JDR Vol.5 No.4 pp. 378-384
doi: 10.20965/jdr.2010.p0378


Application of “Leak Before Break” Assessment for Pressure Tube in Delayed Hydride Cracking

Gintautas Dundulis*, Albertas Grybėnas**, Vidas Makarevicius**,
and Remigijus Janulionis*

*Laboratory of Nuclear Installation Safety, Lithuanian Energy Institute, Breslaujos str. 3, LT-44403 Kaunas, Lithuania

**Laboratory of Material Research &Testing, Lithuanian Energy Institute, Breslaujos str. 3, LT-44403 Kaunas, Lithuania

March 10, 2010
May 20, 2010
August 1, 2010
leak before break, delayed hydride cracking, fracture mechanic, R6 method, J integral

The Ignalina NPP uses an RBMK-1500 reactor, which is graphite-moderated with a water-cooled reactor core. The fuel cell assembly in the center of the moderator column consists of a pressure tube containing the fuel element assembly and through which coolant flows. Pressure tubes are made of Zr-2.5Nb zirconium alloys. Hydrogen absorbed by the zirconium alloy during corrosion is one of the factors determining pressure tube lifetime. If the pressure tube hydrogen concentration exceeds solubility limitations, delayed hydride cracking (DHC) may occur. Hydrides forming under certain conditions may reduce resistance to brittle fracture. Here we evaluate hydride influence on pressure tube fracture and the application of leak before break (LBB) for tubes with DHC. Deterministic analysis employing LBB concept used experimental data. Deterministic LBB analysis confirms that pressure tubes comply with LBB requirements.

Cite this article as:
Gintautas Dundulis, Albertas Grybėnas, Vidas Makarevicius, and
and Remigijus Janulionis, “Application of “Leak Before Break” Assessment for Pressure Tube in Delayed Hydride Cracking,” J. Disaster Res., Vol.5, No.4, pp. 378-384, 2010.
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