HTGR Knowledge Base

Conference Article: Material and fabrication of the HTTR reactor pressure vessel

Tachibana, Y.; Kunitomi, K.; Shiozawa, S. (Japan Atomic Energy Research Isnt., Oarai, Ibaraki (Japan)); Asami, T.; Yamaguchi, S. (Babcock-Hitachi K.K., Hiroshima (Japan))

Abstract

The High Temperature Engineering Test Reactor (HTTR) is under construction at Oarai Research Establishment, Japan Atomic Energy Research Institute (JAERI) and planned to be critical in October 1997. Fabrication of the HTTR reactor pressure vessel (RPV) at Kure Works, Babcock-Hitachi K.K. took about two years, and the RPV was transported to the Oarai site in August 1994. Pressure test of the primary and secondary cooling system including the RPV was performed successfully in March 1996. Because temperature of the HTTR RPV becomes about 400 deg. C at normal operation, 2 1/4 Cr-1 Mo steel is chosen for it. Fluence of the RPV is calculated to be less than 1 X 1017 n/cm2 (E>l MeV), and so irradiation embrittlement, is presumed to be negligible, but temper embrittlement is not. For the purpose of reducing embrittlement, content of some elements is limited on 2 1/4 Cr-1 Mo steel for the HTTR RPV using embrittlement parameters: J-factor and X-bar. In this paper design and structure of the HTTR RPV is briefly reviewed first. Fabrication procedure of the RPV and its special feature is shown. Material data on 2 1/4 Cr-1 Mo steel manufactured for the RPV, especially the embrittlement parameters J-factor and X-bar, and nil-ductility transition temperatures TNDT by drop weight tests, are shown, and increase in the transition temperature is estimated based on data available in literature. Technology of the HTTR RPV is applicable to RPVs of future commercial High Temperature Gas-cooled Reactors (HTGRs).

view the full text of this article (14 pages, format: PDF, size= 584kB)

---

key words: Gas Cooled Reactor, Nuclear Technology

---

Reference:

Technical committee meeting on high temperature gas cooled reactor technology development. Johannesburg (South Africa). 13-15 Nov 1996.

International Atomic Energy Agency, Vienna (Austria)

IAEA-TECDOC--988, pp:305-318