Fire Hazard Calculations - Anchorage, Alaska 2017-74 2016-0425 Coffman...Note that a detailed review of the other requirements of NFPA and API (i.e ... NFPA 59A-2016 Table 15.8.4.1

Port of Anchorage Fuel Terminal

Fire Hazard Calculations

100% Submittal Coffman Project #160201 25 April 2016

Fire Hazard Calculations Crowley Anchorage Fuel Terminal 100% Submittal 25 April 2016

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Fire Hazard Calculations Table of Contents:

1. Summary ........................................................................................................................ 3

2. General Site Conditions .................................................................................................. 5

3. Fire Scenarios ................................................................................................................ 7

4. Heat Flux Hazard Thresholds ......................................................................................... 8

5. Computational Fluid Dynamics (CFD) Calculations ........................................................ 9

6. CFD Modeling Input Criteria ..........................................................................................13

7. Heat Flux based upon Shokri and Beyler (Shaped Based) Detailed Calculations ..........15

8. NIST Acceptable Separation Distance Calculations.......................................................16


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1. Summary

This report provides a review of the expected heat-flux at various distance from the fuel terminal based upon the worst-case pool fire estimated by Crowley and the potential hazards to the surrounding area. The worst-case pool was based upon the complete failure of the largest tank on-site and the resulting combustible liquid contained within the dyke area. Three different calculation methods were utilized to evaluate the expected heat release rates:

1. Computational fluid dynamics (CFD) model utilizing Fire Dynamics Simulator (FDS) Software (with and without wind from the north)

2. Shokri and Beyler (Shaped Based) Detailed Calculations 3. NIST Acceptable Separation Distance Calculations

It is recommended that the results of the FDS model be viewed as the most accurate since they accommodate the specific geometry of the site. This report recommends that the distances provided by the FDS model be doubled to provide a safety factor of two. This practice matches the recommendations of the NIST Acceptable Separation Distance Calculations.

Fire Simulation Recommended distance from edge of fire

* Quasi Steady State Heat-Flux

Potential Hazard

Wood Ignition < 50-feet 25.0 kW/m2 The minimum energy required to ignite wood at indefinitely long exposure

Fatality Exposure

> 50-feet 12.5 kW/m2

This value is typically used as a fatality number. Heat flux required to raise a bare steel plate, insulated on back, to 300°C/572°F. The minimum energy required for piloted ignition of wood, and melting of plastic tubing.

Injury Exposure

> 100-feet

9.5 kW/m2 Sufficient to cause pain in 8 seconds and 2nd degree burns in 20 seconds.

4.0 kW/m2

Sufficient to cause pain to personnel if unable to reach cover within 20 seconds. However, blistering of skin (second degree burns) is likely; 0% lethality

No hazard > 200-feet 1.6 kW/m2 Will cause no discomfort for long exposure

Note that a detailed review of the other requirements of NFPA and API (i.e. dike design, tank supports, emergency venting, process piping, and fire suppression systems) are beyond the scope of this report. In addition, this report does not take into account any potential impact due to explosions.


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Figure 1 - Simplified hazard zone map based upon FDS model with 2x safety factor


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2. General Site Conditions

The fuel terminal is located adjacent to a residential area to the south. There is a significant change in elevation/grade between the two areas. A basic summary of tank sizes is provided below for reference. All tanks are fixed cone-roof type without internal floating roofs.

Tank # Diameter Height Safe Fill Product Stored

1 120-ft 47-ft 89,941 bbl JP-8

2 81-ft 48-ft 42,110 bbl JP-8

9 52-ft 48-ft 17,248 bbl JP-8

20 76-ft 48-ft 36,844 bbl Standby for spill response

24 120-ft 46-ft 88,831 bbl JP-8

25 98-ft 48-ft 61,262 bbl Standby for spill response

26 85-ft 48-ft 46,087 bbl JP-8

27 98-ft 48-ft 61,262 bbl JP-8

28 98-ft 48-ft 61,262 bbl JP-8

29 120-ft 47-ft 89,864 bbl JP-8

30 120-ft 48-ft 91,854 bbl JP-8/SPCC Tank

31 76-ft 48-ft 36,844 bbl JP-8

32 112-ft 56-ft 93,351 bbl JP-8

33 112-ft 56-ft 93,351 bbl JP-8

34 90-ft 56-ft 60,279 bbl JP-8

35 112-ft 56-ft 93,351 bbl JP-8


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Figure 2 – Reference site plan. Green line is top of containment wall/berm. Red line is the outline of the expected liquid level from the complete failure of a single tank (image from an

