ATT F-KWA-FY11-FAC 962-Tank 6-FINAL.pdf

NFESC CONTRACT N62583-09-D-0130, TASK ORDER 0002

TANK 6

API 653 TANK INSPECTION AND

SUITABILITY FOR SERVICE EVALUATION

(PRE-REPAIR)

U.S. Army Kwajalein Atoll, Republic of Marshall Islands

April 2011

Prepared For:

Naval Facilities Engineering Command Engineering Service Center 1100 23rd Avenue, Code 232 Port Hueneme, California 93043-4370

Presented By:

Shaw Environmental Inc.

6330 Commerce, Suite 190 Irving, Texas 75063

Prepared By:

David A. Stchyrba, P.E., API 653 Certificate No. 27187

Submitted By:

Stephen S. Brooks, P.E.

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

EEI PROJECT 10-5452

ABSTRACT

Enterprise Engineering, Inc. (EEI) has completed a comprehensive, out-of-service inspection and suitability for service evaluation of Tank 6 at U.S. Army Kwajalein Atoll, Republic of Marshall Islands. The inspection was performed in accordance with the applicable criteria 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. The inspection was performed on March 17-21, 2010.

This report provides inspection findings, tank suitability for service evaluation, conclusions, and recommendations for repair, prior to returning the tank to service. Recommendations for continued long-term service are also provided. It should be noted that prior to the inspection, the facility reported an inventory loss from the tank. This was confirmed by a third party certified leak detection procedure by MassTech. The API 653 tank inspection was unsuccessful in identifying the source of the leak.

EEI recommends the next API external in-service inspection be scheduled no later than March 2016 (5 years from 2011 inspection), or sooner if a change in condition has occurred.

EEI recommends the next API internal out-of-service inspection be scheduled no later than March 2021 (10 years from 2011 inspection), or sooner if a change in condition has occurred.

In accordance with API Standard 653, this report satisfies the requirement for an out-of-service, 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.

April 27, 2011 David A. Stchyrba, P.E.

API 653 AST Inspector Certificate No. 27187

This tank inspection has determined that mandatory repairs are required prior to return to service. Following completion of the identified repairs and resolution of the reported inventory loss, Tank 6 will be suitable for service.

Tank 6 – API 653 Inspection TABLE OF CONTENTS Kwajalein Atoll April 2011 EEI Project No. 10-5452

TABLE OF CONTENTS

Page

SUMMARY

Scope General

INSPECTION ASSESSMENT

Hydraulic Integrity Structural Integrity Next Inspection

REPAIR ITEMS

Standard of Care Required Repairs Prior to Return to Service (Mandatory) Recommended Repairs Prior to Return to Service (Non-Mandatory) Recommended Repairs per Current Military Criteria Recommended Repairs for Long Term Serviceability

COATING REQUIREMENTS

Coating System at Localized Repairs (Interior and Exterior) Interior Coating System – Out of Service Concerns

SUITABILITY FOR SERVICE EVALUATION

Corrosion Rates Tank Floor Corrosion Rates Hydraulic and Structural Integrity

ADDITIONAL DISCUSSION ITEMS

Seismic Evaluation Gauge Tubes New Floor

CLOSURE

Conclusions Project Team

APPENDICES

Tank Inspection Data Sheet and Evaluation Items ................................................... Tab A Non-Destructive Examination (NDE) and Evaluation Criteria ................................... Tab B Tank Drawings ........................................................................................................ Tab C Tank Photographs ................................................................................................... Tab D NDE Results ............................................................................................................. Tab E Calculations .............................................................................................................. Tab F Repair Documentation ............................................................................................. Tab G Field Inspection Report ........................................................................................... Tab H

Tank 6 – API 653 Inspection Page 1

EEI Project No.: 10-5452

TANK 6

API 653 TANK INSPECTION

SUITABILITY FOR SERVICE EVALUATION

U.S. Army Kwajalein Atoll, Republic of Marshall Islands

SUMMARY

Scope

Enterprise Engineering, Inc. (EEI) has completed a comprehensive, out-of-service inspection and suitability for service evaluation of Tank 6 at U.S. Army Kwajalein Atoll, Republic of Marshall Islands. The inspection was performed in accordance with the applicable criteria 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. The inspection was performed on March 17-21, 2011.

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 6 is a field erected above ground storage tank. The tank was constructed in 1954. The tank is 60 feet in diameter and 54 feet high and is of the open top style, welded construction with butt-welded shell plates and lap-welded floor plates. The tank was originally equipped with an external floating roof. The floating roof has since been removed and an aluminum geodesic dome provided. No aluminum floating pan was installed. The tank floor is of cone up (original) style, with perimeter sump. The nominal shell capacity is 27,000 BBLS. Tank 6 is currently in JP-5 service.

Facility personnel reported an inventory loss from the tank on January 2011 and the tank was subsequently removed from service. Prior to arrival on site, a hydraulic leak test using a 3rd party certified procedure was performed, with water, by a DLA-E approved testing company (Mass Technology). The hydraulic leak test indicated that the tank was leaking at a rate of approximately 3 gallons per hour. EEI performed a visual examination and magnetic particle testing (MT) on all floor welds. Vacuum box testing was performed on all accessible welds including the patch plates, reinforcing plates, floor seams and breakdown welds at the tank shell.

