DECOMMISSIONING POWER PLANTS

//DECOMMISSIONING POWER PLANTS

DECOMMISSIONING POWER PLANTS

Presented at EUEC 2015: February 16, San Diego, CA. (in Session G1 & G2)

 

G1.1 Lessons Learned from the Preparation of Abatement, Demolition, Plant Asset Valuation, and Environmental Regulated Materials Cost Estimates to Support the Retirement of Three Coal-Fired Power Generation Stations

amec

Jerry Archer, D&D / Repurposing Initiative Leader, Amec Foster Wheeler Environment & Infrastructure,

Inc; Keith D Welcher, Consumers Energy

Environmental regulations, soft wholesale electricity prices, political pressures, and other factors have

accelerated the retirement of coal-fired power plants across the nation. Many utilities now face the

complex task of revamping outdated depreciation cost studies to obtain and prudently justify the

critical funding required to decommission, abate, demolish, and remediate environmental liabilities

associated with plant retirements and future redevelopment. These studies require an assessment

of plant assets to optimize financial credits that will be used to minimize the costs of plant retirement.

Engineering studies were conducted at each of three operating, 300 MW coal-fired power plant

sites to quantify the costs associated with the abatement/demolition, plant asset valuation, and

the environmental liability associated with each plant. Existing plant records and surveys formed the

foundation for detailed estimates and field studies. Plant asset valuation studies employed digital

methods to facilitate an automated take-off process used for calculating the value of scrap assets.

Environmental remediation liabilities were estimated using a Probabilistic Cost Analysis approach

developed by the American Society of Testing and Materials (ASTM) to determine defensible estimates

with limited data.

G1.2 The End of Life: Coal-Fired Power Plant Closure Factors & Implementation

BGD logo

Jennifer Cave, Partner, Bingham Greenebaum Doll LLP;

Jeffery L. Pope. PE, Burns & McDonnell

Engineering Co., Inc.

Nationwide, transformational change is occurring within America’s aging fleet of power plants. An

estimated 200 units will be retired nationwide in the next decade as the primary result of regulatory

& technological changes redefining the national electricity generation landscape. A host of

environmental, health & safety issues must be evaluated when considering decommissioning,

decontamination, & demolition projects at a coal-fired plant. Many owners are experienced at

operating & maintaining these units, but are facing a new challenge with the structural demolition

& remediation of the site. Environmental issues that must be considered include asbestos & lead

abatement, remediation of potential PCB impacts from spills & in building materials, mercury

containing device removal, & universal waste disposal (i.e., lighting ballast). Closure of existing

wet ash ponds & ash landfills must also be evaluated as part of the overall site closure. Other

environmental concerns include dust mitigation, noise & vibration limitations, restrictions on stack

removal, coal pile closure, air, water & waste permitting, fuel storage tank closure, & site remediation

& restoration. Utility easements, storm outfalls, & intake lines must be identified & also removed or

abandoned during plant closure or demolition activities.

G1.3 Planning for Closure: Ash Ponds, Landfills & Coal Piles

BurnsMcDonnellLogo

Jeffery Pope, Manager, Facility Decommissioning & Demolition Services, Burns & McDonnell

Engineering Co., Inc.

In December 2014, the EPA will finally unveil the much anticipated final coal combustion residuals

(CCR) regulations. Many utilities have been considering approaches for closure of ash ponds, ash

landfills & coal piles as part of the decommissioning, demolition & decontamination (DDD) of former

coal-fired power plants. Closure of these areas presents a new challenge for many owners. A myriad

of considerations & approaches must be evaluated as part of the development of a final approach

including a determination of what the end use of the site will be once everything is removed &

environmental closure is completed. Regulatory involvement & approval will also be an important

component of the planning & implementation process. This presentation will examine the closure

approaches, design considerations & details as well a touch on implementation issues during closure.

