Development and Verification of Ph Calculation Model of in-Containment Refueling Water Storage Tank under Severe Accidents
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摘要: 为解决事故后核电厂安全壳内水池pH值计算工具缺失的问题,研究开发了可直接建模和实时模拟的pH值计算模型。基于牛顿拉夫森方法,通过建立关键物项物性及反应数据库,构建气-液两相化学平衡计算模型,开发了数据库完整、具备高辐照反应计算能力和事故进程耦合能力的pH值计算软件CalcpH。针对不同计算功能,CalcpH软件计算结果分别与事故分析软件ASTEC和化学平衡计算软件PHREEQC计算结果进行了对比。结果表明,对于非辐照反应,CalcpH软件计算结果与PHREEQC软件计算结果差距在1.3%以内;对于辐照反应,CalcpH软件计算结果与ASTEC软件计算结果差距在2.7%以内。同时,CalcpH软件计算结果与实验对比,其误差在1%以内。通过软件对比与实验对比2种方式充分证明了计算结果的可靠性。因此,CalcpH软件建立的数值计算模型可用于事故后安全壳内水池pH值的预测。Abstract: In order to solve the problem of lacking tools for calculating the pH value of in-containment refueling water storage tank in nuclear power plants after the accident, this paper develops a direct modeling and in-time analysis model for pH value calculation. Based on Newton-Raphson method, by establishing the database of physical properties of key items and reactions, and by building a gas-liquid two-phase chemical equilibrium model, a pH value calculation software CalcpH with a complete database, the capability of high radiation calculation and the capability of coupling calculation with accident evolution is developed. The results of CalcpH are compared with the results calculated by ASTEC (a commonly used severe accident analysis software) and PHREEQC (a commonly used chemical equilibrium analysis software). For non-irradiation reactions, the difference between the calculation results of CalcpH and the results of PHREEQC is within 1.3%. For irradiation reactions, the difference between the results of CalcpH and the results of ASTEC is within 2.7%. While comparing the calculation results of CalcpH with experimental results, the difference is within 1%. The reliability of the calculation results is fully proved by software comparison and experimental comparison. Therefore, the numerical calculation model established by CalcpH can be used to predict the pH value of in-containment refueling water storage tank after the accident..
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Key words:
- Severe accident /
- Source term /
- pH value
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表 1 影响pH值的关键物项
Table 1. Key Items Affecting pH Value
物质名称 来源 酸碱性 硝酸(HNO3) 空气和水辐照分解产物 酸性 盐酸(HCl) 含氯电缆辐照分解和热分解产物 酸性 硼酸(H3BO3) 安注、喷淋、换料水箱、反应堆冷却系统 酸性 氢碘酸 (HI) 酸性裂变产物 酸性 碳酸 (H3CO3) 空气中CO2的溶解 酸性 有机酸 有机物杂质与水辐照分解产物作用产生 酸性 pH值控制添加剂 在回流水流道上调节篮中添加以控制pH值 碱性 氢氧化锂(LiOH) 反应堆冷却系统 碱性 氢氧化铯(CsOH) 碱性裂变产物 碱性 碱性氧化物(NaOH) 堆芯熔融物与混凝土作用产生气溶胶 碱性 -
[1] 郑华. EPR与CPR1000严重事故缓解措施比较[J]. 核科学与工程,2010, 30(3): 250-257. [2] CLÉMENT B, HANNIET-GIRAULT N, REPETTO G, et al. LWR severe accident simulation: synthesis of the results and interpretation of the first Phebus FP experiment FPT0[J]. Nuclear Engineering and Design, 2003, 226(1): 5-82. doi: 10.1016/S0029-5493(03)00157-2 [3] CRIPPS R C, GÜNTAY S, JÄCKEL B. The PSIodine code: a computer program to model experimental data on iodine and other species in irradiated CsI solutions sparged with argon, air, or nitrous oxide[J]. Nuclear Engineering and Design, 2011, 241(10): 4306-4325. doi: 10.1016/j.nucengdes.2011.08.010 [4] WREN J C, BALL J M. LIRIC 3.2 an updated model for iodine behaviour in the presence of organic impurities[J]. Radiation Physics and Chemistry, 2001, 60(6): 577-596. doi: 10.1016/S0969-806X(00)00385-6 [5] MORIYAMA K, MARUYAMA Y, NAKAMURA H. Kiche: a simulation tool for kinetics of iodine chemistry in the containment of light water reactors under severe accident conditions (Contract research): JAEA-Data/Code 2010-034[R]. Tokai: Japan Atomic Energy Agency, 2011. [6] FRANK RAHN. MAAP4 - modular accident analysis, nuclear power division: RP3131-02[R]. U. S. : Electric Power Research Institute, 2007 [7] GAUNTT R O, CASH J E, COLE R K, et al. MELCOR computer code manuals vol. 2: reference manuals: NUREG/CR-6119[R]. Washington: U. S. : Nuclear Regulatory Commission, 2005. [8] COUSIN F. ASTEC V2.2 pH module: Modelling and user manual: IRSN/2016-00117[R]: France: Saint-Paul-Lez-Durance, IRSN, 2016 [9] PARKHURST D L, APPELO C A J. User’s guide to PHREEQC (version 2)-a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations: Water-Resources Investigations Report 99-4259[R]. Denver: U. S. Department of the Interior, 1999. [10] BEAHM E C, LORENZ R A, WEBER C F. Iodine evolution and pH control: NUREG/CR-5950[R]. Washington: U. S. Nuclear Regulatory Commission, 1992. [11] WREN J C, BALL J M, GLOWA G A. Studies on the effects of organic-painted surfaces on pH and organic iodide formation: NEA/CSNI/R(99)7[R]. Vantaa, Finland: OECD Workshop on Iodine Aspects of Severe Accident Management, 1999. [12] BEAHM E C, WEBER C F, KRESS T S, et al. Iodine chemical forms in LWR severe accidents: NUREG/CR-5732[R]. Washington: U. S.: Nuclear Regulatory Commission, 1992. [13] KEKKI T, ZILLIACUS R. Formation of nitric acid during high gamma dose radiation: VTT-R-00774-11[R]. Finland: VTT Technical Research Centre of Finland, 2011. [14] LANGMUIR D. Aqueous environmental geochemistry[M]. Upper Saddle River, New Jersey: Prentice Hall, 1997: 600.