NOC-AE-16003385, 2016 Annual Update to the License Renewal Application

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2016 Annual Update to the License Renewal Application
ML16190A135
Person / Time
Site: South Texas  STP Nuclear Operating Company icon.png
Issue date: 06/28/2016
From: Connolly J
South Texas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-16003385, STI: 34331944, TAC ME4936, TAC ME4937
Download: ML16190A135 (35)
v • d • e


Text

South Texas Project Electric Generating Station P.O. Box 289 Wadsworth, Texas 77483 June 28, 2016 NOC-AE-16003385 10 CFR 54 File: G25 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Units 1and2 Docket Nos. STN 50-498, STN 50-499 2016 Annual Update to the South Texas Project License Renewal Application (TAC NOS. ME4936 and ME4937)

References:

1) STPNOC Letter from G. T. Powell to NRC Document Control Desk, "License Renewal Application", dated October 25, 2010 (NOC-AE-10002607)

(ML103010257)

2) STPNOC Letter from James W. Connolly to NRC Document Control Desk, "Request for Additional Information Set 35 for the Review of the South Texas Project, Units 1 and 2, License Renewal Application", dated May 19, 2016 (NOC-AE-16003380) (ML16154A065)

By Reference 1, STP Nuclear Operating Company (STPNOC) submitted an application to the Nuclear Regulatory Commission (NRC) for the renewal of Facility Operating Licenses NPF-76 and NPF-80, for South Texas Project (STP) Units 1 and 2, respectively. The application included the License Renewal Application (LRA), and the Applicant's Environmental Report -

Operating License Renewal Stage. As required by 10 CFR 54.21(b), each year following submittal of the LRA, an amendment to the LRA must be submitted that identifies any change to the current licensing basis (CLB) that materially affects the contents of the LRA, including the Updated Final Safety Analysis Report (UFSAR) supplement.

This LRA update covers the period from September 1, 2015 through June 29, 2016. A review was performed on the changes to the CLB, completed plant enhancements, and LRA commitments to evaluate if there have been any changes that materially affects the contents of the LRA. Enclosure 1 of this submittal captures the changes to the affected contents of the LRA. Enclosure 2 provides supplemental information for RAI 82.1.18-6 response in Reference

2. Enclosure 3 includes the Line-in/Line-out annotations associated with the changes and supplemental information. Enclosure 4 contains the revisions to the regulatory commitments related to these changes and supplemental information.

Regulatory commitment items 13 and 24 in LRA Table A4-1 have been revised as provided in . There are no other commitments in this letter.

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STI: 34331944

NOC-AE-16003385 Page 2 of 3 Should you have any questions regarding this letter, please contact Rafael Gonzales, STP License Renewal Project regulatory point-of-contact, at 361-972-4779.

I declare under penalty of perjury that the foregoing is true and correct.

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Date '

~o ames Connolly Site Vice President rjg

Enclosures:

1) Changes to the affected contents of the LRA
2) Supplemental Information for RAI 82.1.18-6 response dated May 19, 2016
3) STPNOC LRA Changes with Line-in/Line-out Annotations
4) STPNOC Revision of Regulatory Commitments

NOC-AE-16003385 Page 3 of 3 cc:

(paper copy) (electronic copy)

Regional Administrator, Region IV Morgan, Lewis & Beckius LLP U.S. Nuclear Regulatory Commission Steve Frantz, Esquire 1600 East Lamar Boulevard Arlington, TX 76011-4511 U.S. Nuclear Regulatory Commission Lisa M. Regner Lois James Lisa M. Regner Tam Tran Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (08H04) NRG South Texas LP 11555 Rockville Pike Chris O'Hara Rockville, MD 20852 Jim van Suskil Skip Zahn Lois James License Renewal Project Manager (Safety) CPS Energy One White Flint North (MS 011-F1) Kevin Pollo U.S. Nuclear Regulatory Commission Cris Eugster Washington, DC 20555-0001 L. D. Blaylock Crain Caton & James, P.C.

Tam Tran Peter Nemeth License Renewal Project Manager (Environmental)

One White Flint North (MS 011 F01) City of Austin U. S. Nuclear Regulatory Commission Elaina Ball Washington, DC 20555-0001 John Wester NRC Resident Inspector Texas Dept. of State Health Services U.S. Nuclear Regulatory Commission Helen Watkins P. 0. Box 289, Mail Code: MN116 Robert Free Wadsworth, TX 77483

NOC-AE-16003385 Enclosure 1 Changes to the affected contents of the LRA

NOC-AE-16003385 Enclosure 1 Page 1 of 1 Per STPNOC's request, the NRC issued Amendment No. 210 to Facility Operating License No. NPF-76 and Amendment No. 197 to Facility Operating License No. NPF-80 for the South Texas Project, Units 1 and 2, respectively. These amendments consist of changes to Technical Specification section 6.8.3.j, "Containment Leakage Rate Testing Program," to allow a permanent extension of Type A primary containment integrated leak rate testing frequency from once every 10 years to once every 15 years. , Appendix A1 .30 and 82.1.30, contains the LRA Changes with Line-in/Line-out Annotations to reflect the respective change.

NOC-AE-16003385 Enclosure 2 Supplemental Information for RAI 82.1.18-6 response dated May 19, 2016

NOC-AE-16003385 Enclosure 2 Page 1 of 1 RAI 82.1.18-6

Background:

Supplemental information is required to LRA Section B2.1.18, "Buried Piping and Tanks Inspection Program," and LRA Section A 1.18 (associated UFSAR Summary Description) to clarify the changes to AMP Xl.M41 and the UFSAR Summary Description in LR-ISG-2011-03. STP response to the final version of LR-ISG-2015-01, "Changes to Buried and Underground Piping and Tank Recommendations."

Issue:

In its response to RAI B2.1.18-6 dated May 19, 2016, the applicant did not provide evidence that it will utilize, as recommended in the "parameters monitored or inspected" program element a method that has been demonstrated to be capable of detecting cracking. AMP Xl.M41 recommends that inspections for cracking are conducted when coating degradation has been noted. Given that the buried stainless steel piping is not coated, it is not clear to the staff why inspections for cracking would not be conducted when buried stainless steel piping is inspected as recommended by the "detection of aging effects" program element of AMP Xl.M41. The=

applicant stated that soil samples have demonstrated that there are no environmental chlorides; however, the purpose of inspections is to verify that degradation is not occurring. ,.,

Neither the "acceptance criteria" program element nor "corrective actions" program element state that the measured wall thickness will be extrapolated to the end of the period of extended operation in order for the component to meet acceptance criteria and to not conduct expanded inspections. In addition, the "corrective actions" program element does not state that: (a) unacceptable cathodic protection survey results are entered into the plant corrective action program; (b) sources of leakage detected during pressure tests are identified and corrected; and (c) indications of cracking are evaluated in accordance with applicable codes and plant-specific design criteria.

The staff noted the LRA Section A 1.18 does not state that the number of inspections is based on the effectiveness of the preventive and mitigative actions. In addition, it does not state that where the coatings, backfill or the condition of exposed piping does not meet acceptance criteria such that the depth or extent of degradation of the base metal could have resulted in a loss of pressure boundary function when the loss of material rate is extrapolated to the end of the period of extended operation, an increase in the sample size is conducted.

