The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

Aki Toivonen, Pekka Moilanen, Mika Pyykkönen, Seppo Tähtinen, Rauno Rintamaa, Timo Saario

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Abstract

Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (
Original languageEnglish
Title of host publication23. MPA seminar
Subtitle of host publicationSafety and reliability of plant technology with special emphasis on nuclear technology
Place of PublicationStuttgart
PublisherMaterials Testing Institute University of Stuttgart MPA
Number of pages9
Volume1
Publication statusPublished - 1997
MoE publication typeB3 Non-refereed article in conference proceedings
Event23. MPA-Seminar - Stuttgart, Germany
Duration: 1 Oct 19972 Oct 1997

Conference

Conference23. MPA-Seminar
CountryGermany
CityStuttgart
Period1/10/972/10/97

Fingerprint

Reactor cores
Irradiation
Testing
Boiling water reactors
Materials testing
Nuclear power plants
Fracture toughness
Crack propagation
Stainless steel
Availability
Corrosion
Plastics
Geometry
Costs
Water

Cite this

Toivonen, A., Moilanen, P., Pyykkönen, M., Tähtinen, S., Rintamaa, R., & Saario, T. (1997). The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core. In 23. MPA seminar: Safety and reliability of plant technology with special emphasis on nuclear technology (Vol. 1). Stuttgart: Materials Testing Institute University of Stuttgart MPA.
Toivonen, Aki ; Moilanen, Pekka ; Pyykkönen, Mika ; Tähtinen, Seppo ; Rintamaa, Rauno ; Saario, Timo. / The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core. 23. MPA seminar: Safety and reliability of plant technology with special emphasis on nuclear technology. Vol. 1 Stuttgart : Materials Testing Institute University of Stuttgart MPA, 1997.
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abstract = "Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (",
author = "Aki Toivonen and Pekka Moilanen and Mika Pyykk{\"o}nen and Seppo T{\"a}htinen and Rauno Rintamaa and Timo Saario",
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Toivonen, A, Moilanen, P, Pyykkönen, M, Tähtinen, S, Rintamaa, R & Saario, T 1997, The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core. in 23. MPA seminar: Safety and reliability of plant technology with special emphasis on nuclear technology. vol. 1, Materials Testing Institute University of Stuttgart MPA, Stuttgart, 23. MPA-Seminar, Stuttgart, Germany, 1/10/97.

The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core. / Toivonen, Aki; Moilanen, Pekka; Pyykkönen, Mika; Tähtinen, Seppo; Rintamaa, Rauno; Saario, Timo.

23. MPA seminar: Safety and reliability of plant technology with special emphasis on nuclear technology. Vol. 1 Stuttgart : Materials Testing Institute University of Stuttgart MPA, 1997.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

TY - GEN

T1 - The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

AU - Toivonen, Aki

AU - Moilanen, Pekka

AU - Pyykkönen, Mika

AU - Tähtinen, Seppo

AU - Rintamaa, Rauno

AU - Saario, Timo

N1 - HUO: VAL62 CA2: 1704 CA: VAL Project code: RAVA3 PGN: 9 p. Band 1. Vorträge 17

PY - 1997

Y1 - 1997

N2 - Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (

AB - Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (

M3 - Conference article in proceedings

VL - 1

BT - 23. MPA seminar

PB - Materials Testing Institute University of Stuttgart MPA

CY - Stuttgart

ER -

Toivonen A, Moilanen P, Pyykkönen M, Tähtinen S, Rintamaa R, Saario T. The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core. In 23. MPA seminar: Safety and reliability of plant technology with special emphasis on nuclear technology. Vol. 1. Stuttgart: Materials Testing Institute University of Stuttgart MPA. 1997