• Title/Summary/Keyword: Leakage Rate Test

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Evaluation of Prediction Methods for Containment Integrated Leakage Rate (격납건물 종합누설률 예측방법 평가)

  • Yang, Seung-Ok;Lee, Kwang-Dae;Oh, Eung-Se
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.562-564
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    • 2004
  • The containment leakage rate test performed on the nuclear power plants consists of following phases : pressurizing the containment, stabilizing the atmosphere, conducting a Type A test, conducting a verification test, depressurizing the containment. It takes more than 48 hours from the pressurization to the depressurization and the prediction of the results will help to prepare the next test phase. In this paper, to predict the leakage rate, the prediction methods based on the least square method are evaluated according to the input variables and the measurement period.

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A new method fast measure cryogenic vessel heat leakage

  • LI, Zheng-Qing;LI, Xiao-Jin;LIU, Mo
    • Progress in Superconductivity and Cryogenics
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    • v.22 no.1
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    • pp.24-28
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    • 2020
  • Heat leakage is an important parameter to reflect heat insulated performance of cryogenic vessel. According to the current standard requirements, it needs to measure the daily evaporation rate to indicate heat leakage. The test needs-over 24h after cryogenic vessel in heat equilibrium as standard required, therefore test efficiency is poor and new efficient method is required to cut test time. First of all, the volume of instantaneous evaporated gas and heat leakage are calculated by the current standard corresponding to the maximum allowable daily evaporation rate of cryogenic vessel. Depending on the relationship between real daily evaporation rate and maximum allowable daily evaporation rate of cryogenic vessel, we designed a new test method based on the pressure changes over time in cryogenic vessel to determine whether its heat insulated performance meets requirements or not. Secondly, the heat transfer process was analyzed in measurement of cryogenic vessel, and the heat transfer equations of whole system were established. Finally, the test was completed in four hours; meanwhile the heat leakage and daily evaporation rate of cryogenic vessel are calculated basing on test data.

A Study on the Measurement Method of Leakage Flow-rate for Pneumatic Cylinder (공압실린더의 누설유량 계측방법에 관한 연구)

  • Jang J.S.;Ji S.W.;Jeong J.H.;Kang B.S.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.3 no.1
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    • pp.15-19
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    • 2006
  • In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measure from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing steel wool into it. Therefore, wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

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Development of Standard Procedures for Local Leakage Rate Testing of Containment Vessel (격납건물 국부누설률시험 표준절차 개발)

  • Moon, Yong-Sig;Kim, Chang-Soo
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.8 no.2
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    • pp.42-47
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    • 2012
  • The containment local leakage rate testing in nuclear power plants is performed in accordance with ANSI/ANS 56.8-1994 in Korea. Two methods, the make-up flow rate and the pressure decay, are used for local leakage rate testing. Though ANSI/ANS 56.8-1994 does not define clearly the minimum test duration for the make-up flow rate method, it requires obtaining the data after reaching the stable condition. Thus the prerequisite stable condition for data acquisition and the testing time is differently applied to each NPPs. Therefore, this study presents a standardized test procedure for data stabilization and testing time through experiments to improve the test reliability.

A Study on the Measurement Method of Leakage for Pneumatic Cylinder (공기압실린더의 누설유량 계측에 관한 연구)

  • Jang, J.S.;Ji, S.W.
    • Journal of Power System Engineering
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    • v.11 no.4
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    • pp.98-102
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    • 2007
  • In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measured from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing the steel wool into it. Therefore, a wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

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Pressure Drop and Leakage Performances of Flat Seals with Inclined Grooves (경사 그루브를 갖는 평판 실의 압력 강하 및 누설 성능)

  • Jung, Jin Woo;Jeong, Gwon Jong;Hwang, Sung Ho;Kim, Tae Ho;Kim, Eojin
    • Tribology and Lubricants
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    • v.38 no.5
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    • pp.213-221
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    • 2022
  • This paper presents performance measurements of pressure drop and leakage flow rate of test flat seals with asymmetric inclined grooves. This study aims to reveal the influence of groove shapes, often machined in radial film riding-face seals, in forming a hydrodynamic wedge on leakage performance. A test facility was developed, and test seals were manufactured to study the effects of the inlet pressure level, ratio of inlet to outlet pressure, seal groove length, and seal groove height on the steady-state pressure drop and leakage performance. A series of tests were conducted, and the test data were compared to the predictions from a simple and efficient mathematical model using a one-dimensional Reynolds equation. The test results revealed that an increase in the inlet pressure increased the pressure drop through the test seals. The leakage flow rate increased significantly as the inlet pressure and ratio of the inlet to outlet pressure increased. The groove shape also affects seal performance. An increase in the groove length and height resulted in an evident increase in the leakage flow rate. The simple model predictions underestimated the leakage flow rates but showed good agreement with the trend in the measurements for all test operating conditions and changes in the groove shape.

