Enlightening Lives. Empowering Progress.

TUBE LEAK ANALYSISDECEMBER 09, 2015

CONTENT

• TUBE LEAK OVERVIEW • SIGN OF IMPROVEMENT• WHAT WE DO DIFFERENTLY• ROOT CAUSE ANALYSIS• IMMEDIATE ACTION SUMMARY• MAJOR LONG TERM ACTION PLAN • EXPECTATIONS

TUBE FAILURE OVERVIEW

2010 2011 2012 2013 2014 20150

5

10

15

20

25

1 25

6

1922

Total Tube Leak Incident for GBPC

No. o

f Inc

iden

ts

* including collateral damage

59%5%

37%

Failure Mode 2014 & 2015

Furnace Tube leak collateral damage due to Furnace Tube leakother boiler areas

• > 60% incidents are furnace tube or related collateral damage• From 2014 to 2015, tube leak incident shoot up• Such trend maintains up to 3rd Quarter 2015

TUBE FAILURE OVERVIEW

• 80% of total downtime is caused by furnace tube and roof tube leak (at top of furnace)

*50% by furnace related and 30% by roof tube

2014 2015 2014 2015 2014 2015 2014 2015 2014 2015CEDC1 CEDC2 CEDC3 PEDC1 PEDC2

0

200

400

600

800

1000

1200

CEDC/PEDC Downtime (HRs) vs Failure Mode

Economizer Floor tube Finishing SH Vertical SHRoof tube Kick off tube+Front wall Evaporator Others

Kick off Tube & Furnace wall straight tube

Furnace Roof Tube

SIGN OF IMPROVEMENT

Jan-15 Feb-15 Mar-15 Apr-15 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-150

1

2

3

4

52015 Tube leak Incidents

CEDC 1 CEDC 2 CEDC 3 PEDC 1 PEDC 2 Series6

* Note: represents last front wall and kick out tube leak

SIGN OF IMPROVEMENT

0

1

2

3

4

5

0

100

200

300

400

500

600

700

800

Total Tube Failure Downtime 2015Total Downtime Total Incident

WHAT WE DO DIFFERENTLY – MAJOROPERATING PARAMETER• Maintaining FHI’s recommended operating parameter – bed pressure, furnace

temperature, air flow, etc.

SAND QUALITY & QUANTITY• Secured sufficient supply and controlled sand quality

MAINTENANCE APPROACH• Ruled out tube build up solution• Being proactive than active (more thorough boiler tube Inspection at any outage)• Replace sub-standard tube following unified quality criteria

BED MATERIAL• Maintain ideal bed material size distribution• Recycling bottom ash to replenish bed material

WHAT WE DO DIFFERENTLY – MAJOR

5/1/2

015 3:00

5/4/2

015 11:00

5/7/2

015 19:00

5/11/2015 3:00

5/14/2015 11:00

5/17/2

015 19:00

5/21/2

015 3:00

5/24/2

015 11:00

5/27/2

015 19:00

5/31/2

015 3:00

6/3/2

015 11:00

6/6/2

015 19:00

6/10/2

015 3:00

6/13/2

015 11:00

6/16/2

015 19:00

6/20/2

015 3:00

6/23/2

015 11:00

6/26/2

015 19:00

6/30/2015 3:00

7/3/2

015 11:00

7/6/2

015 19:00

7/10/2

015 3:00

7/13/2

015 11:00

7/16/2

015 19:00

7/20/2

015 3:00

7/23/2

015 11:00

7/26/2015 19:00

7/30/2015 3:00

8/2/2

015 10:00

8/5/2

015 18:00

8/9/2

015 2:00

8/12/2

015 10:00

8/15/2

015 18:00

8/19/2

015 2:00

8/22/2015 10:00

8/25/2

015 18:00

8/29/2015 2:00

9/1/2

015 10:00

9/4/2

015 18:00

9/10/2

015 22:00

9/23/2

015 23:00

10/3/2

015 2:00

10/6/2015 10:00

10/9/2015 18:00

10/13/2

015 2:00

10/16/2

015 10:00

10/19/2

015 18:00

10/23/2

015 2:00

10/26/2

015 10:000

200

400

600

800

1000

1200

1400

1600

1800

2000

PEDC 1 Stable Bed Pressure Trend

Grate Diff. Press. Ksc DPT10081.PV Overall Diff. Press. Ksc DPT10084.PV

Ideal Range recommended by FHI, daily monitoring

WHAT WE DO DIFFERENTLY – MAJOR

Out of Range - Bed Material Size Distribution (2ndquarter)

