1801 R2 XI.M41

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XI.M41 BURIED AND UNDERGROUND PIPING AND TANKS

Program Description

This is a comprehensive program designed to manage the aging of the external surfaces of buried and underground piping and tanks and to augment other programs that manage the aging of internal surfaces of buried and underground piping and tanks. It addresses piping and tanks composed of any material, including metallic, polymeric, cementitious, and concrete materials. This program manages aging through preventive, mitigative, and inspection activities. It manages all applicable aging effects such as loss of material, cracking, and changes in material properties.

Depending on the material, preventive and mitigative techniques may include the material itself, external coatings for external corrosion control, the application of cathodic protection, and the quality of backfill utilized. Also, depending on the material, inspection activities may include electrochemical verification of the effectiveness of cathodic protection, non-destructive evaluation of pipe or tank wall thicknesses, hydrotesting of the pipe, and visual inspections of the pipe or tank from the exterior as permitted by opportunistic or directed excavations.

Management of aging of the internal surfaces of buried and underground piping and tanks is accomplished through the use of other aging management programs (e.g., Open Cycle Cooling Water System (AMP XI.M20), Closed Treated Water System (AMP XI.M21A), Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components (AMP XI.M38), Fuel Oil Chemistry (AMP XI.M30), Fire Water System (AMP XI.M27), or Water Chemistry (AMP XI.M2)). However, in some cases, this external surface program may be used in conjunction with the internal surface aging management programs to manage the aging of the internal surfaces of buried and underground piping and tanks. This program does not address selective leaching. The Selective Leaching of Materials (AMP XI.M33) is applied in addition to this program for applicable materials and environments.

The terms “buried” and “underground” are fully defined in Chapter IX of the GALL Report. Briefly, buried piping and tanks are in direct contact with soil or concrete (e.g., a wall penetration). Underground piping and tanks are below grade but are contained within a tunnel or vault such that they are in contact with air and are located where access for inspection is restricted.

Evaluation and Technical Basis

1. Scope of Program: This program is used to manage the effects of aging for buried and underground piping and tanks constructed of any material including metallic, polymeric, cementitious, and concrete materials. The program addresses aging effects such as loss of material, cracking, and changes in material properties. Typical systems in which buried and underground piping and tanks may be found include service water piping and components, condensate storage transfer lines, fuel oil and lubricating oil lines, fire protection piping and piping components (fire hydrants), and storage tanks. Loss of material due to corrosion of piping system bolting within the scope of this program is managed using this program. Other aging effects associated with piping system bolting are managed through the use of the Bolting Integrity Program (AMP XI.M18).

2. Preventive Actions: Preventive actions utilized by this program vary with the material of the tank or pipe and the environment (air, soil, or concrete) to which it is exposed. These actions are outlined below:

1. Preventive Actions – Buried Piping and Tanks
   1. Preventive actions for buried piping and tanks are conducted in accordance with Table 2a and its accompanying footnotes.