STPNOC Supplemental information:

LRA Appendix A 1.18, Appendix B2.1.18, Table A4-1 and LR Basis Document AMP Xl.M34, Buried Piping and Tanks Inspection, are updated to add clarification information. provides the line-in/line-out revision to LRA Appendix A 1.18 and Appendix B2.1.18. provides the line-in/line-out revision to LRA Table A4-1.

NOC-AE-16003385 Enclosure 3 STPNOC LRA Changes with Line-in/Line-out Annotations Affected LRA Section Appendix A 1.18 Appendix A 1.30 Appendix 82.1.18 Appendix 82.1.30

NOC-AE-16003385 Enclosure 3 Page 1 of 18 A1.18 Buried Piping and Tanks Inspection The Buried Piping and Tanks Inspection program manages the loss of material on external surfaces of buried and underground components. Preventive and mitigative measures, including verification of coatings quality, backfill requirements, and cathodic protection, are employed to manage aging of buried components. Underground components are protectively

  • coated where required.

The cathodic protection system is operated consistent with the guidance of NACE SP0169-2007 for piping and is monitored to ensure that protection is being provided. The cathodic protection system is operational (available) at least 85 percent of the time and provides effective protection for buried piping as evidenced by meeting the acceptance criteria at least 80 percent of the time since either 1O years prior to the period of extended operation or since installation or refurbishment, whichever is shorter. An annual cathodic protection survey is performed consistent with NACE SP0169-2007. If the cathodic protection system fails to meet the acceptance criteria of -850 mV relative to copper/copper sulfate reference electrode (CSE) instant off for steel components alternatives of -750 mV or -650 mV may be used, means to verify the effectiveness of the protection are used, loss of material rates are measured and soil testing will be conducted at a minimum of once in each 10-year period starting 10 years prior to the period of extended operation. The acceptance criterion for copper components is 100 mV minimum polarization.

Opportunistic and directed visual inspections will monitor the condition of external surfaces, protective coatings and wrappings found on steel, stainless steel and copper alloy components.

The number of inspections is based on the effectiveness of the preventive and mitigative actions. Any evidence of damaged wrapping or coating defects will be an indicator of possible corrosion damage to the external surface of the components. Inspections are conducted by qualified individuals.

Where the coatings, backfill or the condition of exposed piping does not meet acceptance ~*

criteria such that the depth or extent of degradation of the base metal could have resulted in a loss of pressure boundary function when the loss of material rate is extrapolated to the next inspection for that pipe section or to the end of the period of extended operation, an increase in the sample size is conducted.

Where coatings, backfill, or the condition of exposed piping that does not meet acceptance criteria, the degraded condition is repaired or the affected component is replaced. In addition, an expansion of sample size is conducted.

Hydrostatic tests of 25 percent of the subject piping will be performed on an interval not to exceed 5 years, or an internal inspection of 25 percent of the subject piping by a method capable of accurately determining pipe wall thickness every 10 years may be performed as an alternate to directed inspections. Flow testing of the fire mains as described in Section 7.3 of NFPA 25, 2011 Edition is credited in lieu of visual inspections.

NOC-AE-16003385 Enclosure 3 Page 2of18 A1.30 10 CFR PART 50, APPENDIX J The 10 CFR 50, Appendix J program manages cracking, loss of material, loss of leak tightness, loss of sealing, and leakage through containment. The program monitors leakage rates through the containment pressure boundary, including the penetrations and access openings, in order to detect degradation of containment pressure boundary. Seals, gaskets, and bolted connections are also monitored under the program. Containment leak rate tests are performed in accordance with 10 CFR 50 Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors (Option B); Regulatory Guide 1.163, Performance-Based Containment Leak-Testing Program, NEI 94-01, Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50 Appendix J; and ANSI/ANS 56.8, Containment System Leakage Testing Roqu.hJmonts.

Containment leak rate tests are performed to assure that leakage through the primary containment, and systems and components penetrating primary containment does not exceed allowable leakage limits specified in the Technical Specifications. Corrective actions are taken if leakage rates exceed established administrative limits for individual penetrations or the overall containment pressure boundary.

NOC-AE-16003385 Enclosure 3 Page 3of18 82.1.18 Buried Piping and Tanks Inspection Program Description The Buried Piping and Tanks Inspection program manages the loss of material on external surfaces of buried and underground components.

The Buried Piping and Tanks Inspection program includes inspections or flow testing of buried steel, stainless steel, copper alloy piping, underground steel, stainless steel piping within the Auxiliary Feedwater System, the Lighting Diesel Generator System, the Essential Cooling Water (ECW) and ECW Screen Wash System, the Fire Protection System, and the Oily Waste System (OW).

Preventive and mitigative actions are taken to ensure the piping is coated, backfilled and cathodically protected. The buried steel, stainless steel, and copper alloy piping manage_d by this program is cathodically protected. The cathodic protection system is designed in accordance with NACE RP-01-69 1972. The performance of the cathodic protection system is consistent with the guidelines of NACE SP0169-2007. An annual survey ensures that the pipe-to-soil potential is acceptable. If the cathodic protection system fails to meet the acceptance criteria of at least -850 mV relative to a CSE instant off for steel components the following alternatives may be used.

  • 100 mV minimum polarization
  • -750 mV relative to a CSE, instant off where soil resistivity is greater than 10,000 ohm-cm to less than 100, 000 ohm-cm
  • -650 mV relative to a CSE, instant off where soil resistivity is greater than 100,000 ohm-cm
  • Verify less than 1 mil/year (mpy) loss of material.

Means to verify the effectiveness of the protection of the most anodic metal when alternatives are used are incorporated into the program. The external loss of material rate is verified by:

  • Every year when verifying the effectiveness of the cathodic protection system by measuring the loss of material rate.
  • Every 2 years when using the 100 mV minimum polarization.
  • Every 5 years when using the -750 mV or -650 mV criteria associated with higher resistivity soils. The soil resistivity is verified every 5 years.

When electrical resistance corrosion rate probes are used the installation locations of the probes and the methods of use will be determined by qualified NACE CP4 Cathodic Protection Specialist. Additionally, the impact of significant site features (e.g., large cathodic protection current collectors, shielding due to large objects located in the vicinity of the protected piping) and local soil conditions will be factored into placement of the probes and use of probe data.

Cathodic protection is operational (available) at least 85 percent of the time from either 10 years prior to the period of extended operation or from installation or refurbishment, whichever is shorter. Cathodic protection is effective protection for buried piping as evidenced by meeting

NOC-AE-16003385 Enclosure 3 Page 4of18 the acceptance criteria at least 80 percent of the time since either 1O years prior to the period of extended operation or since installation or refurbishment, whichever is shorter.

Opportunistic and directed visual inspections monitor the condition of the external surfaces, backfill, protective coatings and wrappings of steel, stainless steel, and copper alloy buried components. Inspection locations are selected based on susceptibility to degradation and consequences of failure. A minimum of 10 feet of pipe of each material type is inspected. The inspections consist of a 100 percent visual inspection of the exposed pipe. Inspections are conducted by qualified individuals.

Inspection of piping shared between STP Units 1 and 2 may be credited towards the required inspections. Inspection quantities are increased by 50 percent as STP has two units and inspections are distributed evenly among the units.

Category C inspections are used when the external cathodic protection system for buried steel or copper alloy pipe meets the acceptance criteria. Category C inspections are 0.5 percent Not-to-Exceed (NTE) two inspections of that piping per inspection period.

