Discussion on Boiler MACT Applicability to

“Test Steam” Boilers Used for Overhaul of 

Nuclear-Powered Vessels

February 16, 2012

Presented by

Newport News Shipbuilding

Newport News, Virginia
Newport News Shipbuilding Attendees

Introductions of all meeting attendees

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NNS Department Name

Plant Operations Ken Allmon, Energy Manager and Government Affairs 

Representative

Plant Engineering Dan Cutshaw, Cubex, Inc., Project Team Lead, Boiler 

Compliance Strategy

Nuclear Propulsion Test Engineering Martin Merenda, Systems Test Engineer

Environmental Engineering Bill Cash-Robertson, Environmental Engineer
Why We Are Here

• The NNS shipyard in Newport News, Virginia, is a major source under the Clean Air Act

• NNS owns and operates a Floating Test Steam Facility (“FTSF”) containing two oil-fired marine boilers 

used for testing aircraft carrier systems during mid-life overhaul

• The FTSF boilers meet the broad definition of “industrial boiler” contained in the major source “Boiler 

MACT” for Industrial, Commercial, and Institutional Boilers and Process Heaters, but are actually marine 

boilers used in a specialized setting

– (NNS also has 3 conventional “Powerhouse” boilers used for shipyard steam generation that are subject to the Boiler MACT)

• The Boiler MACT would impose certain emission limitations, tune-up and energy assessment 

requirements on the FTSF boilers

• Compliance of the FTSF boilers with these Boiler MACT requirements is either infeasible or 

inappropriate, due to the unique and specialized nature of the boilers

• NNS desires to inform EPA about the FTSF boilers and provide an opportunity for discussion and 

questions

• NNS will be submitting written comments in response to the Proposed Rule and Reconsideration of 

Final Rule (76 FR 80598, December 23, 2011) requesting exemption of the FTSF boilers from the major 

source Boiler MACT (Subpart DDDDD)

The FTSF is a one-of-a-kind facility and unlike industrial boilers 

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Newport News Shipbuilding Facts

• Sole Supplier of U.S. Navy Aircraft 

Carriers

• One of two Builders Constructing Virginia 

Class Nuclear Submarines

• Exclusive Provider of Refueling Services 

for Nuclear-Powered Aircraft Carriers

• Largest Non-Governmental Provider of 

Fleet Maintenance Services to the Navy

• Largest Industrial Employer in Virginia –

Approximately 20,000 Employees

• Home of the Western Hemisphere’s 

Largest Dry Dock and Crane
The Newport News Shipbuilding Facility

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• Founded 125 years ago

• Covers 550 acres

• Spans over 2 miles of waterfront on the James River
Life Cycle of an Aircraft Carrier 

Generally, a carrier is delivered by the Navy to NNS

for refueling and overhaul every four to five years

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• Navy is required by law to maintain 11 carriers in its fleet

• ~10 years required to design, build, commission and deliver a carrier to the Navy

• In service for 25 years without refueling

• Returns to NNS for mid-life Refueling and Complex Overhaul (RCOH)

– ~3 years to plan, ~4 years to execute

– Refuel the onboard reactors

– Extensive modernization work to more than 2,300 compartments, 600 tanks, and hundreds of systems

– Major upgrades to the flight deck, catapults, combat systems and the island

• Returns to fleet for another 25 years of service

• Retirement and inactivation after 50 years of service

• Six carriers of eleven will require the FTSF during a future RCOH
Purpose of the FTSF 

• During RCOH a carrier’s nuclear power plant (the “propulsion plant”) is not operational.

• The propulsion plant cannot be returned to service until the overhaul process is nearly 

complete and all of the ship's steam-driven equipment and systems have been tested 

and made operational.

• Use of an off-ship “test steam” source during carrier RCOH is mandatory to support 

propulsion plant testing.

• The off-ship test steam source must supply the ship with steam of the same pressure 

and other characteristics as would the ship’s propulsion plant.

• The test steam source must be able to respond to extreme steam load transients similar 

to those of an operating aircraft carrier without losing steam pressure or “tripping”.

• To meet this requirement in 1985 NNS acquired two marine (vessel propulsion) boilers 

and mounted them on a specially designed barge to permit “steaming” of carriers at any 

of four distinct shipyard locations as required by ship schedules

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The FTSF is used for testing a ship’s steam systems
FTSF Operating Locations at NNS

= FTSF operating locations

NNS’ NPDES permit contains separate outfall designations for all 4 locations

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Unique Design of the FTSF

FTSF boilers are of a marine design and are unlike industrial boilers

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• FTSF contains two marine boilers designed for conventional ship propulsion

– Designed for firing with residual fuel oil, the fuel of choice for oceangoing vessels

– Designed to produce the high pressure steam required by conventional vessels

– Designed to respond to the extreme load swings encountered in vessel operation

• FTSF boilers are mounted inside a specially designed barge to permit “steaming” 

of Navy vessels at any of four distinct shipyard locations

• FTSF includes integral storage of over 500,000 gallons of No. 6 fuel oil below deck

• FTSF boilers must meet specific Navy performance requirements

– Load transients and sustained steam flows and pressures

– Turndown range

– Extremely high steam quality

• FTSF boilers are compact in size to achieve the high ramping rates and other 

performance criteria required to meet Navy aircraft carrier testing protocols
Unique Operation of the FTSF

FTSF operation is not continuous and is subject to unique requirements 

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• Typical FTSF operating schedule

– Shut down and inactive (“laid up”) between RCOHs: 2.5 - 3 years

– Tow to operating location, inspect, startup, systems checks and performance tests: 3-4 months

– Steam carrier: 12-14 months

– Shut down, tow to long term storage location, return to inactive status, and refurbish and 

upgrade equipment before next steaming

• FTSF boilers routinely experience a wide range of condensate return rates (from 

zero to 100%) 

• Test steam specifications are unique and are prohibited from release by the U.S. 