      Table 2a. Preventive Actions for Buried Piping and Tanks
      Material1	Coating2	Cathodic Protection4	Backfill Quality
      Titanium
      Super Austenitic Stainless8
      Stainless Steel	X3		X5, 7
      Steel	X	X	X5
      Copper	X	X	X5
      Aluminum	X	X	X5
      Cementitious or Concrete	X3		X5, 7
      Polymer			X6
      Materials classifications are meant to be broadly interpreted (e.g., all alloys of titanium that are commonly used for buried piping are to be included in the titanium category). Material categories are generally aligned with P numbers as found in the ASME Code, Section IX. Steel is defined in Chapter IX of this report. Polymer includes polymeric materials as well as composite materials such as fiberglass. When provided, coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACE RP0285-2002. Coatings are provided based on environmental conditions (e.g., stainless steel in chloride containing environments). If coatings are not provided, a justification is provided in the LRA. Cathodic protection is in accordance with NACE SP0169-2007 or NACE RP0285-2002. The system should be operated so that the cathodic protection criteria and other considerations described in the standards are met at every location in the system. The duration of deviations from these criteria should not exceed 90 days. The system monitoring interval discussed in section 10.3 of NACE SP0169-2007 may not be extended beyond one year. The equipment used to implement cathodic protection need not be qualified in accordance with 10 CFR 50, Appendix B. Backfill is consistent with SP0169-2007 section 5.2.3. The staff considers backfill that is located within 6 inches of the pipe that meets ASTM D 448-08 size number 67 to meet the objectives of SP0169-2007. For materials other than aluminum, the staff also considers the use of controlled low strength materials (flowable backfill) to meet the objectives of SP0169-2007. Backfill quality may be demonstrated by plant records or by examining the backfill while conducting the inspections conducted in program element 4 of this AMP. Backfill not meeting this standard, in either the initial or subsequent inspections, is acceptable if the inspections conducted in program element 4 of this AMP do not reveal evidence of mechanical damage to pipe coatings due to the backfill. Backfill is consistent with SP0169-2007 section 5.2.3. The staff considers backfill that is located within 6 inches of the pipe that meets ASTM D 448-08 size number 10 to meet the objectives of SP0169-2007. The staff also considers the use of controlled low strength materials (flowable backfill) to meet the objectives of SP0169-2007. Backfill quality may be demonstrated by plant records or by examining the backfill while conducting the inspections conducted in program element 4 of this AMP. Backfill not meeting this standard, in either the initial or subsequent inspections, is acceptable if the inspections conducted in program element 4 of this AMP do not reveal evidence of mechanical damage to pipe coatings due to the backfill. Backfill limits apply only if piping is coated. Super austenitic stainless steel (e.g., Al6XN or 254 SMO).

   2. Fire mains are installed in accordance with National Fire Protection Association (NFPA) Standard 24. Preventive actions for fire mains beyond those in NFPA 24 need not be provided if the system undergoes either a periodic flow test in accordance with NFPA 25 or the activity of the jockey pump (or equivalent equipment or parameter) is monitored as described in program element 4 of this AMP.
   3. When referenced, NACE SP0169-2007 is to be used in its entirety excepting Section 3, Determination of Need for External Corrosion Control. Use of Section 3 of the standard constitutes an exception to this AMP. Exceptions to the AMP related to the need for external corrosion control should include an analysis of issues such as those described in National Cooperative Highway Research Program (NCHRP) Report 408, “Corrosion of Steel Piling in Non Marine Applications and American Association of State Highway and Transportation Officials (AASHTO) Standard R 27.”
2. Preventive Actions – Underground Piping and Tanks
   1. Preventive actions for underground piping and tanks are conducted in accordance with Table 2b and its accompanying footnotes.

Table 2b. Preventive Actions for Underground Piping and Tanks
Material1	Coating2
Titanium
Super Austenitic Stainless3
Stainless Steel
Steel	X
Copper	X
Aluminum
Cementitious or Concrete
Polymer
Materials classifications are meant to be broadly interpreted (e.g., all alloys of titanium that are commonly used for buried piping are to be included in the titanium category). Material categories are generally aligned with P numbers as found in the ASME Code, Section IX. Steel is defined in chapter IX of this report. Polymer includes polymeric materials as well as composite materials such as fiberglass. When provided, coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACE RP0285-2002. A broader range of coatings may be used if justification is provided in the LRA. Super austenitic stainless steel (e.g., Al6XN or 254 SMO).

3. Parameters Monitored/Inspected: The aging effects addressed by this AMP are changes in material properties of polymeric materials, loss of material due to all forms of corrosion and, potentially, cracking due to stress corrosion cracking. Changes in material properties are monitored by manual examinations. Loss of material is monitored by visual appearance of the exterior of the piping or tank and wall thickness of the piping or tank. Wall thickness is determined by a non-destructive examination technique such as ultrasonic testing (UT). Two additional parameters, the pipe-to-soil potential and the cathodic protection current, are monitored for steel, copper, and aluminum piping and tanks in contact with soil to determine the effectiveness of cathodic protection systems and, thereby, the effectiveness of corrosion mitigation.

4. Detection of Aging Effects: Methods and frequencies used for the detection of aging effects vary with the material and environment of the buried and underground piping and tanks. These methods and frequencies are outlined below.

