Eielson AFB-6257 OOS Final Report.pdf

ACOE CONTRACT W911KB-10-D-0006, TASK ORDER 0023

TANK 38 (FACILITY NO. 6257)

API 653 OUT-OF-SERVICE INSPECTION

AND SUITABILITY FOR SERVICE

EVALUATION

FINAL REPORT

(PRE-REPAIR)

Eielson AFB, Alaska

August 2014

Contract Agency:

U.S. Army Engineer District, Alaska P.O. Box 6898 Elmendorf AFB AK 99506-6898

Prepared By:

Andrew D. Litchfield, API 570 Certificate No. 45020 James E. Hall, P.E., API 653 Certificate No. 46418

Submitted By:

Stephen S. Brooks, P.E.

Principal, API 653 Certificate No. 17 2525 Gambell Street, Suite 200, Anchorage, AK 99503

EEI PROJECT 8093

Page Intentionally Left Blank

SUITABILITY FOR SERVICE STATEMENT – TANK 38 (FACILITY NO. 6257)

Enterprise Engineering, Inc. (EEI) has completed an out-of-service external and internal inspection and suitability for service evaluation of Tank 38 at Eielson AFB, Alaska. The inspection was performed on June 24– 25, 2014 in accordance with the applicable criteria of API Standard 653, UFC 3-460-01, and the Statement of Work.

This report provides inspection findings, tank suitability for service evaluation, conclusions, and recommendations for repair. Recommendations for continued long-term service are also provided.

EEI recommends the next API 653 external in-service inspection be scheduled no later than June 2019 (5 years from this 2014 inspection), or sooner if a change in condition has occurred.

EEI recommends the next API 653 internal out-of-service inspection be scheduled no later than June 2034 (20 years from this 2014 inspection), or sooner if a change in condition has occurred.

In accordance with API Standard 653 and ADEC Regulation 18AAC75, this report satisfies the requirement for an out-of-service, tank integrity inspection and as such, should remain available as a historical record for future reference.

I hereby acknowledge that being familiar with the provisions of API Standard 653, the inspection and evaluation was performed in accordance with the provisions of API Standard 653 and good engineering practices, and with the exercise of usual and customary care.

August 15, 2014 James E. Hall, P.E.

API 653 AST Inspector Certificate No. 46418

This tank inspection has determined that mandatory repairs are required prior to return to service. Following completion of the identified repairs, Tank 38 will be suitable for service.

Tank 38 – API 653 Inspection TABLE OF CONTENTS Eielson AFB, Alaska August 2014 EEI Project No.: 8093

TABLE OF CONTENTS

Page

SUMMARY

Scope General

INSPECTION ASSESSMENT

Hydraulic Integrity Structural Integrity Next Inspection

REPAIR ITEMS

Standard of Care Required Repairs (Mandatory) Recommended Repairs (Non-Mandatory) Recommended Repairs for Long Term Serviceability

COATING SYSTEM

Coating Requirements

SUITABILITY FOR SERVICE EVALUATION

Corrosion Rates Tank Floor Corrosion Rates Hydraulic and Structural Integrity

ADDITIONAL DISCUSSION ITEM

Gauge Tubes

CLOSURE

Conclusions Project Team

APPENDICES

Tank Inspection Data Sheet and Evaluation Items ................................................... Tab A Assessment of Compliance with Military Criteria ...................................................... Tab B Non-Destructive Examination (NDE) and Evaluation Criteria .................................. Tab C Tank Drawings ........................................................................................................ Tab D Tank Photographs .................................................................................................... Tab E NDE Results ............................................................................................................. Tab F Calculations ............................................................................................................. Tab G Coating Requirements ............................................................................................ Tab H

Tank 38 – API 653 Inspection Page 1

EEI Project No.: 8093

TANK 38

API 653 TANK INSPECTION

SUITABILITY FOR SERVICE EVALUATION

EIELSON AFB (EIE), ALASKA

SUMMARY

Scope

Enterprise Engineering Inc. (EEI) has been retained to perform an out-of-service internal and external inspection of Tank 38 at Eielson AFB, Alaska. The inspection was performed on June 24-25, 2014. The inspection was performed in accordance with the applicable portions of API Standard 653, UFC 3-460-01 and the Statement of Work. The API 653 criteria were followed in terms of procedure and evaluation to the greatest extent possible. Inspection findings and recommended repairs are provided below.

The scope of this project is to determine the structural and hydraulic condition of the tank, determine suitability for service, provide written recommendations for repairs and develop recommendations for long-term service based on visual inspection and non-destructive examination (NDE).

General

Tank 38 is a field erected aboveground storage tank. The tank was originally fabricated and erected in 1954. A second floor was provided in 1995. The tank is 73 feet 4 inches in diameter and 38 feet 11 inches high and is of welded construction with butt-welded shell plates and lap welded floor and roof plates. The tank floor is cone down with a near center sump. The nominal shell capacity is 27,000 Bbls and includes a column supported fixed cone roof. Tank 38 is currently in JP-8 service and is not equipped with a floating pan.

INSPECTION ASSESSMENT

The Appendices in this report include a comprehensive table identifying tank features with findings and conclusions as appropriate. The Appendices also contain numerous tables with full reporting of data taken. The following discussion only addresses key integrity issues.

This tank inspection has determined that mandatory repairs are required prior to returning the tank to service. To clarify, under API 653 Mandatory Repairs are considered to be those that are required to eliminate an immediate threat to integrity, as well as those that represent a threat to integrity until the next scheduled API out-of-service inspection (i.e. 20+ years). The following are significant findings of the inspection.

Hydraulic Integrity

Hydraulic integrity is the ability of the tank to hold product without compromise to the boundaries of the floor and shell.

