ML102450727

Request for Additional Information for the Review of the Columbia Generating Station, License Renewal Application

ML102450727
Person / Time
Site:	Columbia
Issue date:	09/16/2010
From:	Gettys E License Renewal Projects Branch 1
To:	Gambhir S Energy Northwest
Gettys E, NRR/DLR, 415-4029
References
TAC ME3058
Download: ML102450727 (11)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 16, 2010 Mr. S.K. Gambhir Vice President Technical Services Columbia Generating Station Energy Northwest MD PE04 P.O. Box 968 Richland, WA 99352-0968

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION, LICENSE RENEWAL APPLICATION (TAC NO. 3058)

Dear Mr. Gambhir:

By letter dated January 19, 2010, Energy Northwest submitted an application pursuant to Title 10 of the Code of Federal Regulations Part 54 (10 CFR Part 54), to renew operating license NPF-21 for Columbia Generating Station, for review by the U.S. Nuclear Regulatory Commission (NRC or the staff). The staff is reviewing the information contained in the license renewal application and has identified, in the enclosure, areas where additional information is needed to complete the review. Further requests for additional information may be issued in the future.

Items in the enclosure were discussed with Abbas Mostala and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me at 301-415-4029 or bye-mail at evelyn.gettys@nrc.gov.

Sincerely, Evelyn Gettys, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-397

Enclosure:

As stated cc w/encl: See next page

COLUMBIA GENERATING STATION LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION RAI 3.1.2.3.1-1

Background:

In license renewal application (LRA) Table 3.1.2-1, the applicant stated that the steel nozzle (N06) safe-end extension (RHR/LPCI) exposed to air-indoor uncontrolled (external) does not require any aging effect to be managed. The related aging management review (AMR) line item cites generic note G, indicating that this environment is not in the GALL Report for the aging effects of this component and material combination. Also, the associated plant-specific note 0101 states that there is no identified aging effect for these components, based on their being exposed to indoor air, where temperature is >212°F.

Issue The staff noted that the applicant has listed in row item 313 of LRA Table 3.1.2 that reactor pressure vessel stabilizer brackets made of steel exposed to air-indoor uncontrolled (external) are being managed for "cracking - flaw growth" by the ASME Section XI lSI - IWB, IWC and IWD aging management program (AMP), and classified this with the Generic Note H. This classification does not appear consistent with the AMR item classified with the Generic Note G discussed above.

Request Justify why the treatment of these two AMR items is different for the same material exposed to same environment for managing the aging effect in one and not in the other item, and reconcile the differences.

RAI 3.1.2.3.1-2 Backqround In LRA Tables 3.1.2-1 and 3.1.2-3 the applicant stated that various reactor vessel components of steel, steel with stainless steel cladding, stainless steel, and nickel alloys exposed to reactor coolant (internal) are being managed for "cracking - flaw growth" by the ASME Section XI lSI IWB, IWC and IWD Program. The related AMR line items cite generic note H, indicating that the aging effect is not in the GALL Report for this component, material, and environment combination. These components include: RPV shells or shell rings, various nozzles and associated safe-ends/thermal sleeves, penetrations, and support attachments/welds.

Issue The LRA refers to "Cracking - Flaw Growth" as a time dependent aging effect/mechanism being managed by the ASME Section XI lSI program. The applicant's usage (or intended meaning) of "Cracking - Flaw Growth" is not clear to the staff. Also, depending on the interpretation of "Flaw Growth," it would seem that these items should be addressed as "TLAA" which is covered under the GALL Report, instead of generic note "H" items.

Request (a) Clarify the meaning and intended usage of "Cracking - Flaw Growth" aging effecUmechanism.

(b) Identify any of the items for "Flaw Growth" (as associated with the Generic Note H of this Enclosure

- 2 AMR) in the current licensing basis (CLB) for flaw growth or flaw tolerance evaluations to analyze fatigue that involved the current operating term (40 years) and were determined to be relevant in making the safety determination? If so, justify the adequacy of aging management of applicable items by the ASME Section XIISI-IWB, IWC and IWD Program (as Generic Note H items), or include these under time-limited aging analysis (TLAA) assessment.