G1.4 Plant Decommissioning – A Master Plan for Ensuring Maximum Return & Minimum Liabilities

nth

Jeff Jaros, Sr. Vice President, NTH Consultants, Ltd.; Frank Johnson, R.E. Warner & Associates, Inc.;

Doug Hartman, FirstEnergy Corporation

As a result of environmental regulations targeting the coal-fueled power generation fleet, numerous

shutdowns of older assets have been announced. Additionally, predictions are that up to 50 GW of

generation could be permanently shut down over the next 3 years. Working together, R.E. Warner

& Associates, Inc. and NTH Consultants, Ltd. are assisting our energy clients with master planning to

determine the best course of action after an operating plant has been placed in a safe, secure and

environmental compliance condition. By developing an inventory of all equipment and structures for

sale or scrap, understanding the environmental liabilities and associated mitigation costs, and future

re-use options, companies are better able to understand the value of the asset. Full-scale dismantling

and abatement is not always the most cost-effective solution in the near-term. The presentation will

discuss our approach to developing a master plan for decommissioned assets and provide one such

case example.

G2.1 Optimizing Foam Control for Wet Flue Gas Desulphurization Systems

Minnesota Power

Kristin Glikbarg, Associate Process Engineer, Burns & McDonnell Engineering Company, Inc.; Paul N.

Dyer & Paul T. Brandt, Burns & McDonnell; Misty Worcester, Minnesota Power

Foaming in wet flue gas desulphurization (WFGD) systems is a common and widespread problem across

the steam electric coal-fired power plant fleet. Despite the frequency of occurrences and problems

caused by foaming, the specifics of their formation remains largely unknown, and no universal solution

exists. This paper discusses the dynamics of foam formation and provides practical recommendations

for the control of foam by conventional and new, novel means. The importance of a thorough

laboratory analysis in the optimization of anti-foaming agents is also discussed. Although periodic

addition of anti-foaming agents to scrubber slurry is the most widely used foam control method, lower

operating cost alternatives are also possible. Through experimental study, certain chemical species

which promote foaming in WFGD systems have been identified. By analyzing foam for the presence

of these species, and by understanding the characteristics of a given scrubber slurry, successful

alternative solutions can be developed.

G2.2 Optimization of Fossil Fuel Fired Boilers with Video-based Thermography

durag

Roland Zepeck, Managing Director, DURAG process & systemy technology gmbh; Eagarat

Chaiyarith, Processplus Company Limited; Maurizio Dal Cin, Power Generation Systems

Fossil Fuel fired Boilers produce energy utilizing the basic chemical reaction C + O2 → CO2 + 94.1 kcal.

This reaction is influenced in its efficiency by many parameters, i.e. the type & quality of the fuel, quantity

& temperature of the combustion air, ration & mixing between the two, etc. In addition the overall

efficiency & environmental friendly operation of a boiler is influenced, besides others, by slagging,

heat transport through water walls, combustion temperature, etc. Depending on the firing system

(tangentially, boxer, wall, grate) the balanced or un-balanced distribution of the energy (temperature)

is responsible for heat corrosion & slagging; too high combustion temperature also produces too high

NOx concentration. Therefore there is a high interest in getting on-line information about the thermal

balance inside the combustion chamber. Furnace Cameras continuously visualize the firing zone. This

gives the operators a possibility to control with their eyes the presence, & to some smaller extend, also

the position & shape of the flame(s). Advanced Systems additionally continuously perform an online

thermographic analysis of the entire firing zone. Based on this analysis the thermal position of the flames

& the temperature distribution within the same are detected, continuously showing unbalances of the

flames as well as influences f. e. from changing fuel Quality, allowing the operator or an optimization

system to adjust the combustion efficiently.

G2.3 Improve Heat Rate & Enhance Operational Flexibility through Sootblowing Optimization at La Cygne Unit 1

siemens

Neel Parikh, Sr. Engineer, Siemens Energy, Inc.; Jim Stewart & Kenneth Luebbert, KCP&L

