SBK-L-13115, Clarification to the Third Annual Update Provided in SBK-L-13115

Clarification to the Third Annual Update Provided in SBK-L-13115

ML13298A009
Person / Time
Site:	Seabrook
Issue date:	10/21/2013
From:	Walsh K NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-13115, SBK-L-13183
Download: ML13298A009 (8)

Text

NEXTera October 21, 2013 SBK-L-13183 U.S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 Seabrook Station Clarification to the Third Annual Update Provided in SBK-L-13115

References:

1. NextEra Energy Seabrook, LLC letter SBK-L-10077, "Seabrook Station Application for Renewed Operating License", May 25, 2010. (Accession Number ML101590099)

2. NextEra Energy Seabrook, LLC letter SBK-L-13115, "Third Annual Update to the NextEra Energy Seabrook License Renewal Application", July 2, 2013. (Accession Number ML13189A197)

3. LR-ISG-2011-03: Changes to the Generic Aging Lessons Learned (GALL) Report Revision 2 Aging Management Program XI.M41, "Buried and Underground Piping and Tanks", July, 2012. (Accession Number ML12138A295)

In Reference 1, NextEra Energy Seabrook, LLC (NextEra) submitted an application for a renewed facility operating license for Seabrook Station Unit 1 in accordance with the Code of Federal Regulations, Title 10, Parts 50, 51, and 54.

In Reference 2, NextEra submitted its third annual update in accordance with the License Renewal Rule. Within the third annual update, NextEra made additional changes to the Buried Piping and Tanks Inspection Program to incorporate the guidance provided in LR-ISG-2011-03 (Reference 3). Based on NRC Staff discussion, NextEra provides clarification to the Reference 2 changes in the enclosure to this letter.

To facilitate understanding, the changes are explained, and where appropriate, portions of the LRA are repeated with the change highlighted by strikethroughs for deleted text and bolded italics for inserted text.

There are no revised or new regulatory commitments contained in this letter.

If there are any questions or additional information is needed, please contact Mr. Richard R.

Cliche, License Renewal Project Manager, at (603) 773-7003.

If you have any questions regarding this correspondence, please contact Mr. Michael H. Ossing, Licensing Manager, at (603) 773-7512.

NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874

United States Nuclear Regulatory Commission SBK-L-13183 / Page 2 I declare under penalty of perjury that the foregoing is true and correct.

Executed on October 21, 2013 Sincerely, Kevin T. Walsh Site Vice President NextEra Energy Seabrook, LLC

Enclosures:

Enclosure - Clarification to the Third Annual Update Provided in SBK-L-13115 cc:

W.M. Dean, J. G. Lamb, P.C. Cataldo, R. A. Plasse Jr.,

L. M. James, NRC Region I Administrator NRC Project Manager, Project Directorate 1-2 NRC Senior Resident Inspector NRC Project Manager, License Renewal NRC Project Manager, License Renewal Director Homeland Security and Emergency Management New Hampshire Department of Safety Division of Homeland Security and Emergency Management Bureau of Emergency Management 33 Hazen Drive Concord, NH 03305 John Giarrusso, Jr., Nuclear Preparedness Manager The Commonwealth of Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702-5399

Enclosure to SBK-L-13183 Clarification to the Third Annual Update Provided in SBK-L-13115

United States Nuclear Regulatory Commission Page 2 of 6 SBK-L-13183 / Enclosure NRC Question No. 1:

LR-ISG-2011-03 Section 2.a.iii. states:

Failure to provide cathodic protection in accordance with Table 2a must be justified in the LRA. The justification should include sufficient detail (e.g., soil sample locations, soil sample results, the methodology and results of how the overall soil corrosivity was determined, pipe-to-soil potential measurements) for the staff to independently reach the same conclusion as the applicant. An exception must be stated and justified if the basis for not providing cathodic protection is other than demonstrating that external corrosion control (i.e., cathodic protection and coatings) is not required or demonstrating that installation, operation, or surveillance of a cathodic protection system is not practical. Inspections in excess of those recommended in program element 4 of this AMP may be required based on plant-specific operating experience.