Category E inspections are used when the cathodic protection system has been installed but portions of the piping covered by that system fail to meet the acceptance criteria. Category E inspections are 5 percent, NTE 5 inspections. Where Category E inspections are used, STP will demonstrate that soil is not corrosive using the following:

  • A minimum of three sets of soil samples will be obtained in the vicinity where the cathodic protection system fails to meet the acceptance criteria.
  • The soil will be tested for soil resistivity, corrosion accelerating bacteria, pH, moisture, chlorides, sulfates, and redox potential.
  • The potential soil corrosivity will be determined for each material type of buried in-scope piping in the vicinity of the failed cathodic protection system. In addition to evaluating each individual parameter, the overall soil corrosivity will be determined. "
  • If portions of the installed cathodic protection system fail to meet the acceptance criteria, soil testing will be conducted at a minimum of once in each 10-year period starting at the time when it was determined that the cathodic protection system failed to meet the acceptance.

The Auxiliary Feedwater system has uncoated stainless steel pipl.o.9. underground in a vault and coated stainless steel piping buried outside of the Auxiliary Feedwater Storage tank. +A-is The coated and uncoated stainless steel pipl.o.9. will undergo two-directed visual inspections each 10-year inspection period. The uncoated stainless steel piping and coated stainless steel piping where the coating is not well-adhered will be inspected using a surface examination or other method capable of detecting cracking. Coatings that are intact. well-adhered, and otherwise sound for the remaining inspection interval, and coatings exhibiting small blisters that are few in number and completely surrounded by sound coating bonded to the substrate do not have to be removed.

The OW system has steel pipe underground in sumps located in the yard. This underground pipe will undergo 2% NTE 3 directed visual inspection each 10-year inspection period.

In lieu of visual inspections of the fire protection system, STP credits flow testing of the fire mains as described in Section 7.3 of NFPA 25, 2011 Edition.

NOC-AE-16003385 Enclosure 3 Page 5of18 Inspections will begin during the 10-year period prior to entering the period of extended operation. Upon entering the period of extended operation, inspections will occur every 10 years.

Hydrostatic test of 25 percent of the subject piping on an interval is not to exceed 5 years, or internal inspection of 25 percent of the subject piping by a method capable of accurately determining pipe wall thickness every 10 years may be performed as an alternate to directed inspections. Sources of leakage detected during pressure tests are identified and corrected.

There are no components fabricated with polymeric, cementitious, or concrete materials within the scope of license renewal that credit this program for aging management. There are no buried or underground tanks within the scope of license renewal.

Any evidence of aging effects, such as loss of material, or changes in material properties, requires initiation of corrective actions.

Visual inspections of metallic components are supplemented with surface or volumetric nondestructive testing (NOT) if significant indications are observed to determine local area wall thickness. Wall thickness will be extrapolated to next inspection for that pipe section or to the end of the period of extended operation in order for the component to meet acceptance criteria and to not conduct expanded inspections. Where the depth or extent of degradation of the base metal could have resulted in a loss of pressure boundary function If adverse indications are detected, an expansion of the sample size is conducted. The number of inspections within the affected piping categories is doubled or increased by 5, whichever is smaller. The expanded sample inspection is completed within the 10-year interval in which the original inspection was conducted or, if identified in the latter half of the current 10-year interval, within 4 years after the end of the 10-year interval.

Where damage to the coating has been evaluated as significant and the damage was caused by non-conforming backfill, an extent of condition evaluation is conducted to ensure that the as-left condition of backfill in the vicinity of the observed damage will not lead to further degradation.

Where the coatings, backfill, or the condition of exposed piping does not meet acceptance criteria, the degraded condition is repaired or the affected component is replaced.

Aging management of the internal surfaces of buried and underground piping is accomplished through the use of the Open-Cycle Cooling Water System program (B2.1.9), Closed-Cycle Cooling Water System program (B2.1.10), Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components program (B2.1.22), Fuel Oil Chemistry program (B2.1.14 ), Fire Water System program (B2.1.13) and Water Chemistry program (B2.1.2). Selective leaching of buried or underground components is managed by the Selective Leaching of Materials program (B2.1.17) or the Selective Leaching of Aluminum Bronze program (B2.1.37).

NUREG-1801 Consistency The Buried Piping and Tanks Inspection program is an existing program that, following enhancement, will be consistent with exception to NUREG-1801, Section Xl.M41, Buried and Underground Piping and Tanks.

NOC-AE-16003385 Enclosure 3 .

Page 6of18 Exceptions to NUREG-1801 Preventive Actions (Element 2)

, Section Xl.M41 Table 2a of NUREG-1801 Revision 2, requires the backfill to be consistent with NACE SP0169 Section 5.2.3. NACE SP0169 Section 5.2.3.5 states that pipe should be lowered carefully into the ditch to avoid external coating damage. The original installation specification does not include this practice. However the subgrade of the trench was prepared by removing all debris and unsuitable material, and the subgrade consists of fine clay and sand that makes up the natural soil or backfill. The backfill used is consistent with the ASTM D 448-08 size 67 standard. The subgrade preparation, and small grain size backfill used in the original installation, which provide soft bedding for piping set into the trench, are not expected to have damaged the coating of the piping. Plant procedures will be enhanced to ensure that the piping is lowered carefully into a trench to avoid damage to the external coatings.

Section Xl.M41 Table 2a of NUREG-1801 Revision 2, requires that backfill be consistent with NACE SP0169 Section 5.2.3. NACE SP0169 Section 5.2.3.6 states that care should be taken during backfilling so that rocks and debris do not strike and damage the pipe coating. The '*'

original installation specification for backfilling piping does not include this practice, with the exception of the ECW piping. However a fine grain size backfill was used that met the ASTM D ,, *'*

448-08 size 67 standard. The use of this backfill during backfilling is not expected to damage the pipe coating. Plant procedures will be enhanced so that, during backfill repair or replacement, care is taken to avoid damage to pipe coatings while backfilling the trench.

Section XLM41 Table 2a of NUREG-1801 Revision 2, requires coating of pipe in accordance with NACE SP0169-2007, Table 1. Table 1 recommends that coal tar coatings are in accordance with AWWA C-203, and that prefabricated films are in accordance with AWWA C-214 or C-209. These standards were not referenced in STP installation specifications. **

However, the coatings were applied in accordance with plant-defined specifications. Plant specifications are consistent with the intent of the AWWA coating standards called out in NACE SP 0169-2007. Installation specifications ensure that any defects in the coatings were repaired prior to backfilling over the pipe.

Enhancements Prior to the period of extended operation, the following enhancements will be implemented in the following program elements\

Preventive Actions (Element 2)

Plant specifications will be enhanced to include the following:

Indicate that pipe should be lowered carefully into the ditch to avoid external coating damage.

Proper storage and handling must be used to prevent damage to pipe coating prior to installation. These practices include padded storage, use of proper slings for installation and ultraviolet light-resistant topcoats.

NOC-AE-16003385 Enclosure 3 Page 7of18 Over-excavate trenches and use qualified backfill for bedding piping. Take care during backfilling to prevent rocks and debris from striking and damaging the pipe coating.

