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{{#Wiki_filter:DRAFT - UNCERTIFIED INFORMATIONDRAFT - UNCERTIFIED INFORMATIONQuestionRAI B.1.4-1 2 nd RevisionBackgroundThe "preventive actions" program element of GALL Report AMP XI.M41, "Buried and Underground Piping andTanks," as modified by LR-ISG-2015-01, "Changes to Buried and Underground Piping and TankRecommendations," includes the following recommendations:For buried stainless steel piping or tanks, coatings are provided based on the environmental conditions (e.g.,stainless steel in chloride containing environments). Applicants provide justification when coatings are notprovided.Coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACE RP0285-2002 as wellas the following coating types: asphalt/coal tar enamel, concrete, elastomeric polychloroprene, mastic(asphaltic), epoxy polyethylene, polypropylene, polyurethane, and zinc.For buried steel, copper alloy, and aluminum alloy piping and tanks and underground steel and copper alloypiping and tanks, coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACERP0285-2002.GALL Report AMP XI.M41, as modified by LR-ISG-2015-01, Table XI.M41-2, "Inspection of Buried andUnderground Piping and Tanks," recommends the following: In regard to the inspection quantities in Table XI.M41-2, the "detection of aging effects" programelement states, "[a]dditional inspections, beyond those in Table XI.M41-2 may be appropriate ifexceptions are taken to program element 2, "preventive actions," or in response to plant-specificoperating experience." One inspection per 10-year interval for stainless steel piping (reference Table XI.M41-2). Use of Preventive Action Category F, the highest number of inspections category, for those portions ofin-scope buried steel piping which cannot be classified as Category C, D, or E.IssueDuring the audit, the staff reviewed condition reports and plant-specific documents related to buried steel andstainless steel piping. The staff concluded the following: It is unclear whether all in-scope steel piping is coated. For at least portions of the stainless steel condensate makeup, storage, and transfer system piping, nocoating was installed. Based on the availability of soil sample parameter results, it is not clear that the soil is noncorrosivebecause redox potential values and soil drainage assessments were not available, and based on thepresence of sulfides, a significant corrosivity penalty is applied. In addition, particularly in regard tostainless steel piping, chloride values were not available.Request1. For steel piping:a. State what type and whether coatings were specified to be applied to all in-scope steel buried piping. If thetypes of coatings are not consistent with the recommended coating types in AMP XI.M41, state the basis fortheir effectiveness at preventing aging effects for buried steel piping.b. If coatings were not specified to be applied to all in-scope steel buried piping (in essence, an exception toAMP XI.M41 preventive actions), state which Preventive Action Category will be used for those portions of DRAFT - UNCERTIFIED INFORMATIONDRAFT - UNCERTIFIED INFORMATIONin-scope buried steel piping that were not specified to be coated. If Preventive Action Category F will not beused for those portions of in-scope buried steel piping that were not specified to be coated, state the basisfor why additional inspections, beyond those in Table XI.M41-2, are not required to provide reasonableassurance that the piping will meet its intended function during the period of extended operation.c. Provide sufficient data to demonstrate that for where in-scope steel piping is buried, the soil is not corrosive.d. If the soil is corrosive or cannot be demonstrated to be noncorrosive; state which Preventive ActionCategory will be used for portions of the in-scope buried steel piping where the cathodic protection system isnot meeting performance goals (i.e., operational time period, effectiveness). If Preventive Action Category Fwill not be used for those portions of in-scope buried steel piping where the cathodic protection system isnot meeting performance goals, state the basis for why additional inspections, beyond those in TableXI.M41-2, are not required to provide reasonable assurance that the piping will meet its intended functionduring the period of extended operation.2. For stainless steel piping:a. State what type and whether coatings were specified to be applied to all in-scope stainless steel buriedpiping. If the types of coatings are not consistent with the recommended coating types in AMP XI.M41, statethe basis for their effectiveness at preventing aging effects for buried stainless steel piping.b. For portions of the in-scope buried stainless steel piping that are not coated (by design configuration or asdetected during inspections), state how many inspections will be conducted per 10-year period and thebasis for why the number of inspections will be adequate to manage associated aging effects.ResponseRiver Bend Station (RBS) previously responded to RAI B.1.4-1 by letters dated January 24, 2018 (RBG47813) and April 4, 2018 (RBG-47850). The following is the response to RAI B.1.4-1 revised to includeadditional information requested by the NRC during a telephone conference call held on April 25, 2018. Thisrevised response supersedes the previous response. The locations of changes to the previous response ofApril 4 are indicated with revision bars.Response1.a. RBS design documents specify the application of coal tar epoxy coating to the buried steel piping in thesystems that are within the scope of license renewal. A substitute coating of Tnemec HS 104 epoxy,which is acycloaliphatic amine epoxy, is allowed by the specification for field-installed piping. Entergybelieves that applications of the Tnemec coating are few, if any. While not included in the recommendedcoating types of AMP XI.M41, the Tnemec HS 104 does conform to the recommendations of AmericanWater Works Association (AWWA) C210 "Liquid-Epoxy Coatings and Linings for Steel Water Pipe andFittings" when installed in underground and underwater applications. It protects in immersion, salt sprayand chemical exposures, and is applied in two coats at a minimum 6 mil dry film thickness each. It hassuperior abrasion resistance. As such it is an appropriate coating for preventing aging effects on steelpiping.b.      Coatings were specified to be applied to all in-scope buried steel piping, and as such no further responseis necessary for this question. A 2013 condition report documented one instance of buried steel pipingthat was discovered without protective coating. That piping ran from a drip pan under condensatetransfer pumps to the condensate storage tank sump. The piping, which performs no license renewalintended function, had been installed in a 1986 plant modification that included inadequate directions forcoating application. This condition is considered an isolated event and the modification process has been DRAFT - UNCERTIFIED INFORMATIONDRAFT - UNCERTIFIED INFORMATIONimproved since 1986 to provide more specific installation instructions.c. Site documentation is not adequate to demonstrate that the soil at the site is noncorrosive in accordancewith the guidance in Table XI.M41-2.d. Because the soil at the site has not been demonstrated noncorrosive, Preventive Action Category F ofAppendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01 will be used to determine thenumber of inspections for portions of the in-scope buried steel piping where the cathodic protectionsystem is not meeting performance goals (i.e., operational time period, effectiveness) or where the pipingis not protected by a cathodic protection system unless all the requirements for moving to anotherpreventive action category are met. This provision is added to Appendix A, Section A.1.4 and AppendixB, Section B.1.4.2.a. Site documentation specifies that buried stainless steel piping is coated with coal tar epoxy, consistentwith the recommended coating types in AMP XI.M41, or a silicone-based material. The silicone materialis specified as Thurmalox 70 or Carboline 4674 and is applied in two coats. These silicone-basedcoating materials are rated for use in high-temperature applications and provide an additional layer ofprotection from the soil environment. The Thurmalox coating provides protection from chloride-inducedstress corrosion cracking by preventing chlorides in the environment from coming in contact with thesurface. This includes buried stainless steel piping that is subject to aging management review forlicense renewal. LR-ISG-2015-01 recommends one inspection of stainless steel piping during each 10-year period commencing 10 years prior to the period of extended operation. In order to ensure theadequate management of the effects of aging on buried stainless steel piping with silicone-basedcoatings, RBS will perform an additional inspection of the stainless steel piping during each 10-yearperiod unless the soil is demonstrated non-corrosive and the backfill is in accordance with therecommendations of LR-ISG-2015-01. The additional inspection will be performed on piping with asilicon-based coating. Inspections performed in 2012 and 2013 did not identify any corrosion of stainlesssteel piping with silicon-based coating after 30 years of service. This operating experience provides thebasis for concluding that adding the additional inspection is appropriate for the conditions at RBS.b. The stainless steel piping in a soil environment is specified to be coated. Entergy has identified no buriedstainless steel piping subject to aging management review that was not coated prior to installation.The changes to LRA A.1.4 and B.1.4 follow with additions underlined and deletions lined through.[The following revised LRA sections also reflect changes to the RAI response submitted on April 4, 2018]A.1.4 Buried and Underground Piping and Tanks InspectionThe Buried and Underground Piping and Tanks Inspection Program manages the effects of aging on externalsurfaces of buried piping components and tanks subject to aging management review. Components includedin the program are fabricated from metallic materials. The program will manage loss of material and crackingthrough preventive and mitigative features (e.g., coatings, backfill quality, and cathodic protection) and periodicinspection activities during opportunistic and directed excavations. The number of inspections is based on theavailability and effectiveness of preventive and mitigative actions as specified in Appendix B of LicenseRenewal Interim Staff Guidance LR-ISG-2015-01. In addition to the buried stainless steel piping inspectionrecommended by LR-ISG-2015-01, one additional inspection of buried stainless steel piping with silicon-based DRAFT - UNCERTIFIED INFORMATIONDRAFT - UNCERTIFIED INFORMATIONcoating will be conducted during each 10-year periodunless the soil is demonstrated non-corrosive and thebackfill is in accordance with the recommendations of LR-ISG-2015-01. Preventive Action Category F of LR-ISG-2015-01 will be used in determining the number of inspections for portions of the in-scope buried steelpiping where the cathodic protection system is not meeting performance goals (i.e., operational time period,effectiveness) or where the piping is not protected by a cathodic protection system unless all the requirementsfor moving to another preventive action category are met soil is demonstrated to be noncorrosive. Annualcathodic protection surveys are conducted. For steel components, where the acceptance criteria foreffectiveness of cathodic protection is other than -850 millivolts (mV) instant off, loss of material rates aremeasured.B.1.4 BURIED AND UNDERGROUND PIPING AND TANKS INSPECTIONProgram DescriptionThe Buried and Underground Piping and Tanks Inspection Program is a new program that will manage theeffects of aging on external surfaces of buried piping components and tanks subject to aging managementreview. Components included in the program are fabricated from metallic materials. The program will manageloss of material and cracking through preventive and mitigative features (e.g., coatings, backfill quality, andcathodic protection) and periodic inspection activities during opportunistic and directed excavations. Thenumber of inspections is based on the availability and effectiveness of preventive and mitigative actions asspecified in Appendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01. In addition to the buriedstainless steel piping inspection recommended by LR-ISG-2015-01, one additional inspection of buriedstainless steel piping with silicon-based coating will be conducted during each 10-year periodunless the soil isdemonstrated non-corrosive and the backfill is in accordance with the recommendations of LR-ISG-2015-01.Preventive Action Category F of LR-ISG-2015-01 will be used in determining the number of inspections forportions of the in-scope buried steel piping where the cathodic protection system is not meeting performancegoals (i.e., operational time period, effectiveness) or where the piping is not protected by a cathodic protectionsystem unless all therequirements for moving to another preventive action category are met soil isdemonstrated to be noncorrosive. Annual cathodic protection surveys are conducted. For steel components,where the acceptance criteria for effectiveness of cathodic protection is other than -850 mV instant off, loss ofmaterial rates are measured.}}
{{#Wiki_filter:DRAFT - UNCERTIFIED INFORMATION Question RAI B.1.4-1 2nd Revision
 