Enterprise Engineering report)


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2.1. NFPA 30 - Prescriptive Tank Shell-to-Shell Spacing

The sole product being stored is JP-8. Since it has a flash point above 100°F (37.8°C), the product is defined as a Class II Combustible liquid per NFPA 30-2015. NFPA 30-2015 Table 22.4.2.1 provides prescriptive recommendations for tank spacing as summarized below.

Table 22.4.2.1 Minimum Shell-to-Shell Spacing of Aboveground Storage Tanks

Tank Type Fixed Tank - Class II Liquids

All tanks not over 150-ft in diameter 1/6 x sum of adjacent tank diameters but not less than 3-ft

Based upon a review of the civil drawings, the existing tank layout meets these minimum requirements. 2.2. Active Fire Suppression Systems

All tanks are currently protected by a manually operated 3% AFFF foam-water system applied over the entire interior surface of the tank. The system is “fixed” and does not require any mobile equipment to be manually connected prior to delivering foam to the tanks. The quantity of on-site foam-concentrate storage is approximately 2,200 gallons. 1,100 gallons of this foam is stored in barrels as backup. 1,100 gallons provides sufficient delivery time to comply with NFPA requirements. 3. Fire Scenarios

For these fixed cone-roof tanks without internal floating roof, the worst-case fire scenarios considered was the complete failure of the single largest tank and the resulting combustible liquid within the containment area. Ignition of the spill would subsequently result in the pool fire considered in this report. It should be noted that any accidental discharge in the diked area would be expected to be immediately noticed and the total volume of spill is expected to much less than the total volume of a tank. While not reviewed by this report, the consideration of a potential tank-top fire is a typical second fire scenario. A tank-top fire would be much smaller in size and therefore the containment area pool fire covered by this report is the worst-case condition. In addition the site has fixed foam suppression on all tanks and with prompt response by personnel, a tank-top fire should be contained to a small fire.

Figure 3 - Expected pool size due to a 105,300 Barrel Spill (image from an Enterprise Engineering report)


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4. Heat Flux Hazard Thresholds

The key measurement in determining the potential hazard from a fire is the heat flux at the surface of adjacent materials/equipment. Heat flux is the rate of heat energy transfer through a given surface. The following thresholds provide general guidance on the impact of heat flux at various levels.

Heat Flux Potential Hazard

37.5 kW/m2 Sufficient to cause damage to process equipment and tanks (1)

32.0 kW/m2 Loss of strength of structural steel exposed to the fire to an extent that its primary load-bearing capacity is reduced significantly over the duration of LNG fire being analyzed. (3)

25.0 kW/m2 The minimum energy required to ignite wood at indefinitely long exposure (1)

12.5 kW/m2 Heat flux required to raise a bare steel plate, insulated on back, to 300°C/572°F. The minimum energy required for piloted ignition of wood, and melting of plastic tubing. This value is typically used as a fatality number. (1)

12.0 kW/m2 Additional cooling should be provided to prevent ignition (4)

9.5 kW/m2 Sufficient to cause pain in 8 seconds and 2nd degree burns in 20 seconds. (1)

8.0 kW/m2 Potential ignition of crude oil (4)

5.0 kW/m2

At least 10 persons would suffer second-degree skin burns on at least 10% of their bodies within 30 seconds of exposure to the fire. (3) At least on person inside the building would suffer second-degree burns on at least 10% of the body within 30 seconds of exposure to the fire. (3)

4.0 kW/m2 Sufficient to cause pain to personnel if unable to reach cover within 20 seconds. However, blistering of skin (second degree burns) is likely; 0% lethality (1)

1.7 kW/m2 No pain was shown, regardless of the exposure duration for thermal fluxes below 1.7 kW/m2 (2)

1.6 kW/m2 Will cause no discomfort for long exposure (1)

1.0 kW/m2 Approximate solar constant on a clear summer day

These numbers were obtained from the following sources:

(1) Guidelines for Chemical Process Quantitative Risk Analysis”, Second Edition, page 269, American Institute of Chemical Engineers Center for Chemical Process Safety (CCPS), 2000.