Although the program has been revised to include aspects such as soil sampling and increased inspections based on the effectiveness and availability, or lack of cathodic protection, neither the original proposed plant-specific program, subsequent RAls, and the July 2, 2013 Third Annual Update letter contain a basis for not providing cathodic protection on all buried steel in-scope piping. The October 29, 2010 letter which provided the new plant-specific Buried Piping and Tanks Inspection Program stated, "[s]eabrook Station has no history of failures of buried piping leading to loss of function of a component within the scope of license renewal." However, this does not provide a sufficient basis to address this aspect of LR-ISG-2011-03.

Although LR-ISG-2011-03 provides options for increased inspections based on the effectiveness and availability, or lack of cathodic protection, these inspection recommendations were developed with the understanding that the staff would have sufficient information to evaluate the potential for loss of material to occur in in-scope piping that is not cathodically protected. In past evaluations, the staff's understanding has been supplemented with information such as recent soil corrosivity testing, Area Potential Earth Current or other surveys, or an extensive number of excavated buried piping inspections conducted just prior and during the license renewal application review process.

NextEra Energy Seabrook Response:

In support of the NEI 09-14 Buried Pipe Inspection Initiative (BPI), NextEra Energy Seabrook has performed several excavations, inspections and evaluations of buried piping. Additionally, fourteen locations were selected for soil analysis. The results include a representative selection of plant systems and pipe materials, and locations throughout Seabrook Station.

Soil Analysis The locations selected for soil analysis were scheduled to be sampled in the fall of 2012 and again in the spring of 2013. Approximately half of the fall 2012 analyses were completed and the remainder scheduled for fall of 2013. All of the spring 2013 sampling has been completed as scheduled.

In addition to laboratory analysis of collected soil samples, in-situ measurements of electrical potential and soil resistivity were performed by an experienced geophysicist.

Soil potential measurements were performed within each soil boring following collection of soil samples. Soil resistivity measurements were conducted within the general proximity of each boring location.

United States Nuclear Regulatory Commission Page 3 of 6 SBK-L-13183 / Enclosure AWWA standard C105 was used to determine a corrosivity index at each location. A corrosivity index of 10 points or greater is classified as corrosive soil conditions. With one exception, all locations received a corrosivity point total of 5 or less and soil resistivity measurements ranged from 2297 to 242867 ohm-cm. The soil resistivity readings were 2297 (one location), 3546 -

3736 (two locations), 5063 - 5675 (three locations), 9101 - 12564 (four locations), 21476 - 27789 (six locations), 52657 (one locations), and 145983 - 242867 (two locations) ohm-cm. The single exception was a location selected to inspect a section of 24" cement lined carbon steel pipe in the circulating water system. In the fall of 2012, this location had received a corrosivity point total of 3. In the spring of 2013, it received 14 points primarily due to a decrease in resistivity from 9101 ohm-cm to 1366 ohm-cm. When inspected, this pipe showed no signs of coating damage or pipe wall corrosion. The only LR in-scope piping in the vicinity of this sample location is Fire Protection piping, which is inspected using the jockey pump operation. All other locations sampled in both the fall of 2012 and spring of 2013 were within 1 corrosivity point total for both analyses.

The soil sample results from the spring of 2013 described all samples as having a texture of fine, medium, or course sand with some gravel except for the location that had a corrosivity point total of 14, which had a texture of medium to fine sand with some silt and clay.

Field moisture descriptions ranged from dry (1 location) to moist (7 locations) to saturated (6 locations).

Excavation and Inspection Under the NEI Buried Piping Inspection Initiative, five excavations have been completed to date.

None of the lines excavated during this phase of the project were cathodically protected. All of these excavations showed the pipe coating to be intact except for minor curling of tape edges and minor wear caused by installation/excavation activities with the exception of one stainless steel pipe, coated during installation, which had several areas where the coating had peeled back and some areas had exposed pipe. For metallic pipe, the external protective coating was removed, the pipe was visually examined and ultrasonically tested, and the coating reapplied. With the exception of a not in-scope service air line, no indication of pipe surface corrosion or any external wall loss was noted, including the stainless steel line with coating degradation. Some pitting corrosion was noted on several areas of a not in-scope service air line upon removal of the coating for ultrasonic testing. While the coating appeared intact, identification of pitting following coating removal makes it likely there were holidays in the coating. Ultrasonic testing confirmed that the wall thickness remained well above minimum. No indication of coating or piping damage due to backfill materials was noted. Where feasible, each direct examination included a minimum of ten foot length of pipe in accordance with NEI 09-14. Based on excavation and examination records, all inspections included ten feet of pipe with the exception of one length of cast iron pipe where only nine feet eight inches were accessible between hub fittings for ultrasonic testing.