Include the coating used for copper alloy buried piping in the coating database. The coating system must be in accordance with NACE SP0169-2007, Table 1, and will be used for repair or for new coatings of the buried copper alloy piping in the essential cooling water system.

Indicate that the portion of the essential cooling water system copper alloy piping directly embedded in backfill or directly encased in concrete must be coated, extending the coating 2 feet or more above grade.

Plant procedures will be enhanced to include the following:

  • In lieu of visual inspections of the fire protection system (FP), this program credits flow testing of the fire mains as described in Section 7.3 of NFPA 25, 2011 Edition.

Backfill that is located within 6 inches of the pipe that is consistent with ASTM D 448-08 size number 67 is considered acceptable. Backfill quality is determined through examination during the inspections conducted by this program. Backfill that does *not meet the ASTM criteria during the initial and subsequent inspections of this program is considered acceptable if the inspections of buried piping do not reveal evidence of mechanical damage to the pipe coatings due to the backfill.

Monitor cathodic protection system rectifier output every 2 months. The measured current at each rectifier is recorded and compared against a target value. Following completion of the plant yard cathodic protection system annual survey, record the*

current of the rectifier used to achieve an acceptable pipe/soil potential. That current will be the target current for the rectifier. If the current measured at the rectifier during the bimonthly monitoring deviates significantly from the target value, a condition report should be created. The rectifier current should be adjusted to an acceptable value. The results of the survey will be documented and trended to identify degrading conditions.

When degraded rectifier performance is identified, corrective actions are required to be initiated. The system should not be operated outside of established acceptable limits for longer than 90 days.

During the plant yard cathodic protection system annual survey, evaluate the effectivene-ss of isolating fittings, continuity bonds and casing isolation. This may be accomplished through electrical measurements (NACE SP016-2007, Section 10.4.4).

The personnel performing the plant yard cathodic protection system annual survey must be NACE-certified, certified by a site-approved training procedure consistent with the NACE requirements, or supervised by a NACE-certified inspector.

Use of excessive cathodic protection polarized potential on coated piping should be avoided. The limiting critical potential should not be more negative than 1200 mV relative to a CSE.

NOC-AE-16003385

  • Enclosure 3 ..

Page 8 of 18 Parameters Monitored/Inspected (Element 3) and Detection of Aging Effects (Element 4)

Plant procedures will be enhanced to include the following:

Plant procedures will be enhanced to indicate Specify that piping in this program is inspected using visual inspections and, if significant indications of degradation are observed, the visual inspections are supplemented by surface and/or volumetric non-destructive testing.

Specify uncoated stainless steel piping and coated stainless steel piping where the coating is not well-adhered will be inspected using a surface examination or other method capable of detecting cracking. Coatings that are intact, well-adhered, and otherwise sound for the remaining inspection interval, and coatings exhibiting small blisters that are few in number and completely surrounded by sound coating bonded to the substrate do not have to be removed.

Detection of Aging Effects (Element 4)

Plant procedures will be enhanced to include the following:

  • The inspections of this program are conducted every 1O years, beginning in the 10 year interval prior to the beginning of the period of extended operation.

Buried and underground piping inspection locations are to be selected based on risk, considering susceptibility to degradation and consequences of failure.

  • The risk ranking for buried piping should consider characteristics such as coating type, coating condition, cathodic protection efficiency, backfill characteristics, soil resistivity, pipe contents, and pipe function.

The risk ranking for underground piping should consider characteristics such as coating type, coating condition, exact external environment, pipe contents, pipe function, and flow characteristics within the pipe.

The risk ranking should generally give piping systems that are backfilled using compacted aggregate a higher inspection priority than comparable systems that are completely backfilled using controlled low strength material.

External Corrosion Direct Assessment, as described in NACE Standard Practice SP0502-2010, is recommended for use in identifying inspection locations. It has been demonstrated to be an effective method for identification of pipe locations that merit further inspection.

  • Opportunistic examinations of non-leaking pipes may be credited toward the required examinations, if they meet the risk-ranking selection criteria.

Guided wave ultrasonic techniques or other advanced inspection techniques should be used, if practical, for determining piping locations that should be inspected. However, these inspections may not be used as substitutes for inspections required by this program.

NOC-AE-16003385 Enclosure 3 Page 9of18

  • An inspection of piping shared between Units 1 and 2 may be credited toward the required inspections. Inspection quantities are increased by 50 percent as STP has two units and inspections are distributed evenly among the units.

Any piping, valves, or closure bolting exposed during inspections should be examined.

Examine bolting for loss of material and loose or missing fasteners.

There are two alternatives to directed inspections of the buried or underground piping that is within the scope of license renewal. The first alternative is a hydrostatic test of 25 percent of the subject piping to 110 percent of the design pressure of any component within the boundary with test pressure being held for eight hours on an interval not to exceed 5 years. The second is an internal inspection of 25 percent of the subject piping by a method capable of accurately determining pipe wall thickness. The inspection must also include methods capable of detecting both general and pitting corrosion, and must be qualified by the plant, and approved by the NRC. UT examinations can be considered approved by the NRC. Guided wave inspection does not currently satisfy these inspection technique requirements. Internal inspections are to be conducted every 1O years beginning 10 years prior to the period of extended operation.

In lieu of visual inspection of the fire protection system, this program relies on flow; ,

testing of the fire mains as described in Section 7.3 of NFPA 25, 2011 Edition to detect degradation of the buried pipe.

Each inspection will examine either the entire length of a run of pipe, or a minimum of 10 feet. If the entire run of pipe of that material type is less than 10 feet in total length, then the entire run of pipe should be inspected. The inspection consists of a 100 percent visual inspection of the exposed pipe.

If a transition from Category C to Category E or from Category E to Category F occurs in the latter half of the current 10-year interval, the timing of the additional examinations is based on the severity of the degradation identified and is commensurate with the '~

consequences of a leak or loss of function. In all cases, the examinations are completed within 4 years after the end of the particular 10-year interval. These additional inspections conducted in an inspection interval cannot be credited towards the base number of inspections required for the 10-year interval.

Where steel or copper alloy piping has been coated with the same coating system and the backfill has the same requirements, the total inspections for this piping may be combined to satisfy the recommended inspection quantity. For example, for Category F, 1O percent of the total of the associated steel or copper alloy is inspected; or 9 10-foot segments of steel or copper alloy piping are inspected.

Category C inspections are used when the external cathodic protection system for buried steel or copper alloy pipe meets the acceptance criteria. Category C inspections are 0.5 percent Not-to-Exceed (NTE) two inspections of that piping per inspection period are performed.

Category E inspections are used when the cathodic protection system has been installed but the portions of the piping covered by that system fail to meet the acceptance criteria.

Category E inspections are 5 percent, NTE § inspections. The following condition must be present.

NOC-AE-16003385 Enclosure 3 Page 10of18 a) Coatings and backfill are provided in accordance with STP backfill specification.

b) There have been no leaks in buried piping due to external corrosion and no significant coating degradation or metal loss in more than 10 percent of inspections conducted.

c) Soil has been demonstrated to be not corrosive for the material type.

