Evaluation of the recovery annealing of the reactor pressure vessel of NPP Nord (Geifswald) units 1 and 2 by means of subsize impact specimens

Ralf Ahlstrand, Egon Klausnitzer, Dieter Lange, Christof Leitz, Dieter Pastor, Matti Valo

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleScientificpeer-review

17 Citations (Scopus)

Abstract

In 1988 and 1990, the reactor pressure vessels of Units 1 and 2, respectively, of the Greifswald nuclear power station were subjected to heat treatment at 475°C for annealing of irradiation effects. To demonstrate the effect of annealing and to evaluate a new postannealing transition temperature of vessel base metal and weld metal, boat samples were removed by means of electric discharge machining (EDM) from the (unclad) inner surface of the vessel. From these samples, micronotched bar impact test specimens were fabricated and tested at different temperatures. Transition curves were evaluated from the results. By means of correlation tests, the transition temperatures evaluated from the micro-specimen tests are converted to standard Charpy-V transition temperatures. Results are available for the weld metal of Unit 1 after annealing. The transition temperature TK is lower than the value calculated by the designer of the plant. Specimens removed from Unit 2 before and after annealing are in preparation.
Original languageEnglish
Title of host publicationRadiation Embrittlement of Nuclear Reactor Pressure Vessel Steels
Subtitle of host publicationAn International Review
EditorsLendell E. Steele
Place of PublicationPhiladelphia
PublisherAmerican Society for Testing and Materials (ASTM)
Pages321-343
Volume4
ISBN (Print)978-0-8031-1478-4
DOIs
Publication statusPublished - 1993
MoE publication typeA3 Part of a book or another research book

Publication series

SeriesASTM Selected Technical Papers
Volume1170

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