Inspection of the tank floor, shell, and roof found no holes or indications of leaks. A pit survey was conducted for topside corrosion on the floor and no pits were identified requiring repair. A magnetic flux leakage (MFL) scan of the floor found no relevant indications of corrosion on the bottom side of the floor requiring repair.

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Interior pipe supports are free to slide between two structural angle restraints. The condition of the floor beneath these supports cannot be assessed and could affect the future hydraulic integrity of the tank if not repaired.

The tape gauge bracket is stitch welded to the floor. The condition of the floor beneath this bracket cannot be assessed and could affect the future hydraulic integrity of the tank if not repaired.

Interior column support bases do not have doubler plates beneath them. The condition of the floor beneath the column bases cannot be assessed and could affect the future hydraulic integrity of the tank if not repaired.

Tank 38 will be in acceptable hydraulic condition pending the repairs to the interior pipe supports, tape gauge bracket, and interior columns.

Structural Integrity

Structural integrity is the capability of the tank to remain freestanding, with or without product, under the conditions of its design basis. Structural attributes include the floor, shell, roof and their attachment.

Ultrasonic inspections of the shell were performed on the first course and on the each course up the exterior spiral stair. From interpretation of ultrasonic thickness (UT) readings recorded, only minor metal loss due to corrosion was observed.

Visual inspection found non-compliant weld clearances at nozzle reinforcing plates and the manual gauge doubler plate, and an area of destructive testing of a vertical shell weld that was not properly repaired.

Tank 38 will be in acceptable structural condition pending the examination of non-compliant weld clearances and repair of the area of destructive testing.

Next Inspection

API 653 requires an in-service inspection be performed every 5 years or RCA/4N years whichever is less.

RCA is the remaining corrosion allowance of the shell (i.e. the difference between the minimum measured shell thickness and the minimum required shell thickness in mils) and N is the shell corrosion rate in mils per year. When shell corrosion rates are unknown, API 653 requires the in-service inspection interval not exceed 5 years.

EEI recommends that the next external in-service inspection be scheduled no later than June 2019 (5 years from 2014 inspection), or sooner if a change in condition has occurred.

The Alaska Department of Environmental Conservation (ADEC) requires an inspection per the requirements of API 653. API 653 requires the interval until the next internal in section be determined using corrosion rate procedures or Risk-Based Inspection (RBI) procedures. When corrosion rate procedures are used, the interval shall not exceed 20 years. When RBI procedures are used the interval shall not exceed 25. If the tank has a release prevention barrier and leak detection designed in accordance with API 650 Appendix I and RBI procedures are used, the interval shall not exceed 30 years. As an RBI assessment is not included in the scope of this inspection, the interval until the next out-of-service inspection was determined using corrosion rates.

It should be noted that ADEC may reduce the inspection interval for a specific storage tank if

(a) The storage tank is older than 30 years,

(b) The storage tank is of riveted or bolted construction,

(c) The storage tank has demonstrated structural, corrosion or foundation problems, or

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(d) After a significant seismic event.

As none of the criteria is applicable to Tank 38, it is not anticipated that the State will require a reduced inspection interval.

EEI recommends the next API 653 out-of-service inspection be performed no later than June 2034 (20 years from this 2014 inspection). The next out-of-service inspection should be performed sooner if a change in condition or a change in service occurs.

It should be noted that a maximum interval between inspections of 10 years is also commonly used in many government and commercial facilities.

REPAIR ITEMS

Based upon the API field inspection, engineering judgment and knowledge of funding practices, recommendations developed are listed below as required (mandatory), recommended (non-mandatory) and recommended for long term serviceability. Refer to Appendix B, “Assessment of Compliance with Military Criteria” for comprehensive comments and recommendations of the tanks compliance with military criteria.

Standard of Care

All repairs shall strictly meet the requirements of API 650 and API 653 regarding material, welding procedures and qualification of welders, non-destructive examination (NDE) of welding and testing requirements. Obtaining hot work permits and developing the appropriate hot work procedure for the tank floor is the responsibility of the repair contractor, and shall consider the tank has been in petroleum fuel service. The provisions of API 2207 “Preparing Tank Bottoms for Hot Work” shall be considered.

Required Repairs (Mandatory)

Mandatory repairs are repairs that are critical to the hydraulic and structural integrity of the tank and are required prior to returning Tank 38 to service.

1. Non-compliant weld clearances have been identified with respect to the nozzle reinforcing plates.

Specifically, the clearance from the underside of the reinforcing plates at Manholes 1 & 2 to the floor-to-shell weld, are less than the required API minimum. Provide the following additional inspection per API 653 4.3.9.1:

Remove the coating from the non-compliant welds prior to performing magnetic particle testing.

It is recommended to remove the coating by high pressure water or chemical stripping methods and not by mechanical or sandblasting methods.

Perform magnetic particle testing of the weld along the bottom edge of the reinforcing plate and the shell-to-floor weld on the exterior of the tank. Existing welds (i.e. welds along the periphery of the nozzle reinforcing plate) that are not modified or affected by repairs are acceptable for continued service if the welds have no rejectable defects or indications.

Contact EEI for further direction if weld defects are observed.

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2. Non-compliant weld clearances have been identified with respect to the manual gauge doubler plate.

Specifically, the clearance from the doubler plate to the floor weld is less than the required API minimum.

Remove the coating from the non-compliant welds prior to performing magnetic particle testing.

It is recommended to remove the coating by high pressure water or chemical stripping methods and not by mechanical or sandblasting methods.

Perform magnetic particle testing of the non-compliant welds.

Contact EEI for further direction if weld defects are observed.

3. The guide wires for the tape gauge float are attached to a support plate that has been stitch welded to the floor. The condition of the floor below the plate cannot be assessed.