===Background===
The preventive actions program element of GALL Report AMP XI.M41, Buried and Underground Piping and Tanks, as modified by LR-ISG-2015-01, Changes to Buried and Underground Piping and Tank Recommendations, includes the following recommendations:
For buried stainless steel piping or tanks, coatings are provided based on the environmental conditions (e.g.,
stainless steel in chloride containing environments). Applicants provide justification when coatings are not provided.
Coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACE RP0285-2002 as well as the following coating types: asphalt/coal tar enamel, concrete, elastomeric polychloroprene, mastic (asphaltic), epoxy polyethylene, polypropylene, polyurethane, and zinc.
For buried steel, copper alloy, and aluminum alloy piping and tanks and underground steel and copper alloy piping and tanks, coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACE RP0285-2002.
GALL Report AMP XI.M41, as modified by LR-ISG-2015-01, Table XI.M41-2, Inspection of Buried and Underground Piping and Tanks, recommends the following:
* In regard to the inspection quantities in Table XI.M41-2, the detection of aging effects program element states, [a]dditional inspections, beyond those in Table XI.M41-2 may be appropriate if exceptions are taken to program element 2, preventive actions, or in response to plant-specific operating experience.
* One inspection per 10-year interval for stainless steel piping (reference Table XI.M41-2).
* Use of Preventive Action Category F, the highest number of inspections category, for those portions of in-scope buried steel piping which cannot be classified as Category C, D, or E.
Issue During the audit, the staff reviewed condition reports and plant-specific documents related to buried steel and stainless steel piping. The staff concluded the following:
* It is unclear whether all in-scope steel piping is coated.
* For at least portions of the stainless steel condensate makeup, storage, and transfer system piping, no coating was installed.
* Based on the availability of soil sample parameter results, it is not clear that the soil is noncorrosive because redox potential values and soil drainage assessments were not available, and based on the presence of sulfides, a significant corrosivity penalty is applied. In addition, particularly in regard to stainless steel piping, chloride values were not available.
Request
: 1. For steel piping:
: a. State what type and whether coatings were specified to be applied to all in-scope steel buried piping. If the types of coatings are not consistent with the recommended coating types in AMP XI.M41, state the basis for their effectiveness at preventing aging effects for buried steel piping.
: b. If coatings were not specified to be applied to all in-scope steel buried piping (in essence, an exception to AMP XI.M41 preventive actions), state which Preventive Action Category will be used for those portions of DRAFT - UNCERTIFIED INFORMATION
 