1. Opportunistic Inspections
   1. All buried and underground piping and tanks, regardless of their material of construction, are inspected by visual means whenever they become accessible for any reason. The information in paragraph f of this program element is applied in the event deterioration of piping or tanks is observed.
2. Directed Inspections – Buried Pipe
   1. Directed inspections for buried piping are conducted in accordance with Table 4a and its accompanying footnotes. Modifications to this table may be appropriate if exceptions to program Element 2, Preventive Actions, are taken or in response to plant specific operating experience.
   2. Unless otherwise indicated, directed inspections as indicated in Table 4a will be conducted during each 10-year period beginning 10 years prior to the entry into the period of extended operation.
   3. Inspection locations are selected based on risk (based on susceptibility to degradation and consequences of failure). Characteristics such as coating type, coating condition, cathodic protection efficacy, backfill characteristics, soil resistivity, pipe contents, and pipe function are considered. Piping systems that are backfilled using controlled low strength material generally experience lower corrosion rates and may be more difficult to excavate than piping systems backfilled using compacted aggregate fill. As a result, piping systems that are backfilled using compacted aggregate should generally be given a higher inspection priority than comparable systems that are completely backfilled using controlled low strength material. For many piping systems, External Corrosion Direct Assessment (ECDA) as described in NACE Standard Practice SP0502-2010 has been demonstrated to be an effective method for use in the identification of pipe locations that merit further inspection.
   4. Visual inspections are supplemented with surface and/or volumetric non-destructive testing (NDT) if significant indications are observed.
   5. Opportunistic examinations of non leaking pipes may be credited toward these direct examinations if the location selection criteria in item iii, above, are met.
   6. At multi-unit sites, individual inspections of shared piping may be credited for only one unit.
   7. Visual inspections for polymeric materials are augmented with manual examinations to detect hardening, softening, or other changes in material properties.
   8. The use of guided wave ultrasonic or other advanced inspection techniques is encouraged for the purpose of determining those piping locations that should be inspected but may not be substituted for the inspections listed in the table.
   9. For the purpose of this program element, fire mains will be considered to be code class/safety-related piping and inspected as such unless they are subjected to either a flow test as described in section 7.3 of NFPA 25 at a frequency of at least one test in each 1-year period or the activity of the jockey pump (or equivalent equipment or parameter) is monitored on an interval not to exceed 1 month. At a minimum, a flow test is conducted by the end of the next refueling outage or as directed by current licensing basis, whichever is shorter, when unexplained changes in jockey pump activity (or equivalent equipment or parameter) are observed.
   10. Inspection as indicated in either (A) or (B) below may be performed in lieu of the inspections contained in Table 4a for either code class/safety significant or hazmat piping or both:
       1. At least 25% of the code class/safety-related or hazmat piping or both constructed from the material under consideration is hydrostatically tested in accordance with 49 CFR 195 subpart E on an interval not to exceed 5 years.
       2. At least 25% of the code class/safety-related or hazmat piping or both constructed from the material under consideration is internally inspected by a method capable of precisely determining pipe wall thickness. The inspection method must be capable of detecting both general and pitting corrosion and must be qualified by the applicant and approved by the staff. As of the effective date of this document, guided wave ultrasonic examinations do not meet this paragraph. Internal inspections are to be conducted at an interval not to exceed 5 years. Consideration should be given to NACE SP0169-2007 sections 6.1.2 and 6.3.3.