Vacuum box testing was also performed on the floor plate where MFL suspect locations were identified. It should be noted that all of the NDE was performed with the coating in place. The tank inspection was unsuccessful in identifying the leaking site.

An additional test was conducted by Shaw, consisting of filling the tank with approximately 3 ft.

of water, and injecting compressed air under the floor. A close inspection of the floor, by individuals inside the tank, could not discover any bubbles, thus the leak site remains unidentified. Consideration should be made to replace the floor of Tank 6. If this is accomplished, many of the repair items noted below are no longer required.

Tank 6 – API 653 Inspection Page 2

EEI Project No.: 10-5452

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.

Tank 6 is considered suitable for service after all required repairs are completed. 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.

Visual inspection of the tank shell found no indications of leakage. A pit survey was conducted for topside corrosion on the floor and no pits were identified requiring repair. Magnetic particle testing (MT) of the floor welds did not identify any areas of possible leakage. A magnetic flux leakage (MFL) scan of the tank floor found evidence of active corrosion on the bottom side of the floor plates. No locations were identified requiring repair. A leak was reported by facility personnel January 2011 and the tank was subsequently removed from service. As of the preparation of this report, the location of the leak has not been identified. Discussions are currently taking place between EEI, Shaw and NFESC as to next appropriate steps. Upon completion of the required repairs and resolution of the reported leak, Tank 6 will be in acceptable hydraulic condition.

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 and shell and their attachments. Ultrasonic inspections of the shell were performed on the accessible courses. From interpretation of ultrasonic test (UT) readings recorded, only plate thickness variances were noticed. Based on this inspection of the accessible components, Tank 6 is in acceptable structural condition. However, additional NDE has been recommended. Refer to “Repair Items” identified below.

Next Inspection

API 653 recommends the interval to the next internal inspection be determined based on known corrosion rates, but in no case shall the interval exceed 20 years from the date of inspection.

When corrosion rates are not known or well established, API 653 recommends that the tank be inspected within 10 years. A maximum interval between inspections of 10 years is also commonly used in many government and commercial facilities.

EEI recommends that the next external in-service inspection be scheduled no later than March 2016 (5 years from 2010 inspection), or sooner if a change in condition has occurred.

EEI recommends the next internal out-of-service inspection be scheduled no later than March 2021 (10 years from 2010 inspection), or sooner if a change in condition has occurred. The 10 year inspection is based on active and aggressive corrosion observed throughout the facility.

Tank 6 – API 653 Inspection Page 3

EEI Project No.: 10-5452

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), recommended per military criteria, recommended for long term serviceability and client requested repairs.

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 jet fuel service. The provisions of API 2207 “Preparing Tank Bottoms for Hot Work” shall be considered.

Required Repairs Prior to Return to Service (Mandatory)

Mandatory refers to those API 653 items that are considered critical to the hydraulic or structural integrity of the tank, or are required to meet code, prior to placing Tank 6 back into service.

1. As of the writing of this report, the location of the leak within Tank 6 remains unidentified.

Additional testing is not recommended as it would most likely also be indeterminate. It is recommended to provide a new floor to eliminate the leak.

2. Severe corrosion and through holes were observed on the wind girder support angle near the spiral access stair. The remaining portions of the wind girder are inaccessible for inspection.

The following is required:

Remove and replace the angle support to maintain the stability of the wind girder.

Inspect the remaining inaccessible portions of the wind girder. Construction of scaffolding may be necessary to complete inspection. It is likely that additional repairs will be necessary including coating removal, corrosion abatement, steel replacement and recoating.

3. The weld clearance between the threaded plug at the water draw-off nozzle and the reinforcing plate for the sump drain nozzle do not meet API 653 clearance requirements. The following repair is required per API 653 4.3.9.1:

Examine the welds by magnetic particle testing (MT).

Note: It may be necessary to remove the coating from the affected areas in order to complete the inspection. We recommend removal by high pressure water or paste methods, and not by mechanical or sandblasting methods.

Although this inspection step is considered mandatory under API 653 provisions, as it is very unlikely such testing will result in any work other than light grinding (per API 653 criteria) the coating stripping, MT testing, and restoration work can be provided after the tank is returned to service with relatively low risk of creating any problems.

Tank 6 – API 653 Inspection Page 4

EEI Project No.: 10-5452

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

Recommended Repairs Prior to Return to Service (Non-Mandatory)

The repairs listed below are not mandatory per API 653 or for structural and hydraulic integrity of the tank. EEI highly recommends these repairs for long-term preservation and integrity of the tank, and believes that the repairs should be performed concurrently with required repairs noted above.

1. The reinforcing plates for two manways, fill and issue nozzles are not equipped with tell tale holes. The following repair is recommended:

Provide tell tale holes in the reinforcing plates in accordance with API 653 requirements.

Pressure test reinforcing plate welds to a pressure of 15 psig. In the event the welds do not pass, notify government for direction.

Pack the tell tale hole with general purpose grease to prevent moisture migration between the reinforcing plate and the shell.

2. The tell tale hole in the reinforcing plate at the Low Fuel nozzle is open. The following repair is recommended:

Pack the tell tale hole with general purpose grease to prevent moisture migration between the reinforcing plate and the shell.

3. Coating failure and corrosion was observed on the exterior tank shell, shell stiffener, the manway flanges, shell valves, stair treads, handrails, platform and support for the fire piping.

The following repair is recommended:

Remove the coating from the affected areas and recoat to prevent further degradation.

4. Corrosion and severe metal loss is present on the manway cover plate handles. The following repair is recommended:

Provide new cover plate handles.

5. Coating failure and corrosion was observed on approximately 40% of the floor projection.

The following repairs are recommended:

Remove the sealant between the floor projection and the concrete ringwall.

Remove the coating from the entire floor projection and the lower 6 inches of the tank shell.

Clean the surfaces of the concrete ringwall and underside of the floor to be sealed.

Provide jet-fuel resistant sealant and recoat as required.

6. A wood pipeline cross over stair is present within the containment area. Structures are to be constructed of noncombustible materials per section 4.3.2.3.4.5 of NFPA 30. The following repair is recommended:

Remove the wood stair and provide a new access stair. Suggested materials of construction include galvanized steel, aluminum or fiberglass.

Tank 6 – API 653 Inspection Page 5

EEI Project No.: 10-5452

7. An API tank identification plate was formerly located in the reinforcing plate at manway #1.

The plate was subsequently removed but one of the rivet-type attachments remains. The following repair is recommended:

Remove the rivet-type attachment.

Repair the location by providing additional weld passes.

Perform integrity inspection of the entire weld by visual examination and either dye penetrant testing (PT) or magnetic particle testing (MT).

8. Tank 6 is equipped with an aluminum dome roof. Holes were observed in the top of the roof adjacent to the access stair platform, the tape gauge appurtenance, and on the east side of the roof. The following repair is recommended:

Repair the damaged roof by providing an aluminum patch plate.

9. The portion of the steel gauge tube above the dome roof containing the ENRAF ATG is severely corroded and has through-holes. The ATG is currently disconnected. The following repair is recommended:

Replace the steel gauge tube with an aluminum gauge tube including the roof reinforcing pad and boot seal. Gauge tube recommendations have been provided in “Additional Discussion Items – Gauge Tubes.”

Notify SPAWAR of status of ATG system. Contact DLA-E help desk at (800) 446-4950 to schedule SPAWAR authorized technician for re-connection of ATG components.

10. Tank 6 has been provided with a thermometer in the first shell course. The glass display is cracked and debris has accumulated inside. The following repair is recommended:

Temperature measurements are incorporated as part of the ATG system. Remove the thermometer and backweld a threaded plug in the existing nozzle.

11. Tank 6 is equipped with a Varec tape gauge. The cover plate on the tape gauge display is open to the weather. It is likely that it has been infiltrated by water. The following repair is recommended:

Provide a new tape gauge head, tape, tension springs, float, conduit and guide wires.

This recommendation is based on historical observations by EEI at multiple government facilities. A Varec or Shand & Jurs tape gauge is recommended.

12. A tee segment is present downstream of the shell valve on the issue nozzle. The pipe closure consists of a flat plate welded to a flange. The following repair is recommended:

Replace the closure with a rated blind flange.

13. Tank 6 is located within a reinforced concrete containment dike. The dike walls include expansion and construction joints. The caulking within the joints is cracked and failing. The following repair is recommended:

Remove the caulking and backer rods, if present, from the joints.

Clean and prepare the concrete surfaces.

Provide jet-fuel resistant sealant and backer rod, if required, due to width.

Tank 6 – API 653 Inspection Page 6

EEI Project No.: 10-5452

14. Six test port patch plates are present on the tank floor. The plates are 6 inch square and are each topped with a 1-1/2 inch nipple with welded plug. The square plates do not have rounded corners. The following repair is recommended, but considered optional:

Remove the patch plates.

Remove the coating from the affected surfaces and prep surfaces for welding.

Provide 5/16 inch thick x 8 inch square steel plates with radius corners.

Weld the plates to the floor with a full fillet weld, continuous on all edges of each plate.

The completed welds shall have no cracks, porosity or lack of fusion.

In preparation for recoating, remove edge on topside of plate by grinding a 45-degree chamfered rounded edge.

Perform integrity inspection of the entire weld by vacuum box testing (BT) and either dye penetrant testing (PT) or magnetic particle testing (MT).

15. The old sump patch plate is 4 ½ inches from chine within the critical zone resulting in a weld clearance issue. API 653, 9.10.1.2 calls for a minimum of 6 inch spacing between floor-to-shell weld and a patch plate. The following is recommended:

Remove the coating over the patch plate welds and perform integrity inspection of the welds by either dye penetrant testing (PT) or magnetic particle testing (MT).

Advise EEI for repair direction if cracks are detected.

16. The tombstone patch plate at Manway 1 exceeds maximum dimension along the shell for welded-on patch plate in the critical zone. The patch plate is 31 inches along shell; the maximum permitted length is 24 inches (API 653, 9.10.1.2). The following is recommended:

Remove the coating over the patch plate welds and perform integrity inspection the welds by either dye penetrant testing (PT) or magnetic particle testing (MT).