DRAFT - UNCERTIFIED INFORMATION in-scope buried steel piping that were not specified to be coated. If Preventive Action Category F will not be used for those portions of in-scope buried steel piping that were not specified to be coated, state the basis for why additional inspections, beyond those in Table XI.M41-2, are not required to provide reasonable assurance that the piping will meet its intended function during the period of extended operation.
: c. Provide sufficient data to demonstrate that for where in-scope steel piping is buried, the soil is not corrosive.
: d. If the soil is corrosive or cannot be demonstrated to be noncorrosive; state which Preventive Action Category will be used for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness). If Preventive Action Category F will not be used for those portions of in-scope buried steel piping where the cathodic protection system is not meeting performance goals, state the basis for why additional inspections, beyond those in Table XI.M41-2, are not required to provide reasonable assurance that the piping will meet its intended function during the period of extended operation.
: 2. For stainless steel piping:
: a. State what type and whether coatings were specified to be applied to all in-scope stainless steel buried piping. If the types of coatings are not consistent with the recommended coating types in AMP XI.M41, state the basis for their effectiveness at preventing aging effects for buried stainless steel piping.
: b. For portions of the in-scope buried stainless steel piping that are not coated (by design configuration or as detected during inspections), state how many inspections will be conducted per 10-year period and the basis for why the number of inspections will be adequate to manage associated aging effects.
 