   Table 4a. Inspections of Buried Pipe
   Material1	Preventive Actions2	Inspections3
   		Code Class Safety-related4	Hazmat5
   Titanium
   Super Austenitic Stainless7
   Stainless Steel		16	16
   HDPE8	A B	16 2	16 1%
   Other Polymer9	A B	16 2	16 1%
   Cementitious or Concrete		16	16
   Steel	C D E F	16 1 410 8	16 2% 5%10 10%
   Copper	C D E F	16 1 110 2	16 1% 2%10 5%
   Aluminum	C D E F	16 1 1 2	16 2%10 5% 10%
   Materials classifications are meant to be broadly interpreted (e.g., all alloys of titanium that are commonly used for buried piping are to be included in the titanium category). Material categories are generally aligned with P numbers as found in the ASME Code, Section IX. Steel is defined in chapter IX of this report. Polymer includes polymeric materials as well as composite materials such as fiberglass. Preventive actions are categorized as follows: Backfill is in accordance with Table 2a of this AMP. Backfill is not in accordance with Table 2a of this AMP. External corrosion control is provided in accordance with NACE SP0169-2007. Each cathodic protection system (a) was installed at least 5 years prior to the period of extended operation and was operational for 90% of the time during that 5-year period or (b) was operational for 90% of the time since the last inspection conducted under this program. External corrosion control is provided in accordance with NACE SP0169-2007. Each cathodic protection system (a) was installed less than 5 years prior to the period of extended operation or was operational for less than 90% of the time during that 5-year period or (b) was operational for less than 90% of the time since the last inspection conducted under this program. Coatings and backfill are in accordance with Table 2a of this AMP, but cathodic protection is not provided or is not consistent with criteria C or D. This category is provided for use during the 10 years prior to the period of extended operation by applicants who are not able to install cathodic protection in accordance with program element 2 prior to entry into the period of extended operation. Following entry into the period of extended operation, consistency with program element 2 or an approved alternative is expected. Preventive actions provided do not meet criteria C, D, or E. This category is provided for use during the 10 years prior to the period of extended operation by applicants who are not able to install cathodic protection in accordance with program element 2 prior to entry into the period of extended operation. Following entry into the period of extended operation, consistency with program element 2 or an approved alternative is expected. Inspections are listed as either a discrete number of visual examinations (excavations) or as a percentage of the linear length of piping under consideration. The following guidance related to the extent of inspections is provided: Each inspection will examine either the entire length of a run of pipe or a minimum of 10 feet. If the number of inspections times the minimum inspection length (10 feet) exceeds 10% of the length of the piping under consideration, only 10% need be inspected. If the total length of in-scope pipe constructed of a given material times the percentage to be inspected is less than 10 feet, either 10 feet or the total length of pipe present, whichever is less, will be inspected. Code Class and safety-related pipe that also meets the definition of hazmat pipe will be inspected as hazmat pipe. Hazmat pipe is pipe that, during normal operation, contains material that, if released, could be detrimental to the environment. This includes chemical substances such as diesel fuel and radioisotopes. To be considered hazmat, the concentration of radioisotopes within the pipe during normal operation must exceed established standards such as the EPA drinking water standard. In the absence of such standards, the concentration of the radioisotope must exceed the greater of background or reliable level of detection. For tritium, the EPA drinking water standard (20,000 pCi/L) is used. (This approach for defining hazmat is consistent with that used in classifying fluid services in ASME B31.3 appendix M.) Only one inspection is conducted even if both Code Class/safety-related and hazmat pipe are present. No inspections are necessary if all the piping constructed from the material under consideration is fully backfilled using controlled low strength material. Super austenitic stainless steel (e.g., Al6XN or 254 SMO). High Density Polyethylene (HDPE) pipe includes only HDPE pipe approved for use by the NRC for buried applications. Other polymer piping includes some HDPE pipe and all other polymeric materials including composite materials such as fiberglass. Inspections may be reduced to one-half the level indicated in the table when performing the indicated inspections necessitates excavation of piping that has been fully backfilled using controlled low strength material. In conducting these inspections, the backfill may be excavated and the pipe examined, or the soil around the backfill may be excavated and the controlled low strength material backfill examined. The corrosion rate of piping that is fully encased within controlled low strength material backfill that shows no signs of degradation, particularly cracking, is expected to be minimal.

3. Directed Inspections – Underground Pipe
   1. Directed inspections for underground piping are conducted in accordance with Table 4b and its accompanying footnotes.
   2. Unless otherwise indicated, directed inspections as indicated in Table 4b will be conducted during each 10-year period beginning 10 years prior to the entry into the period of extended operation.
   3. Inspection locations are selected based on risk (based on susceptibility to degradation and consequences of failure). Characteristics such as coating type, coating condition, exact external environment, pipe contents, pipe function, and flow characteristics within the pipe, are considered.
   4. Underground pipes are inspected visually to detect external corrosion and by a volumetric technique such as UT to detect internal corrosion.
   5. Opportunistic examinations may be credited toward these direct examinations if the location selection criteria in item iii, above, are met.
   6. At multi-unit sites, individual inspections of shared piping may be credited for only one unit.
   7. When access permits, visual inspections for polymeric materials are augmented with manual examinations to detect hardening, softening, or other changes in material properties.
   8. The use of guided wave ultrasonic or other advanced inspection techniques is encouraged for the purpose of determining those piping locations that should be inspected but may not be substituted for the inspections listed in the table.
   9. For the purpose of this program element, fire mains will be considered to be code class/safety-related piping and inspected as such unless they are subjected to either a flow test as described in section 7.3 of NFPA 25 at an frequency of at least one test in each 1-year period or the activity of the jockey pump (or equivalent equipment or parameter) is monitored on an interval not to exceed 1 month. At a minimum, a flow test is conducted by the end of the next refueling outage or as directed by current licensing basis, whichever is shorter, when unexplained changes in jockey pump activity (or equivalent equipment or parameter) are observed.