RAI3.1.1.x-1

Background

Cracking due to intergranular stress corrosion cracking (IGSCC) has occurred in small- and large-diameter boiling water reactor (BWR) piping made of austenitic stainless steels and nickel alloys. The IGSCC has also occurred in a number of vessel internal components, such as core shrouds, access hole covers, top guides, and core spray spargers (NRC Bulletin 80-13, NRC Information Notice [IN] 95-17, NRC Generic Letter [GL] 94-03, and NUREG-1544). Cracking due to thermal and mechanical loading have occurred in high pressure coolant injection (HPCI) piping (NRC IN 89-80) and instrument lines (NRC Licensee Event Report [LER] 50-249/99-003 1). Jet pump BWRs are designed with access holes in the shroud support plate at the bottom of the annulus between the core shroud and the reactor vessel wall. These holes are used for access during construction and are subsequently closed by welding a plate over the hole. Both circumferential (NRC IN 88-03) and radial cracking (NRC IN 92-57) have been observed in access hole covers.

Issue Columbia Generating Station (CGS) has a jet-pump BWR designed with access holes in the shroud support plate which were closed by a welded cover plate. In this case one of the plates is welded only from the top and the plate material is austenitic stainless steel. This has the potential for IGSCC from the bottom where crevice conditions exist, requiring augmentation of the ASME Section XIISI-IWB, IWC and IWD Program. In contrast to these plant conditions, the applicant, in its LRA Table 3.1.1 Item 3.1.1-49, states that access hole covers were modified to eliminate the crevice and that the component material is nickel alloy.

Request Clarify and reconcile the actual plant conditions for the access hole welded cover plates and the LRA Table 3.1.1 Item 3.1.1-49. Justify the absence of any augmented inspection plan for the creviced location(s) and provide the method and basis for monitoring and inspection for the potential IGSCC of these locations such that their intended function(s) will be maintained consistent with the CLB during the period of extended operation, as required by 10 CFR 54.21 (a)(3).

RAI 3.3.1.68-1

Background

LRA Table 3.3.1, item 3.3.1-68 addresses steel piping, piping components, and piping elements and item 3.3.1-70 addresses copper alloy piping, piping components, and piping elements exposed to raw water (internal) which are being managed for loss of material due to pitting,

-3 crevice, and microbiologically influenced corrosion (MIC), and fouling. To manage these aging effects, in LRA Table 3.3.2-22, the applicant credits the Diesel-Driven Fire Pumps Inspection Program (B.2.18) for the components in the fire protection system, and in LRA Tables the applicant credits the Monitoring and Collection Systems Inspection Program (B.2.41) for the components in the fuel pool cooling, plant sanitary drains, and reactor closed cooling water systems.

For line items 3.3.1-68 and 3.3.1-70, the GALL Report recommends using GALL AMP XI.M27 "Fire Water System" which recommends performing wall thickness evaluations of system components using nonintrusive volumetric testing or plant maintenance visual inspections of the internal surfaces to ensure that aging effects are being adequately managed. GALL AMP XI.M27 recommends that these inspections be performed before the end of the current operating term and at plant-specific intervals thereafter during the period of extended operation to ensure that degradation will be detected before the loss of intended function.

Issue The staff noted that the Diesel-Driven Fire Pumps Inspection Program and the Monitoring and Collection Systems Inspection Programs propose to manage the aging of steel and copper alloy piping, piping components, and piping elements through the use of one-time inspections involving a combination of established volumetric and visual examination techniques that will detect and characterize the conditions on the internal surfaces of subject mechanical components that are exposed to raw water (or antifreeze). It is not clear to the staff how these programs are adequate to manage loss of material for these components given that the GALL Report recommends periodic inspections to ensure that aging effects are being adequately managed and the system maintains its intended function during the period of extended operation.

Request Justify how the Diesel-Driven Fire Pumps Inspection and Monitoring and Collection Systems Inspection Programs, which are both one-time inspection programs, are adequate to manage loss of material and reduction in heat transfer for piping and components in the fire protection, fuel pool cooling, plant sanitary drains, and reactor closed cooling water systems in place of a periodic inspection program as recommended by the GALL Report.

RAI 3.4.2.3-1

Background

In LRA Table 3.4.2-3, row number 33, the applicant proposes to manage loss of material for the external surfaces of steel piping exposed to uncontrolled indoor air using its Buried Piping and Tanks Inspection Program. The applicant cites plant-specific note 0408 which states that the carbon steel piping from the condensed storage tank (CST) is buried and is enclosed in guard pipe. The applicant also cites generic note E and line item 3.4.1-28. The GALL Report recommends GALL AMP GALL AMP XI.36 "External Surfaces Monitoring" to ensure that these aging effects are adequately managed.