===Response===
River Bend Station (RBS) previously responded to RAI B.1.4-1 by letters dated January 24, 2018 (RBG 47813) and April 4, 2018 (RBG-47850). The following is the response to RAI B.1.4-1 revised to include additional information requested by the NRC during a telephone conference call held on April 25, 2018. This revised response supersedes the previous response. The locations of changes to the previous response of April 4 are indicated with revision bars.
 
===Response===
1.a. RBS design documents specify the application of coal tar epoxy coating to the buried steel piping in the systems that are within the scope of license renewal. A substitute coating of Tnemec HS 104 epoxy, which is a cycloaliphatic amine epoxy, is allowed by the specification for field-installed piping. Entergy believes that applications of the Tnemec coating are few, if any. While not included in the recommended coating types of AMP XI.M41, the Tnemec HS 104 does conform to the recommendations of American Water Works Association (AWWA) C210 Liquid-Epoxy Coatings and Linings for Steel Water Pipe and Fittings when installed in underground and underwater applications. It protects in immersion, salt spray and chemical exposures, and is applied in two coats at a minimum 6 mil dry film thickness each. It has superior abrasion resistance. As such it is an appropriate coating for preventing aging effects on steel piping.
: b.      Coatings were specified to be applied to all in-scope buried steel piping, and as such no further response is necessary for this question. A 2013 condition report documented one instance of buried steel piping that was discovered without protective coating. That piping ran from a drip pan under condensate transfer pumps to the condensate storage tank sump. The piping, which performs no license renewal intended function, had been installed in a 1986 plant modification that included inadequate directions for coating application. This condition is considered an isolated event and the modification process has been DRAFT - UNCERTIFIED INFORMATION
 
