0
RESEARCH PAPERS

Estimation of Master Curve Based $RTTO$ Reference Temperature From CVN Data

[+] Author and Article Information
Kim R. Wallin

VTT Industrial Systems, P.O. Box 1704, FIN-02044 VTT, Finlandkim.wallin@vtt.fi

Gerhard Nagel

E.ON Kernkraft GmbH, Tresckowstrasse 5, 30457 Hannover, Germanygerhard.nagel@eon-energie.com

Elisabeth Keim

AREVA NP GmbH, Freyeslebonstrasse 1, 91058 Erlangen, Germanyelisabeth.keim@areva.com

Dieter Siegele

Fraunhofer IWM, Woehlerstrasse 11, 79108 Freiburg, Germanysi@iwm.fhg.de

J. Pressure Vessel Technol 129(3), 420-425 (Jun 08, 2006) (6 pages) doi:10.1115/1.2748823 History: Received September 12, 2005; Revised June 08, 2006

Abstract

The ASME code cases N-629 and N-631 permit the use of a master curve-based index temperature $(RTTo≡T0+19.4°C)$ as an alternative to traditional $RTNDT$-based methods of positioning the ASME $KIC$ and $KIR$ curves. This approach was adopted to enable the use of master curve technology without requiring the wholesale changes to the structure of the ASME code that would be needed to use all aspects of master curve technology. For the brittle failure analysis considering irradiation embrittlement an additional procedure to predict the adjustment of fracture toughness for end of life (EOL) from irradiation surveillance results must be available as by NRC R.G. 1.99 Rev. 2, e.g., the adjusted reference temperature is defined as $ART=initialRTNDT+ΔRTNDT+margin$. The conservatism of this procedure when $RTNDT$ is replaced by $RTTo$ is investigated for western nuclear grade pressure vessel steels and their welds. Based on a systematic evaluation of nearly 100 different irradiated material data sets, a simple relation between $RTToirr$, $RTToref$, and $ΔT41JRG$ is proposed. The relation makes use of the R.G. 1.99 Rev. 2 and enables the minimizing of margins, necessary for conventional correlations based on temperature shifts. As an example, the method is used to assess the $RTTo$ as a function of fluence for several German pressure vessel steels and corresponding welds. It is shown that the method is robust and well suited for codification.

<>

Figures

Figure 1

Original uncorrected data used to establish ASME KIC reference curve (1)

Figure 2

Justification for ASME code cases N-629 and N-631

Figure 3

Irradiated size corrected fracture toughness data for A302 type plates, compared to code cases N‐629∕631 prediction

Figure 4

Irradiated size corrected fracture toughness data for A508 type forgings, compared to code cases N‐629∕631 prediction

Figure 5

Irradiated size corrected fracture toughness data for A533B type plates, compared to code cases N‐629∕631 prediction

Figure 6

Irradiated size corrected fracture toughness data for welds, compared to code cases N‐629∕631 prediction

Figure 7

Irradiated size corrected fracture toughness data from German database (5), compared to code cases N‐629∕631 prediction

Figure 8

Comparison of R.G. 1.99 fluence function with data from German database (5)

Figure 9

Irradiated size corrected fracture toughness data, for welds and base materials, from German database (5), with valid T0ref values and ΔT41JRG determined according to R. G. 1.99, compared to code cases N‐629∕631 prediction

Figure 10

Irradiated size corrected fracture toughness data from German database (5), with valid T0ref values and ΔT41J determined according to R. G. 1.99, compared to code cases N‐629∕631 prediction, without a margin term

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections