Formal External Inspection Guidelines Amendment 0003.docx

1 FORMAL EXTERNAL INSPECTION (FEI) GUIDELINES – FOR REFERENCE

1.1 General

1.1.8.1 Visually inspect the general condition of the containment area to ensure that it is in good condition and that there is not a breach in the containment structure. Note changes from the original design and installation information if available.

1.1.8.2 Inspect for foreign materials in the containment area. Inspect for liquid in the containment system and CRDM. If liquid is present, find the source and report findings. Record other ASTs or containers within the same containment area.

1.1.8.3 Verify that the drain valves are operable and in good condition. Report penetrations through the secondary containment that may compromise the integrity of the containment area. Report penetrations that are likely to lead to failure of the secondary containment should the liquid level of water or liquid rise to these penetrations.

1.1.9 Inspect and verify the operability of ancillary equipment, including the following items:

1.1.9.1 Visually inspect accessible piping, piping supports and piping connections for signs of stress or leakage, due to severe corrosion, rusted bolted connections, or other severe degradation.

1.1.9.2 Inspect normal and emergency vents and pressure/vacuum devices. Verify that the devices are of adequate size and capacity, operable, and in good condition. Refer to the device manufacturer’s literature, typical industry venting requirements, and other appropriate resources. Record the types and locations of these devices.

1.1.9.3 Inspect primary tank level gauge and secondary tank interstitial gauge for free movement and determine if the floats, guides, and attachments are in working order. Verify the liquid level gauge length is sized correctly for the tank diameter.

1.1.9.4 Inspect the secondary tank interstitial monitoring equipment where present. Where possible verify free movement of floats and attachments and external alarms. Note that prior to triggering any alarm, proper warnings need to be made to the tank owner.

1.1.9.5 Verify and inspect tank overfill prevention devices including high level alarms and high level shut off valves. It may not be possible to verify operability of all devices, but where possible verify equipment is functional and calibrated to the appropriate liquid levels within the tank.

1.1.10 Inspect the bonding and grounding system of the AST, if present. (Refer to NFPA 780 Standard for the Installation of Lightning Protection Systems, NFPA 77 Standard Practice on Static Electricity or other applicable standard.)

1.2 Determine the original shell thickness of the AST. Suggested methods are:

1.3 Horizontal AST Requirements - in addition to the applicable items in 1.1:

1.3.1.2 Existence of external corrosion may require the use of a pit depth measurement device in addition to the UTT to determine the remaining wall thickness.

1.3.2 Inspect shell attachments for changes made after the AST was fabricated. Refer to previous drawings or make new sketches that show all the appurtenances, attachments, and nozzle locations on the AST shell and heads or roof. Record repads (reinforcing plates) and/or insert plates. Inspect attachment welds for signs of stress and corrosion.

1.4 Vertical or Rectangular AST Requirements - in addition to the applicable items in 1.1:

measure thicknesses in previously measured areas for corrosion rate determination. If significant corrosion is detected, further investigation using ultrasonic testing scans (UTS) is required. Refer to Section 10.0 of STI SP001.

1.5 Double-wall and Double-bottom AST Requirements - in addition to the applicable items in 1.1:

1.6 Steel Diked AST Requirements - in addition to the applicable items in 1.1 to 1.4:

1.7 Insulated AST Requirements - in addition to the applicable items in 7.1 through 7.4, except as modified below:

1.7.1 Inspect the insulation material and outer jacket for indications of damage where water may be allowed to wick into the insulating layer. Specifically inspect for areas where water may be trapped behind or within the insulation. If any of the following conditions are identified, then remove sections of the insulation to check for corrosion:

· Evidence that the tank may be compromised,

· Evidence that the base of the tank is consistently in contact with standing water, or

· Insulation is significantly compromised and has not been repaired or replaced in a timely manner

1.8 Concrete Exterior ASTs (CE-ASTs) Requirements - in addition to the applicable items in 1.1:

· Cracks larger than 1/16 of an inch in thickness require repair.

· If cracks greater than 1/16 of an inch are present on all four top chamfer edges, then the tank shall be further evaluated and repaired in consultation with the tank manufacturer, due to the possibility of damage or over-pressurization of the secondary containment.

1.9 Additional requirements for field-erected ASTs are included in Appendix B of STI SP001.

1.10 In the final report, include field data, measurements, pictures, drawings, tables, and an inspection summary. In the summary, identify unacceptable conditions and recommended and/or mandatory corrective actions. Determine the suitability for continued service of the AST per Section 10.0 of STI SP001 and document this in the final report. Include the date of the next scheduled FEI or FII, as applicable. Include the inspector’s name and certification number in the report.