DRAFT - UNCERTIFIED INFORMATION improved since 1986 to provide more specific installation instructions.
: c. Site documentation is not adequate to demonstrate that the soil at the site is noncorrosive in accordance with the guidance in Table XI.M41-2.
: d. Because the soil at the site has not been demonstrated noncorrosive, Preventive Action Category F of Appendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01 will be used to determine the number of inspections for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness) or where the piping is not protected by a cathodic protection system unless all the requirements for moving to another preventive action category are met. This provision is added to Appendix A, Section A.1.4 and Appendix B, Section B.1.4.
2.a. Site documentation specifies that buried stainless steel piping is coated with coal tar epoxy, consistent with the recommended coating types in AMP XI.M41, or a silicone-based material. The silicone material is specified as Thurmalox 70 or Carboline 4674 and is applied in two coats. These silicone-based coating materials are rated for use in high-temperature applications and provide an additional layer of protection from the soil environment. The Thurmalox coating provides protection from chloride-induced stress corrosion cracking by preventing chlorides in the environment from coming in contact with the surface. This includes buried stainless steel piping that is subject to aging management review for license renewal. LR-ISG-2015-01 recommends one inspection of stainless steel piping during each 10-year period commencing 10 years prior to the period of extended operation. In order to ensure the adequate management of the effects of aging on buried stainless steel piping with silicone-based coatings, RBS will perform an additional inspection of the stainless steel piping during each 10-year period unless the soil is demonstrated non-corrosive and the backfill is in accordance with the recommendations of LR-ISG-2015-01. The additional inspection will be performed on piping with a silicon-based coating. Inspections performed in 2012 and 2013 did not identify any corrosion of stainless steel piping with silicon-based coating after 30 years of service. This operating experience provides the basis for concluding that adding the additional inspection is appropriate for the conditions at RBS.
: b. The stainless steel piping in a soil environment is specified to be coated. Entergy has identified no buried stainless steel piping subject to aging management review that was not coated prior to installation.
The changes to LRA A.1.4 and B.1.4 follow with additions underlined and deletions lined through.
[The following revised LRA sections also reflect changes to the RAI response submitted on April 4, 2018]
A.1.4     Buried and Underground Piping and Tanks Inspection The Buried and Underground Piping and Tanks Inspection Program manages the effects of aging on external surfaces of buried piping components and tanks subject to aging management review. Components included in the program are fabricated from metallic materials. The program will manage loss of material and cracking through preventive and mitigative features (e.g., coatings, backfill quality, and cathodic protection) and periodic inspection activities during opportunistic and directed excavations. The number of inspections is based on the availability and effectiveness of preventive and mitigative actions as specified in Appendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01. In addition to the buried stainless steel piping inspection recommended by LR-ISG-2015-01, one additional inspection of buried stainless steel piping with silicon-based DRAFT - UNCERTIFIED INFORMATION
 
