Dismantlement of Martin 1 and 2

Indiantown, FL

September 2020 – March 2023

$35 M

Florida Power & Light Company

NorthStar was contracted by Florida Power & Light to perform the controlled dismantlement (everything on the hook) and removal of Martin Plant Units 1 & 2 Boilers and steam turbines with all associated facilities, including #6 oil storage tanks, transfer pumps, piping, air preheaters, gas ducts, electrostatic precipitators, and chimneys.

The work under this contract was performed near a high hazard dam, and accordingly, it was critical that the excavations did not result in short- or long-term increases in the risk of dam failure. The two mechanisms for increased risk to the dam were 1) loss of stability due to damaging vibration and 2) increased risk of piping failure due to an increased gradient associated with dewatering and the development of piping failure due to the loosening of soils or the placement of improper or incompatible or insufficiently compacted fill or some combination thereof.

The first risk was addressed by requiring that the work did not result in a velocity of one inch per second at the toe of the dam, with compliance checked by continuous monitoring with automatic notification as vibration approached or exceeded the limit. Eliminating the second risk required that all excavations below the water table were performed with well points or horizontal wells with properly designed and installed screens and filter sand that were capable of maintaining the water level well below the bottom of the excavation during the entire excavation and backfilling process, and that the backfill had the correct composition and compaction for long-term stability.

The dismantlement work was performed using a non-explosive methodology. The contractor dismantled using rig and lowering only except for the chimneys, which were based on a limited use drop analysis. The two units were 800-megawatts each and had conventional dual fuel fired steam boilers, steam turbine generators, associated support facilities, #6 Oil fuel system, natural gas delivery systems, preheaters, electrostatic precipitators, and two 500’ tall concrete chimneys. The units’ On-Line dates were 1980 and 1981 respectively. The project had some unique challenges working within proximity of the cooling pond dam, as well as working on top of and near underground Circulating water pipes that were to be preserved.

The project scope included 24-hour vibration monitoring of 12 locations, daily dam inspections by a full-time dam safety specialist, and weekly dam surveys of 120 monuments.

Environmental work included.

• Asbestos Abatement of friable and non-friable asbestos-containing
• Draining and cleaning the #6 Oil heaters, transfer pumps, burner pumps, booster pumps, and 4,000 feet of transfer piping from the tank farm to the burner tips.
• Removal and recycling of 120,000 gallons of transformer
• Removal and restoration of Ash Disposal Storage Cells and removal of the stockpiled lime area encompassing over 8 With this work within 200’ of the cooling pond dam, work was performed in phases, gross removal, detail removal below grade, backfill and compaction as well as placement of topsoil and sodding.
• Closure of ash settling ponds which included removal of ash, demolition of concrete ash pit, removal and disposal of pond liners from blowdown system and restoration of the area.

Project Totals:

Total Manhours- 320,000 Total Steel- 59,000 Net Tons

Trash- 725 loads 7,500 Net Tons

Special Waste- 1,500 loads 28,653 Net Tons Chimney Brick- 420 loads 7,500 Net Tons

Chimney Concrete w/ACM- 820 loads 15,119 Net Tons Concrete Crushed for recycling- 30,000 Net Tons