Improving now

Ideal Range Recommended by FHI, daily monitoring

WHAT WE DO DIFFERENTLY - MAJOR

* Note: 1 unit represents 10cm tube

ROOT CAUSE – TWO MAJOR CYCLES

More Frequent Tube Leaks in 2014/2015

Tube Leaks in 2014/2015

Theoretically Accelerated Tube Erosion

Higher Gas Velocity in Furnace

Unstable & Low Furnace Bed Pressure

More Aggressive Sand Required to Maintain Bed Pressure

Shift from Semirara to Kalimandan Coal from 2013

Sand Quantity &Quality

Grid Nozzle Wear

Vortex Finder Defects

Inconsistent Workmanship

Excessive Tube Build UpConstruction/

Design Imperfection

ROOT CAUSE – THEORITICAL CYCLE

Indonesian Coal – Kalimandan

Design Coal – Semirara

The ash deviation requires much more sand to be injected to maintain acceptable boiler operating condition recommended by FHI

ROOT CAUSE – THEORETICAL CYCLE

2010 2011 2012 2013 2014 20150.00

1000.00

2000.00

3000.00

4000.00

5000.00

6000.00

7000.00

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

Ash Content vs Sand Consumption vs Bed Pressure

ROOT CAUSE – PRACTICAL CYCLECEDC 3 TUBE NO 48/49 – FRONT WALL (EROSIVE AREA)

2010~2014 August

No problem

Sept 2014 First Build up on

49 (layer 4/5)

Jan 2015 Second Build up48/49 (Layer 2~20)

Feb 2015 Third Build up 48 (Layer 5~7)

Ruptured on March 23 (layer 5)

48 49

OTHER NOTICEABLE CAUSES CONSTRUCTION IMPERFECTIONS• Rough membrane • Tube misalignment • Field welding imperfections

REPAIR WORKERMANSHIP• Repetitive localized tube failure

DESIGN IMPERFECTION• Floor tube interfered by bottom ash discharge port• Erosion shield are not designed at certain sensitive area (first super

heater/economizer/hanger tube)

IMMEDIATE ACTIONSCOAL/BED MATERIAL• Continuously sourcing coal supply complying design base (New Russian Coal is

tested positive, 20% sand consumption reduction per unit per actual test)• Secure sand quality and quantity• Recycle less aggressive bottom ash to replenish bed material

MAINTENANCE APPROACH• Ruled out Tube Build up solution• Aligned GBP inspection and Quality Criteria/Full boiler inspection at forced outage• Covering applicable sensitive area with refractory protection and thermal Spray• New hire of QA/QC personnel

OPERATING PARAMETER• Corporate Office daily monitoring• FHI consultant daily operating report

MAJOR LONG TERM ACTION PLANS

FORSTER WHEELER ENGAGED FOR FURTHER ADVISE

STRATEGIZE CONDUCT OF REGULAR PMS/MOH

FURTHER OPTIMIZE BOILER TUBE INSPECTION PROCEDURE AND MANUALIZED OUTAGE WORK FLOW

CONTINUE HONING SKILL SET OF QUALITY CONTROL TEAM AND ACQUIRE NECESSARY CREDENTIALS

ENHANCE PLANNING SKILLS OF MANAGEMENT AND IN-HOUSE PLANNING TEAMS

MAINTAIN KNOWLEDGE SHARING PRACTICE ACROSS SITES AND ESTABLISH REGULAR TECHNICAL SEMINAR

EXPECTATIONS

BY END OF 2ND QUARTER 2016, THE FOLLOWING ARE ANTICIPATED:

LESS DOWNTIME

HIGHER BOILER RELIABILITY

IMPROVED FINANCIAL PERFORMANCE

ENHANCED IN-HOUSE TECHNICAL KNOWLEDGE

Enlightening Lives. Empowering Progress.

