Analyses of the Failed Impulsion Lines of NPP Dukovany Steam Generator

Volume 1: Plant Operations, Maintenance, Engineering, Modifications and Life Cycle; Component Reliability and Materials Issues; Next Generation Systems ◽

10.1115/icone17-75928 ◽

2009 ◽

Author(s):

M. Postler ◽

J. Burda ◽

P. Tkadlcˇi´k

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Steam Generator ◽

Confined Space ◽

Steam Generators ◽

Root Cause ◽

Secondary Steam ◽

Control Procedures ◽

And Control ◽

Tube Segment

Over the years the cracks have been detected on the impulsion lines of all steam generators of the NPP Dukovany. The tubing is made from the austenitic stainless steel. These lines are designed for purposes of measurement and also containment of possible leaks, e.g. between the primary and secondary steam generator seals. Their integrity is periodically tested during each outage and if the leak is detected the tube segment must be cut out and the new one is welded in place. Most of the time the tubes are “dry”, i.e. no medium is flowing inside. Due to confined space the movement of persons around the steam generator is difficult and often the relatively subtle impulsion lines have been subjected to stresses leading to their bending. This deformation has then led to evolution of the failure. To address the issue the original manufacturing, test and control procedures for the impulsion tubing have been studied. Several cracked tubes have been analyzed thoroughly to find the root cause and offer possible remedies.

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Corrosion by Acetic Acid—A Report of Task Group T-5A-3 On Corrosion by Acetic Acid (1)

CORROSION ◽

10.5006/0010-9312-13.11.79 ◽

1957 ◽

Vol 13 (11) ◽

pp. 79-88

Keyword(s):

Stainless Steel ◽

Acetic Acid ◽

Austenitic Stainless Steel ◽

Glacial Acetic Acid ◽

Copper Alloys ◽

Austenitic Stainless Steels ◽

Control Measures ◽

Acid Processing ◽

Corrosion Risk ◽

And Control

Abstract A summary of data and experience on the use of various materials of construction for the storage and handling of refined glacial acetic acid and dilute acetic acid, submitted to NACE Technical Practices Committee 5A-3 is presented. Discussion of common corrosion problems, laboratory and field corrosion test results and photographs of common types of failure are included. Aluminum alloy or austenitic stainless steel tankage is recommended for the storage of refined glacial acetic acid. Austenitic stainless steel heating coils, pumps, valves and piping are recommended for both glacial and dilute acetic acid storage systems. The corrosion risk involved in the use of aluminum for dilute acetic acid storage is emphasized and the limitations on the use of copper and copper alloys for acetic acid storage are discussed. The importance of minor contaminants and of the oxidizing or reducing nature of the environment is discussed in relation to choosing the proper materials for construction of acetic acid processing equipment. It is pointed out that the austenitic stainless steels and copper and copper alloys satisfactorily meet most of the acetic acid processing conditions though higher alloys or non metallic materials may be required occasionally. Common corrosion problems encountered in acetic acid processing and control measures for such problems are discussed. 4.4.2

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CRUCIBLE 303 Se

Alloy Digest ◽

10.31399/asm.ad.ss1005 ◽

2008 ◽

Vol 57 (1) ◽

Keyword(s):

Fracture Toughness ◽

Stainless Steel ◽

Corrosion Resistance ◽

Austenitic Stainless Steel ◽

Physical Properties ◽

Tensile Properties ◽

Heat Treating ◽

Bend Strength ◽

Good Consistency ◽

And Control

Abstract Crucible 303 Se is a machinable austenitic stainless steel. Selenium addition is principally responsible for major characteristics. Other element control and control in manufacturing produce good consistency. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1005. Producer or source: Crucible Service Centers Divisional Headquarters.

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Cracking in stabilized austenitic stainless steel piping of German boiling water reactors—characteristic features and root cause

Nuclear Engineering and Design ◽

10.1016/s0029-5493(96)01320-9 ◽

1997 ◽

Vol 171 (1-3) ◽

pp. 113-123 ◽

Cited By ~ 6

Author(s):

M. Erve ◽

U. Wesseling ◽

R. Kilian ◽

R. Hardt ◽

G. Brümmer ◽

...

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Boiling Water ◽

Boiling Water Reactors ◽

Root Cause ◽

Water Reactors ◽

Characteristic Features ◽

Steel Piping

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Some aspects of the defect structure in an austenitic stainless steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108714 ◽

1978 ◽

Vol 36 (1) ◽

pp. 314-315

Author(s):

R. Gonzalez ◽

L. Bru

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Cellular Structures ◽

Total Strain Amplitude ◽

Total Deformation ◽

Density Of Dislocations ◽

Planar Arrays ◽

Stacking Fault Tetrahedra ◽

Distribution Of Dislocations ◽

Very High

The analysis of stacking fault tetrahedra (SFT) in fatigued metals (1,2) is somewhat complicated, due partly to their relatively low density, but principally to the presence of a very high density of dislocations which hides them. In order to overcome this second difficulty, we have used in this work an austenitic stainless steel that deforms in a planar mode and, as expected, examination of the substructure revealed planar arrays of dislocation dipoles rather than the cellular structures which appear both in single and polycrystals of cyclically deformed copper and silver. This more uniform distribution of dislocations allows a better identification of the SFT.The samples were fatigue deformed at the constant total strain amplitude Δε = 0.025 for 5 cycles at three temperatures: 85, 293 and 773 K. One of the samples was tensile strained with a total deformation of 3.5%.

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A TEM microscopical investigation of the magnetic domain structure of a metastable austenitic stainless steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171213 ◽

1994 ◽

Vol 52 ◽

pp. 696-697

Author(s):

G. Fourlaris ◽

T. Gladman

Keyword(s):

Tensile Strength ◽

Stainless Steel ◽

Austenitic Stainless Steel ◽

Cold Rolling ◽

Solution Treatment ◽

Magnetic Domain ◽

High Strength ◽

Medium Carbon Steel ◽

Magnetic Characteristics ◽

Metastable Austenitic Stainless Steel

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.

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