      Table 4b. Inspections of Underground Pipe
      Material1	Inspections2
      	Code Class Safety-related3	Hazmat4
      Titanium
      Super Austenitic Stainless6
      Stainless Steel	15	15
      HDPE7	15	15
      Other Polymer8	15	15
      Cementitious or Concrete	15	15
      Steel	2	2%
      Copper	1	1%
      Aluminum	1	1%
      Materials classifications are meant to be broadly interpreted (e.g., all alloys of titanium that are commonly used for buried piping are to be included in the titanium category). Material categories are generally aligned with P numbers as found in the ASME Code, Section IX. Steel is as defined in chapter IX of this report. Polymer includes polymeric materials as well as composite materials such as fiberglass. Inspections are listed as either a discrete number of visual examinations or as a percentage of the linear length of piping under consideration. The following guidance related to the extent of inspections is provided: Each inspection will examine either the entire length of a run of pipe or a minimum of 10 feet. If the number of inspections times the minimum inspection length (10 feet) exceeds 10% of the length of the piping under consideration, only 10% need be inspected. If the total length of in scope pipe constructed of a given material times the percentage to be inspected is less than 10 feet, either 10 feet or the total length of pipe present, whichever is less, will be inspected. Code Class and safety-related pipe that also meets the definition of hazmat pipe will be inspected as hazmat pipe. Hazmat pipe is pipe that, during normal operation, contains material that, if released, could be detrimental to the environment. This includes chemical substances such as diesel fuel and radioisotopes. To be considered hazmat, concentration of radioisotope within the pipe during normal operation must exceed established standards such as the EPA drinking water standard. In the absence of such standards, the concentration of the radioisotope must exceed the greater of background or reliable level of detection. For tritium, the EPA drinking water standard (20,000 pCi/L) is used. (This approach for defining hazmat is consistent with that used in classifying fluid services in ASME B31.3 appendix M.) Only one inspection is conducted even if both Code Class/safety-related and hazmat pipe are present. Super austenitic stainless steel (e.g., Al6XN or 254 SMO). HDPE pipe includes only HDPE pipe approved for use by the US NRC for buried applications. Other polymer piping includes some HDPE pipe and all other polymeric materials including composite materials such as fiberglass.

   10. Inspection as indicated in (A), and (B) below may be performed in lieu of the inspections contained in Table 4a for either code class/safety significant or hazmat piping or both:
       1. At least 25% of the code class/safety-related or hazmat piping or both constructed from the material under consideration is hydrostatically tested in accordance with 49 CFR 195 subpart E on an interval not to exceed 5 years.
       2. At least 25% of the code class/safety-related or hazmat piping or both constructed from the material under consideration is internally inspected by a method capable of precisely determining pipe wall thickness. The inspection method must be capable of detecting both general and pitting corrosion and must be qualified by the applicant and approved by the staff. As of the effective date of this document, guided wave ultrasonic examinations do not meet this paragraph. Internal inspections are to be conducted at an interval not to exceed 5 years. Consideration should be given to SP0169-2007 sections 6.1.2 and 6.3.3.
4. Directed Inspections – Buried Tanks
   1. Directed inspections for buried tanks are conducted in accordance with Table 4c and its accompanying footnotes. Modifications to this table may be appropriate if exceptions to program Element 2, preventive actions, are taken or in response to plant specific operating experience.
   2. Directed inspections as indicated in Table 4c will be conducted during each 10-year period beginning 10 years prior to the entry into the period of extended operation.
   3. Each buried tank is examined if it is Code Class/safety-related or contains hazardous materials as defined in footnote 5 to Table 4a and it is constructed from a material for which an examination is indicated in Table 4c.
   4. Examinations may be conducted from the external surface of the tank using visual techniques or from the internal surface of the tank using volumetric techniques. If the tank is inspected from the external surface, a minimum 25% coverage is required. This area must include at least some of both the top and bottom of the tank. If the tank is inspected internally by UT, at least one measurement is required per square foot of tank surface. UT measurements are distributed uniformly over the surface of the tank. If the tank is inspected internally by another volumetric technique, at least 90% of the surface of the tank must be inspected. Double wall tanks may be examined by monitoring the annular space for leakage.
   5. Visual inspections for polymeric materials are augmented with manual examinations to detect hardening, softening, or other changes in material properties.
   6. Opportunistic examinations may be credited toward these direct examinations.