(2) SFPE Handbook, third edition, chapter 11 page 3-309 (3) NFPA 59A-2016 Table 15.8.4.1 “Radiant Heat Flux and Thermal Dosage Outside the

Plant Boundary” include the following recommendations: (4) BP, EI, Lastfire studies for crude oil (5) 49 CFR, Part 193 (Liquefied natural gas facilities: Federal Safety Standards) §193.2057

“Thermal radiation protection”.


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5. Computational Fluid Dynamics (CFD) Calculations

The CFD calculations in this report have been completed utilizing the Fire Dynamics Simulator (FDS) software, developed by the National Institute of Standards and Technology (NIST). The Fire Dynamics Simulator (FDS) is the most peer-reviewed and experientially verified software available. A CFD model provides the most realistic model as it accounts for wind (flame leaning), convective heat transfer, and detailed information on all sides/surfaces of the tanks. A summary of the worst-case heat-flux values measured along a north-south axis centered between tanks 32 and 33 are shown in the table below. Two models were run: one with no wind and one with a 16 mph wind from the north.

Figure 4 – Location of heat-flux measurement points (two separate views)

Distance from edge of source to target

Radiant Heat Flux with a 16 mph wind from the North*

Radiant Heat Flux with No Wind*

33 feet 7.80 kW/m2 5.73 kW/m2

66 feet 3.63 kW/m2 2.72 kW/m2

98 feet 1.96 kW/m2 1.56 kW/m2

131 feet 1.35 kW/m2 1.13 kW/m2

* All measurements are Quasi Steady State Heat-Flux averaged from 30 to 60 seconds after simulation has stabilized.

Thermocouples spaced along this axis at 10-meters on-center starting at the edge of the containment berm.


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Figure 5 – Visual of model entered into FDS

Figure 6 – Visual of smoke from FDS with 16 mph wind from the north


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Figure 7 – Overlay of radiant head flux from FDS and aerial photo with no wind

Note that due to the visual rendering this color presented are for horizontal surfaces only. Vertical surfaces experience higher heat fluxes due to the geometery. For display purposes all values over 12.50 kW/m2 are represented with the same color (e.g. heat fluxes greater than

12.5 kW/m2 are present).


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Figure 8 – Overlay of radiant head flux from FDS and aerial photo with 16 mph wind

Note that due to the visual rendering this color presented are for horizontal surfaces only. Vertical surfaces experience higher heat fluxes due to the geometery. For display purposes all values over 12.50 kW/m2 are represented with the same color (e.g. heat fluxes greater than

12.5 kW/m2 are present).


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6. CFD Modeling Input Criteria

6.1. Atmospheric Wind Speeds and Direction

Historical wind data was reviewed for the project site and incorporated into the model. Wind direction varies significantly depending upon the season. The worst-case condition of a prevailing wind from the North blowing at 16 mph (7.15 m/s) towards the residential area was used in the CFD model based upon conservative historical data for the area.

https://weatherspark.com/averages/33017/Anchorage-Alaska-United-States

https://weatherspark.com/averages/33017/Anchorage-Alaska-United-States


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6.2. Heat Release Rate per Area (HRRPUA) of JP-8

The heat release rate of a fire is the best measure of its potential to do harm. This section provides backup reference for the source of data used in the model and any experimental data to validate the results. JP-8 is a Kerosene based jet propellant. As such where detailed chemical / thermal proprieties were not available, those from Kerosene were applied. For our specific model, the speed at which the fire will ramp-up or how long it will burn does not matter in this evaluation as we are only interested in the worst-case heat-flux expected adjacent to the fuel terminal. It should also be noted that the analysis of hazardous liquid fires is relatively independent of the type of liquid; burning rates and heat release rates do not vary significantly from fuel to fuel, nor does the nature of the fire. As such if in the future the type of fuel is slightly different than that modeled, there is limited impact on the calculation results. Extensive large-scale open pool fire experiments utilizing JP-8 were conducted by Sandia National Laboratories (SNL) around 2008 (Blanchat, T. and Figueroa, V., 2008. Large-Scale Open Pool Experimental Data and Analysis for Fire Model Validation and Development. Fire Safety Science 9: 105-115. doi:10.3801/IAFSS.FSS.9-105). The results of this testing have been utilized as inputs for the modeling of the pool fire. The SNL testing included am 8-meter diameter pool fire with a 5.76 m/s wind speed that resulted in a Pool Surface Heat Flux of 97 kW/M2. Numerous other NIST tests of large scale pool fires have an average surface heat flux of 100 kW/m2. Our model is utilized the 97 kW/M2 number. From the NIST report “Thermal Radiation from Large Pool Fires” a steady-state HRRPUA (q”f) value of 1,700 kW/m2 was utilized in the CFD model.