Remove existing coating on the plate and the floor as necessary for welding.

Seal weld the support plate to the tank floor with a 1/4-inch fillet weld, continuous on all edges of the plate. The completed weld shall have no cracks, porosity, or lack of fusion.

Perform integrity inspection of the entire weld by vacuum box testing and magnetic particle examination.

Recoat areas affected by the repair.

4. Six pipe supports have been provided at the internal piping for the Low Fuel and Water Draw-off lines. The pipe is held at the top of the support with a tight fitting U-bolt. The bottom of each of the six supports include a 12-inch round plate that is free to slide between two structural angle clips that have been welded to the floor. The condition of the floor below each of the plates cannot be assessed.

Remove all of the existing pipe supports and structural angles.

Provide new stanchion type pipe supports that include 1/4-inch thick by 6-inch round doubler plates and loose fitting U-bolts and low friction interfaces. Remove existing coatings as necessary.

Seal weld each pipe support doubler plate to the tank floor with a 1/4-inch fillet weld, continuous on all edges of the plate. The completed welds shall have no cracks, porosity, or lack of fusion.

Perform integrity inspection of the welds by vacuum box testing and magnetic particle examination.

Coat pipe supports and repair all areas of coating affected by the repairs.

5. Two pipe supports have been provided at the Fill/Issue piping. The base of each support includes a slide plate held between two structural angles welded to the floor. The condition of the floor below each of the plates cannot be assessed and there are weld clearance violations at the support located furthest from the shell.

Remove the structural angles and pipe supports at each support.

Provide H-Frame style pipe supports. Remove coatings as necessary for welding.

Seal weld pipe supports to tank floor with a 1/4-inch fillet weld. The completed welds shall have no cracks, porosity, or lack of fusion.

Perform integrity inspection of the welds by vacuum box testing and magnetic particle examination.

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Coat the pipe supports and all other areas affected by the repairs.

6. The Water Draw-Off piping and Low Fuel piping extend from the shell into the center sump. A short section of angle is present at the bottom of the piping. The angles are capable of striking the bottom of the sump.

Remove the angles from the end of the pipes.

Relocate one of the pipe supports at each line closer to the edge of the sump to provide adequate support of the piping or provide a new stanchion type support.

Repair all coating affected by the repairs.

7. The tank roof framing is supported by six built-up channel columns. Each column base is comprised of structural channels in an “H” shape configuration. As required by API 650 for seismic regions, the bases are not welded to the floor to allow lateral movement. Excessive movement is restricted by restraint angles that have been welded to the floor. The bases have not been equipped with doubler plates and the condition of the floor plate below each channel base cannot be assessed.

Remove all of the existing restraint angles.

Provide 1/4-inch thick by 38-inch wide by 40-inch long doubler plates below all 6 of the column bases. Take care to prevent excessive bending of roof framing and other components when lifting columns to install doubler plates. Note that since the diameter of the shell manholes are only 24-inches, the doubler plates will have to be fabricated in two pieces and butt welded together inside of the tank.

Seal weld each doubler plate to the tank floor with a 1/4-inch fillet weld. The completed welds shall have no cracks, porosity, or lack of fusion.

Perform integrity inspection of the completed welds by vacuum box testing and magnetic particle examination.

Reinstall the restraint angles on top of the doubler plates by welding.

Coat the doubler plates and all other areas affected by the repairs.

8. There is an area where destructive testing of the weld (sectioning) was performed during original construction in the second course vertical shell weld above Manhole #1. This location was not properly repaired on the inside of the tank shell.

Provide weld overlay in the interior of the shell over the sectioned disk.

Grind weld smooth with the adjacent tank shell.

Provide visual examination and magnetic particle examination of the completed weld. Inspect for cracks, lack of fusion, and porosity. Repair all defects found by grinding the weld to remove the defect and re-welding.

9. Provide surface preparation and recoat all interior and exterior repair areas and areas that are damaged as a result of repairs in accordance with Coating Requirements. When welding on the shell or roof, the coating on the opposite side from the weld shall be inspected and repaired if damaged.

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Recommended Repairs (Non-Mandatory)

The repairs listed below are not mandatory per API 653 or for structural and hydraulic integrity of the tank. EEI highly recommends performing these repairs for the long term preservation and integrity of the tank.

1. Tank is equipped with 2 leak detection standpipes. Fluid was observed in the bottom of one standpipe.

Eielson AFB is providing testing of the water in the standpipes to confirm lack of any hydrocarbon constituent. Continue to monitor the standpipes for hydrocarbons.

2. Moss was observed on the floor projection and on the tank shell welds.

Remove the moss by power washing or other suitable non-abrasive means.

3. Moss and vegetation were observed growing adjacent to the dead shell and throughout the containment dike.

Remove the moss and vegetation.

4. The telltale holes in the reinforcing plates for the two shell manholes, fill/issue, low fuel, and water draw-off nozzles are open to the atmosphere.

Pack the telltale holes with general purpose grease to prevent moisture migration between the reinforcing plate and the tank shell.

5. Tank is equipped with two roof pressure/vacuum vents.

Disassemble and clean the vent pallets and screens.

6. The clips securing the access hatch for the ENRAF ATG displacer are loose.

Adjust the clips so that the displacer access door will close tightly to prevent the ingress of water.

7. Chips were observed in the coating on the roof plate. Corrosion and coating failure was observed on the roof appurtenances, handrail, stairs, and at random locations on the tank shell.

Remove the coating from the affected areas, clean and recoat.

8. Eielson AFB is located in an arctic climate with significant ice buildup on the tank shell. The valve at the water draw-off nozzle is equipped with hydraulic tubing. The potential exists for falling ice to shear off the tubing and spill product.