   Table 4c. Inspections of Buried Tanks
   Material1	Preventive Actions2	Inspections
   Titanium
   Super Austenitic Stainless3
   Stainless Steel
   HDPE4	A B	X
   Other Polymer5	A B	X
   Cementitious or Concrete		X
   Steel	C D E	X
   Copper	C D E	X
   Aluminum	C D E	X
   Materials classifications are meant to be broadly interpreted (e.g., all alloys of titanium that are commonly used for buried piping are to be included in the titanium category). Material categories are generally aligned with P numbers as found in the ASME Code, Section IX. Steel is defined in chapter IX of this report. Polymer includes polymeric materials as well as composite materials such as fiberglass. Preventive actions are categorized as follows: Backfill is in accordance with Table 2a of this AMP. Backfill is not in accordance with Table 2a of this AMP. External corrosion control is provided in accordance with NACE RP0285-2002. Each cathodic protection system (a) was installed at least 5 years prior to the period of extended operation and was operational for 90% of the time during that 5-year period or (b) was operational for 90% of the time since the last inspection conducted under this program. External corrosion control is provided in accordance with NACE RP0285-2002. Each cathodic protection system (a) was installed less than 5 years prior to the period of extended operation or was operational for less than 90% of the time during that 5-year period or (b) was operational for less than 90% of the time since the last inspection conducted under this program. Cathodic protection is not provided. This category is provided for use during the 10 years prior to the period of extended operation by applicants who are not able to install cathodic protection in accordance with program element 2 prior to entry into the period of extended operation. Following entry into the period of extended operation, consistency with program element 2 or an approved alternative is expected. Super austenitic stainless steel (e.g., Al6XN or 254 SMO). HDPE includes only HDPE material approved for use by the US NRC for buried applications. Other polymer includes some HDPE material and all other polymeric materials including composite materials such as fiberglass.

5. Directed Inspections – Underground Tanks
   1. Directed inspections for underground tanks are conducted in accordance with Table 4d and its accompanying footnotes.
   2. Directed inspections as indicated in Table 4d will be conducted during each 10-year period beginning 10 years prior to the entry into the period of extended operation.

      Table 4d. Inspections of Underground Tanks
      Material1	Inspections
      Titanium
      Super Austenitic Stainless2
      Stainless Steel
      HDPE3
      Other Polymer4
      Cementitious or Concrete
      Steel	X
      Copper
      Aluminum
      Materials classifications are meant to be broadly interpreted (e.g., all alloys of titanium that are commonly used for buried piping are to be included in the titanium category). Material categories are generally aligned with P numbers as found in the ASME Code, Section IX. Steel is as defined in chapter IX of this report. Polymer includes polymeric materials as well as composite materials such as fiberglass. Super austenitic stainless steel (e.g., Al6XN or 254 SMO). HDPE includes only HDPE material approved for use by the US NRC for buried applications. Other polymer includes some HDPE material and all other polymeric materials including composite materials such as fiberglass.

