1 6 th St. 250K Package Boiler

2 6 th St 250K Boiler Condition Assessment Boiler condition – prior to cleaning  Boiler has been boiler shut down in 2010  Drum developed corrosion in 2011  Corrosion was mitigated via power wash and dried.  Nitrogen was introduced to drum under constant pressure.

After the Power Wash (moisture at the bottom of the mud drum - Jan 2011) 3

After the Power Wash and Air Drying (No moisture observed - Jan 2011) 4

May, 2012, after nitrogen introduction Magnetite protective layer at the mud drum surface affected but no significant metal lost was observed Power water washing, drying with plant air and nitrogen blanketing seems like worked pretty well protecting from severe metal corrosion No fast phase of active corrosion was observed Metals above the mud drum are expected to be in a good shape Steam drum is in an excellent condition Critical pipes located outside and welded connections to the vessels are in a good shape Seal between the rolled tubes and mud drums are intact 5

Corrosion seems to be slow to dormant (May 2012) 6

Magnetite is peeling off but no significant damage yet (May 2012) 7 No damage between the tube role and drum

Red Marks but No Fast Active Sings of Corrosion (Mud Drum) 8

Steam Drum Is in Excellent Condition (May 2012) 9

Nitrogen Bottle Used for Lay Up 10