Where Category E inspections are used, STP will demonstrate that soil is not corrosive using the following.

o A minimum of three sets of soil samples will be obtained in the vicinity where the cathodic protection system fails to meet the acceptance criteria.

o The soil will be tested for soil resistivity, corrosion accelerating bacteria, pH, moisture, chlorides, sulfates, and redox potential.

o The potential soil corrosivity will be determined for each material type of buried in-scope piping in the vicinity of the failed cathodic protection system. In addition to evaluating each individual parameter, the overall soil corrosivity will be determined.

o If portions of the installed cathodic protection system fail to meet the acceptance criteria, soil testing will be conducted at a minimum of once in each 10-year period starting at the time when it was determined that the cathodic protection system failed to meet the acceptance.

The inspection scope for piping that does not meet Category C or E inspection schedule requirements is 10 percent, NTE 9 inspections.

The AF system underground uncoated stainless steel piping located in a vault and buried coated stainless steel piping will undergo two inspections each 10-year inspection period.

The OW system underground piping will undergo 2% NTE 3 inspection each 10-year inspection period.

Cathodic protection shall be operational (available) at least 85 percent of the time since either 10 years prior to the period of extended operation or since installation or refurbishment, whichever is shorter.

Cathodic protection shall provide effective protection for buried piping at least 80 percent of the time since either 1O years prior to the period of extended operation or since installation or refurbishment, whichever is shorter.

As found results of annual surveys are to be used to demonstrate locations within the plant's population of buried pipe where cathodic protection acceptance criteria have, or have not, been met.

Indicate that adverse indications discovered during the monitoring of the cathodic protection system may warrant increased monitoring of the cathodic protection system and/or additional inspections.

Include examples of adverse indications discovered during piping inspections including leaks, material thickness less than minimum, and general or local degradation of

NOC-AE-16003385 Enclosure 3 Page 11 of 18 coatings that exposes the base material. The presence of coarse backfill within 6 inches of a coated pipe or tank, with accompanying coating degradation, is considered an adverse condition.

Adverse indications that fail to meet the acceptance criteria described in this program require corrective actions for the repair or replacement of the affected component.

If adverse indications are detected, an expansion of the sample size is conducted. The number of inspections within the affected piping categories is doubled or increased by 5, whichever is smaller. If adverse indications are found in the expanded sample, an analysis is conducted to determine the extent of condition and extent of cause. The size of the follow-on inspections will be determined based on the extent of condition and extent of cause. The timing of the additional examinations should be based on the severity of the degradation identified and should be commensurate with the consequences of a leak or loss of function. However, in all cases, the expanded sample inspections should be completed within the 10-year interval in which the original inspection was conducted or, if identified in the latter half of the current 10-year interval, within 4 years after the end of the 10-year interval. Expansion of the sample size may be limited by the extent of piping subject to the observed degradation mechanism .. If adverse conditions are extensive within the 10-year interval in which the inspections were conducted or, if identified in the latter half of the current 10-year interval, within 4 years after the end of the 10-year interval, inspections may be halted in an area of concern that is planned for replacement, provided continued operation does not pose a significant hazard.

During the inspection of buried piping, observe for brittle failure at flanges, connections, and joints due to frost heaving, soil stresses, or ground water effects.

Monitoring and Trending (Element 5)

Plant procedures will be enhanced to include the following:

Where wall thickness measurements are conducted, the results should be trended if follow-up examinations are conducted.

Acceptance Criteria (Element 6)

Plant procedures will be enhanced to include the following:

The cathodic protection system pipe-to-soil potential when using a saturated copper/copper sulfate reference electrode must be at least -850 mV instant off for steel piping. 100 mV minimum polarization is required for copper alloy piping. The cathodic protection system is operational (available) at least 85 percent of the time and provides effective protection for buried piping as evidenced by meeting the acceptance criteria at least 80 percent of the time since either 10 years prior to the period of extended operation or since installation or refurbishment, whichever is shorter.

NOC-AE-16003385 Enclosure 3 Page 12of18 If the cathodic protection system fails to meet the acceptance criteria of at least -850 mV relative to a CSE instant off for steel components the following alternatives may be used.

  • 100 mV minimum polarization
  • -750 mV relative to a CSE, instant off where soil resistivity is greater than 10,000 ohm-cm to less than 100,000 ohm-cm e -650 mV relative to a CSE, instant off where soil resistivity is greater than 100,000 ohm-cm
  • Verify less than 1 mpy loss of material.
  • Means to verify the effectiveness of the protection of the most anodic metal when alternatives are used are incorporated into the program. The external loss of material rate is verified by:
  • Every year when verifying the effectiveness of the cathodic protection system by measuring the loss of material rate.

" Every 2 years when using the 100 mV minimum polarization.

  • Every 5 years when using the -750 mV or -650 mV criteria associated with higher resistivity soils. The soil resistivity is verified every 5 years.

When electrical resistance corrosion rate probes are used the installation locations of the probes and the methods of use will be determined by qualified NACE CP4 Cathodic Protection Specialist.

  • The impact of significant site features (e.g., large cathodic protection current collectors, shielding due to large objects located in the vicinity of the protected piping) and local soil conditions will be factored into placement of the probes and use of probe data.
  • For coated piping, there should be no evidence of coating degradation. If coating degradation is present, it may be considered acceptable if it is determined to be insignificant by an individual possessing a NACE Coating Inspector Program Level 2 or 3 inspector qualification, or an individual has attended the Electric Power Research Institute (EPRI) Comprehensive Coatings Course and completed the EPRI Buried Pipe Condition Assessment and Repair Training Computer Based Training Course.
  • Where damage to the coating has been evaluated as significant and the damage was caused by non-conforming backfill, an extent of condition evaluation should be conducted to ensure that the as-left condition of backfill in the vicinity of observed damage will not lead to further degradation.

Backfill is acceptable if the inspections do not reveal evidence that the backfill caused damage to the component's coatings or the surface of the component.

  • The flow test of the fire protection system that is credited by this program in lieu of inspection of the fire protection system buried piping must be in accordance with NFPA 25, 2011 Edition.
  • For any hydrostatic tests credited by this program, the condition acceptance criteria is no visible indications of leakage and no drop in pressure within the isolated portion of the piping that is not accounted for by a temperature change in the test media or quantified leakage across test boundary valves.

NOC-AE-16003385 Enclosure 3 ..

Page 13of18 Corrective Actions (Element 7)

Plant procedures will be enhanced to include the following:

Where damage to the coating has been evaluated as significant and the damage was caused by non-conforming backfill, an extent of condition evaluation should be conducted to ensure that the as-left condition of backfill in the vicinity of observed damage will not lead to further degradation.

If coated or uncoated metallic piping show evidence of corrosion, the remaining wall thickness in the affected area is determined to ensure that the minimum wall thickness is maintained.

Wall thickness will be extrapolated to next inspection for that pipe section or to the end of the period of extended operation in order for the component to meet acceptance criteria and to not conduct expanded inspections.

  • If the wall thickness meets minimum wall thickness requirements, recommendations for expansion of sample size do not apply.

Where the coatings, backfill, or the condition of exposed piping does not meet acceptance criteria, the degraded condition is repaired or the affected component is replaced. The number of inspections within the affected piping categories is doubled or increased by 5, whichever is smaller.

If the acceptance criteria are not met in any of the expanded samples, an analysis is conducted to determine the extent of condition and extent of cause. The number of the follow-on inspections is determined based on the extent of condition and extent of cause.

  • The timing of the additional examinations is based on the severity of the degradation identified and is commensurate with the consequences of a leak or loss of function.