   3. Each underground tank that is Code Class/safety-related or contains hazardous materials as defined in footnote 5 to Table 4a and is constructed from a material for which an examination is indicated in Table 4d is examined.
   4. Examinations may be conducted from the external surface of the tank using visual techniques or from the internal surface of the tank using volumetric techniques. If the tank is inspected from the external surface, a minimum 25% coverage is required. This area must include at least some of both the top and bottom of the tank. If the tank is inspected internally by UT, at least one measurement is required per square foot of tank surface. If the tank is inspected internally by another volumetric technique, at least 90% of the surface of the tank must be inspected. Double wall tanks may be examined by monitoring the annular space for leakage.
   5. Tanks that cannot be examined using volumetric examination techniques are examined visually from the outside.
   6. When access permits, visual inspections for polymeric materials are augmented with manual examinations to detect hardening, softening, or other changes in material properties.
   7. Opportunistic examinations may be credited toward these direct examinations.
6. Adverse indications
   1. Adverse indications observed during monitoring of cathodic protection systems or during inspections are entered into the plant corrective action program. Adverse indications that are the result of inspections will result in an expansion of sample size as described in item iv, below. Adverse indications that are the result of monitoring of a cathodic protection system may warrant increased monitoring of the cathodic protection system and/or additional inspections. Examples of adverse indications resulting from inspections include leaks, material thickness less than minimum, the presence of coarse backfill with accompanying coating degradation within 6 inches of a coated pipe or tank (see Table 2a Footnotes 5 and 6), and general or local degradation of coatings so as to expose the base material.
   2. Adverse indications that fail to meet the acceptance criteria described in program element 6 of this AMP will result in the repair or replacement of the affected component.
   3. An analysis may be conducted to determine the potential extent of the degradation observed. Expansion of sample size may be limited by the extent of piping or tanks subject to the observed degradation mechanism.
   4. If adverse indications are detected, inspection sample sizes within the affected piping categories are doubled. If adverse indications are found in the expanded sample, the inspection sample size is again doubled. This doubling of the inspection sample size continues as necessary.

5. Monitoring and Trending: For piping and tanks protected by cathodic protection systems, potential difference and current measurements are trended to identify changes in the effectiveness of the systems and/or coatings. If aging of fire mains is managed through monitoring jockey pump activity (or similar parameter), jockey pump activity (or similar parameter) is trended to identify changes in pump activity that may be the result of increased leakage from buried fire main piping.

6. Acceptance Criteria: The principal acceptance criteria associated with the inspections contained with this AMP follow:

1. Criteria for soil-to-pipe potential are listed in NACE RP0285-2002 and SP0169-2007.
2. For coated piping or tanks, there should be either no evidence of coating degradation or the type and extent of coating degradation should be insignificant as evaluated by an individual possessing a NACE operator qualification or otherwise meeting the qualifications to evaluate coatings as contained in 49 CFR 192 and 195.
3. If coated or uncoated metallic piping or tanks show evidence of corrosion, the remaining wall thickness in the affected area is determined to ensure that the minimum wall thickness is maintained. This may include different values for large area minimum wall thickness, and local area wall thickness.
4. Cracking or blistering of nonmetallic piping is evaluated.
5. Cementitious or concrete piping may exhibit minor cracking and spalling provided there is no evidence of leakage or exposed rebar or reinforcing “hoop” bands.
6. Backfill is in accordance with specifications described in program element 2 of this AMP.
7. Flow test results for fire mains are in accordance with NFPA 25 section 7.3.
8. For hydrostatic tests, the condition “without leakage” as required by 49 CFR 195.302 may be met by demonstrating that the test pressure, as adjusted for temperature, does not vary during the test.
9. Changes in jockey pump activity (or similar parameter) that cannot be attributed to causes other than leakage from buried piping are not occurring.

7. Corrective Actions: The site corrective actions program, quality assurance (QA) procedures, site review and approval process, and administrative controls are implemented in accordance with the requirements of 10 CFR 50, Appendix B. The staff finds the requirements of 10 CFR 50, Appendix B, acceptable to address the corrective actions, confirmation process, and administrative controls.

8. Confirmation Process: The confirmation process ensures that preventive actions are adequate to manage the aging effects and that appropriate corrective actions have been completed and are effective. The confirmation process for this program is implemented through the site's QA program in accordance with the requirements of 10 CFR 50, Appendix B.

9. Administrative Controls: The administrative controls for this program provide for a formal review and approval of corrective actions. The administrative controls for this program are implemented through the site's QA program in accordance with the requirements of 10 CFR 50, Appendix B.