In this case, more than ten feet were excavated and visually inspected.

The five excavations included carbon steel, stainless steel, and cast iron piping as well as pre-stressed concrete pipe and storm drain conduit (concrete). Excavation #1 examined a section of 24" carbon steel, cement lined circulating water system pipe identical to the 24" service water pipe in-scope for license renewal but without cathodic protection. Excavation #2 included a 2" stainless steel in-scope condensate system line and 4 not in-scope of lines (4" and 2" carbon steel pipes, a 6" stainless steel pipe, and a 12" cast iron pipe). Additionally, this excavation was in the immediate vicinity of a 24" carbon steel in-scope condensate system line and close proximity to

United States Nuclear Regulatory Commission Page 4 of 6 SBK-L-13183 / Enclosure a 4" cast iron in-scope floor drain system line and a 4" carbon steel in-scope feedwater system line. Excavation #2a included a 3" carbon steel floor drain system line similar and adjacent to an in-scope floor drain system line. Excavations #4 and #6 were made in areas of concrete pipe where there was no nearby buried piping in-scope for license renewal. Planned excavations #3 and #5 have not yet been completed.

Prior to entry into the PEO, additional soil samples and analyses will be performed consistent with the requirements of LR-ISG-2011-03 to confirm the classification of buried piping not provided with cathodic protection. This action is consistent with the LRA Appendix A, Table A.3, Commitment #64.

On further review of LR-ISG-2011-03, the following changes have been made to the NextEra Seabrook License Renewal Application, in Section B.2.1.22, as submitted in SBK-L-13115, Seabrook Station Third Annual Update to the NextEra Energy Seabrook License Renewal Application, Enclosure 1.

1. In Section B.2.1.22, Element 4 - Detection of Aging Effects, the last sentence of the fifth paragraph is revised as follows:

The EPRI report arrives at a corrosion index using combined values for soil resistivity, pH, redox potential, sulfides, and moisture in accordance with American Water Works Association standard C 105, and considers the soil to be corrosive if the combined value is 10 or greatertha*-0.

2. In Section B.2.1.22, Element 4 - Detection of Aging Effects, the following new paragraphs are added after the fifth paragraph as follows:

Seabrook Station has already performed soil sampling and analyses to determine the corrosivity of the soil and pipe-to-soil potential. Fourteen locations were sampled throughout the site.

In addition to laboratory analysis of collected soil samples, in-situ measurements of electrical potential and soil resistivity were performed by an experienced geophysicist. Soil potential measurements were performed within each soil boring following collection of soil samples. Soil resistivity measurements were conducted within the general proximity of each boring location.

A WWA standard C105 was used to determine a corrosivity index at each location. A corrosivity index of 10 points or greater is classified as corrosive soil conditions. With one exception, all locations received a corrosivity point total of 5 or less, had a soil resistivity ranging from 2,297 to 242,867 ohm-cm, and were noted to be in areas offine, medium, or course sand with some gravel. Field moisture observations ranged from dry (1 location) to moist (7 locations) to saturated (6 locations).

The single exception was a location selected to inspect a section of 24" cement lined carbon steel pipe in the circulating water system. In the fall of 2012, this location received a corrosivity point total of 3. In the spring of 2013, it received 14 points primarily due to a decrease in resistivity from >3000 ohm-cm to less than 1500 ohm-cm. The texture of the soil in that area was described as medium to fine sand, some silt and clay. The only LR in-scope piping in the vicinity of this sample location is Fire Protection piping, which is inspected using the jockey pump operation.

United States Nuclear Regulatory Commission Page 5 of 6 SBK-L-13183 / Enclosure Seabrook Station has performed site excavations in support of the NEI 09-14 Buried Piping Inspection Initiative which included locations representative of systems and pipe materials that are in-scope for license renewal. These excavations and subsequent removal of the protective coating, and visual examination and ultrasonic testing of the exterior pipe wall in general showed no indications of coating damage or pipe wall corrosion or external wall loss. The only exceptions were a stainless steel line, coated during installation, which had several areas where the coating had peeled back and had areas of exposed pipe, and a not in-scope service air line which showed some pitting corrosion following removal of the coating. Where feasible, each direct examination included at minimum of a ten foot length of pipe.

