Main-coolant-pump shaft-seal reliability investigation. Interim report

The US NRC’s post-Fukushima taskforce recommend extending the coping time up to at least 72 hours. In PWRs, the reactor coolant pump (RCP), and more particularly the shaft seal system located between the motor and the impeller, are directly impacted by these recommendations [AREVA, 2012]. Considering the importance of station black out (SBO) condition, seal performance of RCP shaft seal assembly shall be verified especially under an extended SBO condition. As a final stage of the localization program of the RCP, KAERI performed a seal LOCA test to verify seal leakage characteristics and to produce qualified experimental data for a plant safety analysis during the extended SBO condition. The seal verification test was performed using the localized seal assembly, fabricated by DOOSAN Heavy Industries & Construction Company of Korea, along with the commercial APR1400’s RCP for the Shin-Kori unit-5 nuclear plant to simulate an actual condition of the commercial nuclear power plant. Test condition was derived from a series of safety analysis for the APR1400 plant which reflected the FLEX procedure, and it consisted of three major sub-conditions such as high-pressure and high-temperature condition, saturated condition, and low-pressure and low-temperature condition. The major concerning point of the test is to measure a seal leakage flow rate during the test period. Total leakage amount and maximum leakage flow rate through the localized shaft seal assembly during the whole period of the test are in comparatively smaller ranges than the conventional input values used for a safety analysis of APR1400.

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Design of Test Bench for Flyweel of the Shaft-Seal Nuclear Coolant Pump and ANSYS Analysis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.644-650.559 ◽

2014 ◽

Vol 644-650 ◽

pp. 559-562 ◽

Cited By ~ 1

Author(s):

Sheng Song Wang ◽

Ping Hu ◽

Hai Ni Yao

Keyword(s):

Test Bench ◽

Ansys Software ◽

Shaft Seal ◽

Element Analysis ◽

Coolant Pump ◽

Pump Design ◽

Ansys Analysis ◽

Strength And Stiffness ◽

Test Requirements ◽

Nuclear Coolant

Due to the test requirements of flyweel of the shaft-seal nuclear coolant pump, design the structure of the test bench.Based on the theory of finite element analysis,use ANSYS software carries on its ststic analysis to gain the displacement and the stress form in order to check the strength and stiffness,and then carries on modal analysis to get its first six natural frequency and vibration in order to verify the rationality of design.CLC :TH122

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Vibration Alarm Analysis and Treatment of Main Coolant Pump in Nuclear Power Plant

Volume 1: Operations and Maintenance, Engineering, Modifications, Life Extension, Life Cycle and Balance of Plant; I&C, Digital Controls, and Influence of Human Factors ◽

10.1115/icone25-67481 ◽

2017 ◽

Author(s):

Zhen Li ◽

Pengcheng Du ◽

Gujian Ma

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Water Flow ◽

Vibration Analysis ◽

Nuclear Power ◽

Dynamic Balance ◽

Coolant Pump ◽

Pump Design ◽

Pump Shaft ◽

Shaft Vibration

The structure of main coolant pump in a nuclear power plant and vibration alarm are introduced. Vibration analysis and trouble diagnosis have been carried out. It shows that pump shaft vibration is mainly composed of running frequency (1×) and half of running frequency (0.5×), motor shaft vibration is just composed of 1×. The vibration fluctuation in pump shaft is caused by the variation of amplitude in 0.5×. Based on vibration analysis result, the fault investigation has been launched, in which it includes installment, measurement, dynamic balance and pump design. After detailed investigation, the excessive vibration was induced by the dynamic unbalance of pump shaft and unsteady vortex of shaft seal water. The research for treatment has been implemented on dynamic balance and seal water flow. It is suggested to increase the seal water flow to control vibration fluctuation. The result shows that this method is effective, economical, safe, and very easy to implement for suppressing flash vibration alarm.

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Decontamination of a Contaminated RCP Shaft Using the SP-HyBRID Process

Processes ◽

10.3390/pr9101725 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1725

Author(s):

Hee-Chul Eun ◽

Na-On Chang ◽

Wang-Kyu Choi ◽

Sang-Yoon Park ◽

Seon-Byeong Kim ◽

...

Keyword(s):

Decontamination Factor ◽

Hybrid Process ◽

Waste Generation ◽

Nuclear Facility ◽

Experimental Conditions ◽

Coolant Pump ◽

Reactor Coolant ◽

Pump Shaft ◽

Shaft Surface ◽

Coolant System

It is very important to minimize the waste generation for decontamination of the reactor coolant system in a nuclear facility. As an alternative to commercial decontamination technologies, an inorganic acid chemical decontamination (SP-HyBRID) process can be effectively applied to the decontamination because it can significantly reduce the waste generation. In this study, the decontamination of a contaminated reactor coolant pump shaft from a nuclear facility was conducted using the SP-HyBRID process. First, equipment for a mock-up test of the decontamination was prepared. Detailed experimental conditions for the decontamination were determined through the mock-up test. Under the detailed conditions, the contaminated shaft was successfully decontaminated. The dose rate on the shaft surface was greatly reduced from 1400 to 0.9 μSv/h, and the decontamination factor showed a very high value (>1500).

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