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6.3. Mesh Size

The entire model has dimensions of X:305-m [1,000-Feet], Y:470-m [1,542-Feet], Z:160-m [525-Feet]. The model will be divided up into 2,099,520 cells with an approximate cubic dimension of 2.2-meters (7.22-feet). A mesh sensitivity study was conducted with smaller mesh sizes, but had no appreciable differences in results were noted beyond this size. The cell size (dx) for a given simulation can be related to the characteristic fire diameter (D*), i.e., the smaller the characteristic fire diameter, the smaller the cell size should be in order to adequately resolve the fluid flow and fire dynamics. A reference within the FDS User Guide (Verification and Validation of Selected Fire Models for Nuclear Power Plant Applications. NUREG 1824, United States Nuclear Regulatory Commission, 2007) used a D*/dx ratio between 4 and 16 to accurately resolve fires in various scenarios. From the FDS User Guide: “These values were used to adequately resolve plume dynamics, along with other geometrical characteristics of the models as well. This range does not indicate what values to use for all models, only what values worked well for that particular set of models.” The 2.2-meter cell size correlates to a D*/dx ratio of 16. 6.4. Simulation Duration

As the FDS model essentially has no ramp up time for the fire, the model only needs to be run until the heat flux has quasi stabilized. Based upon several different simulations, the analysis only needed to be run for at least 30 seconds before becoming quasi steady state. A total simulation time of 60-seconds was used to be conservative. 7. Heat Flux based upon Shokri and Beyler (Shaped Based) Detailed Calculations

As a validation check of the outputs from the CFD model, a traditional “shape based” source heat flux calculation was performed based upon the Shokri and Beyler detailed method. This type of calculation is algebraic in nature and ignores convection. Known issues with this type of model area as follows:

1. Wind is not taken into consideration 2. Limited accuracy for pool fires over 50-meters in diameter because no experiments of

this size have been performed for validation. 3. Under estimates radiation to near-field targets 4. Over estimates radiation to far-field targets

The output of the calculations for this specific site are summarized below:

Distance from edge of source to target

Estimated heat flux at target

33 feet 6.050 kW/m2

244 feet 1.6 kW/m2


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8. NIST Acceptable Separation Distance Calculations

Another guideline for determining the radiation from a fire comes from the Department of Housing and Urban Development (HUD) Regulation 24 CFR Part 51, Subpart C which is titled “Siting of HUD-Assisted Projects Near Hazardous Operations Handling Conventional Fuels or Chemicals of an Explosive or Flammable Nature”. Specifically paragraph 51.203 of this section states the following recommendations:

(a) Thermal Radiation Safety Standard – Projects shall be located so that: (1) The allowable thermal radiation flux level at the building shall not exceed 10,000 BTU/sq ft per hour [31.5 kWh/sq m] (2) The allowable thermal radiation flux level for outdoor, protected facilities or areas of congregation shall not exceed 450 BTU/sq ft per hour [1.4 kWh/sq m] These recommendations basically flow the same guidelines as noted in section 4 of this report. The recommended calculation method for the ASD comes from the National Institute of Standards and Technology (NIST) report from Nov 2000 “Thermal Radiation from Large Pool Fires”. A basic summary of the recommendations of this report is noted in the tables below. Note that these numbers are very conservative so as to provide a simplistic base line when doing an initial review of a site. It is estimated that these numbers have at least a two-times safety factor.

Simplified NIST Thermal Radiation from Large Pool Fires Table 1

Liquids Mass Burning Rate Kg/m2 / s

Heat of Combustion kJ/kg

HRR Per Unit Area kW/m2

ASD to Structures*

ASD to People*

Kerosene 0.039 43,200 1,700 15 meters 50 feet

400 meters 1312 feet

* The ASD noted is the distance beyond which the thermal radiation flux criteria is satisfied, regardless of fire size.