Advise EEI for repair direction is cracks are detected.

17. Eight 1 inch diameter bars are welded around the perimeter of each octagonal doubler plate.

The bars prohibit floor scanning and may be a possible leak source The following repair is recommended:

Grind the bars flush with the floor surface at each octagonal plate.

Upon completion of grinding, perform integrity inspection of the bars by vacuum box testing and either dye penetrant testing (PT) or magnetic particle testing (MT).

18. Tank 6 is not equipped with a water draw-off line at the sump. A threaded plug is present in the shell nozzle. The following repair is recommended:

Perform integrity inspection of the existing nozzle weld by either dye penetrant testing (PT) or magnetic particle testing (MT).

Provide a 1¼-inch water draw-off line with ¼-turn ball valve in the existing water draw-off nozzle.

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EEI Project No.: 10-5452

19. Approximately 110 sq. ft. of coating failure was observed at multiple locations on the tank floor plates. The following repair is recommended:

Remove the coating from the affected areas and recoat to prevent further degradation.

Note: The locations and quantities are provided in Appendix G.

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

The following items were added after the release of the Field Inspection Report.

21. The 6 inch sump drain piping at the tank shell includes a gate valve. The following repair is recommended:

Remove the gate valve and provide a double block and bleed plug valve.

Note: At the time of the inspection, the gate valve was in the process of being replaced.

No further action is required.

22. Two locations on the tank floor with three-plate laps do not meet the current API 650 requirements for weld spacing. The following is recommended:

Remove the coating from the lap welds and perform integrity inspection of the welds by either dye penetrant testing (PT) or magnetic particle testing (MT).

23. Three insert plates are present in the first shell course. The plate diameters are less than the 12 inch minimum per API 653. The following repair is recommended:

Perform shear wave ultrasonic thickness examination to verify the integrity of the welds.

24. Twelve locations with weld undercuts greater than the API 650 allowed depth were observed along the interior shell-to-floor weld. The following repair is recommended:

Remove the coating from the affected surfaces and prep surfaces for welding.

Provide weld overlay for the areas of undercut as recommended by API 653. The completed welds shall have no cracks, porosity or lack of fusion.

The repair locations have been provided in Appendix G.

25. The tank has not been provided with an ID number or product type stenciled on the shell.

The following repair is recommended:

Provide tank signage including the tank identification number, facility number and product type. The signage shall be clearly visible from the nearest roadway(s) as required by NFPA 30 and MIL-STD-161G.

26. Tank 6 is currently out of service and has been scheduled to be re-strapped. Gauge tube recommendations have been provided in “Additional Discussion Items – Gauge Tubes”. The following is recommended:

Co-ordinate the new gauging locations with the re-strapping effort so that the new strapping tables have correct reference points.

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EEI Project No.: 10-5452

27. Calculations were performed to the current API 650 for seismic forces. Refer to “Additional Discussion Items - Seismic Evaluation” for further commentary.

28. As the repairs to this tank are considered significant, it is recommended that the API Inspector of Record is engaged during the construction repair process to audit repairs via construction inspection records, testimony and photographs. A final “Post Repair” API Inspection Report front end will then be prepared and attached to the Pre-Repair report, and be more suitable for use by DLA-E and filing on the SRM database for this facility.

Additional information can be provided if this is of interest.

29. Provide a mounting bracket on the underside of the dome roof for the water probe to meet intent of DLA directive. Since the floor is cone up, any location would be acceptable. It would be preferable to locate it near the dome roof inspection hatch for servicing.

Recommended Repairs per Current Military Criteria

The following recommended repairs are in accordance with UFC 3-460-01, Table 8-1, and Chapter 12, §12.3:

Table 8-1 of UFC 3-460-01 (Aug 2010 issue) describes appurtenances for vertical aboveground storage tanks.

1. Tank 6 is not equipped with item (k) an individual automatic level alarm system independent of the gauging system.

Note: The installation of an independent level alarm system is currently in progress.

2. Tank 6 is not equipped with item (q) one 8 inch flange nozzle for ATG (planned or future) near the edge of the roof. The following is noted:

The existing ATG system is located within a 6 inch gauge tube near the stairway. The portion of the gauge tube above the dome roof is severely corroded. Replace the existing gauge tube with a new 8 inch aluminum slotted gauge tube for the ENRAF ATG displacer.

3. Tank 6 is not equipped with item (r) one 8 inch gauge hatch for water bottom sampling as close to the center as possible. The following is noted:

The tank is equipped with a side sump. As there is no accessible roof, no center gauge tube is possible. Bottom water sampling is not possible from the gauging platform as it is located on the opposite side of the tank.

The only method effective is an active ongoing tank sumping program. Installation of a product saver (recommended below) is warranted.

4. Tank 6 is not equipped with item (s) one 8 inch gauge hatch with aluminum, slotted stilling well extended to within 3 inches of the bottom of the lowest point in the tank. The following is noted:

Provide an 8 inch aluminum slotted gauge tube for manual gauging. Alternatively, retract the ATG displacer and use the ATG stilling well (Item #2).

