Closure of a power station is a rare event and more so when it is the Hirakud system, which was the back bone of Orissa power grid. The then OSEB authorities decided to take a "3 month" closure of Hirakud Power System to take up some critical unavoidable works before commissioning the 7th unit.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/hirakud-power-development-stage-iii-particular-reference-power-channel-closure-works
[2] http://admin.indiaenvironmentportal.org.in/category/author/s-k-mohanty-0
[3] http://admin.indiaenvironmentportal.org.in/category/journal/water-energy-international
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hirakund
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hydroelectricity
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/energy
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/orissa