Calculated Radiant Heat Flux based upon NIST method

Estimated heat flux of source Distance from edge of source to target

Estimated heat flux at target

100 kW/m2 (no obstructions between source and target) H/D = 0.060

Beyond scope of equation 31.5 kW/m2

107 feet 12.5 kW/m2

498 feet 1.6 kW/m2

50 kW/m2 (substantial thermal barrier between source and target) H/D = 0.060

Beyond scope of equation 31.5 kW/m2

53 feet 12.5 kW/m2

296 feet 1.6 kW/m2

Crowley Anchorage Fuel Terminal Fire Hazard Study GHCC Review Comments/Reponses, September 2016

# Comment Response

1 Fire Dynamic Simulation (FDS)

1.a Radiant Heat Flux at burning pool edge -

Figure 2 shows a red line indicating the

expected liquid level, or pool size, from the

modeled tank failure. Why do the FDS

calculations show zero kW/m2 at the

southeastern edge of the pool fire under no

wind conditions (Figure 7) and many pockets

of zero kW/m2 with a 16 mph wind (Figure

8)?

Figures 7 and 8 are snapshots of the model at a

specific split-second of the model simulation

and the images are not averaged over any

amount of time. As such, they provide an easy

to understand visual of general heat-flux

location, but not necessarily average heat flux

anticipated.

To address the variation of the visual

representation, point measurement devices

have been utilized (referenced as

thermocouples for the purposes of this report).

The thermocouple data has been averaged over

30-seconds and better accommodates for the

volatility of the burning pool fire. Please

reference the table on page 9 of the report for

expected heat-flux values at different points

from the pool fire.

In regards, to the lack of heat flux in Figures 7

(no wind), there is the significant shielding by

tanks 2, 29, and 30 and therefore minimal heat-

flux in this corner (i.e. line-of-sight situation).

Also when the pool fire outline is converted to

“cubes” within the FDS model, there is some

accuracy lost due to mesh size (see section 6.3

of the report for further discussion). Since the

pool depth between tanks 2 and 29 is very

shallow, the model correlates this small area to

be ground and not the pool fire which also

reduces the heat-flux in this corner of the

model. The FDS thermocouple readings

located between tanks 33 and 32 are not

affected by this minimal reduction in pool fire

size.

In regards to the “blank” spots on Figure 8 (16

mph wind), this is a result of the significant

volatility of these pool fires and the specific

split-second time the snapshot was taken.


1.b Radiant Heat Flux on Vertical Surfaces -

Figures 7 and 8 note that the visual

rendering illustrates heat flux for horizontal

surfaces only but that vertical surfaces (not

shown) experience higher heat fluxes due to

geometry. Because of the close proximity of

the bluff and homes on top important

vertical or near vertical surfaces could be

presented to the fire face. Please interrogate

the modeling results with and without wind

to see if sufficient energy is released to

cause vegetation on the steep bluff side to

ignite or the north sides of homes on the

bluff edge to burn.

The limitations of Figures 7 and 8 are

addressed by utilizing thermocouples within

the model located at 10-feet above-grade and

located every 33-feet (10-meters) as shown on

page 9 of the report.

As discussed in item 1.a above, the

thermocouple measurements provide a better

indication of the expected heat flux. Page 9,

section 5 provides expected heat fluxes at

different distances and addresses the potential

impact on the bluff and houses.

1.c Radiant Heat Flux and Wind – there appears

to be very little difference in modeling

results between Figure 7 with no wind and

Figure 8 with 16 mph wind. What is the

elevation of these horizontal slices, are they

the same? Does the radiant flux stay

roughly centered on the tank farm at all

elevations under the modeled wind

condition?

Figures 7 and 8 are not slices, but a snapshot

of the heat flux through the surfaces

boundaries within the model. As such there is

no elevation and they are the same

measurement points.

The tilting of the flames is fairly limited due to

the significant amount of tanks creating

shielding of the flames. See attached additional

figures, with and without wind, which show an

approximation of the flame locations based

upon the FDS model. See response to item 1.d

below for additional discussion of flame

representation.