5. Tank 6 is not equipped with a Product Saver Tank.

Tank 6 – API 653 Inspection Page 9

EEI Project No.: 10-5452

Recommend providing a Product Saver Tank including associated connections to the tank. The unit should be standard packaged military product saver, all stainless steel construction, with 50 gallon (nominal) tank and electric pump (hazardous rated) for recirculation and pumpout.

Note: A source of power (110V) must be identified.

Recommended Repairs for Long Term Serviceability

1. Program the tank for an API in-service external inspection no later March 2016.

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

COATING REQUIREMENTS

All repairs involving steel surface grinding, cutting and welding shall be preceded by proper coating removal. At this time it is not known if any of the existing coating layers have significant lead or chromate components. The contractor shall be responsible for testing coating systems for lead and chromate levels, and develop engineered controls to prevent worker safety hazards, and spread of contaminated dusts. Coating removal method shall be contractor determined to suit contamination levels and follow-up steps.

Coating System at Localized Repairs (Interior and Exterior)

Provide repair of localized areas of failed and damaged coating on the exterior of the tank and areas affected by the contractor’s work. Provide surface preparation with the coating manufacturer’s recommendations to ensure adhesion of the coating system. Prior to surface preparation, test surfaces for soluble salts, oil and grease and clean as required to remove contaminants.

For interior coating repairs, provide a 3-coat epoxy polyamide system as specified in Unified Facilities Guide Specifications (UFGS) section 09 97 13.17, Interior Coating of Petroleum Storage Tanks. Tank interior coatings shall cure for not less than 14 days prior to introducing fuel into the tank. Provide a longer cure time when recommended by the coating manufacturer.

For exterior coating repairs, provide 2-coat epoxy polyamide system with polyurethane topcoat as specified in UFGS section 09 97 13.27, Exterior Coating of Steel Structures.

Interior Coating System – Out of Service Concerns

Tank 6 is currently out-of-service awaiting repairs. At the time of the inspection, the coating on the floor was found to be in good condition. It should be noted that degradation of the coating system may occur the longer the tank remains out-of-service. This can be attributed to possible original application defects such as incorrect surface profile preparation or insufficient removal of chlorides with potable water between coats. All of these potential defects could result in stress points and cracking during extreme temperature changes.

Inter-layer chloride contaminants, if present, will absorb water from moist air and swell. The coating is generally protected from temperature changes and contact with moist air by immersion in product, thus it may appear to exhibit certain characteristics when first cleaned but degrade over time.

Tank 6 – API 653 Inspection Page 10

EEI Project No.: 10-5452

SUITABILITY FOR SERVICE EVALUATION

Corrosion Rates

Corrosion rates for the tank floor and shell were calculated using assumed nominal metal thicknesses when the tank was constructed in 1954 and the plate thicknesses obtained from UT measurements at the time of the inspection. The corrosion rates are summarized as follows:

Floor: 0.003404 inches per year

Shell: 0.000670 inches per year

Tank Floor Corrosion Rates

The tank floor coating, with an average thickness of 29.2 mils, is a thick-film lining. For tanks with coated floors, API 653 permits a product side corrosion rate (StPr) of 0.00 in/yr. The age of the coating is unknown and is in good condition, with a few areas of coating failure and disbanding between coatings. A nominal pit depth of 1/16 inch was assumed to conservatively calculate a product side corrosion rate (StPr). No pits were identified in the floor during the inspection.

Bottom side corrosion with small volumetric metal loss may be present and not detected by MFL scanning. The metal loss used to calculate the bottom side corrosion rate (Upr) 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 setup to indicate (alarm) for minor metal loss. Backside corrosion was detected; however, no areas were identified for repair.

The minimum remaining floor thickness (MRT) used in the calculations is based on API 653 Section 4.4.7 and Table 6-1. The tank has not been equipped with the means to detect a bottom leak. Based on this information, the MRT used in the calculations is 0.100 inch.

It was found that the floor plate thickness will not be reduced below the limiting MRT at a 10 year inspection interval. EEI recommends that the next API internal inspection should be scheduled no later than March 2021 (10 years from 2011 inspection), or sooner if a change in condition has occurred.

Tank 6 – API 653 Inspection Page 11

EEI Project No.: 10-5452

Hydraulic and Structural Integrity

The following table summarizes the hydraulic and structural integrity of Tank 6:

HYDRAULIC AND STRUCTURAL INTEGRITY

Evaluation Item

Findings Comments

Foundation Tank 6 sits on a concrete ringwall. The tank passes API 653 criteria for levelness and differential settlement.

Acceptable

Floor Visual inspection of the floor joints found no relevant indications. Magnetic particle testing of the floor welds found no indications of possible leaks. MFL scanning of the floor found no locations requiring repair. A pit survey was conducted for topside corrosion and no pits were identified requiring repair.

Upon completion of required repairs, the floor plate thickness will not be reduced below the requirements for minimum floor plate thickness of 0.100 inch at a 10 year inspection interval.

Acceptable after completion of repairs and resolution of the reported leak.

Shell Visual inspection of the accessible shell joints found no relevant indications. Visual inspection of the tank shell found three insert plates that do not meet API minimum requirements.