Provide an ice/snow shield above the tubing. From past experience, it is the recommendation of EEI to provide a 6 inch x 6 inch x 1/4 inch angle x 2 feet long with the heel facing up. Weld the angle to a 1/4 inch thick doubler plate that is 10 inches wide and 14 inches long with 2 inch radius corners. The angle should be braced with one 1/4 inch thick tapered gusset plate, oriented vertically.

9. The valve actuators on the three 4-inch DB&B plug valves at the Low Fuel nozzle contact each other when operated.

Option 1

Provide a minimum 6-inch long pipe spool between the tee and the valve with the camlock connection.

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EEI Project No.: 8093

Option 2

Rotate the other two valves 1 bolt hole to provide clearance for the actuators.

10. Water ponding was observed on two of the perimeter roof plates. Over time, this condition may cause coating failure and corrosion.

Repair action is not recommended at this time. Monitor for coating failure and corrosion during routine maintenance.

11. A pit was observed in the roof plate weld between plates D3 and E3 near the center of the tank.

Grind pit to a smooth contour.

Provide weld overlay to restore weld profile.

Provide visual examination of the completed weld. Inspect for cracks, lack of fusion, and porosity. Repair all defects found by grinding the weld to remove the defect and re-welding.

12. Weld artifacts were observed on the interior of the tank shell plates. The artifacts consist of remnants of removed plates during tank construction. Approximately 120 weld artifacts were observed on the tank shell.

After coating removal, grind weld artifacts flush with the shell plate.

Repair any gouges in shell plates by weld overlay.

Inspect welds on tank shell by visual inspection and either magnetic particle testing or liquid penetrant testing.

This repair should be programmed to be performed concurrently with the next shell recoat.

13. The perimeter roof handrail is equipped with a 4-inch high toe board. The toe board is 2 inches above the walking surface. OSHA 1910.23 requires the toe board to be no more than 1/4-inch above the walking surface.

At the discretion of the government, move the toe board to within 1/4-inch of the walking surface to comply with OSHA requirements.

14. The Low Fuel piping is not equipped with thermal relief.

Provide line relieving differential thermal relief (LR/DTR) piping at the low fuel shell nozzle.

Piping shall relieve to the tank.

15. The existing gauge tubes were evaluated for compliance with the DESC/DLA-E Memorandum and

UFC 3-460-01.

Continue to use the existing 8 inch aluminum gauge tube for manual gauging. Note that a waiver may be required since only the lower 4 feet of the gauge tube is slotted.

Provide an 8 inch aluminum fully slotted gauge tube below the roof nozzle with the ENRAF ATG displacer.

Provide a 6 inch roof nozzle riser for the water probe directly over the sump.

Note: These recommendations must be validated by DLA-E.

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16. The tank was evaluated for compliance with current military criteria per UFC 3-460-01, Table 8-1.

The tank is not equipped with item (k); ladders, railings, toe boards, a spiral stairway, top platform, and handrail in accordance with API 650 and OSHA requirements. Roof handrail toe boards do not meet OSHA requirements for distance above the walking surface. See Recommended Repair Item No. 13 for repair recommendations. Stair treads are not equipped with non-slip nosings. It is not compelling to provide non-slip nosing, but could be done at the discretion of the government.

The tank is not equipped with item (r); a 10-inch roof flanged nozzle with an 8-inch aluminum, fully slotted, stilling well for ATG near the edge of the roof near the top of the stair platform. See Recommended Repair Item No. 15 for gauge tube recommendations.

The tank is not equipped with item (s); a 8-inch roof flanged nozzle with a 6-inch aluminum, fully slotted, stilling well for temperature and water bottom sensor, as close to or in the tank sump as possible. See Recommended Repair Item No. 15 for gauge tube recommendations.

The tank is not equipped with item (t); a 10-inch roof nozzle and an aluminum, slotted stilling well extended to within 3 inches of the bottom of the tank for gauging and sampling. See Recommended Repair Item No. 15 for gauge tube recommendations.

Refer to Appendix B “Assessment of Compliance with Military Criteria” for further discussion.

17. Provide surface preparation and recoat all interior and exterior repair areas and areas that are damaged as a result of repairs in accordance with Coating Requirements. When welding on the shell or roof, the coating on the opposite side from the weld shall be inspected and repaired if damaged.

Recommended Repairs for Long Term Serviceability

1. Program the tank for the next API 653 in-service external inspection no later than June 2019 and the next API 653 out-of-service internal and external inspection no later than June 2034.

2. Test all level alarms and switches as part of on-going maintenance.

COATING SYSTEM

Coating Requirements

Refer to Appendix H for complete coating materials and application requirements for type and location of coating repair items identified by the inspection.

SUITABILITY FOR SERVICE EVALUATION

Corrosion Rates

Corrosion rates for the tank floor, shell and roof were calculated using thickness measurements that were obtained during the inspection and are as follows:

Floor: 0.002579 inches per year

Shell: 0.000700 inches per year

Roof: Negligible – Plate thickness is within mill tolerance

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The corrosion rate for the floor was calculated using an assumed original metal thickness and a 1995 year of construction. Corrosion rates for the shell and roof were calculated using an assumed original metal thickness and a 1954 year of construction.

Tank Floor Corrosion Rates

The tank floor coating, with an average thickness of 14.0 mils, is a thin-film lining. The floor coating is 19 years old. No product side pitting was observed.

Bottom side corrosion with small volumetric metal loss may be present and not detected by magnetic flux leakage (MFL) scanning. The metal loss used to calculate the bottom side corrosion rate was conservatively calculated using the average thickness of the floor minus a 20% threshold value for undetected bottom side pits. The MFL floor scanner is not configured to indicate (alarm) for minor metal loss.

