Plan for Post-Irradiation Examination of Zion Reactor Pressure Vessel Beltline Materials

Journal Article · Sat Jul 01 04:00:00 EDT 2017 · Transactions of the American Nuclear Society

OSTI ID:23047448

Sokolov, Mikhail A.; Rosseel, Thomas M.; Nanstad, Randy K.; Chen, Xiang ^[1]

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1. Oak Ridge National Laboratory, P.O.Box 2008, Oak Ridge, TN 37831 (United States)

The reactor pressure vessel (RPV) is a potentially life-limiting component in light-water reactors (LWR) because replacement of the RPV is not considered a viable option. Researchers studying the effects of radiation on RPV materials have long been interested in evaluating service-irradiated materials to assess currently available models for predicting radiation embrittlement of RPV steels. The decommissioning of the Zion Unit 1 NPP in Zion, Illinois presents a unique opportunity for characterization of an actual reactor pressure vessel (RPV) material after inservice degradation. The main interests in this case are the belt-line weld and base metals. Through-RPV wall thickness attenuation and chemical composition distributions are the obvious objectives of this characterization program. However, it also provides an opportunity to examine the inservice degradation and its comparison with currently available models for prediction of radiation embrittlement of RPV steels. All of these efforts will provide a better understanding of materials degradation and other issues associated with extending the lifetime of existing NPPs beyond 60 years of service. The primary foci are the Linde 80 flux, wire heat 72105 (WF-70) circumferential belt-line weld and the A533B-1 base metal from the intermediate shell harvested from a region of peak fluence (0.7 x 10{sup 19} n/cm{sup 2}, E > 1.0 MeV) on the internal surface of the Zion Unit 1 vessel. Following determination of the through-thickness chemical composition, Charpy impact, fracture toughness, tensile, and hardness testing will be being performed to characterize the through-thickness mechanical properties of the base metal and belt-line-weld materials. In addition to mechanical properties, microstructural characterizations will be performed using various techniques, including Atom Probe Tomography, Small Angle Neutron Scattering, and Positron Annihilation Spectroscopy.

• OSTI ID: 23047448
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 116; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
ATTENUATION
CHEMICAL COMPOSITION
EMBRITTLEMENT
FRACTURE PROPERTIES
HARDNESS
HEAT
METALS
MEV RANGE
NEUTRON DIFFRACTION
NUCLEAR POWER PLANTS
POSITRON ANNIHILATION SPECTROSCOPY
POST-IRRADIATION EXAMINATION
PRESSURE VESSELS
SMALL ANGLE SCATTERING
STEELS
THICKNESS
TOMOGRAPHY
WATER COOLED REACTORS
WATER MODERATED REACTORS
WELDED JOINTS