10. Operating Experience: Operating experience shows that buried and underground piping and tanks are subject to corrosion. Corrosion of buried oil, gas, and hazardous materials pipelines have been adequately managed through a combination of inspections and mitigative techniques, such as those prescribed in NACE SP0169-2007 and NACE RP0285-2002. Given the differences in piping and tank configurations between transmission pipelines and those in nuclear facilities, it is necessary for applicants to evaluate both plant-specific and nuclear industry operating experience and to modify its aging management program accordingly. The following industry experience may be of significance to an applicant’s program:

1. In February 2005, a leak was detected in a 4-inch condensate storage supply line. The cause of the leak was microbiologically influenced corrosion or under deposit corrosion. The leak was repaired in accordance with the American Society of Mechanical Engineers (ASME) Section XI, “Repair/Replacement Plan.”
2. In September 2005, a service water leak was discovered in a buried service water header. The header had been in service for 38 years. The cause of the leak was either failure of the external coating or damage caused by improper backfill. The service water header was relocated above ground.
3. In October 2007, degradation of essential service water piping was reported. The riser pipe leak was caused by a loss of pipe wall thickness due to external corrosion induced by the wet environment surrounding the unprotected carbon steel pipe. The corrosion processes that caused this leak affected all eight similar locations on the essential service water riser pipes within vault enclosures and had occurred over many years.
4. In February 2009, a leak was discovered on the return line to the condensate storage tank. The cause of the leak was coating degradation probably due to the installation specification not containing restrictions on the type of backfill allowing rocks in the backfill. The leaking piping was also located close to water table.
5. In April 2009, a leak was discovered in an aluminum pipe where it went through a concrete wall. The piping was for the condensate transfer system. The failure was caused by vibration of the pipe within its steel support system. This vibration led to coating failure and eventual galvanic corrosion between the aluminum pipe and the steel supports.
6. In June 2009, an active leak was discovered in buried piping associated with the condensate storage tank. The leak was discovered because elevated levels of tritium were detected. The cause of the through-wall leaks was determined to be the degradation of the protective moisture barrier wrap that allowed moisture to come in contact with the piping resulting in external corrosion.

References

10 CFR Part 50, Appendix B, Quality Assurance Criteria for Nuclear Power Plants, Office of the Federal Register, National Archives and Records Administration, 2009.

49 CFR 195 subpart E, Transportation of Hazardous Liquids by Pipeline, Pressure Testing. Office of the Federal Register, National Archives and Records Administration, 2009.

AASHTO R 27, Standard Practice for Assessment of Corrosion of Steel Piling for Non Marine Applications, American Association of State Highway and Transportation Officials, Washington DC, 2006.

ASME Boiler and Pressure Vessel Code, Section IX, Welding and Brazing, American Society of Mechanical Engineers, 2004.

ASME Standard B31.3, Process Piping, Appendix M, American Society of Mechanical Engineers, 2002.

ASTM Standard D 448-08, Standard Classification for Sizes of Aggregate for Road and Bridge Construction, 2008.

J. A. Beavers and C. L. Durr, Corrosion of Steel Piping in Non Marine Applications, NCHRP Report 408, Transportation Research Board, National Research Council, Washington DC, 1998.

NACE Recommended Practice RP0285-2002, Standard Recommended Practice Corrosion Control of Underground Storage Tank Systems by Cathodic Protection, revised April 2002.

NACE Recommended Practice RP0502-2010, Pipeline External Corrosion Direct Assessment Methodology, 2010.

NACE Standard Practice SP0169-2007, Control of External Corrosion on Underground or Submerged Metallic Piping Systems, 2007.

NFPA Standard 24, Standard for the Installation of Private Fire Service Mains and Their Appurtenances, 2010 edition.

NFPA Standard 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, 2008 edition.

American Society of Mechanical Engineers

Ultrasonic Test - A nondestructive test method using ultrasonic waves to determine the thickness of a component and to detect cracks or other degradation.

Aging Management Program

Nuclear Regulatory Commission - The US federal government agency that regulates nuclear power plants

United States of America

Code of Federal Regulations - The US federal government regulations. 10 CFR 54 is the regulation for renewal of nuclear power plant operating licenses.

Quality Assurance