• Title/Summary/Keyword: 방사성 부식생성물

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Study on the Simulation of Crud Formation using Piping Materials of Nuclear Power Plant in High Temperature Water (원자력 발전소 배관재를 이용한 고온 수화학 조건에서의 방사화 부식생성물 모사에 관한 연구)

  • Kim Sang Hyun;Kim In Sup;Lee Kun Jai
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.1
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    • pp.31-40
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    • 2005
  • High temperature - high pressure apparatus was developed to simulate nickel fewite corrosion products which were main compositions of the radioactive crud in the nuclear power plant. Corrosion product similar to the crud was obtained by a tube accumulator system. Nickel alloy (Inconel 690) and carbon steel (SA106 Gr. C) were corroded at 270 $\^{circ}C$ in the corrosion product generator. Ni ions and Fe ions dissolved by corrosion reaction were able to be transported to the accumulator because the crud generation mechanism was the solubility change with temperature. To evaluate the properties of simulated corrosion products, scanning electron microscope (SEM) observation and EDAX analysis were performed. SEM observation of corrosion product showed the needlelike or crystal structure of oxide depending on precipitating location. The crystal oxide was the nickel ferrite, which was similar to the crud in nuclear power plants.

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원전 출력감발 운전에 따른 방사성 부식생성물 거동 분석

  • 성기방
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11a
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    • pp.103-109
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    • 1996
  • 고리 원자력 1호기 14주기(‘95년도) 운전기간 중 증기발생기 세관 열전달 용량 저하로 전출력 운전 기간동안 정격출력보다 15% 감발 운전한 경험이 있었는데, 이 기간중 냉각재내 방사성 부식생성물(CRUD) 농도가 약 80% 감소됨을 발견하였다. 이때 출력감소 비율보다 많은 CRUD 감소현상 규명을 위해 냉각재 수질관리인자와 EPRI 피복재 부식모델인 PFCC코드를 사용한 피 복재 산화물 두께변화 등을 비교한 결과, 운전중 용출되는 방사성 부식생성물은 핵연료 표면의 피복재 산화물에 흡착된 Co핵종이 피복재 산화물 이탈시 함께 거동하는 것으로 확인되었으며, 피복재 산화물 이탈은 산화막 두께 및 열유속에 주로 의존함이 밝혀졌다. 따라서 냉각재내에서 방사성 부식 생성물의 생성률 저감을 위해서는 정상운전시 핵연료 표면의 산화막 증가를 억제할 수 있는 수질 조건을 도출하고 그에따른 운전을 통해 원전 작업자의 방사선 피폭량 저감 및 방사성폐기물의 발생을 줄일 수 있을 것으로 여겨진다.

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A Study on Corrosion Product Behavior Prediction for Domestic PWR Primary System by using CRUDTRAN (CRUDTRAN을 이용한 국내 PWR 1차계통내 부식생성물 거동예측에 관한 연구)

  • Song, Jong Soon;Yoon, Tae-Bin;Lee, Sang-Heon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.4
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    • pp.253-262
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    • 2015
  • Radionuclide deposited on the surface of several internal and external systems in a nuclear power plant is created by the activation of corrosion products from nuclear reactor structural materials and fission products. Especially, the constant contact between water and the surface corrodes the inside where primary system makes coolants and corrosion products mixed. Also, these are circulated along the systems. For comparing models, CRUDTRAN, DISER, MIGA-RT and CPAIR codes are analyzed to predict the quantity of radionuclide and corrosion product of primary reactor that are used at the stage of designing. The corrosion products behavior of domestic PWR primary system was predicted by using CRUDTRAN. This study aims to increase the reliability of corrosion product evaluation model by comparing the actual values and calculated values with the data of a Westing House-type Nuclear Power Plant.

