• Title/Summary/Keyword: Reactivity control

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Virtual Simulator Rod Control System Modeling for Nuclear Power Plant Operator Training (원자력 발전소 운전원 훈련용 가상 시뮬레이터 제어봉 제어계통 모델링)

  • Choi J.H.
    • Proceedings of the KIPE Conference
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    • 2003.07a
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    • pp.133-136
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    • 2003
  • 이 논문은 고리 $\#$1 원자력 발전소를 기준 발전소로 하여 개발되고 있는운전원 교육용 가상 시뮬레이터 의 일부로서, 제어봉 제어계통 모델링에 대한 내용을 제시하는 것이 주된 목적이다. 제어봉 제어 계통의 목적은 원자로 출력을 변화시키기 위하여 제어봉 집합체(RCCA)를 동작시켜 단기적인 반응도(Short Term Reactivity)를 조절하기 위한 것이다. 실제 발전소와 똑같은 제어봉 제어가 가능하면, 실제로 운전원이 가상 시뮬레이터를 통해서 모든 상황과 사고들을 대처하는 능력을 가질 수 있도록 설계되었다 본 논문에서는 고리 $\#$1 원자력 발전소 운전원 교육용 가상 시뮬레이터를 구현하기 위해 현재까지 설계된 제어봉 제어계통의 기능, 구성, 제어봉 제어에 대한 전반적인 내용을 제시하고자 한다.

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Spontaneous Multicentric Malignant Schwannoma in a Male Fischer 344 Rat

  • Kim, Bang-Hyun;Cho, Wan-Seob;Han, Beom-Seok
    • Toxicological Research
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    • v.27 no.3
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    • pp.149-152
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    • 2011
  • We describe here a multicentric spontaneous malignant schwannoma obtained from one male F344 rat, and this animal was the subject of a carcinogenicity study for which it was treated with diisodecyl phthalate. The animal of the control group not treated with diisodecyl phthalate showed dyspnea and severe lordosis. On the necropsy, two tan, firm, encapsulated masses were observed in the subcutis of the lumbosacral region and the left inguinal region of the abdominal cavity, respectively; the masses were $25{\times}17{\times}8$ mm and $16{\times}14{\times}8$ mm in size, respectively. Histologically, the tumor consisted of spindle and pleomorphic cells that grew in various patterns, that was, sweeping fascicles and herringbone and local organoid patterns. The pleomorphic neoplastic cells had more than two nuclei. Additionally, the diagnosis of malignant schwannoma was confirmed by the immune reactivity of the tumor cells for S-100 protein.

Effect of Panax ginseng Extract on Passive Avoidance Retention in Old Rats

  • Jaenicke, Bernhard;Kim, Eun-Joo;Ahn, Jong-Woong;Lee, Hye-Sook
    • Archives of Pharmacal Research
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    • v.14 no.1
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    • pp.25-29
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    • 1991
  • Female rats of two groups (6 and 27 months) were tested in the passive avoidance test to investigate the age-dependency of the learning ability. The results showed a significantly better avoidance behavior in the young adult animals compared to the older ones. The influence of a 13-day treatment with Panax ginseng (30 mg/kg/d, oral) on 27 month old rats caused a considerably prolonging of the latency time in comparison to the untreated control group of the same age. In the open field the treated rats exhibited neither an altered locomotion nor exploration nor a changed emotional reactivity which could explain the improved avoidance reaction.

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CANDU형 원자로에서의 증분격자상수 계산 방법 평가

  • 배창준;김봉기;민병주;정창준;이상용
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.10a
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    • pp.55-60
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    • 1995
  • CANDU형 원자로의 노심해석을 위해 핵연료 격자 및 반응도 설비(reactivity devices)에 대한 2군 군정수가 필요하다. 특히 CANDU형 원자로의 노심해석에 있어서 반응도 설비나 구조물은 증분격자 상수(Incremental Cross Section)에 의해 묘사된다. 현재 CANDU형 원자로의 반응도 설비의 증분격자 상수를 계산하기 위해 MULTICELL 코드를 사용하여 계산하고 있다. 그러나 weak absorber에 대해 기존의 증분격자 상수를 이용하여 계산한 반응도가는 시운전(Phase-B)조건에서의 노물리 시험치보다 다소 과소평가하고 있다. 본 연구에서는 증분격자 상수 계산 방법의 개선 방향을 모색하기 위해 SHETAN 및 MCNP 코드로 단일 격자에서의 반응도가를 계산하여 비교, 평가하였다. HCNP 계산의 결과는 조정봉(Adjuster rods)과 흡수봉/정지봉 (Mechanical Control Absorber/Shutoff rod)은 MULTICELL의 계산 결과보다 적으며, 경수영역 조절기(Liquid Zone Controller)는 크게 나타났다. 또한 SHETAN 코드를 이용한 결과는 MULTICELL의 결과보다 약간 크게 나타났다.