1.d Radiant Heat Flux Visual Representation –

Figure 6 showing the smoke plume is a

helpful image which would be easily

understood by residents of the

neighborhood. From the modeling results

would it also be possible to similarly

illustrate the Heat Flux “plumes” for

injury, fatality, and wood ignition, with

and without wind?

The FDS software can provide a visual

representation of the “Heat Release Rate Per

Unit Volume (HRRPUV)”. Attached are

several snapshots at different times, with-and-

without wind, for reference.

We typically don’t include these images as

they are slightly misleading since the

HRRPUV is not an exact representation of the

luminous flame.


1.e Simplified Hazard Zone Map – please

provide the modeling contours overlaid on

the site map for the three critical heat flux

hazards (wood ignition 25.0 kW/m2, fatality

12.5 kW/m2, and injury 4.9 kW/m2). Please

then explain what distances were doubled

(for the 2x engineering model uncertainty

factor) to arrive at the Simplified Hazard

Map Figure 1.

Figures 7 and 8 are basically the contour heat-

flux map overlaid the site map. However, these

figures are only applicable for the single pool

fire modeled and should not be over analyzed.

Please reference response to item 1.b for

discussion on why the thermocouple point

measurements provide a more accurate

representation of the expected heat flux.

Please reference response to item 1.f for

discussion of the 2x safety factor applied to the

FDS results.

1.f Appropriate Engineering Model Uncertainty

Factor – please provide references which cite

that 2x modeling results is suitable for

overcoming FDS model limitations to assess

impacts on the general public and private

residences.

The FDS results fairly closely match the

“Shokri and Beyler” method. The Shokri and

Beyler meathod is referenced in multiple

standards and recommends a safety factor of

2x when used in design.

This is the basis of the recommended 2x safety

factor recommended in the report. References

can be found within the following:

NFPA Handbook (12th edition) section 3,

chapter 9 (page 3-156)

SFPE Engineering Guide for Assessing

Flame Radiation to External Targets from

Pol Fires (June 1999)

SFPE Journal of Fire Protection

Engineering Vol 1, No 4, 1989, “Radiation

from Large Pool Fires”


2.a NIST/HUD Modeling of Acceptable

Separation Distances

FDS vs. HUD - the report states that

modeling methods and allowable radiant heat

flux levels used by the US Department of

Housing and Urban Development in their

CFR Regulation 24 “Siting of HUD-Assisted

Projects near Hazardous Operations

Handling Conventional Fuels of Chemicals

of an Explosive or Flammable Nature” are

similar to the FDS approach. However, the

radiant heat flux contours calculated by the

HUD approach indicate harm to people well

inside the boundaries of the neighborhood.

Please provide an overlay map of the

neighborhood comparing the key contours of

both approaches and describe why the HUD

method is deemed inappropriate given the

limitations of both approaches and the higher

standards required when dealing with

engineering uncertainty and the public.

As noted on page 16, the HUD method is “…

very conservative so as to provide a simplistic

base line when doing an initial review of a site.

It is estimated that these numbers have at least

a two-times safety factor.”

HUD’s general guidance is if you can meet

their simplified procedures, then a more

detailed calculation is not required. The site

does comply with the HUD ASD

recommendation of 50-feet for structures (see

simplified NIST Thermal table on page 16).

However, the site does not comply with the

1,312 foot ASD recommendation for people.

As such, HUD recommended their more

detailed calculation method which resulted in a

minimum fatal exposure distance of 107-feet.

When the 2x safety factor included in the HUD

method is removed, we arrive at the same

recommended fatal exposure distance of

approximately 50-feet.

As basic comparison of the agreement all three

methods within the report is provided below:

Distance

from

edge of

source

target

FDS

values

with

2x

safety

factor

FDS

16

mph

wind

Shokri

and

Beyler

method

NIST

method

without

barrier

and no

2x

safety

33-feet - 7.80 6.050 -

50-feet 11.47

(Max

12.5

for

range)

5.74 5.308 6.25

66-feet - 3.63 4.726 -

98-feet 3.92

(Max

4.0

for

range)

1.96 3.792 -

244-feet - - 1.600 -


3.a Fuel type

JP8 vs. Gasoline, etc. – the report states that,

"the analysis of hazardous liquid fires is

relatively independent of the type of liquid"

and, "if in the future the type of fuel is

slightly different than that modeled, there is

limited impact on calculation results". The

modeling was done for jet fuel JP8

(kerosene). Specifically, would gasoline,

naphtha or any other flammable liquid

product stored in bulk by any other operator at

the Anchorage port tank farms result in a

more adverse impact on the neighborhood

(i.e. anything with characteristics more than

slightly different from JP8)?