Today’s coal-fired power plants are faced with increasing demands for operational flexibility and

better efficiency. Variable load operation, fuel variations and operating constraints present interesting

challenges. Closedloop optimizers reduce the need for manual adjustments and provide consistency

in unit operation. Such optimizers are typically computer software-based and work by interfacing an

algorithmic and/or artificial intelligence based decision making system to plant control system. Dynamic

adjustment of sootblowing activities and different operational parameters is required to control

slagging and fouling, while maintaining unit load capacity and avoiding adverse impacts of different

operational constraints such as exit gas temperatures, steam temperatures, differential pressures and

attemperation spray flows. Siemens SPPA-P3000 Sootblowing Optimizer solution determines the need

for sootblowing based on dynamic plant conditions, equipment availability and plant operational

drivers. The closed-loop system then propagates individual sootblower activation signals to the

existing sootblower control system at ‘optimal’ times. This paper discusses successful implementation

experience of the Sootblowing Optimizer and presents operational results from La Cygne Unit 1, an

810-MW, cyclonefired boiler, firing a 90 percent Powder River Basin coal blend.

G2.4 Burner Air & Fuel Measurement & Control for Combustion Optimization

Combustion Tech

David Earley, President, Combustion Technologies Corporation

Coal Fired Power Plants today are being challenged to improve efficiency, meet stringent emissions

standards, burn cheaper fuels to compete with gas and more. The MATS regulation also requires

better tuning for reduced CO. All of this is more easily achievable if the plants can control the air

and fuel to the boiler on a burner to burner basis. In recent years, new technologies have become

available to accurately and continuously measure the coal in each conduit. The use of these devices

combined with coal line valves has led to better balance of coal to burners. Furthermore, the use of

these measurements has helped plants burning more challenging fuels prevent common problems

such as coal layout and pipe fires. The data from these measurement devices is now being used to

better control Primary Airflow to the mills to prevent layout/fires as well as to prevent operators from

using too MUCH Primary Air. Today’s low NOx burners have dampers to allow for control of Secondary

Airflow to burners. Measurement devices applied to these burners allow for adjustment to precisely

control the mass flow of air to each burner. Combining burner airflow with coal line fuel flow allows

plants to optimize combustion at each burner. This level of optimization will be critical to meeting MATS

regulations for boiler tuning.

G2.5 Thermodynamic Optimization of Power Plants: Maximum Efficiency versus Minimum Entropy Generation

Western NE Univ

Yousef Haseli, Visiting Assistant Professor, Western New England University

System level optimization of power plants is mainly based on the thermodynamic laws. Various objective

functions are proposed by researchers that are based on the 1st and 2nd law of thermodynamics.

Given the fast technological advancement of power plants, it is important to understand which

optimization objective should be used in practical applications. The idea is to explore whether there

is any consistent relation between the entropy production of a power plant and its thermal efficiency

and work production. The study considers four configurations of gas turbine cycles: a regenerative

gas turbine, a reheat regenerative gas turbine, an intercooled regenerative gas turbine, and an

integrated solid oxide fuel cell and gas turbine power plant. The operational regimes at maximum

thermal efficiency, maximum work output and minimum entropy production of these power plants

are compared. The results reveal that a reduction in entropy production is neither equivalent to an

increase in thermal efficiency; nor to an increase in work output. Under special circumstances, minimum

entropy production design may be identical to maximum thermal efficiency design and/or maximum

work output design. It is demonstrated that for practical applications, thermodynamic optimization of

power plants should continue to be based upon maximum thermal efficiency or maximum work output

criteria. In other words, for real life applications, entropy-based design of power plants may lead to a

deficient design.

G2.6 Re-Engineering Coal-Fired Power Plants to meet EPA Regulations

castle light

Keith Moore, President, Castle-Light Energy Corp

Are FGD & SCR emission control technologies Obsolete? Technologies do not evolve……………,

they LEAP FROG! With many U.S. coal-fired plants being shut down, moth balled, or abandoned, is

it possible to Re-Engineer these plants to meet EPA regulations & continue to operate with low SO2,

NOx & CO2 emissions & also competitively dispatch electricity? CastleLight Energy will discuss recent

developments in Coal Beneficiation to remove water, ash, mercury & even the oil values, coupled

with its field demonstrated “hybrid of coal-gasification” furnace modifications for very low SO2 & NOx

emissions & improved boiler efficiency (reduced CO2) to provide coal-fired power plants a significant

reduction in operating costs & pollutant emissions. See www.castle-light.com

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