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Axial BP Zoning for the Soluble Boron Free Operation in Medium-Sized PWR

  • Kim, Jong-Chae;Kim, Myung-Hyun
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11a
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    • pp.59-64
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    • 1996
  • Feasibility of soluble boron free operation for the medium-sized commercial reactors was investigated. Westinghouse advanced reactor, AP-600 was chosen as a design prototype. Design modification was applied for the assembly design with gadolinia burnable poison-high Gd enrichment and axial poison zoning. CASMO and NECTA-C code system checked axial offset and peaking factors as fuels burned up. A core with complex axial burnable poison zoning satisfied design goals - small excess reactivity for 18 month cycle. Therefore, critical bank positioning for three control rod banks was sought with ease. A.O. value and Fq value were kept within the safety limit.

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Mono-layer Compositional Analysis of Surface of Mineral Grains by Time-of-Flight Secondary-Ion Mass Spectrometry (TOF-SIMS).

  • Kim, Ju-Yeong;Chryssoulis, S.;Gong, Bong-Seong
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2005.05a
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    • pp.50-57
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    • 2005
  • Although the bulk composition of materials is one of the major considerations in extractive metallurgy and environmental science, surface composition and topography (edges and dislocations are preferred sites for physicochemical reactions) control surface reactivity, and consequently play a major role in determining metallurgical phenomena and pollution by heavy metals and organics. An understanding of interaction mechanisms of different chemical species with the mineral surface in an aqueous media is very important in natural environment and metallurgical processing. X-ray photoelectron spectroscopy (XPS) has been used as an ex-situ analytical technique, but the material to be analyzed can be any size from $100{\mu}m$ up to about 1 cm. It can also measure mixed solids powders, but it is impossible to ascertain the original source of resulting x-ray signals where they were emitted from, since it radiates and scans the macro sample surface area.

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Ozonation of Reactive Dyes and Control of THM Formation Potentials (오존산화에 의한 반응성염료의 제거 및 THM생성능의 제어)

  • 한명호;김범수;허만우
    • Textile Coloration and Finishing
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    • v.16 no.2
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    • pp.34-40
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    • 2004
  • This study was conducted to remove the reactive dyes by the Ozone demand flask method which are one of the main pollutants in dye wastewater, Ozone oxidation of three kinds of the reactive dyes was examined to investigate the reactivity of dyes with ozone, Trihalomethane formation potentials(THMFPs), competition reaction and ozone utilization on various conditions for single- and multi-solute dye solution. Concentration of dyes was decreased continuously with increasing ozone dosage in the single-solute dye solutions. THMFPs per unit dye concentration were gradually increased with increase of ozone dosage. By the result of THMFPs change with reaction time, THMFPs were rapidly decreased within 1 minute in single-solute dye solutions. Dey were increased after 1 minute of reaction time, and then they were consistently decreased again after longer reaction time. Competition quotient values were calculated to investigate the preferential oxidation of individual dyes in multi-solute dye solutions. Competition quotients$(CQ_i)$ and values of the overall utilization efficiency, no$_3$, were increased at 40mg/1 of ozone dosage in multi-solute dye solutions.

Solid-state Synthesis of $Mg_2X$ (X=Si, Ge, Sn and Pb) via Bulk Mechanical Alloying

  • Aizawa, Tatsuhiko;Song, Renbo
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.831-832
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    • 2006
  • Solid-state processing via the bulk mechanical alloying enables us to directly fabricate $Mg_2X$ semi-conductive material performs. Precise control of chemical composition leads to investigation on the dilution and enrichment of X in $Mg_2X$. Two types of solid-state reactivity are introduced: e.g. synthesis of $Mg_2Si$ from elemental mixture Mg-Si is nucleation-controlled process while synthesis of $Mg_2Sn$ from Mg-Sn, diffusion-controlled process. Thermoelectricity of these $Mg_2X$ is evaluated for discussion on the validity and effectiveness of this new PM route as a reliable tool for fabrication of thermoelectric compounds.

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Particle Size and Shape Analysis : The Key to Success in Metal Powder Production

  • Pankewitz, Axel;Park, Yong-Jae
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.702-703
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    • 2006
  • The particle size distribution and shape are among the important parameters for characterisation of quality of metal powders. Specific material properties such as ability to flow, reactivity as well as compressibility and its hardening potentials hence the most important characteristics of sintered metals - are determined by the size distribution and shape. The correct particle size distribution and particle shape information are the key to best product quality in atomisation processes of aluminium, milling of pure metals and other processes. This paper presents state-of-the-art technology for characterization of particle size distribution and shape.

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Utilization of waste fine tailing as cement mineral admixture (폐광미 미립분의 시멘트 혼화재로의 활용)

  • An, Yang-Jin;Yu, Seung-Wan;Mun, Kyoung-Ju;Park, Won-Chun;Soh, Yang-Seob
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.381-384
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    • 2005
  • The purpose of this study reutilization of waste fine tailing (FT) as admixture for cement and concrete. Various admixtures were made of Fine tailings and 2 Types of OPC, fly-ash and blast furnace slag. Cement mortars and concrete with FT are tested for fluidity and compressive strength. Also, the hydration reactivity of cement mortar with FT was examined by XRD and SEM morphology analysis. This work showed that the waste fine tailing could be effectively utilized as replacement materials of cement without any decrease in the strength if we can control the blaine of materials like cement, blast furnace slag and fly ash.

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