The minimum remaining thickness (MRT) used in the calculations is based on API 653 Section 4.4.5 and Table 4.4. The tank is equipped with the means to detect and contain a bottom leak. A liner is present beneath the sand cushion. Based on this information, the MRT used in the calculations is 0.050 inch for general floor plates. The MRT at the critical zone shall be the smaller of one-half the original floor thickness or 50% of the minimum thickness of the lower shell course, but not less than 0.100 inches.

Based on this information, the MRT used in the calculations is 0.125 inch at the critical zone.

It was found that the tank floor plate thickness will not be reduced below the limiting MRT at a 20 year inspection interval.

Hydraulic and Structural Integrity

The following table summarizes the hydraulic and structural integrity of Tank 38:

HYDRAULIC AND STRUCTURAL INTEGRITY

Evaluation Item

Findings Comments

Foundation Tank 38 sits on an earth foundation. The tank passes API 653 criteria for levelness and differential settlement.

Acceptable

Floor Multiple conditions were identified where the condition of the floor could not be assessed.

Acceptable after repairs.

Shell There is an area where destructive testing of the weld (sectioning) was performed during original construction in the second course vertical shell weld above manhole #1.

This location was not properly repaired on the inside of the tank shell.

Non-compliant weld clearances were at shell nozzle reinforcing plates the manual gauge doubler plate that affects the structural integrity of the tank.

Acceptable after repairs and examinations.

Roof Spot ultrasonic testing of the roof plates found no noticeable thinning of the plates.

Acceptable

Internal Fluid Pressure

Hoop stresses by internal fluid pressure pass API 653 criteria.

Acceptable

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HYDRAULIC AND STRUCTURAL INTEGRITY

Evaluation Item

Findings Comments

Hydrostatic Test

Shell is adequate to resist the internal fluid pressure caused by a full height hydrostatic test with water.

Acceptable

Brittle Fracture The API 653, Section 5, Figure 5.1, Brittle Fracture Considerations has been evaluated with the following findings:

1. Does the tank meet API 650(7th edition or later, 1980): No, constructed in 1954.

2. Has a prior hydrotest been performed demonstrating fitness: Yes, with the new floor in 1995.

3. Is the tank shell thickness < 0.5 inch: Yes.

4. Does the tank operate at metal temperature above 60 deg F?: No.

5. Is the tank membrane stress below 7 ksi?: No.

6. Tank steel exempt per API 650, Figure 4.1 or API 653 Figure 4.1: Yes.

7. Tank full at lowest one day temperature per API 650 Figure 4.1: Unknown.

The tank, with a shell thickness less than 0.5 inches, and having had a hydrotest performed with the installation of the second floor, does not fit the API 653 at-risk profile for brittle fracture failure.

Seismic Evaluation

Seismic calculations were performed in accordance with API 650 Appendix E. It was found that the tank shell stresses are within limits at the design liquid level of 33 feet 9 3/8 inches. Tank resistance to seismic sliding satisfies criteria. There is no required minimum fill height to prevent uplift.

Calculations were performed utilizing the specific gravity for JP-8 (S.G. = 0.84), seismic parameters Ss = 1.06, S1 = 0.29, an importance factor of 1.00.

Acceptable

Wind Evaluation

A wind analysis was performed per API 650, Section 5.11.

Calculations were performed using an importance factor of

1.00 and a wind velocity of 90 mph.

The evaluation determined that an empty tank is stable and not at risk of overturning or sliding.

Evaluation of the shell buckling determined that the shell is adequate, without stiffeners, for wind speeds in excess of 90 mph.

Acceptable

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ADDITIONAL DISCUSSION ITEM

Gauge Tubes

Gauge Tube Requirements

The requirements for stilling wells have been reviewed. These requirements are based on the DESC/DLA-E Memorandum “Automated Tank Gauge (ATG) Installation Policy” of December 2009.

The comments below represent concept solutions based on the memorandum. It is recommended that the concept be submitted to DESC/DLA-E for ratification or redirection. Field verification of constructability by the prime contractor is also recommended.

Tank 38 Existing Conditions

Tank 38 is an AST with a cone-down floor with a near center sump. The tank is not equipped with a floating pan. The tank is equipped with a single 8-inch aluminum gauge tube used for manual gauging and sampling. The temperature probe for the ENRAF ATG is located in a 10-inch nozzle approximately 15 feet from the shell. The ENRAF ATG displacer is located in a 10-inch nozzle that is approximately 5 feet from the shell. The displacer is not located in a gauge tube.

Gauge Tube Recommendations

The following are recommended for compliance with the DESC/DLA-E Memorandum (for ATG) and UFC 3-460-01 (for operations) based on continuing to use the existing ENRAF ATG system:

Continue to use the existing 8-inch aluminum gauge tube for manual gauging. Note that a waiver may be required since only the lower 4 feet of the gauge tube is slotted.

Provide an 8-inch aluminum fully slotted gauge tube below the roof nozzle with the ENRAF ATG displacer.

Provide a 6-inch roof nozzle riser for the water probe directly over the sump.

Note: These recommendations must be validated by DLA-E.

CLOSURE

Conclusions

Based on the extent of this inspection and completion of mandatory repairs, Tank 38 is considered suitable to return to service.

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EEI Project No.: 8093

Project Team

Site Team

James E. Hall, P.E. Structural Engineer, API 653 AST Inspector Certificate No. 46418, API Inspector of Record.