DRAFT - UNCERTIFIED INFORMATION coating will be conducted during each 10-year period unless the soil is demonstrated non-corrosive and the backfill is in accordance with the recommendations of LR-ISG-2015-01. Preventive Action Category F of LR-ISG-2015-01 will be used in determining the number of inspections for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness) or where the piping is not protected by a cathodic protection system unless all the requirements for moving to another preventive action category are met soil is demonstrated to be noncorrosive. Annual cathodic protection surveys are conducted. For steel components, where the acceptance criteria for effectiveness of cathodic protection is other than -850 millivolts (mV) instant off, loss of material rates are measured.
B.1.4     BURIED AND UNDERGROUND PIPING AND TANKS INSPECTION Program Description The Buried and Underground Piping and Tanks Inspection Program is a new program that will manage the effects of aging on external surfaces of buried piping components and tanks subject to aging management review. Components included in the program are fabricated from metallic materials. The program will manage loss of material and cracking through preventive and mitigative features (e.g., coatings, backfill quality, and cathodic protection) and periodic inspection activities during opportunistic and directed excavations. The number of inspections is based on the availability and effectiveness of preventive and mitigative actions as specified in Appendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01. In addition to the buried stainless steel piping inspection recommended by LR-ISG-2015-01, one additional inspection of buried stainless steel piping with silicon-based coating will be conducted during each 10-year period unless the soil is demonstrated non-corrosive and the backfill is in accordance with the recommendations of LR-ISG-2015-01.
Preventive Action Category F of LR-ISG-2015-01 will be used in determining the number of inspections for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness) or where the piping is not protected by a cathodic protection system unless all the requirements for moving to another preventive action category are met soil is demonstrated to be noncorrosive. Annual cathodic protection surveys are conducted. For steel components, where the acceptance criteria for effectiveness of cathodic protection is other than -850 mV instant off, loss of material rates are measured.
DRAFT - UNCERTIFIED INFORMATION}}

Latest revision as of 06:49, 21 October 2019

RAI B.1.4-1 R2 Revised - w- header-footer-watermark
ML18123A495
Person / Time
Issue date: 05/02/2018
From: Wong A
NRC/NRR/DMLR/MRPB
To:
Albert Wong, NRR/DMLR/MRPB, 415-3081
References
Download: ML18123A495 (5)
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Text

DRAFT - UNCERTIFIED INFORMATION Question RAI B.1.4-1 2nd Revision

Background

The preventive actions program element of GALL Report AMP XI.M41, Buried and Underground Piping and Tanks, as modified by LR-ISG-2015-01, Changes to Buried and Underground Piping and Tank Recommendations, includes the following recommendations:

For buried stainless steel piping or tanks, coatings are provided based on the environmental conditions (e.g.,

stainless steel in chloride containing environments). Applicants provide justification when coatings are not provided.

Coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACE RP0285-2002 as well as the following coating types: asphalt/coal tar enamel, concrete, elastomeric polychloroprene, mastic (asphaltic), epoxy polyethylene, polypropylene, polyurethane, and zinc.

For buried steel, copper alloy, and aluminum alloy piping and tanks and underground steel and copper alloy piping and tanks, coatings are in accordance with Table 1 of NACE SP0169-2007 or Section 3.4 of NACE RP0285-2002.

GALL Report AMP XI.M41, as modified by LR-ISG-2015-01, Table XI.M41-2, Inspection of Buried and Underground Piping and Tanks, recommends the following:

  • In regard to the inspection quantities in Table XI.M41-2, the detection of aging effects program element states, [a]dditional inspections, beyond those in Table XI.M41-2 may be appropriate if exceptions are taken to program element 2, preventive actions, or in response to plant-specific operating experience.
  • One inspection per 10-year interval for stainless steel piping (reference Table XI.M41-2).
  • Use of Preventive Action Category F, the highest number of inspections category, for those portions of in-scope buried steel piping which cannot be classified as Category C, D, or E.

Issue During the audit, the staff reviewed condition reports and plant-specific documents related to buried steel and stainless steel piping. The staff concluded the following:

  • It is unclear whether all in-scope steel piping is coated.
  • For at least portions of the stainless steel condensate makeup, storage, and transfer system piping, no coating was installed.
  • Based on the availability of soil sample parameter results, it is not clear that the soil is noncorrosive because redox potential values and soil drainage assessments were not available, and based on the presence of sulfides, a significant corrosivity penalty is applied. In addition, particularly in regard to stainless steel piping, chloride values were not available.

