Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: Creep/fatigue damage prediction of fast reactor components using shakedown methods

Buckthorpe, D.E. (NNC Ltd, Knutsford, Cheshire (United Kingdom))

Abstract

The present status of the shakedown method is reviewed, the application of the shakedown based principles to complex hardening and creep behaviour is described and justified and the prediction of damage against design criteria outlined. Comparisons are made with full inelastic analysis solutions where these are available and against damage assessments using elastic and inelastic design code methods. Current and future developments of the method are described including a summary of the advances made in the development of the post process ADAPT, which has enabled the method to be applied to complex geometry features and loading cases. The paper includes a review of applications of the method to typical Fast Reactor structural example cases within the primary and secondary circuits. For the primary circuit this includes structures such as the large diameter internal shells which are surrounded by hot sodium and subject to slow and rapid thermal transient loadings. One specific case is the damage assessment associated with thermal stratifications within sodium and the effects of moving sodium surfaces arising from reactor trip conditions. Other structures covered are geometric features within components such as the Above Core structure and Intermediate Heat Exchanger. For the secondary circuit the method has been applied to alternative and more complex forms of geometry namely thick section tubeplates of the Steam Generator and a typical secondary circuit piping run. Both of these applications are in an early stage of development but are expected to show significant advantages with respect to creep and fatigue damage estimation compared with existing code methods. The principle application of the method to design has so far been focused on Austenitic Stainless steel components however current work shows some significant benefits may be possible from the application of the method to structures made from Ferritic steels such as Modified 9Cr 1Mo. This aspect is briefly discussed as a potential application and future development of the method.

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key words: Fast Neutron Spectrum Systems, Nuclear Technology
Reference:
Creep-fatigue damage rules for advanced fast reactor design. Technical committee meeting, Manchester (United Kingdom). 11-13 Jun 1996
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--933, pp:47-73