Determination of plutonium in soil and bottom sediments in the region of the scientific-research institute of atomic reactors

Scientific-Industrial Firm The Radium Institute. Scientific-Research Institute of Atomic Reactors, Dimitrovgrad. Translated from Atomnaya Énergiya, Vol. 75, No. 4, pp. 319-324, October, 1993.     

Transformation of the forms of90Sr and137Cs in soil and bottom deposits

A method is proposed for estimating the distribution factors of¹³⁷Cs and⁹⁰Sr in soil and deposits. The method is based on predicting the forms in which these radionuclides occur and estimating the exchange distribution factor. It is shown that fixation of the radionuclides is a reversible process. A model is proposed for the transformation of the chemical forms of¹³⁷Cs and⁹⁰Sr. including leaching from fuel particles, fixation, and remobilization. It is shown that a first-order kinetic model satisfactorily describes the transformation of the forms of⁹⁰Sr as well as¹³⁷Cs for time periods of about one month. For longer periods of time, a diffusion fixation model is best for¹³⁷Cs. Recommendations are made for the key parameters for various types of soils. 1 figure, 2 tables, 11 references. Scientific and Industrial Association “Taifun.” Translated from Atomnaya énergiya, Vol. 88, No. 1, pp. 55–60, January, 2000.     

Analysis of the content of global 90Sr in the water and bottom deposits of reservoirs

A computational scheme, based on the systematic use of two models and permitting detailed (with different degrees of accuracy) estimation of the volume and specific activity of global-fallout ⁹⁰Sr in the water and bottom deposits of reservoirs, is proposed. As an example of the application of this approach, a comparison is made between the computational results and measurement data for reconstruction of the background contamination with global ⁹⁰Sr of Lakes Pes’vo and Udomlya-reservoirs for the Kalinin nuclear power plant. The computational results agree satisfactorily with the experimental data. __________ Translated from Atomnaya énergiya,Vol. 100, No. 6, pp. 471–478, June, 2006.     

南海北部深海沉积物热释光测量研究

本文用热释光断代研究了深海沉积物的年龄,测得南海北部陆坡维玛一、五、六井中的沉积物年龄分别36、100和128千年。     

某铀成矿带地下水中同位素组成特征与铀矿找矿标志探讨

鄂尔多斯盆地北部某铀成矿带是近10年发现的大型可地浸砂岩型铀成矿带,诸多生产和研究部门对其成矿地质条件、成矿环境、控矿因素与成矿远景进行了研究,取得了可喜的找矿成果。由于此类矿床属盲矿,其找矿和矿体定位预测有较大的难度。为进一步扩大找矿成果,试图通过同位素水文学的应用,探索铀成矿环境和盲矿找矿的水文地球化学及同位素水文地球化学标志。     

同位素分子势能函数的核运动及同位素效应

一般的分子势能函数均未考虑核运动效应,仅是Born-Oppenheimer近似下电子的本征能量函数,因此,具有相同电子数和不同质量数的同位素分子势能函数不可区分.基于核运动效应,用核的振动、转动和平动能修正Born-Oppenheimer近似下的电子能量,可求得同位素分子的离解能和力常数,并以此确定三体项的参数.利用同位素效应,可推导同位素两体项势能函数的各参数,由此可获得同位素分子的多体项展式解析势能函数.以HTO((X)1A1)为例,用核运动效应和同位素效应获得了其多体项展式解析势能函数,其等值势能图正确反映了((X)1A1)的平衡构型和离解能、H和T的同位素效应,以及H OT-HTO和T OH-HTO的反应特征.     

Isotopic composition and residual heat release of oxide fuel with a high americium content after irradiation in bor-60

Calculations of the isotopic composition, residual heat release, and helium content in mixed oxide fuel with a high americium content during a run and during prolonged cooldown were performed for a BOR-60 fast reactor as part of the preparation for the experimental program RETSIKL. The fuel composition consisted of 75% enriched uranium and 20 or 50% by mass of americium-curium fraction and rare-earth elements of spent VVéR-1000 fuel (burnup 40 GW-daylton, 10 year holding period). The americium transmutation rate is about 16.5% for the reactor run, the mass of the accumulated curium is about 13% of the mass of the transmuted americium, the plutonium mass is 35–45% of the latter (almost all on the plutonium consists of nonfissioning isotopes). The total helium accumulation can reach 1 kg/ton of heavy metals. The residual heat release due to α decay²⁴²Cm in about 1 month is ∼1 MW/ton, which has important consequences for planned or emergency shutdown of a reactor. 1 figure, 5 tables, 3 references. Federal Science Center of the Russian Federation-A.I. Leipunskii Physics and Power-Engineering Institute. Translated from Atomnaya énergiya, Vol. 87, No. 5, pp. 360–365, November, 1999.