Request

1. For steel piping:
a. State what type and whether coatings were specified to be applied to all in-scope steel buried piping. If the types of coatings are not consistent with the recommended coating types in AMP XI.M41, state the basis for their effectiveness at preventing aging effects for buried steel piping.
b. If coatings were not specified to be applied to all in-scope steel buried piping (in essence, an exception to AMP XI.M41 preventive actions), state which Preventive Action Category will be used for those portions of DRAFT - UNCERTIFIED INFORMATION

DRAFT - UNCERTIFIED INFORMATION in-scope buried steel piping that were not specified to be coated. If Preventive Action Category F will not be used for those portions of in-scope buried steel piping that were not specified to be coated, state the basis for why additional inspections, beyond those in Table XI.M41-2, are not required to provide reasonable assurance that the piping will meet its intended function during the period of extended operation.

c. Provide sufficient data to demonstrate that for where in-scope steel piping is buried, the soil is not corrosive.
d. If the soil is corrosive or cannot be demonstrated to be noncorrosive; state which Preventive Action Category will be used for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness). If Preventive Action Category F will not be used for those portions of in-scope buried steel piping where the cathodic protection system is not meeting performance goals, state the basis for why additional inspections, beyond those in Table XI.M41-2, are not required to provide reasonable assurance that the piping will meet its intended function during the period of extended operation.
2. For stainless steel piping:
a. State what type and whether coatings were specified to be applied to all in-scope stainless steel buried piping. If the types of coatings are not consistent with the recommended coating types in AMP XI.M41, state the basis for their effectiveness at preventing aging effects for buried stainless steel piping.
b. For portions of the in-scope buried stainless steel piping that are not coated (by design configuration or as detected during inspections), state how many inspections will be conducted per 10-year period and the basis for why the number of inspections will be adequate to manage associated aging effects.

Response

River Bend Station (RBS) previously responded to RAI B.1.4-1 by letters dated January 24, 2018 (RBG 47813) and April 4, 2018 (RBG-47850). The following is the response to RAI B.1.4-1 revised to include additional information requested by the NRC during a telephone conference call held on April 25, 2018. This revised response supersedes the previous response. The locations of changes to the previous response of April 4 are indicated with revision bars.

Response

1.a. RBS design documents specify the application of coal tar epoxy coating to the buried steel piping in the systems that are within the scope of license renewal. A substitute coating of Tnemec HS 104 epoxy, which is a cycloaliphatic amine epoxy, is allowed by the specification for field-installed piping. Entergy believes that applications of the Tnemec coating are few, if any. While not included in the recommended coating types of AMP XI.M41, the Tnemec HS 104 does conform to the recommendations of American Water Works Association (AWWA) C210 Liquid-Epoxy Coatings and Linings for Steel Water Pipe and Fittings when installed in underground and underwater applications. It protects in immersion, salt spray and chemical exposures, and is applied in two coats at a minimum 6 mil dry film thickness each. It has superior abrasion resistance. As such it is an appropriate coating for preventing aging effects on steel piping.

b. Coatings were specified to be applied to all in-scope buried steel piping, and as such no further response is necessary for this question. A 2013 condition report documented one instance of buried steel piping that was discovered without protective coating. That piping ran from a drip pan under condensate transfer pumps to the condensate storage tank sump. The piping, which performs no license renewal intended function, had been installed in a 1986 plant modification that included inadequate directions for coating application. This condition is considered an isolated event and the modification process has been DRAFT - UNCERTIFIED INFORMATION

DRAFT - UNCERTIFIED INFORMATION improved since 1986 to provide more specific installation instructions.

c. Site documentation is not adequate to demonstrate that the soil at the site is noncorrosive in accordance with the guidance in Table XI.M41-2.
d. Because the soil at the site has not been demonstrated noncorrosive, Preventive Action Category F of Appendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01 will be used to determine the number of inspections for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness) or where the piping is not protected by a cathodic protection system unless all the requirements for moving to another preventive action category are met. This provision is added to Appendix A, Section A.1.4 and Appendix B, Section B.1.4.