WHAT WE DO DIFFERENTLY – MAJOR

2015-01 2015-02 2015-03 2015-04 2015-05 2015-06 2015-070

500

1,000

1,500

2,000

2,500

HISTORICAL BUILD UP VS REPLACEMENT - 2015Build Up Replacement

* Note: 1 unit represents 10cm tube

WHAT WE DO DIFFERENTLY – MAJOR

2013 20140

500

1,000

1,500

2,000

2,500

473

1,632

608

2,032

HISTORICAL BUILD UP VS REPLACEMENT 2013 - 2014

Build Up Replacement

* Note: 1 unit represents 10cm tube

ROOT CAUSE – PRACTICAL CYCLECEDC 1 TUBE NO 11/12 – FRONT WALL ABOVE COAL CHUTE (MOST EROSIVE AREA)

2010~2013 MarchNO PROBLEM

April 2013 First Build up Dec 2013 Build up

June 2014 Total Replacement Dec 2014 Build up March 2015 Build

up

2015 May Outage No Finding after

inspection

2015 June 18 Ruptured

ROOT CAUSE – PRACTICAL CYCLECEDC 1 TUBE NO 208 – REAR WALL (LESS EROSIVE AREA)

2010~2014 AprilNO PROBLEM

May 2014 First Build up (layer

2/3)

March 2015 Second Buildup

(layer 1~8)

2015 Outage No Finding

After inspection

2015 June 18 Ruptured

(layer 5~6)

ROOT CAUSE – PRACTICAL CYCLECEDC 2 TUBE NO 65/66 – FRONT WALL ABOVE COAL CHUTE (MOST EROSIVE AREA)

2010~2012 August

NO PROBLEM

September 2012 First Build up

July 2013 Build up

March 2014 Third Buildup

July 2014 Total Replacement

Mid March 2015 Build up

2015 April 12 Tube Leak

65 66

ROOT CAUSE – PRACTICAL CYCLECEDC 3 TUBE NO 90/91 – FRONT WALL (EROSIVE AREA)

2010~2012 October

NO PROBLEM

November 2012 PMS Total

Replacement

September 2014 First Build up on

91 (layer 3/8)

Nov 2014 Second Build up on 91

(layer 3/8)

Jan 2015 First Build up on 90

(layer 4-5)

Feb 2015 Third Build up on 91

(layer 3~5)

March 2015 Again build up

90/91 (layer 4~6)

May 2015 Replacement 90

90/91 Ruptured on July 21 Layer 5

90 91

Enlightening Lives. Empowering Progress.

FORCED OUTAGE ANALYSISDECEMBER 09, 2015

CEDC FORCED OUTAGE OVERVIEW

Tube leak external Electrical Human Error other mechanical control failure0

1

2

3

4

5

6

0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

900.0

CEDC 1 OUTAGE NATURE Vs INCIDENT OCCURENCE VS OUTAGE TIME IMPACT

Series 1 – Outage Time ImpactSeries 2 – Outage Occurrence

CEDC FORCED OUTAGE OVERVIEW

Series 1 – Outage Time ImpactSeries 2 – Outage Occurrence

Tube leak external Electrical Human Error other mechanical control failure0

1

2

3

4

5

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

CEDC 2 OUTAGE NATURE Vs INCIDENT OCCURENCE VS OUTAGE TIME IMPACT

CEDC FORCED OUTAGE OVERVIEW

Series 1 – Outage Time ImpactSeries 2 – Outage Occurrence

Tube leak external Electrical Human Error other mechanical control failure0.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

900.0

0

1

2

3

4

5

6

CEDC 3 OUTAGE NATURE Vs INCIDENT OCCURENCE VS OUTAGE TIME IMPACT

CEDC FORCED OUTAGE OVERVIEW

Tube leak external Electrical Human Error other mechanical control failure0.0

500.0

1,000.0

1,500.0

2,000.0

2,500.0

0

2

4

6

8

10

12

14

CEDC FORCED OUTAGE NATURE Vs INCIDENT OCCURENCE VS OUTAGE TIME IMPACT

Hours Incident

CEDC FORCED OUTAGE OVERVIEW

Tube leak external Electrical Human Error other mechanical control failure0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

CEDC OUTAGE NATURE CONTRIBUTING TO IMPACT HOURS