NRC Question No. 2 LR-ISG-2011-03 Section 2.a.iv. states:

If cathodic protection is not provided for any reason, the applicant should review 10 years of plant-specific operating experience to determine if adverse conditions as described in Section 4.f., Adverse Indications, of this AMP have occurred at the station. This search should include components that are not in-scope for license renewal if, when compared to in-scope piping, they are buried in a similar soil environment. The results of this expanded plant-specific operating experience search should be included in the LRA.

The October 29, 2010 letter included plant-specific operating experience examples as early as the Fall of 1995. However, it is not clear that these examples include all instances related to buried piping or if, "components that are not in-scope for license renewal if, when compared to in-scope piping, they are buried in a similar soil environment" were included in the search of operating experience. The staff needs to review all of the available plant-specific operating experience in order to evaluate the potential for loss of material to occur in in-scope piping that is not cathodically protected.

NextEra Energy Seabrook Response:

The Seabrook Station operating experience discussed in Appendix B, Section B.2.1.22, "Buried Piping and Tanks Inspection" includes in-scope and out of scope buried piping leaks, excavations, and inspection. All of the OE discussed in the Seabrook Station basis document is also included in Appendix B, Section B.2.1.22.

The License Renewal operating experience database for AMP effectiveness review was populated with plant condition reports for the period from August 1998 to February 2009.

The only OE that is not discussed in the Seabrook Station basis document and Appendix B, Section, B.2.1.22 was a leak in a sanitary drainage line outside of the plant's protected area. The details of this underground leak are as follow:

In April of 2003, an underground leak was identified in four inch sanitary drainage piping, which is fabricated from schedule 40, hot-dipped zinc coated, steel pipe in accordance with AWWA specification A120. The sanitary drainage piping was assembled with malleable iron screwed and galvanized fittings. The subject piping was wrapped with a coal-tar protective coating in accordance with AWWA specification C203.

United States Nuclear Regulatory Commission Page 6 of 6 SBK-L-13183 / Enclosure Upon inspection, it was reported that the overall condition of the coal-tar protective coating was intact and in very good condition with the exception of the area where the through wall leakage had occurred. The perforation in the coating was located at the pipe to pipe fitting intersection at an area that had coal-tar protective coating applied in place during installation.

NextEra Energy determined that the coal-tar protective coating was probably damaged at some point during or after the piping was installed and tested. A nine inch section of the pipe was replaced, wrapped with protective coating, and holiday tested.

This OE has been added to Appendix B, Section B.2.1.22, "Buried Piping and Tanks Inspection" and to the Seabrook Station's basis document as written above.

NRC Question No. 3 Footnote 6 of the Buried Piping Inspection Locations chart provided in the July 2, 2013 Third Annual Update letter states, "[t]he number of inspections for non-cathodically protected steel piping in corrosive soil apply only to the inspections performed during the period of extended operation." The staff does not understand the intent of this footnote.

NextEra Energy Seabrook Response:

Footnote 6 of the Buried Piping Inspection Locations table provided in the July 2, 2013 third annual update letter (SBK-L-13115) has been revised as follows:

6. Soil corrosivity is determined by soil analysis using a demonstrated methodology such as EPRI report 1021470, Table 8-1. A soil corrosivity value of 10 or greater than l-using this method is considered corrosive. The number-of ins p.tion. for-non cath.dially pr.Otected steel pipn ineorsivc soil apply enly to the inspeefiefns per-formed during the period of ctded peratiefn.

NRC Question No. 4 LR-ISG-2011-03 Section 6.c. states, "[i]f coated or uncoated metallic piping or tanks show evidence of corrosion, the remaining wall thickness in the affected area is determined to ensure that the minimum wall thickness is maintained. This may include different values for large area minimum wall thickness, and local area wall thickness." It is not clear that this recommendation has been incorporated into the program.

NextEra Energy Seabrook Response:

The following new paragraph has been added to the end of "Element 6, Acceptance Criteria" as follows:

If coated or uncoated metallic piping or tanks show evidence of corrosion, the remaining wall thickness in the affected area is determined to ensure that the minimum wall thickness is maintained. This may include different values for large area minimum wall thickness, and local area wall thickness.