However, in all cases, the expanded sample inspection is completed within the 10-year interval in which the original inspection was conducted or, if identified in the latter half of the current 10-year interval, within 4 years after the end of the 10-year interval. The number of inspections may be limited by the extent of piping subject to the observed degradation mechanism.

The expansion of sample inspections may be halted in a piping system or portion of system that will be replaced within the 10-year interval in which the inspections were conducted or, if identified in the latter half of the current 10-year interval, within 4 years after the end of the 10-year interval.

Unacceptable cathodic protection survey results are entered into the plant corrective action program.

Sources of leakage detected during pressure tests are identified and corrected.

Indications of cracking are evaluated in accordance with applicable codes and plant-specific design criteria.

NOC-AE-16003385 Enclosure 3 Page 14of18 Operating Experience A 10-year review of plant operating experience shows 30 events which were associated with buried piping. Nine of these events were related to systems or components in scope of license renewal. All of these events were leaks shown to not be a result of corrosion of materials, making them not relevant to this program. The program includes availability, reliability, maintainability, and capacity measurement analyses, published in bi-annual Health Reports.

The events described in the Health Reports are all attributed to causes other than corrosion due to contact with an aggressive environment (most leaks were associated with mechanical joints).

The need to enhance the STP Buried Piping program was initially identified by INPO as an area for improvement. Since that time, involvement with the industry has identified areas for program enhancement. Enhancement of the program is ongoing, utilizing guidance from NEI 09-14 Revision 1, Guideline for the Management of Buried Piping Integrity, and industry operating experience.

The following industry operating experience was reviewed to identify aging effects applicable to STP.

In February 2005, a leak was detected in a 4-inch condensate storage supply line. The cause of the leak was microbiologically influenced corrosion (MIC) or under deposit corrosion. MIC and under deposit corrosion are typically internal corrosion, and managed by the**water Chemistry program (B2.1.2) and verified with the One-Time Inspection program (B2.1.16).

In SeptelJlber 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. STP has a very fine grain of the natural soil, and the installation specifications for backfilling require a backfill that is consistent with ASTM D-448 08 size number 67. Considering this, there is a low probability that pipe coatings have sustained damage due to backfill. The cathodic protection system is operated in accordance with NACE SP0169 and will assure that the piping has a low probability of corrosion, even in the event of coating degradation or failure.

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. This degradation is not expected at STP, as all steel and copper alloy piping managed by this program are coated and cathodically protected.

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. STP has a very fine grain of the natural soil, and the installation specifications for backfilling require a backfill that is consistent with ASTM D-448 08 size number 67. Considering this, there is a low probability that pipe coatings have sustained damage due to backfill. Plant specifications will be enhanced to prevent rocks and debris from striking the pipe coatings during the backfill of piping. The cathodic protection system is operated in accordance with NACE SP0169 and will assure that the piping has a low probability of corrosion, even in the event of coating degradation or failure.

NOC-AE-16003385

_Enclosure 3 Page 15of18 In April 2009, a leak was discovered in an aluminum pipe where it went through a concrete wall.

This leak is not relevant to STP, as the plant has no buried aluminum piping that requires management by this program.

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 leak was determined to be degradation of the protective moisture barrier wrap, which allowed moisture to come in contact with the piping, resulting in external corrosion. STP inspected pipe coatings during installation, and verified an acceptable condition of wrap as it was installed. The cathodic protection system is operated in accordance with NACE SP0169 and will assure that the piping has a low probability of corrosion, even in the event of coating degradation or failure. The inspection of high risk piping by this program can be used to verify that this degradation is unlikely at STP.

The Buried Piping and Tanks Inspection program requires review of plant and industry operating experiences for impacts to the program. This program ensures long-term strategies to address Buried Piping and Tank Inspection are developed and implemented.

Conclusion The continued implementation of the Buried Piping and Tanks Inspection program provides reasonable assu'rance that aging effects are managed such that the systems and components within the scope of this program will continue to perform their intended functions consistent with the current licensing basis for the period of extended operation.

NOC-AE-16003385 Enclosure 3 Page 16of18 82.1.30 10 CFR Part 50, Appendix J Program Description The 10 CFR Part 50 Appendix J program manages cracking, loss of material, loss of leak tightness, loss of sealing, and leakage through containment to assure leakage through the primary containment, and systems and components penetrating the primary containment, does not exceed allowable leakage rate limits specified in the Technical Specifications. The 10 CFR Part 50 Appendix J program does not prevent degradation due to aging effects but provides measures for. monitoring to detect the degradation prior to the loss of intended function.

Periodic monitoring of leakage from the containment, containment isolation valves, and containment penetrations assures proper maintenance and repairs can be performed prior to the loss of intended function. The 10 CFR Part 50 Appendix J program establishes compliance with the regulations and guidance provided in 10 CFR Part 50 Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors (Option B); Regulatory Guide 1.163, Performance-Based Containment Leak-Testing Program; NEI 94-01, Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50 Appendix J~

/\NSl,~'\NS 56.8, Containment System Leakage Testing Requirements. -~**

NUREG-1801 Consistency The 10 CFR Part 50 Appendix J program is an existing program that, following enhancement, will be consistent... with exception with NUREG-1801, *section Xl.S4, 10 CFR Part 50 Appendix J.

Exceptions to NUREG-1801 Nooe-The STP 10 CFR Part 50, Appendix J program is revised to use the guidance provided in NEI 94-01 Revision 2-A. NUREG-1801 Rev 2 removed the revision number from NEI 94-01 which allows the use of the guidance provided in NEI 94-01 Revision 2-A. Additionally, STP Amendment to Facility Operating Nos 210 and 197, Docket Nos 50-498 and 50-499 revises Technical Specification Section 6.8.3.j to state, this program shall be in accordance with the guidelines contained in Nuclear Energy Institute (NEI) topical report NEI 94-01 Revision 2-A, dated October 2008.

Enhancements Prior to the period of extended operation, the following enhancement will be implemented in the following program element:

Corrective Actions (Element 7)

Procedures will be enhanced to specify a surveillance frequency of 4-015 years following a successful _Type A test.

Operating Experience STP most recent Type A tests for each unit are as follows. STP maximum allowable leakage rate (La) at test pressure is 0.3 percent of containment air by weight per day (wt%).

NOC-AE-16003385 Enclosure 3 Page 17of18 Unit 1 Date of last Type A test: 10/5/09 As-Found Leakage: 0.1180 wt%

Approximate date of next Type A test: ~2024 Unit 2 Date of last Type A test: 5/5/07 As-Found Leakage: 0.1423 wt%

Approximate date of next Type A test: ~2022 Types B and C leakage are listed below in terms of standard cubic centimeters per minute (seem). The min path from as found tests is represented by AF; the min path from as left conditions is represented by AL.

Unit 1 Max Path Min Path AF Min Path AL 94655.3 21380.6 21196.1 Unit 2 Max Path Min Path AF Min Path AL 98717.2 40120 32911 STP allowable Band C leakage (0.6 La) is 455,050 seem. As a percentage of 0.6 La that makes the above values:

Unit 1 Max Path Min Path AF Min Path AL 20.8% 4.7% 4.7%

Unit2 Max Path Min Path AF Min Path AL 21.7% 8.8% 7.2%

STP also has an administrative maintenance limit of 200,000 seem. As a percent of this value, then:

NOC-AE-16003385 Enclosure 3 Page 18of18 Unit 1 Max Path Min Path AF Min Path AL 47.3% 10.7% 10.6%

Unit 2 Max Path Min Path AF Min Path AL 49.4% 20.1% 16.456%

The results of these tests show that the STP containment leakage rates are well below the allowable rates for all tests. Type A rates are less than half the maximum allowable leakage rate at test pressure. Type B and C leakage is less than one fourth of the maximum allowable and less than half of the administrative maintenance limit.

