Criteria for Optimizing Technical Solutions for NPP

Atomic Energy - Criteria for optimizing technical solutions in designing and modernizing NPP are considered. Based on their analysis, it is shown that it is economically efficient to increase the...     

地震工况下设备土建载荷的计算方法

在设备抗震分析中,设备对基础的作用力是土建设计时所需的重要参数。本文根据不同的工程实例,给出2种设备在地震工况下土建载荷的计算方法,即简便方法和谱分析计算中的刚性区域法,并给出了算例。     

Need for and requirements for a neutron irradiation facility for fusion materials testing

The construction and operation of an intense 14-MeV neutron source is essential for the development and eventual qualification of structural materials for a fusion reactor demonstration plant (DEMO). Because of the time required for materials development and the scale-up of materials to commercial production, a decision to build a neutron source should precede engineering design activities for a DEMO by at least 20 years. The characteristic features of 14-MeV neutron damage are summarized including effects related to cascade structure, transmutation production, and dose rate. The importance of a 14-MeV neutron source for addressing fundamental radiation damage issues, alloy development activities, and the development of an engineering database is discussed. For these considerations, the basic requirements and machine parameters are derived.     

Experimental Results for an Acoustic Driver for MTF

General Fusion is planning to form an FRC or spheromak of 10¹⁷ cm⁻³, 100 eV, 40 cm diameter by merging two spheromaks with reverse or co-helicity. This target will be further compressed in a 3 m diameter tank filled with liquid PbLi with the plasma in the center. The tank is surrounded with pneumatically powered impact pistons that will send a convergent shock wave in the liquid to compress the plasma to 10²⁰ cm⁻³, 10 keV, 4 cm diameter for 7 μs. General Fusion has built a 500 kJ, 80 μs, 6 GW pneumatic impact piston capable of developing 2 GPa (300 kpsi). In this paper we will present the performances achieved to date.     

Principles for Finding Matrices for Immobilizing High-Level Wastes

The principles for selecting matrices for immobilizing high-level wastes are examined. It is concluded that actinides should be separated and embeeded in the matrix separately from fission products. The minimum significant specific activity, regulated by NRB-99, cannot be used to estimate the storage time. It is suggested that such values be established as a function of the leach rate of radionuclides and matrix materials from matrices. For this, a standard leaching method using pulverized materials must be specified. Two criteria are proposed for comparing matrix materials.     

Software for gamma cameras for mapping radioactive contamination

The software for portable systems for obtaining γ image with coding apertures (masks) is described. The software developed controls all systems that form an image and obtain shadow patterns, reconstructs the initial γ-image, and processes previously obtained images. The software is used with portable systems in which URA and MURA type masks with different rank are used as the coding aperture. Programs for modeling the process of obtaining shadow patterns using real apparatus which has different positionsensitive detectors are described. Possible configurations of new apparatus which could be of practical interest are examined.     

Basis for developing samarium AMS for fuel cycle analysis

Modeling of nuclear reactor fuel burnup indicates that the production of samarium isotopes can vary significantly with reactor type and fuel cycle. The isotopic concentrations of ¹⁴⁶Sm, ¹⁴⁹Sm, and ¹⁵¹Sm are potential signatures of fuel reprocessing, if analytical techniques can overcome the inherent challenges of lanthanide chemistry, isobaric interferences, and mass/charge interferences. We review the current limitations in measurement of the target samarium isotopes and describe potential approaches for developing Sm-AMS. AMS sample form and preparation chemistry will be discussed as well as possible spectrometer operating conditions.     

AC—600非能动安全特性分析

AC-600概念设计的研究重点包括堆芯、非能动安全系统及简化系统。本文讨论 AC-600自然循环能力、LOCA 或全厂断电期间,非能动安全系统的性能,也初步讨论了 AC-600对过剩反应性及热工水力瞬态的非能动限制。     

New code for digital imaging system for track measurements

A code for the numerical analysis of images from a CCD camera, including correction of acquisition system defects, has been written and applied to the visualization of α-particle tracks in the solid state nuclear track detectors CR39 and LR115. A standard mask having different diameter holes permitted the calibration of the imaging system. Comparison of manual scanning results with those given by the automatic system are presented for detectors exposed to α-particles of ²⁴¹Am source. As application, the system was used to measure specific activities of ²³⁸U in the Moroccan phosphates and their phosphogypsums samples by contact autoradiography.     

Construction materials for reactor buildings for decommissioning and recycling

A conceptual fluid–steel structure was studied to investigate the seismic characteristics of its use in the reactor building of nuclear power plants. The results of the earthquake response analysis of the conceptual fluid–steel structure showed that the structure had the same seismic safety ability as conventional reactor buildings. Applying the fluid–steel structure to a rector building, results in the following advantages: more elastic and light weight building materials, reducing the decommissioning wastes; the ability to recycle the structure materials because the fluid in the steel structure can be discharged the steel can be reused easily; the fluid in the steel structure has the possibility of reducing the seismic response of the structure by the sloshing damper effect. Further study is encouraged by this results.