Applicability of Chemical Cleaning Process to Steam Generator Secondary Side, (I)

For safe and reliable operation of NPP steam generators, it is required to remove the sludge from heat exchanging tubes and steam generator (SG) volume in due time. Chemical cleaning technology of SG secondary side during NPP cooling down will be used in Tianwan NPP, which was used to remove iron and copper oxides from steam generators secondary side in Russia NPPs and to resume the heat exchange capacity of heat exchange tubes. To validate and evaluate the effectiveness and safety of the SG cleaning formula during NPP cooling down provided by Russia (RF) for Tianwan NPP, cleaning effective tests and safety tests were done in autoclave with the chemical cleaning process parameters simulated. To compared with RF, cleaning effective tests and safety tests were done with A3B1 under the same condition. Cleaning effective test results showed that the simulated sludge for Tianwan NPP can be more effectively dissolved and removed with A3B1 than with RF. Cleaning safety test results showed that the general corrosion amount of 0Cr18Ni10Ti stainless steel was very low but the general corrosion amount of SA508-III steel was high both with A3B1 formula and the formula provided by Russia.

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TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

10.2172/1023279 ◽

2011 ◽

Author(s):

B. Wiersma

Keyword(s):

Cleaning Process ◽

Chemical Cleaning ◽

Treatment Tank ◽

Corrosion Studies

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Poster 29. Assessment of chemical cleaning options for the secondary side of PWR steam generators

Water chemistry of nuclear reactor systems 5 ◽

10.1680/wconrs5v1.15470.0061 ◽

1989 ◽

pp. 1: 331-332 ◽

Cited By ~ 2

Author(s):

D. Schneidmiller ◽

J. B. Mason

Keyword(s):

Steam Generators ◽

Chemical Cleaning ◽

Secondary Side

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Copper dissolution and electrochemical behavior in EDTA- and EDA-based solutions for steam generator chemical cleaning

Nuclear Engineering and Design ◽

10.1016/s0029-5493(03)00100-6 ◽

2003 ◽

Vol 224 (2) ◽

pp. 207-212 ◽

Cited By ~ 4

Author(s):

Do Haeng Hur ◽

Myung Sik Choi ◽

Eun Hee Lee ◽

Uh Chul Kim

Keyword(s):

Steam Generator ◽

Electrochemical Behavior ◽

Chemical Cleaning ◽

Copper Dissolution

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Transient Thermal-Hydraulic Responses of the Nuclear Steam Generator Secondary Side to a Main Steam Line Break1

Journal of Pressure Vessel Technology ◽

10.1115/1.4028774 ◽

2015 ◽

Vol 137 (4) ◽

Cited By ~ 6

Author(s):

Jong Chull Jo ◽

Frederick J. Moody

Keyword(s):

Steam Generator ◽

Steam Line ◽

Analysis Model ◽

Pressurized Water ◽

Line Pipe ◽

Short Period ◽

Main Steam Line ◽

Main Steam ◽

Transient Thermal ◽

Secondary Side

This paper presents a multidimensional numerical analysis of the transient thermal-hydraulic response of a steam generator (SG) secondary side to a double-ended guillotine break of the main steam line attached to the SG at a pressurized water reactor (PWR) plant. A simplified analysis model is designed to include both the SG upper space, which the steam occupies and a part of the main steam line between the SG outlet nozzle and the pipe break location upstream of the main steam isolation valve. The transient steam flow through the analysis model is simulated using the shear stress transport (SST) turbulence model. The steam is treated as a real gas. To model the steam generation by heat transfer from the primary coolant to the secondary side coolant for a short period during the blow down process following the main steam line break (MSLB) accident, a constant amount of steam is assumed to be generated from the bottom of the SG upper space part. Using the numerical approach mentioned above, calculations have been performed for the analysis model having the same physical dimensions of the main steam line pipe and initial operational conditions as those for an actual operating plant. The calculation results have been discussed in detail to investigate their physical meanings and validity. The results demonstrate that the present computational fluid dynamics (CFD) model is applicable for simulating the transient thermal-hydraulic responses in the event of the MSLB accident including the blowdown-induced dynamic pressure disturbance in the SG. In addition, it has been found that the dynamic hydraulic loads acting on the SG tubes can be increased by 2–8 times those loads during the normal reactor operation. This implies the need to re-assess the potential for single or multiple SG tube ruptures due to fluidelastic instability for ensuring the reactor safety.

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