A Study on the Method for the Removal of Radioactive Corrosion Produce Using Permanent and Electric Magnets

  • Kong Tae-Young;Song Min-Chul;Lee Kun-Jai
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.2
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    • pp.113-123
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    • 2005
  • The removal of radioactive corrosion products from the reactor coolant through a magnetic filter system is one of the many approaches being investigated as a means to reduce radiation sources and exposures to the operational and maintenance personnel in a nuclear power plant. Many research activities in water chemistry, therefore, have been performed to provide a filtration system with high reliability and feasibility and are still in process. In this study, it was devised the magnetic filter system with permanent and electric magnets to remove the corrosion products in the coolant stream taking an advantage of the magnetic properties of corrosion particles. Permanent magnets were used for separation of corrosion products and electric magnets were utilized for flocculation of colloidal particles to increase in their size. Experiments using only permanent magnets, in the previous study, displayed the satisfactory outcome of filtering corrosion products and indicated that the removal efficiency was more than 90 $\%$ for above 5 $\mu$m particles. Experiments using electric magnets also showed the good performance of flocculation without chemical agents and exhibited that most corrosion particles were flocculated into larger aggregates about 5 $\mu$m and over in diameter. It is, thus, expected that the magnetic filter system with the arrangement of permanent and electric magnets will be an effective way for the removal of radioactive corrosion products with considerably high removal efficiency.

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A Study on Radioactive Source-term Assessment Method for Decommissioning PWR Primary System (PWR 1차계통내 해체 방사성선원항 평가방법에 관한 연구)

  • Song, Jong Soon;Kim, Hyun-Min;Lee, Sang-Heon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.2
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    • pp.153-164
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    • 2014
  • Currently, there are many programs which are now being developed or already developed to predict radionuclide and corrosion product at the stage of designing NPP. However, since there are not many developments in evaluating quantity of activation corrosion products occurring when disassembling a nuclear power plant there exist some difficulties in calculating accurately. In order to evaluate activation products inventory for the research of effect of neutron activation in the reactor vessel, component of nuclear reactor and adjacent structures, it should be evaluated by using operation history of nuclear reactor, material composition of structure and average neutron flux in every field representing fixed structure of nuclear reactor. In this study, CORA, PACTOLE, CRUDSIM, CREAT and ACE codes are analyzed to predict the quantity of radionuclide and corrosion product of primary reactor which is used at the stage of designing. As a future study, the accuracy in calculating the quantity of product corrosion can be increase by finding out the possibility of use and improvement for evaluation of the decontamination.

A Study on the Removal Method of Radioactive Corrosion Product using its Magnetic Property (방사성 부식생성물의 자기적 성질을 이용한 제거방법에 대한 연구)

  • 송민철;공태영;이건재
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.1 no.1
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    • pp.73-79
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    • 2003
  • In a pressurized water reactor, radioactive corrosion products (CRUD) in primary coolant system are one of the major sources for the occupational radiation exposure of the personnel in a nuclear power plant. Through the recent trend of long term fuel cycle in a nuclear power Plant, radioactive corrosion products deposited in reactor core for a long time are also the cause of Axial Offset Anomaly (AOA) having m effect on reactor power by the hideout of boron. CRUD consist primarily of magnetite, nickel ferrite, cobalt ferrite, and so on. They have the characteristic of strong magnetism. Therefore it is performed the conceptual design to develop the filter which removes the CRUD by magnetic field that is generated by an arrangement of permanent and electric magnets. Contrary to the conventional filter, the proposed filter does not interrupt the fluid flow, so there is little pressure drop and it can be used continuously. It is expected to be applied as one of the technologies for removal of the CRUB.

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Conceptual Design of the Filter using Electromagnet and Permanent Magnets for Removal of Radioactive Corrosion Products (방사성 부식생성물 제거를 위한 전자석 및 영구자석을 이용한 필터의 개념설계)

  • 송민철;공태영;이건재
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.38-42
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    • 2003
  • In a pressurized water reactor, radioactive corrosion products (CRUD) in primary coolant system are one of the major sources for the occupational radiation exposure of the personnel in a nuclear power plant. Through the recent trend of long term fuel cycle in a nuclear power plant, radioactive corrosion products deposited in reactor core for a long time are also the cause of Axial Offset Anomaly (AOA) having an effect on reactor power by the hideout of boron. CRUD consist primarily of magnetite, nickel ferrite, cobalt ferrite, and so on. They have the characteristic of strong magnetism. Therefore it is peformed the conceptual design to develop the filter which removes the CRUD by magnetic field that is generated by an arrangement of permanent and electric magnets. Contrary to the conventional filter, the proposed filter does not interrupt the fluid flow, so there is little pressure drop and it can be used continuously. It is expected to be applied as one of the technologies for removal of the CRUD.

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