• Title/Summary/Keyword: Reaction Cross Section

Search Result 113, Processing Time 0.022 seconds

A Study on the Inventory Estimation for the Activated Bioshield Concrete of KRR-2 (연구로 2호기 방사화 수조 콘크리트의 재고량 평가에 관한 연구)

  • Hong, Sang Bum;Seo, Bum Kyoung;Cho, Dong Keun;Jeong, Gyeong Hwan;Moon, Jei Kwon
    • Journal of Radiation Protection and Research
    • /
    • v.37 no.4
    • /
    • pp.202-207
    • /
    • 2012
  • The radioactivity inventory significantly affects all steps of decommissioning projects including planning, cost estimation, risk assessment, waste management and site remediation. The decommissioning project of the KRR-2 was completed in 2009 and a large amount of activated concrete waste was generated. The bioshield concrete, containing minute amount of impurity elements, was activated by neutron reaction during the operation of the reactor. A variety radionuclides was generated in the concrete, including $^3H$, $^{14}C$, $^{55}Fe$, $^{60}Co$ $^{63}Ni$, $^{134}Cs$, $^{152}Eu$ and $^{154}Eu$. In this paper, the comparison between the calculated results and previous measured results was carried out to estimate the inventory of the bioshield concrete of the KRR-2. The combined computer codes of MCNP5 and ORIGEN 2.1 for calculation of the distribution of neutron flux, cross-section and generation of radionuclides were used. The results were shown that 99.8% of the total radioactivity of $^3H$, $^{55}Fe$, $^{60}Co$ and $^{152}Eu$ in the bioshield concrete 12 years after shutdown. The effects on the variation of inventory were analysed depending on the operation periods and the cooling times in the bioshield concrete.

Morphology and Histology of the Digestive Organ in the Sablefish, Anoplopoma fimbria (Teleostei: Anoplopomatidae) (은대구, Anoplopoma fimbria 소화기관의 형태 및 조직학적 특징)

  • Kim, Suji;Kang, Ju Chan;Lee, Jung Sick
    • Korean Journal of Ichthyology
    • /
    • v.28 no.1
    • /
    • pp.19-27
    • /
    • 2016
  • The RLG (relative length of gut) is 1.52 (n=12) in the sablefish, Anoplopoma fimbria. The digestive tract has five or six pyloric caeca in the posterior region of stomach. Morphology of mucosal fold is unbranched type in the esophagus and stomach, but branched type in the intestine. The histological structure of digestive tract can be divided into mucosal layer, submucosal layer, muscular layer and serous membrane in the cross section. In the esophagus, mucosal epithelial layer is a simple, and consists of ciliated columnar epithelia and mucous cells. In the stomach, gastric gland of mucosal epithelial layer is a tubular, and is composed of chief cell, parietal cell and mucin secreting cell, which is columnar and contained secretory granules of red and blue colors in the AB-PAS (pH 2.5) reaction. In the intestine, mucosal epithelial layer is a simple, and consists of ciliated columnar epithelia and goblet cells. The submucosal layer is composed mainly of collagen fibers, and well developed in the esophagus. And the muscular layer of digestive tract is divided into longitudinal and circular muscle layer, and well developed in the stomach. The liver is composed of numerous lobular structure and bile canaliculi. Stainability of hepatocyte cytoplasm was eosinophilic, and nucleus and nucleolus showed basophilic in the H-E stain. The pancreatic tissue was scattered in the fatty tissue near the digestive tract, and acinar gland consisting of numerous exocrine cells. And cytoplasmic stainability of exocrine cell was basophilic, and contained numerous zymogen granules of eosinophilic in the H-E stain.

Effects of the Ge Prearmophization Ion Implantation on Titanium Salicide Junctions (게르마늄 Prearmophization 이온주입을 이용한 티타늄 salicide 접합부 특성 개선)

  • Kim, Sam-Dong;Lee, Seong-Dae;Lee, Jin-Gu;Hwang, In-Seok;Park, Dae-Gyu
    • Korean Journal of Materials Research
    • /
    • v.10 no.12
    • /
    • pp.812-818
    • /
    • 2000
  • We studied the effects of Ge preamorphization (PAM) on 0.25$\mu\textrm{m}$ Ti-salicide junctions using comparative study with As PAM. For each PAM schemes, ion implantations are performed at a dose of 2E14 ion/$\textrm{cm}^2$ and at 20keV energy using $^{75}$ /As+and GeF4 ion sources. Ge PAM showed better sheet resistance and within- wafer uniformity than those of As PAM at 0.257m line width of n +/p-well junctions. This attributes to enhanced C54-silicidation reaction and strong (040) preferred orientation of the C54-silicide due to minimized As presence at n+ junctions. At p+ junctions, comparable performance was obtained in Rs reduction at fine lines from both As and Ge PAM schemes. Junction leakage current (JLC) revels are below ~1E-14 A/$\mu\textrm{m}^{2}$ at area patterns for all process conditions, whereas no degradation in JLC is shown under Ge PAM condition even at edge- intensive patterns. Smooth $TiSi_2$ interface is observed by cross- section TEM (X- TEM), which supports minimized silicide agglomeration due to Ge PAM and low level of JLC. Both junction break- down voltage (JBV) and contact resistances are satisfactory at all process conditions.

  • PDF