This statement matches the findings from the

NIST “Thermal Radiation from Large Pool

Fires” report. As the burning rates and heat-

release rates do not vary significantly, the

models provided can be used for a variety of

products. As quick summary of the burning

rates and heat-release rates for a couple sample

products is provided below:

Material

Burning

Rate

kg/m2/s

Heat-

Release

rate

kW/m2

JP-4 0.051 2,200

JP-5 0.054 2,300

Gasoline 0.055 2,400

4 Fire Suppression

4.a Required Foam Quantity – what is the

surface area of the modeled pool fire? How

much foam concentrate is required to

suppress a pool fire of that size and shape?

If the first foam suppression effort fails,

how much foam concentrate remains for a

second attempt.

The approximate surface area of the worst-case

pool evaluated was approximately 124,560 sq

ft. This was based upon a pool fire due to

complete failure of the largest single tank

within the containment area.

The exact amount of foam-concentrate

required to suppress a fire of this size is

difficult to establish absolutely based upon

historical fire scenarios. The goal should be to

contain vs. suppress if the fire reached the size

to cover almost the entire site.

2,200 gallons of foam is stored on-site for the

purposes of suppressing any tank-top fire

scenario with a safety factor of at least two.

4.b Required Fire Water Rate – what is the rate

of water required to be mixed with the foam

concentrate to suppress the modeled pool

fire? What is the delivery rate of the fire

hydrants adjacent to the site? If there is not

enough water supply from the municipal

system (this was a finding of the

conflagration desktop drill) what is the

backup plan? Is the backup plan codified

with formal Inter-Governmental, Inter-

Agency, or Government-Industry

agreements?

The city hydrants in this area can provide

roughly 3,000 gpm in this area.

As noted above, a complete pool fire due to

complete failure of the largest single tank will

be a containment plan and not a suppression

plan.

The worst-case tank combined foam-water

flow rate of 1016 gpm is required for tank-top

fire at tank 32 based upon as-builts. We would

also assume two individual monitors flowing

750 gpm each (1,500 gpm total) for cooling of

exposed tanks for individual tank fires.

Combined this is a flow rate of 2,516 gpm at

the available water supply is adequate for these

type of fire.


5 Risk Mitigation Measures

5a. The original Hazard Study indicated the

importance of risk mitigation measures as

the key barrier to adverse consequences on

the neighborhood. Listed in Table 5.2 are

the 118 risk mitigation measures identified.

It was also noted that keeping up to date on

industry standards and best practices will

insure the safest possible operation.

Assurance of Regular Monitoring – what is

Crowley’s plan for periodically updating

compliance with Table 5.2 and reporting

status to the Community Council?

Crowley’s management system includes

regular on-going facility inspections to assure

compliance with regulatory requirements,

industry best practice and safety. As part of the

current expansion project at the Terminal we

are eliminating all underground pipelines.

Crowley keeps the GHCC informed and up to

date with activities at the Terminal through

attendance at regularly held council meetings

and presentations/briefings as requested or

needed. Crowley can provide annual updates

to the GHCC reflecting operational integrity

and regulatory compliance.

5b. Continuous Improvement – what is

Crowley’s plan for maintaining pace with

the evolution of industry standards and the

acquisition and implementation of best

practices with regard to the identified

measures?

Crowley is affiliated with several national and

international industry organizations, including

the National Institute for Storage Tank

Management, the American Petroleum

Institute, and the International Facility

Maintenance Association. Through these

many professional connections Crowley takes

advantage of ongoing educational

opportunities, resources, and training seminars

about the operation, regulation, and

management of tank farm systems, industry

standards, and best practices.

Documents

Fire Hazard Calculations - Anchorage, Alaska 2017-74 2016-0425 Coffman...Note that a detailed review of the other requirements of NFPA and API (i.e ... NFPA 59A-2016 Table 15.8.4.1