Acceptable after shear wave UT inspection of the insert plates.

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, built in 1954.

2. Has a prior hydrotest been performed demonstrating fitness: Unknown.

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

4. Does the tank operate at metal temperature above

60 deg F?: Yes.

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

6. Tank steel exempt per API 650, Figure 4-1 or API 653 Figure 5-2: Yes.

7. Tank full at lowest one day temperature per API 650 Figure 2.2: Unknown.

The tank, having a shell thickness less than 0.5 inch thick does not fit the API 653 at-risk profile for brittle fracture failure.

Internal Fluid Pressure

Hoop stresses caused by internal fluid pressure pass API 653 criteria.

Acceptable

Hydrostatic Test

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

Acceptable

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EEI Project No.: 10-5452

HYDRAULIC AND STRUCTURAL INTEGRITY

Evaluation Item

Findings Comments

Seismic Evaluation

Tank 6 is not anchored. Seismic calculations were performed in accordance with API 650 Appendix E. It was found that at a fill height of 52’-7” (HI-HI), the tank anchorage ratio J > 1.54 which is considered unstable, although longitudinal stresses are acceptable. It was found that at a fill height of 38’-2”, the tank anchorage ratio J =

1.54 which is considered stable.

Calculations were performed utilizing the specific gravity for JP-5 (S.G. = 0.845), a ringwall foundation, seismic parameters Ss = 1.19, S1 = 0.48 and I = 1.0.

See “Seismic Evaluation” for Additional Comments

Wind Evaluation

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

Calculations were performed using an importance factor of

1.0 and a wind velocity of 105 mph.

Evaluation determined that an empty unanchored tank is not at risk of overturning.

Evaluation of the shell buckling determined that the shell is adequate, without stiffeners, for wind speeds in excess of 105 mph.

Acceptable

ADDITIONAL DISCUSSION ITEMS

Seismic Evaluation

API 653 4.3.3.5 stipulates that loads shall be evaluated according to the original standard of construction and that engineering judgment shall be used to evaluate different conditions or new information. The seismic evaluation was performed using the formulas and criteria contained in the 11th edition of API 650 (latest edition). It was found that at a fill height of 52 ft 7 in, the tank anchorage ratio J > 1.54 which is considered unstable, although longitudinal stresses are acceptable. It was found that at a fill height of 38 ft 2 in, the tank anchorage ratio J = 1.54 which is considered stable. However, there is no mandatory requirement to upgrade an existing tank to current API 650 standards as compared to the other proscriptive repair requirements found in

API 653.

EEI takes no formal position as to repairing the tank, or accepting the risk of failure and consequence of a release, beyond advising the owner of cases such as this where engineering analysis finds the original design does not meet current tank design and construction standards.

The decision to reduce the fill height or maintain the status quo is entirely up to the tank owner and the level of risk that they are willing to assume.

The analysis, provided in Appendix F, determined that the tank is subject to overturning in a seismic event. However, the calculations also indicate that the shell is not at risk of being overstressed. The installation of tank anchors and additional foundation mass would eliminate the risk of overturning due to seismic loading. The size and mass of the existing tank ringwall foundation is unknown and may not be sufficient to prevent overturning even if anchors were

Tank 6 – API 653 Inspection Page 13

EEI Project No.: 10-5452 installed. If a new floor were installed, a secondary concrete mass could be provided outside of the present ringwall to provide sufficient mass to resist overturning.

Gauge Tubes

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

The comments below represent concept solutions based on the memorandum. We recommend the concept be submitted to DESC for ratification or redirection. Field verification of constructability by the prime contractor is also recommended.

Tank 6 Existing Conditions

Tank 6 is equipped with an aluminum geodesic dome roof. There is a 6 inch slotted steel gauge tube currently used for the ENRAF ATG displacer and temperature probe. It is located near the tank shell and is accessible from the spiral stair. There are no spare nozzles or gauge tubes.

The present gauge tube is showing excessive corrosion when outside of the normally wetted elevation.

The tank is equipped with a side sump. As there is no accessible roof, no center gauge opening or location is possible. Bottom water sampling from the sump is not possible from the gauging platform as it is located on the opposite side of the tank from the sump.

Gauge Tube Recommendations

The following are recommended for compliance with the DESC/DLA Memorandum (for ATG) and UFC 3-460-01 (for operations):

1. Provide a new 8 inch aluminum slotted gauge tube for the ENRAF ATG displacer (DLA directive). Locate the gauge tube near the tank shell and accessible from the stair platform.

A new penetration in the dome roof will be required. Alternatively, obtain a waiver to continue using the existing 6 inch steel tube as the ATG stilling well.

2. Provide a new 6 inch aluminum slotted gauge tube for manual gauging (UFC criteria).

Alternatively, retract the ATG displacer and use the proposed 8 inch ATG gauge tube.

3. Provide a mounting bracket on the underside of the dome roof for the water probe (DLA directive). Since the floor is cone up, any location should be acceptable. It would be preferable to locate it near the dome roof inspection hatch for servicing.