Conclusion The continued implementation of the 10 CFR Part 50, Appendix J program provides reasonable assurance that aging effects will be managed such that the systems and components within the scope of this program will continue to perform their intended functions consistent with the current licensing basis for the period of extended operation.

NOC-AE-16003385 Enclosure 4 STPNOC Revision of Regulatory Commitments

NOC-AE-16003385 Enclosure 4 Page 1of8 Table A4-1 License Renewal Commitments

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13 Enhance plant specifications to: B2.1.18 Start implementation

  • Lower coated piping carefully into a trench to avoid external coating damage. during the 10 years
  • Use proper storage and handling practices to prevent damage to pipe coating prior to prior to the period of installation. These practices include padded storage, use of proper slings for extended operation.

installation and ultraviolet light resistant topcoats.

o Over excavate trenches and use qualified backfill for bedding piping. Take care during Inspections to be backfilling to prevent rocks and debris from striking and damaging the pipe coating. complete no later s Include the coating used for copper alloy buried piping in the coating database. The than six months prior coating system must be in accordance with NACE SP0169-2007, and will be used for to the PEO or the repair or for new coatings of the buried copper alloy piping in the essential cooling water end of the last system. refueling outage

  • Coat the portion of the essential cooling water system copper alloy piping directly prior to the PEO, embedded in backfill or directly encased in concrete, extending the coating 2 feet or whichever occurs more above grade. later.

Enhance the Buried Piping and Tanks Inspection program procedures to: CR 10-23268

  • Specify that In lieu of visual inspections of the fire protection system (FP), this program credits flow testing of the fire mains as described in Section 7.3 of NFPA 25, 2011 Edition.

o Consider backfill located within 6 inches of the pipe, and consistent with ASTM D 448-08 size number 67, acceptable. Backfill quality is determined through examination during the inspections conducted by the program. Backfill that does not meet the ASTM criteria, during the initial and subsequent inspections of the program, is considered acceptable if the inspections of buried piping do not reveal evidence of mechanical damage to the pipe coatings due to the backfill.

o Ensure th.e cathodic protection system survey is performed annJ.Jally.

Following the completion of the plant yard cathodic protection system annual survey, record the current of the rectifier used to achieve an acceptable pipe/soil potential. That current will be the target current for the rectifier until the next annual survey. If the current measured at the rectifier durin the bimonthl monitorin deviates si nificantl

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NOC-AE-16003385 Enclosure 4 Page 2 of 8 License Renewal Commitments

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from the target value, a condition report should be created. The rectifier current should be adjusted to an acceptable value. The results of the survey will be documented and trended to identify degrading conditions. When degraded rectifier performance is identified, documentation is required in accordance with the corrective action program.

The system should not be operated outside of established acceptable limits for longer than 90 days.

  • Evaluate the effectiveness of isolating fittings, continuity bonds and casing isolation, during the plant yard cathodic protection system annual survey. This may be accomplished through electrical measurements.
  • The personnel performing the plant yard cathodic protection system annual survey must be NACE-certified, certified by a site-approved training procedure consistent with the NACE requirements, or supervised by a NACE-certified inspector.
  • Use of excessive cathodic protection polarized potential on coated piping should be avoided. The limiting critical potential should not be more negative than 1200 mV relative to a CSE.
  • Visually inspect buried piping and, if significant indications of degradation are observed, the visual inspections are supplemented by surface and/or volumetric non-destructive testing.
  • Specify uncoated stainless steel piping and coated stainless steel piping where the coating is not well-adhered be inspected using a surface examination or other method capable of detecting cracking. Coatings that are intact, well-adhered. and otherwise sound for the remaining inspection interval. and coatings exhibiting small blisters that are few in number and completely surrounded by sound coating bonded to the substrate do not have to be removed.
  • Define the inspection interval for the program directed inspections as every 10 years, beginning the 10 year interval prior to the period of extended operation.
  • Select the buried and underground piping inspection locations based on risk, considering susceptibility to degradation and consequences of failure.
  • The risk ranking for buried piping should consider characteristics such as coating type, coatin condition, cathodic protection efficienc , backfill characteristics, soil resistivit ,

NOC-AE-16003385 Enclosure 4 Page 3 of 8 Table A4-1 License Renewal Commitments

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pipe contents, and pipe function.

  • The risk ranking for underground piping should consider characteristics such as coating type, coating condition, exact external environment, pipe contents, pipe function, and flow characteristics within the pipe.
  • The risk ranking should generally give piping systems that are backfilled using compacted aggregate a higher inspection priority than comparable systems that are completely backfilled using controlled low strength material.
  • External Corrosion Direct Assessment, as described in NACE Standard Practice SP0502-2010, will be considered for use in identifying inspection locations.
  • Credit opportunistic examinations of non-leaking pipes toward required examinations, only if they meet the risk ranking selection criteria.
  • Guided wave ultrasonic, or other advanced inspection techniques should be used, if practical, for the purpose of determining piping locations that should be inspected.

These inspections may not be used as substitutes for inspections required by the program.

  • Credit an inspection of piping shared between Units 1 and 2 toward the required inspections and inspections are distributed evenly among the units.
  • Examine any piping, valves and closure bolting exposed during inspections.
  • Examine bolting for loss of material and loose or missing fasteners.
  • Include two alternatives to directed inspections of the buried or underground piping that is safety related, hazmat or both within the scope of license renewal. The first alternative is to hydrostatically test 25 percent of the subject piping to 110 percent of the design pressure of any component within the boundary with test pressure being held for eight hours_on an interval not to exceed 5 years. The second is an internal inspection of 25 percent of the subject piping by a method capable of accurately determining pipe wall thickness on an interval of every 10 years.
  • Flow testing of the fire mains, as described in NFPA 25, 2011 Edition, to detect degradation of the buried pipe in lieu of visual inspections of the fire protection system buried and underground piping.
  • Specify that each inspection will examine either the entire length of a run of pipe, or a minimum of 10 feet. If the entire run of pipe of that material type is less than 10 feet in total length, then the entire run of pipe should be inspected. The inspection consists of a 100 percent visual inspection of the ex osed i e.