Andrew D. Litchfield Tank Technician, API 570 Piping Inspector Certificate No. 45020

Mike R. Lawrence Tank Technician

Support Team

Stacy M. Kaplan-McMillan Project Manager

Stephen S. Brooks, P.E. Technical Advisor, QA Review, API 653 AST Inspector Certificate No. 17

APPENDIX A

Tank Inspection Data Sheet and Evaluation Items

DLA-E TANK CMP CONDITION FORM

TANK INSPECTION SUMMARY SHEET

Tank Location Eielson AFB, Alaska Tank No. 38

Facility No. 6257 Inspection Date(s): June 24 - 25, 2014

Tank Type: Vertical AST Type of Inspection: Internal & External w/ Suitability for Service Evaluation

Contract Number, Task Order: W911KB-10-D-0006, 0023 Prime Contractor Name: Enterprise Engineering, Inc.

Inspector, Certificate #: James E. Hall, P.E.

API-653 AST Inspector Certificate No. 46418

Inspection Company: Enterprise Engineering, Inc.

2525 Gambell Street, Suite 200 Anchorage, Alaska 99503

(907) 563-3835

Manufacturer, Date, Design Standard Original: Unknown, 1954, API 12C Altered: Morse Construction Group, 1995, API 653 1st Edition Morse Construction Group, 1998, API 653 2nd Edition

Diameter: 73'-4" Shell Height: 38'-11"

Product, Specific Gravity: JP-8, 0.84 Design Pressure / Temperature: Unknown

Gross Capacity / Nominal Capacity: 27,636 Bbls / 27,000 Bbls Safe Fill Height: 33 feet 9 3/8 inches (from facility)

GPS Latitude & Longitude: 64 Deg 39’ 28.30” N, 147 Deg 2’ 45.04” W (Source – Google Earth) Foundation Configuration: Earthen

Shell Configuration: Butt Welded, 5 courses Roof: Fixed, column supported cone roof

Cathodic Protection: None Still Wells: 8-inch at manual gauge nozzle

Last Inspection (Type, Date): In-service, 2005 Last Coated Internally (Product): 1995 – At time that second floor was installed Last Coated Externally (Product): 1995 – At time that second floor was installed

INSPECTION RESULTS

Can tank return to service? Yes, upon completion of mandatory repairs.

Deficiencies identified as mandatory repairs: Yes, see paragraph titled “Mandatory Repairs” in body of report Deficiencies identified as recommended repairs: Yes, see paragraph titled “Recommended Repairs” in body of report.

Deficiencies identified as long term repairs: Yes, see paragraph titled “Recommended Repairs for Long Term Serviceability” in body of report

Next Scheduled Inspections (Type, Date): In-Service: June 2019 (5 Years) Out-of-Service: June 2034 (20 Years)

ADDITIONAL ITEMS

Change in Service: None

As-Built Drawings, Specifications: None available

Tank 38 – API 653 Inspection Appendix A, TANK SUMMARY SHEET Eielson AFB, Alaska EEI Project No.: 8093

Tank 38 – API 653 Inspection Appendix A, TABLE OF CONTENTS

AST EVALUATION ITEMS

TABLE OF CONTENTS

Page

FOUNDATION

FLOOR

SHELL

ROOF

COATINGS

APPURTENANCES

PIPING

Tank 38 – API 653 Inspection Appendix A, Page 1

EEI Project No.: 8093

FOUNDATION

Evaluation Item Finding(s) Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

FOUNDATION

Type Compacted soil foundation.

Levelness Tank 38 is relatively level. The maximum measured differential between max and min elevations is 0.14 feet.

Tank 38 passes API 653 criteria for levelness and differential settlement.

Rigid Body Tilt Tank 38 is slightly tilted. The amount of tilt is

0.07 inches.

Tilt is within acceptable limits.

Height Above Dike Floor Original floor is covered by liner and ballast.

The second floor is approximately 6 to 7 inches above the containment dike floor.

Material Below Tank Floor

The material below the tank floor could not be inspected. Design drawings indicate that there is a sand cushion and liner present between the floors.

Drainage Around Tank Drainage around the tank appears to be adequate.

Tank Anchors Tank is not equipped with anchors. Calculations show that tank meets the requirements for a self‐anchored tank at the current fill height of 33 feet 9 3/8 inches.

Secondary Containment Tank sits within an earthen dike with a membrane liner. Stone ballast holds the liner in place.

Moss and vegetation were observed growing adjacent to the dead shell and in the containment dike.

Recommend removing all moss and vegetation.

Settlement No evidence of excessive settlement was observed.

Erosion/Washouts No indications of washouts or erosion were

Sealed at Foundation

The dike liner is attached to the dead shell.

Additional Foundation Items, Comments or Notes:

None.

Tank 38 – API 653 Inspection Appendix A, Page 2

FLOOR

Evaluation Item Finding(s) Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

TANK FLOOR

Type Lap welded steel floor plates. A second bottom was installed above the original floor in 1995.

Annular Ring Plates Tank is not equipped with annular ring plates.

Nominal Thickness Floor consists of 1/4‐inch thick floor plates.

Thickness The average thickness of the floor plates based on 5 UT readings per floor plate is 0.245 inch.

Interior Width See floor drawing.

Floor seam welds No relevant indications were found on the floor plate seam welds.

MFL Floor Scan MFL of the accessible areas of the floor found 10 locations requiring an ultrasonic test (UT) prove‐up. The UT prove‐up identified the minimum thickness at these locations. The lowest UT measurement was 0.224 inch.

No repairs are required.

Bottom Side Floor Pitting/Corrosion

Based on MFL and UT examination, bottom side pitting/corrosion is not prevalent.

Top Side Floor Pitting/Corrosion

No top side pits or corroded areas were identified for repair.

Patch Plates No patch plates present.

Oil Canning/Flexing No significant flexing of floor plates was

Edge Settlement Edge settlement was not noted.

Floor Bulges, Depressions No relevant bulges or depressions were noted.