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

New Floor

In the field trip report dated March 25, 2011, it was recommended that the government consider replacing the tank floor. As of the preparation of this report, the following has occurred:

1. The facility originally reported an inventory loss.

2. The Mass Tech certified leak test failed, thus confirming that there is a leak. The reported leak rate during the test was 3 gallons per hour.

3. The initial API 653 Inspection of the floor included magnetic particle testing and vacuum box testing, with the coatings in place. The leak path could not be determined by these normally reliable methods.

Tank 6 – API 653 Inspection Page 14

EEI Project No.: 10-5452

4. Shaw completed a test that involved drilling air injection points in the floor, filling the tank with approximately 3 feet of water, and subjecting the underside of the floor to a 5 psig air pad overnight. Several hours were spent the next day looking for any evidence of bubbles indicating a floor breach. None were found.

5. In short, additional testing will likely remain inconclusive. Tank 7 had a similar fate, with additional testing consisting of a helium floor leak test and as well as the removal of floor coupons to search for product. The results were inconclusive.

Backside corrosion has been identified at other tanks within the facility. At the time that this document was prepared, the location of the leaks in both Tanks 6 and 7 remain unidentified.

Although rare, it is been discovered on past tanks that on occasion, a floor crack will open when under pressure from liquid, but be closed when empty, making leak site detection impossible.

While very rare, this may be the condition here. It would appear that backside corrosion and through holes will continue to be occur and likely increase in severity over time. Consideration should be made to replace the floor of Tank 6. Floor replacement programs should be reviewed for the remaining tanks in the facility. If the floor of Tank 6 was replaced at this time, several of the repairs identified in this document would no longer be necessary. This would include the following:

Magnetic particle testing of the non compliant weld clearances at the shell nozzles. All of the nozzles would have to be relocated as part of the new floor design.

Repair of tell tales holes in the nozzle reinforcing plates.

Coating repairs at the floor projection.

Repair of the test port patch plates on the tank floor.

Repair of weld undercut at the floor-to-shell weld.

Magnetic particle testing of the non-compliant weld clearances of the floor patch plates.

Magnetic particle testing of the non-compliant weld clearances of the floor lap welds.

Removal of the 1 inch bars present around each doubler plate for the old floating roof support legs.

Repair of floor coating.

As tank inspectors, it is our primary responsibility to report problems identified, and appropriate remedies. In most cases single tank floors can remain a viable means of keeping tanks in service, unless a double bottom is mandated under a regulatory provision.

The recommended replacement of otherwise serviceable tank floors with double bottoms then becomes a policy issue within the owners organization (US Government in this case). However in the case of these tanks at Kwajalien, the repeated floor leaking condition (3 identified so far) results in EEI taking the position that the original 1954 tank floor have outlived their useful life, and are in need of replacement. EEI agrees with the position of API, that whenever a floor replacement is indicated, the owner is encouraged to install a system meeting the requirements of providing both a release prevention barrier and a leak detection system, which would be satisfied by installation of a double bottom.

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EEI Project No.: 10-5452

EEI also notes that if a double bottom is authorized, we recommend the installation of a cone down floor, which will improve the ability to remove water, which is considered particularly important with tanks filled by Tankers, and is consistent with military criteria.

CLOSURE

Conclusions

Based on the extent of this inspection and completion of the mandatory repairs, Tank 6 will be suitable to return to service.

Project Team

Site Team

David A. Stchyrba, P.E. Structural Engineer, API 653 Aboveground Storage Tank Inspector Certificate No. 27187, API Inspector of Record.

D. Ryan Eide Sr. NDE Technician, Level II Inspector

Todd Lichtenberg NDE Technician, Level II Inspector

Matt F. Fritz, EIT Mechanical Engineer

Support Team

Stacy M. Kaplan-McMillan Project Manager

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

APPENDIX A

Tank Inspection Data Sheet and Evaluation Items

APPENDIX A - AST Evaluation Items Page 1 Tank 6 – API 653 Inspection April 2011 EEI Project No.: 10-5452

DLA-E TANK CMP CONDITION FORM

TANK INSPECTION SUMMARY SHEET

Tank Location Reagan Test Site (RTS), Kwajalein Atoll Republic of Marshall Islands (RMI)

Tank No. 6 Facility No. 962

Inspection Date(s): March 17-21, 2011 Tank Type: Vertical AST

Type of Inspection: Internal & External w/ Suitability for Service Contract Number, Task Order: N62583-09-D-0130, Task Order 0002

Prime Contractor Name: Shaw Environmental, Inc.

Inspector, Certificate #: David A. Stchyrba

ANSI/API-653 AST Inspector Certificate No. 27187

Inspection Company: Enterprise Engineering, Inc.

2525 Gambell Street, Suite 200 Anchorage, AK 99503

(907) 563-3835

Manufacturer, Date, Design Standard Unknown, 1954, Not Specified; Assume API 12C, 11th Ed.