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NOC-AE-16003385 Enclosure 4 Page 4 of 8 License Renewal Commitments Commitment:: \liRA

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  • Specify that if a transition from Category C to Category E or from Category E to Category F occurs in the latter half of the current 10-year interval, the timing of the additional examinations is based on the severity of the degradation identified and is commensurate with the consequences of a leak or loss of function. In all cases, the examinations are completed within 4 years after the end of the particular 10-year interval. These additional inspections conducted in an inspection interval cannot be credited towards the base number of inspections required for the 10-year interval.
  • Specify where steel or copper alloy piping has been coated with the same coating system and the backfill has the same requirements, the total inspections for this piping may be combined to satisfy the recommended inspection quantity. For example, for Category F, 10 percent of the total of the associated steel or copper alloy is inspected; or 9 10-foot segments of steel or copper alloy piping are inspected.
  • Specify that Category C inspections be used when the external cathodic protection system for buried steel or copper alloy pipe meets the acceptance criteria. Category C inspections are 0.5 percent Not-to-Exceed (NTE) two inspections of that piping per inspection period performed.
  • Specify that Category E inspections be used when the cathodic protection system has been installed but the portions of the piping covered by that system fail to meet the acceptance criteria. Category E inspections are 5 percent, NTE 5. The following condition must be present.

o Coatings and backfill are provided in accordance with STP backfill specification.

o There have been no leaks in buried piping due to external corrosion and no significant coating degradation or metal loss in more than 10 percent of inspections conducted.

o Soil has been demonstrated to be not corrosive for the material type using the following.

  • A minimum of three sets of s.Qil samples will be obtained in the vicinity where the cathodic protection system fails to meet the acceptance criteria.
  • The soil will be tested for soil resistivity, corrosion accelerating bacteria, pH, moisture, chlorides, sulfates, and redox potential.
  • The potential soil corrosivity will be determined for each material type of buried in-scope i in in the vicinit of the failed cathodic rotection

NOC-AE-16003385 Enclosure 4 Page 5 of 8 License Renewal Commitments Commitll)ent * . :*1rriplementation d" >,:§tt1~'du1l¥.* .

system. In addition to evaluating each individual parameter, the overall soil corrosivity will be determined.

  • If portions of the installed cathodic protection system fail to meet the acceptance criteria, soil testing will be conducted at a minimum of once in each 10-year period starting at the time when it was determined that the cathodic protection system failed to meet the acceptance.
  • Specify that inspection scope for piping that does not meet Category C or E inspection schedule requirements is 10 percent, NTE 9 inspections.
  • Specify that the AF system underground uncoated stainless steel piping located in a vault and buried coated stainless steel piping will undergo two inspections each 10-year inspection period.
  • Specify that the OW system underground piping will undergo 2% NTE 3 inspection each 10-year inspection period.
  • Include acceptance criteria for the cathodic protection to be operational (available) at least 85 percent of the time since either 10 years prior to the period of extended operation or since installation or refurbishment, whichever is shorter.
  • Include acceptance criteria for the cathodic protection system to provide protection for buried piping at least 80 percent of the time since either 10 years prior to the period of extended operation or since installation or refurbishment, whichever is shorter.
  • Include examples of adverse indications discovered during piping inspections.
  • Repair or replacement of the affected component when adverse indications failing to meet the acceptance criteria described in the program are discovered.
  • Specify that if adverse indications are detected, an expansion of the sample size is conducted. The number of inspections within the affected piping categories is doubled or increased by 5, whichever is smaller. If adverse indications are found in the expanded sample, an analysis is conducted to determine the extent of condition and extent of cause. The size of the follow-on inspections will be determined based on the extent of condition and extent of cause. The timing of the additional examinations should be based on the severity of the degradation identified and should be commensurate with the consequences of a leak or loss of function. However, in all cases, the expanded sample inspections should be completed within the 10-year interval in which the original inspection was conducted or, if identified in the latter half of the current 10- ear interval, within 4 ears after the end of the 10- ear interval. If

NOC-AE-16003385 Enclosure 4 Page 6 of 8 License Renewal Commitments

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adverse conditions are extensive within the 10-year interval in which the inspections were conducted or, if identified in the latter half of the current 10-year interval, within 4 years after the end of the 10-year interval, inspections may be halted in an area of concern that is planned for replacement, provided continued operation does not pose a significant hazard. Expansion of sample size may be limited to the piping subject to the observed degradation mechanism.

  • Observe for brittle failure at flanges, connections, and joints due to frost heaving, soil stresses, or ground water effects during inspection of buried piping.
  • Where wall thickness measurements are conducted, the results should be trended if follow-up examinations are conducted.
  • Specify that the cathodic protection system pipe-to-soil potential when using a saturated copper/copper sulfate reference electrode must be at least -850 mV relative to a CSE, instant off for steel piping. 100 mV minimum polarization is required for copper alloy piping.
  • Specify that If the cathodic protection system fails to meet the acceptance criteria of at least -850 mV relative to a CSE instant off for steel components the following alternatives may be used.

o 100 mV minimum polarization o -750 mV relative to a CSE, instant off where soil resistivity is greater than 10,000 ohm-cm to less than 100,000 ohm-cm o -650 mV relative to a CSE, instant off where soil resistivity is greater than 100,000 ohm-cm o Verify less than 1 mil/year (mpy) loss of material.

  • Specify means to verify the effectiveness of the protection of the most anodic metal when alternatives are used are incorporated into the program. The external loss of material rate is verified by:

o Every year when verifying the effectiveness of the cathodic protection system by measuring the loss of material rate.

o Every 2 years when using the 100 mV minimum polarization.

o Every 5 years when using the -750 mV or -650 mV criteria associated with higher resistivity soils. The soil resistivity is verified every 5 years.

NOC-AE-16003385 Enclosure 4 Page 7 of 8 License Renewal Commitments Commitment LRA, : * . ltnpf~ment~tion .. *

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  • Specify where electrical resistance corrosion rate probes are used the installation locations of the probes and the methods of use will be determined by qualified NACE CP4 Cathodic Protection Specialist.
  • Require the impact of significant site features (e.g., large cathodic protection current collectors, shielding due to large objects located in the vicinity of the protected piping) and local soil conditions be factored into placement of the probes and use of probe data.
  • Indicate that for coated piping, there should be no evidence of coating degradation. If coating degradation is present, it may be considered acceptable if it is determined to be insignificant by an individual possessing a NACE Coating Inspector Program Level 2 or 3 inspector qualification, or an individual has attended the Electric Power Research Institute (EPRI) Comprehensive Coatings Course and completed the EPRI Buried Pipe Condition Assessment and Repair Training Computer Based Training Course.
  • Specify where damage to the coating has been evaluated as significant and the damage was caused by non-conforming backfill, an extent of condition evaluation should be conducted to ensure that the as-left condition of backfill in the vicinity of observed damage will not lead to further degradation.
  • Specify that backfill is acceptable if the inspections do not reveal evidence that the backfill caused damage to the component's coatings or the surface of the component..
  • Indicate that for any hydrostatic tests credited by the program, the condition acceptance criteria is no visible indications of leakage and no drop in pressure within the isolated portion of the piping that is not accounted for by a temperature change in the test media or quantified leakage across test boundary valves.
  • Specify that if coated or uncoated metallic piping show evidence of corrosion, the remaining wall thickness in the affected area is determined to ensure that the minimum wall thickness is maintained.
  • Indicate that wall thickness will be extrapolated to next inspection for that pipe section or to the end of the period of extended operation in order for the component to meet acceptance criteria and to not conduct expanded inspections.
  • Specify where wall thickness meets minimum wall thickness requirements, recommendations for expansion of sample size does not apply.
  • Require unacceptable cathodic protection survey results be entered into the plant corrective action ro ram.

NOC-AE-16003385 Enclosure 4 Page 8 of 8 License Renewal Commitments

  • Specify that sources of leakage detected during pressure tests be identified and corrected .
  • 24 82.1.30 Completed
  • Complete no later than six months prior to the period of extended operation CR 15-848-5 CR 10 23599
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