Elliott Molnar

Intern-Engineer

August 5th, 2016

Intern Power DownEnd of Summer Presentation

Overview

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Job Title

— Intern, Engineer

Education

— Texas A&M University, Senior, Mechanical Engineer

Purpose

— Provide Engineering Support to Plant Operations and Maintenance

Location

— W.A.Parish Generating Station

Hiring Manager

— Keith Nemec

— Keith.Nemec@nrg.com

Projects

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Baghouse Failure Tracking Sheets

Main Coal Pile Dust Suppression

Fuel Handling Conveyor Bearing Failures

Other Tasks

— Use of PDP Viewer for Process History

— Design of Water-Filled Gravity Take-up Counterweights

— Intake Water Bleach System

— Bottom Ash HP Conveyor Pumps

Baghouse Tracking Sheets

3© [2016] NRG Energy, Inc. All rights reserved. / Proprietary and Confidential Information

Provide Baghouse Failure History

— There are ~15,000 Baghouse Filters for each Coal Unit

— Failures are difficult to track

— Details on bag failures are not recorded

— Tool needed to identify failure trends for root cause

Process

— Researched baghouse methodology and scale in manuals

— Identified Common Failure modes

— Developed Excel program using conditional and VBA

commands

— Developed new field reporting sheet for baghouse failures

Impact

— User-friendly input of reported failures

— Ability to identify failure trends

— Improve communication between field and administration

Coal Pile Dust Suppression

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Dust Suppression needed on Inactive Main Coal Pile

— Fugitive emissions limited to 29 tons per year

— Water or Chemical Surfactants to be used

Process

— Identified alternatives for dust suppression which are currently permitted on site

— Contacted contractors for additional information and preliminary pricing

— Met with primary contractor to discuss scope of work

— Planned water and power supply infrastructure to be used on project

— Contacted engineering services contractor for development of a TSD for Bids

Impact

— Preliminary project planning for new environmental controls system

Conveyor Bearing Failures

5© [2016] NRG Energy, Inc. All rights reserved. / Proprietary and Confidential Information

Increase in conveyor outages for bearing replacement

— O&M costs and risk of heat stress for maintenance staff

— Possible outages of units, including U8 (FG supply for Petra Nova)

Process

— Spoke to maintenance personnel about what they have seen historically

— Developed and use tool for identifying failure trends based on SAP work orders

— Walked-down fuel handling system to identify possible root causes

— Inspected failed bearings for signs of wear and possible causes for failure

— Provided feedback and solutions to engineering, operations, and maintenance

Impact

— New grease chosen and installed

— Autogreasers and sensors being installed on troublesome systems

— Shared knowledge established between administration on the state of the system

Intake Water Bleach System

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Improve safety and reliability of circulating water bleach system

— UV exposure leading to embrittlement

— Currently using Schedule 80 PC with quick-setting glue

Process

— Researched Pros and Cons to alternative materials

— Observed issues with existing system at WAP and compare to improved system at

Limestone

— Developed bill of materials and cost sheets for replacement of entire system

Impact

— CPVC to be used with Weld-On® 724 CPVC cement in the future

Fitting Description Quantity Sch 80 PVC Cost/Pack($/n) Pack Size (n) Cost ($) Sch 80 CPVC Cost/Pack($/n) Pack Size (n) Cost Red Kynar Cost Per ($) Pack Size (n) Cost

1 2" Flange to Pipe 1 NIBCO 39.85$ 12 3.32$ NIBCO 64.73$ 10 6.47$ NIBCO 375.00$ 2 187.50$

2,3 2" 90 degree 2 NIBCO 12.44$ 25 1.00$ NIBCO 37.53$ 10 7.51$ NIBCO 175.70$ 2 175.70$

4 2" to 1" reducer 2 NIBCO 17.80$ 25 1.42$ NIBCO 43.15$ 10 8.63$ NIBCO 180.50$ 5 72.20$

4 2" Tee 1 NIBCO 44.32$ 20 2.22$ NIBCO 50.03$ 10 5.00$ NIBCO 277.20$ 2 138.60$

5,6,9-11,17-20 1" 90 degree 11 NIBCO 7.20$ 50 1.58$ NIBCO 12.89$ 15 9.45$ NIBCO 92.89$ 5 204.36$

7,8,12-16 1" Tee 5 NIBCO 12.91$ 25 2.58$ NIBCO 18.59$ 10 9.30$ NIBCO 114.60$ 5 114.60$

Valve Description Quantity Sch 80 PVC Cost/Pack($/n) Pack Size (n) Cost ($) Sch 80 CPVC Cost/Pack($/n) Pack Size (n) Cost Red Kynar Cost Per ($) Pack Size (n) Cost

1 2" Valve 1 NIBCO 179.00$ 1 179.00$ NIBCO 281.70$ 1 281.70$ NIBCO 1,177.00$ 1 1,177.00$

2 2" Check Valve 1 NIBCO 213.60$ 1 213.60$ NIBCO 335.90$ 1 335.90$ NIBCO 994.00$ 1 994.00$

3-11 1" Valve 8 NIBCO 77.34$ 1 618.72$ NIBCO 128.30$ 1 1,026.40$ NIBCO 495.30$ 1 3,962.40$

Pipe Description Feet Sch 80 PVC Cost Per Foot ($/ft) Cost ($) Sch 80 CPVC Cost Per Foot ($/ft) Cost Red Kynar Cost Per Foot ($/ft) Cost

1-5 2" ID 6.5 PVC PIPE SUPP 1.35$ 8.78$ PVC PIPE SUPP 4.44$ 28.86$ NIBCO 97.18$ 631.67$

6-24 1" ID 70 PVC PIPE SUPP 0.65$ 45.50$ PVC PIPE SUPP 1.91$ 133.70$ NIBCO 43.84$ 3,068.80$

TOTAL 1,077.72$ TOTAL 1,852.92$ TOTAL 10,726.83$

PDP Process History Viewer

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PDP Viewer is an Intranet based system which takes process history

from PI Processbook and Honeywell PHD to create alarms

Used for:

— Reviewed bearing temperature data following a Primary Air Fan failure

o Inboard bearing temperature increase on startup should have tripped alarms

— Identifieda signal filter being used on a bad BFP turbine speed sensor

o Speed sensor is reading ~4000rpm when actual speed is ~5600rpm

o Later it was found that a filter was on the signal going to the control room

— Addressed alarms from units 4-6 as sensor or model parameter issues

Gravity Take-up Counterweights

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Conveyor counterweights weigh up to 17,000lb

— Must be supported by chain-falls for safety when replacing bearings

— Maintenance time for hanging chain-falls can be high

Process

— Identified weight necessary to tension belts

— Considered size limitations within structure

— Develop new design using a drainable water fill

— Produced first draft drawings for manufacturing of new counterweights

— Passed on to Maintenance Supervisor and Fuel Handling Crew Leader for review

Bottom Ash Conveyor Pumps

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Degraded or failed OEM pumps need to be replaced

— Replacement HP Pumps were purchased but not installed

Process

— Observed issues with system and compare purchased pumps to OEM pumps

— Contacted vendor of the new HP pumps to discuss concerns and request

information

— Plan piping routes for new system.