-018-0414-0.
9 Boustani E,Hassanzadeh M.Neutronic design investigation of a liquid injection-based second shutdown system for a typical research reactor using MCNPX[J].Nuclear Science and Techniques,2018,29(3):33.DOI:10.1007/s41365-018-0372-6.
10 Koger J W.Corrosion and mass transfer characteristics of NaBF4-NaF(92~0.8 mol%)in hastelloy n[R].ORNL-TM-3866,Tennessee,America:ORNL,1972.
11 Shaffer J H,Grimes W R,Watson G M.Boron trifluoride as a soluble poison in molten salt reactor fuels[J].Nuclear Science and Engineering,2017,12:337-340.