Excessive Leakage Measurement Using Pressure Decay Method in Containment Building Local Leakage Rate Test at Nuclear Power Plant (원전 격납건물 국부누설률시험에서의 압력감소법을 이용한 과다누설 측정 방법)

  • Lee, Won Kyu;Kim, Chang Soo;Kim, Wang Bae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.36 no.3
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    • pp.231-235
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    • 2016
  • There are two methods for conducting the containment local leakage rate test (LLRT) in nuclear power plants: the make-up flow rate method and the pressure decay method. The make-up flow rate method is applied first in most power plants. In this method, the leakage rate is measured by checking the flow rate of the make-up flow. However, when it is difficult to maintain the test pressure because of excessive leakage, the pressure decay method can be used as a complementary method, as the leakage rates at pressures lower than normal can be measured using this method. We studied the method of measuring over leakage using the pressure decay method for conducting the LLRT for the containment building at a nuclear power plant. We performed experiments under conditions similar to those during an LLRT conducted on-site. We measured the characteristics of the leakage rate under varies pressure decay conditions, and calculated the compensation ratio based on these data.

A study on performance of outdoor air flow rate through viovent for hybrid ventilation equipment (자연급기구내 플리머필터 설치 시 외기 침기량 분석에 관한 연구)

  • Yi, Seong-Hwan;Choi, Jong-Ak
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1337-1342
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    • 2009
  • This test was progressed in the test house of KICT as sectional research of Center for Sustainable Housing. It included a ventilation rate of hybrid ventilation equipment, temperature, and gas test using the SF-6. The purpose of this test is to demonstrate the performance of viovent by estimating an outdoor air flow rate through viovent which the flimmer filter is installed and decide the leakage after operating the constant airflow fan within a house. First, the outdoor airflow rate through viovent measured $130\;m^3/h$ more than a legal required ventilation rate, $104\;m^3/h$. And then it sufficiently satisfy a legal standard, 0.7 air change/h. Secondly, the result of this test exposes that the leakage in the residence is about $20{\sim}25%$. Especially, the outdoor air flowing through the gate occupies 50% of the total leakage.

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Dynamic Boric Acid Corrosion of Low Alloy Steel for Reactor Pressure Vessel of PWR using Mockup Test (가압형 경수로 압력용기 재료인 저합금강의 동적 붕산 부식 실증 연구)

  • Kim, Sung-Woo;Kim, Hong-Pyo;Hwang, Seong-Sik
    • Corrosion Science and Technology
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    • v.12 no.2
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    • pp.85-92
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    • 2013
  • This work is concerned with an evaluation of dynamic boric acid corrosion (BAC) of low alloy steel for reactor pressure vessel of a pressurized water reactor (PWR). Mockup test method was newly established to investigate dynamic BAC of the low alloy steel under various conditions simulating a primary water leakage incident. The average corrosion rate was measured from the weight loss of the low alloy steel specimen, and the maximum corrosion rate was obtained by the surface profilometry after the mockup test. The corrosion rates increased with the rise of the leakage rate of the primary water containing boric acid, and the presence of oxygen dissolved in the primary water also accelerated the corrosion. From the specimen surface analysis, it was found that typical flow-accelerated corrosion and jet-impingement occurred under two-phase fluid of water droplet and steam environment. The maximum corrosion rate was determined as 5.97 mm/year at the leakage rate of 20 cc/min of the primary water with a saturated content of oxygen within the range of experimental condition of this work.

Mechanical Face Seal Performance Test for 75ton Class Turbopump (75톤급 터보펌프 기계평면 실의 작동 성능 시험)

  • Jeon, Seong-Min;Kwak, Hyun-Duck;Park, Min-Joo;Kim, Jin-Han
    • Tribology and Lubricants
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    • v.25 no.3
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    • pp.187-191
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    • 2009
  • A leakage performance test and an endurance performance test of a 75 ton class turbopump mechanical face seal are performed using water under high speed and high temperature environment. A prototype mechanical face seal is manufactured for the purpose of sealing of fuel between a fuel pump and turbine. By simulating operating condition experimentally, the leakage rate and seal carbon wear rate are obtained to evaluate the performance of the prototype mechanical face seal. The test results show the acceptable leakage performance and reasonable wear tendency as well.