2.a. Site documentation specifies that buried stainless steel piping is coated with coal tar epoxy, consistent with the recommended coating types in AMP XI.M41, or a silicone-based material. The silicone material is specified as Thurmalox 70 or Carboline 4674 and is applied in two coats. These silicone-based coating materials are rated for use in high-temperature applications and provide an additional layer of protection from the soil environment. The Thurmalox coating provides protection from chloride-induced stress corrosion cracking by preventing chlorides in the environment from coming in contact with the surface. This includes buried stainless steel piping that is subject to aging management review for license renewal. LR-ISG-2015-01 recommends one inspection of stainless steel piping during each 10-year period commencing 10 years prior to the period of extended operation. In order to ensure the adequate management of the effects of aging on buried stainless steel piping with silicone-based coatings, RBS will perform an additional inspection of the stainless steel piping during each 10-year period unless the soil is demonstrated non-corrosive and the backfill is in accordance with the recommendations of LR-ISG-2015-01. The additional inspection will be performed on piping with a silicon-based coating. Inspections performed in 2012 and 2013 did not identify any corrosion of stainless steel piping with silicon-based coating after 30 years of service. This operating experience provides the basis for concluding that adding the additional inspection is appropriate for the conditions at RBS.

b. The stainless steel piping in a soil environment is specified to be coated. Entergy has identified no buried stainless steel piping subject to aging management review that was not coated prior to installation.

The changes to LRA A.1.4 and B.1.4 follow with additions underlined and deletions lined through.

[The following revised LRA sections also reflect changes to the RAI response submitted on April 4, 2018]

A.1.4 Buried and Underground Piping and Tanks Inspection The Buried and Underground Piping and Tanks Inspection Program manages the effects of aging on external surfaces of buried piping components and tanks subject to aging management review. Components included in the program are fabricated from metallic materials. The program will manage loss of material and cracking through preventive and mitigative features (e.g., coatings, backfill quality, and cathodic protection) and periodic inspection activities during opportunistic and directed excavations. The number of inspections is based on the availability and effectiveness of preventive and mitigative actions as specified in Appendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01. In addition to the buried stainless steel piping inspection recommended by LR-ISG-2015-01, one additional inspection of buried stainless steel piping with silicon-based DRAFT - UNCERTIFIED INFORMATION

DRAFT - UNCERTIFIED INFORMATION coating will be conducted during each 10-year period unless the soil is demonstrated non-corrosive and the backfill is in accordance with the recommendations of LR-ISG-2015-01. Preventive Action Category F of LR-ISG-2015-01 will be used in determining the number of inspections for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness) or where the piping is not protected by a cathodic protection system unless all the requirements for moving to another preventive action category are met soil is demonstrated to be noncorrosive. Annual cathodic protection surveys are conducted. For steel components, where the acceptance criteria for effectiveness of cathodic protection is other than -850 millivolts (mV) instant off, loss of material rates are measured.

B.1.4 BURIED AND UNDERGROUND PIPING AND TANKS INSPECTION Program Description The Buried and Underground Piping and Tanks Inspection Program is a new program that will manage the effects of aging on external surfaces of buried piping components and tanks subject to aging management review. Components included in the program are fabricated from metallic materials. The program will manage loss of material and cracking through preventive and mitigative features (e.g., coatings, backfill quality, and cathodic protection) and periodic inspection activities during opportunistic and directed excavations. The number of inspections is based on the availability and effectiveness of preventive and mitigative actions as specified in Appendix B of License Renewal Interim Staff Guidance LR-ISG-2015-01. In addition to the buried stainless steel piping inspection recommended by LR-ISG-2015-01, one additional inspection of buried stainless steel piping with silicon-based coating will be conducted during each 10-year period unless the soil is demonstrated non-corrosive and the backfill is in accordance with the recommendations of LR-ISG-2015-01.

Preventive Action Category F of LR-ISG-2015-01 will be used in determining the number of inspections for portions of the in-scope buried steel piping where the cathodic protection system is not meeting performance goals (i.e., operational time period, effectiveness) or where the piping is not protected by a cathodic protection system unless all the requirements for moving to another preventive action category are met soil is demonstrated to be noncorrosive. Annual cathodic protection surveys are conducted. For steel components, where the acceptance criteria for effectiveness of cathodic protection is other than -850 mV instant off, loss of material rates are measured.

DRAFT - UNCERTIFIED INFORMATION

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