Tank 38 – API 653 Inspection Appendix A, Page 3

EEI Project No.: 8093

FLOOR

Evaluation Item Finding(s) Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

Doubler/Striker Plates Doubler plates are present at the manual gauge tube and pipe supports.

There are non‐compliant weld clearances between the manual gauge doubler plate and the floor weld.

The column bases are not equipped with doubler plates to provide load distribution per

API 650 5.10.4.7.

Six pipe supports have been provided at the internal piping for the low fuel and water draw‐ off lines. The bottom of each of the six supports include a 12‐inch round doubler plate that is free to slide between two structural angle clips that have been welded to the floor. The condition of the floor below each of the plates cannot be assessed.

Two pipe supports have been provided at the Fill/Issue piping. The base of each support includes a doubler plate between two structural angles welded to the floor. The condition of the floor below each of the plates cannot be assessed and there are weld clearance violations at the support located furthest from the shell.

Perform magnetic particle testing of the non‐compliant welds.

Provide a doubler plate below each column base and seal weld to the floor.

At low fuel and water draw‐off pipe supports, remove existing pipe supports and structural angles. Provide new stanchion‐style pipe supports with loose fitting U‐bolts and low friction interfaces.

Seal weld doubler plates to the floor.

At the fill/issue pipe supports, remove the structural angles and pipe support at both supports. Provide H‐Frame style pipe supports.

Plug Welds No plug welds were observed.

Weld Artifacts No weld artifacts were observed.

Vacuum Box Testing Vacuum box testing was not performed.

Helium Leak Testing Helium leak testing was not performed.

Floor Critical Zone No corrosion or deflection was observed within the critical zone.

Floor Profile The floor is cone down with one sump near the center of the tank. The tank floor has a 2% slope to the sump.

Sumps The tank is equipped with a 42‐inch diameter near center sump.

Secondary Liner Below

Secondary liner was installed during installation of the second floor in 1995.

Leak Detection Below

The tank has two standpipes. The standpipes are connected to piping that extends to below the near center sump.

Fluid was observed in the bottom of one standpipe.

Eielson AFB is providing testing of the water in the standpipes to confirm lack of any hydrocarbon constituent. Continue to monitor the standpipes for hydrocarbons.

Tank 38 – API 653 Inspection Appendix A, Page 4

EEI Project No.: 8093

FLOOR

Evaluation Item Finding(s) Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

Cathodic Protection The tank is not equipped with cathodic protection of the tank floor.

The lack of an interstitial cathodic system was not uncommon at the time of the tank repairs, but is no longer a supported position. Thus, the periodic floor scanning for underside corrosion is critical for this circumstance.

Additional Floor Items, Comments, Notes:

Tank 38 – API 653 Inspection Appendix A, Page 5

SHELL

Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

TANK SHELL

Nominal Thickness UT Thickness Coating

1st Course 0.422 inch 12.2 mils

2nd Course 0.336 inch 13.7 mils

3rd Course 0.248 inch 13.8 mils

4th Course 0.255 inch 14.6 mils

5th Course 0.255 inch 12.0 mils

Rim Angle Not accessible

Plumbness Visual observations found no noticeable out‐ of‐plumbness.

Roundness No noticeable out‐of‐roundness was observed.

Dents/Buckles No significant dents or buckles requiring repairs were observed.

Banding/Peaking No significant banding or peaking was

Interior Shell pitting/corrosion

No pits or significant corrosion were observed on the interior of the shell.

Exterior Shell pitting/corrosion

No pits or significant corrosion were observed on the exterior of the shell.

Insert plates Insert plates are present at the shell manholes, low fuel nozzle, fill/issue nozzle, and the water draw‐off nozzle.

Welded Patch Plates No welded patch plates were observed.

Floor Projection The floor projection extends an average of 2.70‐inches beyond the tank shell. The average thickness is 0.247‐inch.

Interior Shell Welds There is an area where destructive testing of the weld (sectioning) was performed during original construction in the second course vertical shell weld above manhole #1. This location was not properly repaired on the inside of the tank shell.

Provide weld overlay in the interior of the shell over the sectioned disk.

Exterior Shell Welds Visual inspection of accessible exterior shell welds found no indications for further inspections or examinations.

Moss was observed on the floor projection and on the tank shell welds.

Remove the moss by power washing or other suitable non‐abrasive means.

Door sheet One full height door sheet at MH‐2.

Floor‐to‐Shell Weld – Interior

Visual inspection of the interior floor‐to‐shell weld found no indications for further inspections or examinations.

Tank 38 – API 653 Inspection Appendix A, Page 6

EEI Project No.: 8093

SHELL

Evaluation Item Finding(s) Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

Floor‐to‐Shell Weld – Exterior

Visual inspection of the exterior floor‐to‐shell weld found no indications for further inspections or examinations.

Shell Manholes The tank is equipped with two 24‐inch shell manholes.

Flush Cleanouts Tank is not equipped with a flush cleanout.

Shell Reinforcing Plates

Manhole‐1

(Size, Thickness, Telltale Hole)

Size: 24‐inch diameter nozzle, 0.373 inch thick

(UT).

Reinforcing Plate: Diamond shaped, 65‐inch x 54‐inch x 0.450‐inch thick (UT). There is non‐ compliant weld clearance between the reinforcing plate and the floor‐to‐shell weld.

Telltale hole is open to the atmosphere.

Perform magnetic particle testing of the weld along the bottom edge of the reinforcing plate and the shell‐to‐floor weld on the exterior of the tank.

Pack telltale hole with general purpose grease to prevent water migration between the reinforcing plate and the tank shell.

Fill/Issue

(Size, Thickness, Telltale Hole)

Size: 8‐inch nozzle, 0.490 inch thick (UT).

