NRC Gives Davis-Besse Shield Building Clean Bill of Health [View all]

[FBaggins]

In a report issued Monday, federal regulators formally closed their inspection of shield building cracking discovered at the Davis-Besse nuclear plant during a reactor pressure vessel head replacement in October.

The Nuclear Regulatory Commission said it was satisfied with FirstEnergy’s plan to deal with the cracks, and that no violations or adverse findings had been identified in the inspection. “Based on an evaluation of (First Energy Nuclear Operating Company’s) extent of condition and technical analysis of the shield building cracking, the NRC staff concluded that FENOC provided reasonable assurance that the shield building was capable of performing its safety functions,” NRC staff wrote in the inspection report.

On Oct. 10, a contractor noticed subsurface cracks in the concrete while performing hydro-cutting to create the hole needed to swap out the RPV head. Following a subsequent investigation, FirstEnergy blamed the cracking on a blizzard in 1978, not long after the plant began operating, and indicated it would add weather-proofing material to the concrete.

The 913 megawatt Babcock & Wilcox pressurized water reactor’s design does not incorporate the unit’s primary containment into the walls of the shield building, which sets it apart from the Crystal River nuclear plant that’s experienced costly delamination of its building concrete that has yet to be resolved. Instead, the Davis-Besse shield building provides environmental protection, biological shielding and protection from external hazards, according to the NRC.

http://nuclearstreet.com/nuclear_power_industry_news/b/nuclear_power_news/archive/2012/05/09/nrc-gives-davis_2d00_besse-shield-building-clean-bill-of-health-050902.aspx