Published Online: 14 May 2010
Page Count: 11
ATI Consulting, Pinehurst, NC
Electric Power Research Institute, Charlotte, NC
(Received 8 August 2008; accepted 17 April 2010)
A carefully designed irradiation experiment was conducted in which a 190 mm thick reactor pressure vessel (RPV) wall has been simulated using nineteen 10 mm thick slices, 18 of which are made from key RPV steels, and irradiated under test reactor conditions to investigate the through-wall attenuation of neutron embrittlement. Preliminary results for two of the irradiated materials (a low copper content plate and a high copper content Linde 80 flux weld) were reported earlier. The third irradiated RPV steel was the international reference steel designated JRQ, and this paper describes the results for this steel along with updated analyses for the other two steels. Comparisons of predicted attenuation changes in toughness properties with measured fracture toughness and Charpy V-notch results are presented for all three RPV steels. The predictions of through-wall attenuation follow the practice defined in ASTM E900-02 and Regulatory Guide 1.99, Revision 2, in which the attenuation of high energy neutron fluence (E>1 MeV) is projected based upon an approximate displacements per atom (dpa) change through the wall thickness. The resultant degree of material damage using this dpa-based fluence change is estimated using current embrittlement correlation models.
Paper ID: JAI102070