Diameter: 60'-0"

Shell Height: 54'-0" Product, Specific Gravity: JP-5, 0.845

Design Pressure / Temperature: Unknown Gross Capacity / Nominal Capacity: 26,597 bbls / 27,000 bbls

Safe Fill Height: 52' – 7” (From facility) GPS Latitude & Longitude: 8 Deg 43’ 40.24” N, 167 Deg 44’ 12.56” E

(Source – Google Earth) Foundation Configuration: Concrete Ringwall

Shell Configuration: Butt Welded w/ 8 courses (Add’l info enclosed) Floor Configuration: Cone up w/ lap welded plates oriented in rows with side sump

(Add’l info enclosed) Roof: Aluminum Geodesic Dome Roof (Add’l info enclosed)

Cathodic Protection: Present and operational Still Wells: Yes (Add’l info enclosed)

Last Inspection (Type, Date): Facility reported that last inspection was September 1998 Last Coated Internally (Product): Unknown

Last Coated Externally (Product): Unknown

INSPECTION RESULTS

Can tank be returned to service? Yes, following mandatory repairs. The tank reportedly failed a certified leak test, which confirmed an unexpected inventory loss.

The location of the leak has not been determined. Repairs must consider identifying leak site and repairing or eliminating current leak from being in the hydraulic boundary.

Deficiencies identified as mandatory repairs: Yes. (See paragraph titled “Repair Items” in body of report) Deficiencies identified as recommended repairs:

Yes. (See paragraph titled “Repair Items” in body of report)

Deficiencies identified as long term repairs: Yes. (See paragraph titled “Repair Items” in body of report) Next Scheduled Inspections (Type, Date:) In-Service: March 2016 (5 Years)

Out-of-Service: March 2021 (10 Years)

ADDITIONAL ITEMS

Change in Service: None As-Built Drawings, Specifications: None available

APPENDIX A AST Evaluation Items - TOC Tank 6 – API 653 Inspection April 2011 EEI Project No.: 10-5452

AST EVALUATION ITEMS

TABLE OF CONTENTS

PAGE

FOUNDATION

FLOOR

SHELL

ROOF

COATINGS

APPURTENANCES

PIPING

APPENDIX A - AST Evaluation Items Page 1 Tank 6 – API 653 Inspection April 2011 EEI Project No.: 10-5452

FOUNDATION

Evaluation Item Finding(s) Comments/Recommendations (A blank in comments column indicates lack of significance, or condition is acceptable.)

FOUNDATION

Type Concrete ring wall. No spalling or cracking was observed.

Levelness The maximum differential between max and min elevations is 0.1 feet (1.2 inch).

Tank 6 passes API 653 criteria for shell levelness.

Rigid Body Tilt Tank 6 has small amount of tilt. The amount of tilt is 0.09 feet (1.08 inch).

Calculations of data acquired at the shell determine that the tank is slightly tilted but within acceptable limits.

Height of Ringwall Above Grade

The top of the concrete ringwall above grade is approximately 9-5/8 inches. It extends approximately 4-5/8 inches past the shell.

No information known on foundation size and configuration that would be useful in determining if it could serve as anchor for seismic conditions.

Material Below Tank Floor The material below the tank floor was inaccessible during the inspection.

Drainage Around Tank Drainage around the tank is adequate.

Tank Anchors Tank 6 does not have anchors.

Containment Dike Tank 6 sits within a containment dike.

The dike wall contains several expansion joints. The caulking within the joints is cracked and failing.

Remove existing sealant and backer rod and repair the expansion joints with jet-fuel resistant sealant and backer rod.

Secondary Containment Tank 6 sits within a concrete dike wall with a ballasted geo-membrane liner attached to the concrete ringwall.

A separate Dike Condition Report has been prepared, and concluded that repairs to dike lining are needed.

Settlement Tank 6 sits on a concrete ring wall – edge settlement is not a factor.

Erosion/Washouts No indications of washouts or erosion were observed.

Sealed at Foundation The sealant between the floor projection (chine) and the ringwall is satisfactory.

Additional Foundation Items, Comments or Notes:

None.

APPENDIX A - AST Evaluation Items Page 2 Tank 6 – API 653 Inspection April 2011 EEI Project No.: 10-5452

FLOOR

Evaluation Item Finding(s) Comments/Recommendations (A blank in comments column indicates lack of significance, or condition is acceptable.)

TANK FLOOR

Type The tank floor configuration is cone up with lap welded steel plates oriented in rows.

A cone up floor does not provide as much ability for water control, which is important on tanks resupplied by tankers, as would a cone down floor now required for military tanks.

Nominal Thickness The floor consists of 3/8 (0.375 inch) thick floor plates.

Annular Ring Plates Tank 6 is not equipped with an annular ring.

Thickness The average thickness of the interior floor plates based on 5 UT readings per floor plate is 0.348 inch. The exterior floor projection (chine) has an average thickness of 0.304 inch based on ten locations.

Interior Width The floor plate width is approximately 94 inches.

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

Two locations with three-plate lap welds do not meet the current API 650

5.1.5.4 requirements for weld separation.

Remove the coatings on the welds at the two locations with three-plate lap welds and perform magnetic particle testing (MT) of the welds. Advise contracting agency if cracks are observed.

MFL Floor Scan MFL of the accessible areas of the floor found no areas requiring repair.

Bottom Side Floor Pitting/Corrosion

Based on MFL and UT examination, some bottom side pitting/corrosion is present.

Backside corrosion should be vigorously checked during the next out of service inspection.

Top Side Floor Pitting/Corrosion

No pits were…