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

1989 ◽  
pp. 1: 331-332 ◽  
Author(s):  
D. Schneidmiller ◽  
J. B. Mason
Keyword(s):  
Steam Generators ◽  
Chemical Cleaning ◽  
Secondary Side

Steam Generator Secondary Side Chemical Cleaning During Reactor Plant Cooling Down

2013 ◽  
Author(s):  
Xiaojiao Xia ◽  
Juhua Wen ◽  
Weigang Ma
Keyword(s):  
Heat Exchange ◽  
Steam Generator ◽  
Exchange Capacity ◽  
General Corrosion ◽  
Test Results ◽  
Steam Generators ◽  
Chemical Cleaning ◽  
Safety Test ◽  
Cleaning Technology ◽  
Secondary Side

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.

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

2004 ◽  
Vol 41 (1) ◽  
pp. 44-54 ◽  
Author(s):  
Kazutoshi FUJIWARA ◽  
Hirotaka KAWAMURA ◽  
Hiromi KANBE ◽  
Hideo HIRANO ◽  
Hideki TAKIGUCHI ◽  
...  
Keyword(s):  
Steam Generator ◽  
Cleaning Process ◽  
Chemical Cleaning ◽  
Secondary Side

Loads Applied to Clogged Steam Generators Internal Structures

2009 ◽  
Author(s):  
Olivier Brunin ◽  
Geoffrey Deotto
Keyword(s):  
Cooling Capacity ◽  
Operating Conditions ◽  
Steam Generators ◽  
Numerical Application ◽  
Flow Area ◽  
Internal Structures ◽  
Order Of Magnitude ◽  
Water Mass Balance ◽  
Side Flow ◽  
Secondary Side

During their commissioning, steam generators are clean, which means there is no fouling of the heat transfer surface of tubes and no clogging of the flow area on the secondary side. Then sludge appears steadily at a slow pace during operation. Sludge initiates a partial loss of cooling capacity which is modeled by a fouling factor and which mainly results in vapor pressure decrease. Sludge also initiates a reduction of the secondary side flow area, known as clogging. Four safety-related issues are dependant on clogging [1]: the secondary water mass balance, the thermohydraulics oscillations, the tube vibration risk and the resistance of internal structures. This paper focuses on the last of these issues. A numerical application, based on the modeling of a fictitious steam generator, is detailed in this presentation. The order of magnitude is an 8-times increase of the loads in normal operating conditions in case of a typical 60% clogging ratio of the upper tube support plate, and a 12-times increase in case of incidental depressurization transient. These theoretical results emphasize the need to take these loads properly into account in the checking of the mechanical behavior of the internal structure of the steam generators in operation in case of significant sludge deposits.

Role of aluminum and silicon species in the formation of hard sludge on the secondary side of PWR steam generators: Potential geopolymers contribution

2020 ◽  
Vol 118 ◽  
pp. 103136
Author(s):  
Rocío Fernández-Saavedra ◽  
M. Belén Gómez-Mancebo ◽  
Marta Fernández-Díaz ◽  
Dolores Gómez-Briceño
Keyword(s):  
Steam Generators ◽  
Secondary Side

scholarly journals Qualification of TRACE V5.0 Code against Fast Cooldown Transient in the PKL-III Integral Test Facility

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Eugenio Coscarelli ◽  
Alessandro Del Nevo ◽  
Francesco D'Auria
Keyword(s):  
Heat Transfer ◽  
Test Facility ◽  
Steam Generators ◽  
Integral Test ◽  
Pressurized Thermal Shock ◽  
Vessel Integrity ◽  
Main Steam Line ◽  
Main Steam ◽  
Secondary Side ◽  
Reactor Pressure

The present paper deals with the analytical study of the PKL experiment G3.1 performed using the TRACE code (version 5.0 patch1). The test G3.1 simulates a fast cooldown transient, namely, a main steam line break. This leads to a strong asymmetry caused by an increase of the heat transfer from the primary to the secondary side that induces a fast cooldown transient on the primary side-affected loop. The asymmetric overcooling effect requires an assessment of the reactor pressure vessel integrity considering PTS (pressurized thermal shock) and an assessment of potential recriticality following entrainment of colder water into the core area. The aim of this work is the qualification of the heat transfer capabilities of the TRACE code from primary to secondary side in the intact and affected steam generators (SGs) during the rapid depressurization and the boiloff in the affected SG against experimental data.

Power Rising and Descending Transient for the OTSG of a Small PWR

2020 ◽  
Author(s):  
Baihui Jiang ◽  
Zhiwei Zhou ◽  
Zhaoyang Xia ◽  
Qian Sun
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Two Phase Flow ◽  
Flow Instability ◽  
Flow Stability ◽  
Phase Flow ◽  
Steam Generators ◽  
Two Phase ◽  
Water Reactors ◽  
Secondary Side

Abstract As key heat transfer system in small and medium size pressurized water reactors, once-through steam generators are important parts of energy exchange between primary and secondary circuits, and are very important for the design and operation of reactors. However, two-phase flow and heat transfer in once-through steam generators are very complicated. When a reactor experience power rising and descending transient, the heat removal of once-through steam generator, the flow rate, the inlet fluid temperature and outlet steam temperature will all change accordingly. Especially when a reactor is running at a low power, the flow rate of the secondary side of OTSG is extremely small and the single-phase region of the secondary side of OTSGs is also too small. The two-phase flow instability may occur, which has a serious impact on reactor operation and safety. So, a reasonable power-up and power-down transient scheme is required to ensure operational stability when starting up and shutting down a reactor. RELAP5/MOD4.0 is a commercial software developed by Innovative System Software, LCC for transient analysis of light water reactors (LWR). After years of development and improvement, RELAP5 has been a basic tool for analysis and calculation of various simulators of nuclear power plants. Scholars all over the world have carried out a large number of analysis of two-phase flow stability using RELAP5, and the results are reliable. This paper takes once through steam generators with given structural parameters as the research object, and uses RELAP5 as the calculation tool. The influencing factors of flow instability are discussed in this paper, and the operating parameters of the fluid on the primary and secondary sides are designed to satisfy the flow stability under different powers. And a set of power-up and power-down schemes for stable operation is proposed.

Preoperational Cleaning Requirements for HRSG Units

2004 ◽  
Author(s):  
Robert D. Bartholomew ◽  
Emory H. Hull
Keyword(s):  
Iron Oxide ◽  
Heat Recovery ◽  
Steam Generators ◽  
Chemical Cleaning ◽  
Contingency Plan ◽  
Subsequent Operation ◽  
Oxide Removal ◽  
Detergent Solutions

There have been no generally agreed upon practices regarding preoperational chemical cleaning of new heat recovery steam generators (HRSGs). Some have been cleaned only with warm detergent solutions while others are cleaned using alkaline detergents followed by iron oxide removal and passivation stages. Thorough inspection and monitoring of waterside surfaces from fabrication through commissioning are necessary to assess unit cleanliness. However, these activities are sometimes neglected. In some cases, there is no contingency plan should inspection reveal fouled or corroded surfaces. Poor waterside cleanliness has caused startup delays and problems during subsequent operation. This paper summarizes the recommended requirements for both companies that plan to clean and for those companies that do not expect to clean.

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