Reinforcing Plate: Circular shaped, 18‐inch diameter x 0.470 inch thick (UT).

Telltale hole is open to the atmosphere.

Pack telltale hole with general purpose grease to prevent water migration between the reinforcing plate and the tank shell.

Low Fuel

(Size, Thickness, Telltale Hole)

Size: 4‐inch nozzle, 0.357 inch thick (UT).

Reinforcing Plate: Circular shaped, 12‐inch diameter x 0.458 inch thick (UT).

Telltale hole is open to the atmosphere.

Pack telltale hole with general purpose grease to prevent water migration between the reinforcing plate and the tank shell.

Manhole‐2

(Size, Thickness, Telltale Hole)

Size: 24‐inch diameter nozzle, 0.387 inch thick

(UT).

Reinforcing Plate: Diamond shaped, 63‐inch x 56‐inch x 0.446‐inch thick (UT). There is non‐ compliant weld clearance between the reinforcing plate and the floor‐to‐shell weld.

Telltale hole is open to the atmosphere.

Perform magnetic particle testing of the weld along the bottom edge of the reinforcing plate and the shell‐to‐floor weld on the exterior of the tank.

Pack telltale hole with general purpose grease to prevent water migration between the reinforcing plate and the tank shell.

Water Draw‐Off

(Size, Thickness, Telltale Hole)

Size: 3‐inch nozzle.

Reinforcing Plate: Tombstone shaped, 10‐inch wide.

Telltale hole is open to the atmosphere.

Pack telltale hole with general purpose grease to prevent water migration between the reinforcing plate and the tank shell.

Shell Vents Tank is not equipped with shell vents.

Overflow Ports Tank is not equipped with overflow ports.

Wind Girders and Shell Stiffeners (Size & Elevation)

Tank is not equipped with wind girders or shell stiffeners.

Tank 38 – API 653 Inspection Appendix A, Page 7

EEI Project No.: 8093

SHELL

Evaluation Item Finding(s) Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

Tank Nameplate Data (Complete as Possible):

Repaired/Altered to API 653 Second Edition, Dec 96 Addendum

Altered by: Morse Construction Group, Rockford Corporation

Tank No. 38

Nominal Diameter: 73’ – 3”

Nominal Height: 38’ 11 1/2”

S.G.: JP‐8

Year Altered: 1998

Liquid Level Max: 36’‐8”

Capacity: 1,164,671 Gallons

Additional Shell Items, Comments or Notes:

Weld artifacts were observed on the interior of the tank shell plates. Recommend removing the weld artifacts and repairing the areas.

Tank 38 – API 653 Inspection Appendix A, Page 8

ROOF

Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

TANK ROOF

Type Column supported fixed cone roof.

Roof Plate Thickness The roof consists of 3/16 inch (0.188) thick roof plates. Average measured thickness is

0.189 inch (UT).

Roof Topside Pitting/corrosion

No significant pitting or corrosion was identified on the topside of the roof.

Roof Topside Condition

No distortions present. Water ponding was observed on two of the perimeter roof plates.

Repair action is not recommended at this time. Monitor for coating failure and corrosion during routine maintenance.

Roof Welds A pit was observed in the roof plate weld between plates D3 and E3 near the center of the tank.

Provide weld overlay to restore weld profile.

Frangible Joint (Size/Condition)

3/16 inch nominal roof plates, lap welded to rim angle with 3/16 inch fillet weld.

The roof connection at the shell meets the definition of a frangible joint for emergency venting.

Roof Vents (Size & Type) Two Shand & Jurs 6 inch pressure‐vacuum vents.

Recommend disassembling and cleaning vent screens and pallets.

Roof Hatch/Manholes The tank is equipped with one 20‐inch roof manhole.

The tank is equipped with an inspection hatch for the tape gauge float.

Roof Nozzles 10‐inch nozzle for ATG.

8‐inch nozzle for water/temperature probe.

10‐inch nozzle with hatch for manual gauge.

Three nozzles for the float gauge tape and guides.

Two 6‐inch nozzles for pressure‐vacuum vents.

Handrails The roof of the tank is equipped with a full perimeter handrail constructed of structural angles. The toe board is 2 inches above the walking surface. OSHA requires the toe board to be no more than 1/4 inch above the walking surface.

Recommend moving the toe board within 1/4 inch of the walking surface at the discretion of the government.

Roof Access From the Ground

Roof access is via a spiral stair that is supported from the shell.

Roof Access to Adjacent Tank

There is no roof access to adjacent tanks.

Tank 38 – API 653 Inspection Appendix A, Page 9

EEI Project No.: 8093

ROOF

Evaluation Item Finding(s) Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

Roof Framing/Roof Underside Condition

Visual inspection of the underside of the roof from the tank floor found no indication of leaks and no areas of significant corrosion or other degradation.

Interior Columns One center built‐up column and five perimeter columns comprised of C8x11.5 and C10x15.3 channels.

See “Floor ‐ Floor/Doubler Support Plates” for further comments.

FLOATING ROOF

Type The tank is not equipped with either an external floating roof or an internal floating pan.

SEE TANK APPURTENANCES FOR ATG, GAUGING, LEVEL ALARMS, ETC.

Additional Roof Items, Comments or Notes:

Tank 38 – API 653 Inspection Appendix A, Page 10

COATINGS

Comments/Recommendations

(A blank in comments column indicates lack of significance, or condition is acceptable.)

Exterior Coatings

Shell

Type/age 2‐coat epoxy with polyurethane topcoat, 1995.

General Condition In general, the exterior coating is in good condition with good adherence. Corrosion and coating failure was observed at the handrail, stairs, and random locations on the tank shell.

Remove…