Department of Defense (DoD) and the Naval Nuclear Propulsion Program. 

• FTSF boilers operate at or below 25% load 85% of the time

– Below 25% load is defined in Boiler MACT as the startup/shutdown threshold

– Sustained boiler operation is required at low loads (high turndown ratio)

– Operation in the startup/shutdown range may continue for many weeks
Demonstration of Normal FTSF Boiler Operating Range

The FTSF boilers routinely operate at turndown rates

not achievable by industrial boilers, in the range defined as “startup” or 

“shutdown” mode under the Boiler MACT

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Energy Efficiency Aspects of the FTSF

FTSF boilers are tuned to emulate a vessel operating at sea and meet 

steam performance needs

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• FTSF boiler operation entirely driven by steam demand from a Navy 

vessel undergoing testing

• Navy determines system testing requirements

– Ship’s systems demand steam when/as needed according to test requirements

– FTSF boilers automatically respond to demand

– Steam demand cannot be predicted or controlled

– Ancillary boiler systems (feedwater, condensate, etc.) must be closely managed by 

operators

– Barge list and trim maintained continuously by onboard fuel transfers during operation

• FTSF boilers are tuned prior to each RCOH to ensure required steam 

production performance and optimize fuel efficiency

• Current tune-up practices conflict with Boiler MACT tune-up objectives of 

optimizing specific emission rates

– Flue gas oxygen (O2) levels

– Flue gas carbon monoxide (CO) levels
Feasibility of Add-on Air Emission Controls

Use of add-on controls on the portable FTSF is unproven and not feasible

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• Portable emission source

– Add air pollution control equipment to FTSF barge

• Seaworthiness

• Reduced cost effectiveness driven by unique construction requirements

– Construct up to four redundant land-based air pollution control systems

• Reduces cost effectiveness anticipated by EPA by up to 4x

• Untried/unproven design of a flexible capture and collection system

• Current schedule would not allow for installation of controls by the 

compliance date

– Significant risk to the Navy’s carrier RCOH schedule

– RCOH schedule changes driven by Navy’s needs and outside the control of NNS

– FTSF operation cannot be interrupted during ship steaming

– Window of availability between RCOH steamings determined by Navy schedules
Feasibility of Conversion to Natural Gas

Use of natural gas in marine boilers designed for fuel oil presents high risks

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• Untried/unproven replacement fuel for existing fuel oil-fired marine boilers

– Safety risk is high due to uncertain gas and flame behavior

• Risk of fuel supply interruption

– Natural gas supply system has numerous potential failure points

– Delay of carrier contract delivery date is unacceptable

• Several technical fuel combustion issues

– Firebox not designed for gaseous fuel

– Flame impingement and tube damage potential

– Different flame emissivity than oil

– Excessive superheater temperatures

– Alteration of overall boiler heat balance and steam performance 

• Recertification and Navy acceptance of modifications to steam delivery equipment

– Risk to RCOH schedule

• Boiler MACT energy assessment and tune-up requirements would still apply
Feasibility of Conversion or Replacement with 

No. 2 Fuel Oil-Fired Boilers

Conversion from No. 6 to No. 2 fuel oil is not a viable Boiler MACT 

compliance option

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• Is a liquid fuel, so Boiler MACT emission limits would continue to apply

• Raises same issues of feasibility of add-on controls

• Boiler MACT energy assessment and tune-up requirements would still 

apply

• Conversion or replacement would provide no meaningful reduction in 

Boiler MACT requirements 

• Recertification and Navy acceptance of modifications to steam delivery 

equipment

– Risk to RCOH schedule

• Conversion would have fewer technical issues than natural gas
Feasibility of Replacement with New Gas-Fired Units

Replacement of the FTSF with a new facility not a feasible option

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• High risk of fuel supply interruption

– Natural gas supply system has numerous potential failure points

– Delay of carrier contract delivery date is unacceptable

• Recertification and Navy acceptance of modifications to steam delivery 

equipment

– Risk to RCOH schedule

• Boiler MACT energy assessment and tune-up requirements would still 

apply

• Cannot be procured, constructed and commissioned within required 

timeframe

• Not yet known to be capable of meeting Navy steaming requirements 
Summary

The FTSF boilers do not fit within the class of Industrial, Commercial, and 

Institutional Boilers intended to be regulated under the Boiler MACT 

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• FTSF boilers do not fit the model of conventional industrial boilers envisioned to be 

regulated under the Boiler MACT

– Design

– Operation

– Purpose

– Portability

– Downtime

– Energy efficiency considerations

• Compliance by installing add-on controls not practical or cost-effective

• Compliance by fuel switching not practical or cost-effective

• Compliance by complete replacement not practical or cost-effective

• No other boilers of this type and used for this purpose exist in the US 
NNS Will Request an Exemption from the 

Boiler MACT for the FTSF Boilers

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• Preferred: a specific exemption under 63.7491 for test steam boilers 

used at Newport News Shipbuilding for military vessel propulsion plant 

testing

• Alternative: a general exemption under 63.7491 for test steam boilers 

used for military vessel propulsion plant testing

• Alternative: An Applicability Determination that the FTSF test steam 

boilers used at Newport News Shipbuilding constitute test equipment 

and are exempt from the Boiler MACT by operation of 63.7491(c)

• Alternative: An Applicability Determination that the FTSF test steam 

boilers used at Newport News Shipbuilding are marine boilers not 

within the scope of the Industrial, Commercial, and Institutional Boilers 

category that EPA intended to regulate under the Boiler MACT 
Questions and Discussion

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