Issue The staff notes that GALL AMP XI.36 "External Surfaces Monitoring" recommends periodic direct visual inspections of the surfaces managed by the program. The staff also notes that the

-4 applicant's Buried Piping and Tanks Inspection Program provides for visual inspections of the external surfaces of buried piping and tanks to determine coating integrity, but does not include access to or direct inspection of the external surfaces of buried pipe enclosed in an outer guard pipe. The staff further notes that the applicant's Buried Piping and Tanks Inspection Program does not include flow testing, pressure testing, or any other means to manage aging for piping within a guard pipe. It is unclear to the staff how the buried piping within a guard pipe will be adequately managed by the Buried Piping and Tanks Inspection Program.

Request Explain how the external surface of the underground piping enclosed in an outer guard pipe will be adequately managed for loss of material.

RAI 3.3.2.2.3.3 - 1

Background

The GALL Report, Table 3 item 6 ~tates that cracking due to stress corrosion cracking could occur in stainless steel diesel engine exhaust piping, piping components, and piping elements exposed to diesel exhaust. The GALL Report further states that these components require a further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed. The LRA Section 3.3.2.2.3.3 states that during normal plant operations, diesel exhaust piping, piping components, and piping elements are exposed to outdoor air and are only exposed to diesel exhaust infrequently and for short durations. The LRA further states that due to these infrequent and short duration exposures, stress corrosion cracking is not identified as an aging effect requiring management for stainless steel diesel engine exhaust components.

Issue Stress corrosion cracking is a potential aging affect for stainless steel diesel engine exhaust piping, piping components, and piping elements exposed to diesel exhaust as indicated in the GALL Report. While there is an initiation period required for stress corrosion cracking to occur, it will depend on the material and environment. The LRA does provide enough information to rule out stress corrosion cracking of the stainless steel diesel engine exhaust piping, piping components, and piping elements exposed to diesel exhaust.

Request

1. Clarify how stress corrosion cracking was quantitatively ruled out by providing additional information on the actual cumulative exposure time that the stainless steel diesel exhaust components are expected to be subjected to diesel exhaust greater than 60°C

[140 OF] during the total period of extended operation.

2. Clarify what type of stainless steel is used in the diesel exhaust and provide the technical basis that substantiates the claim that the diesel exhaust piping, piping components, and piping elements are not susceptible to stress corrosion cracking under the cumulative exposure time during the period of extended operation.

- 5 RAI 3.3.2.2.7.3 - 1

Background

The GALL Report, Table 3 item 18 states that loss of material due to general (steel only), pitting, and crevice corrosion could occur for steel and stainless steel diesel engine exhaust piping, piping components, and piping elements exposed to diesel exhaust. The GALL Report further states that these components require a further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed.

Issue The LRA Section 3.3.2.2.7.3 states that during normal plant operations, diesel exhaust piping, piping components, and piping elements are exposed to outdoor air and are only exposed to diesel exhaust infrequently and for short durations. The LRA further states that the loss of material will be managed by the Diesel Systems Inspection or the Diesel-Driven Fire Pumps Inspection Programs. It is not clear to the staff how the Diesel System Inspection or the Diesel-Driven Fire Pumps Inspection Programs, which is a one-time inspection program, will appropriately manage this aging effect.

Request Provide additional information on the technical basis for how the Diesel System Inspection and the Diesel-Driven Fire Pumps Inspection Programs will adequately managing loss of material for steel and stainless steel diesel engine exhaust piping, piping components, and piping elements exposed to diesel exhaust. Secondly, provide additional information why a program with a periodic inspection is not being used to manage this aging effect.

RAI 3.3.2.2.7.3 - 2

Background

The GALL Report, Table 3 item 18 states that loss of material due to general (steel only), pitting, and crevice corrosion could occur for steel and stainless steel diesel engine exhaust piping, piping components, and piping elements exposed to diesel exhaust. The GALL Report further states that these components require a further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed. The LRA Section 3.3.2.2.7.3 states that during normal plant operations, diesel exhaust piping, piping components, and piping elements are exposed to outdoor air and are only exposed to diesel exhaust infrequently and for short durations. The LRA further states that the loss of material will be managed by the Diesel Systems Inspection or the Diesel-Driven Fire Pumps Inspection Programs, which are one-time inspection programs. The GALL Report states that the One Time Inspection Program is used to verify the effectiveness of an AMP or may also be used to provide additional assurance that aging that has not yet manifested itself is not occurring. The GALL Report states that the One-Time Inspection Program may also be used to provide additional assurance that the evidence of aging shows that the aging is so insignificant that an AMP is not warranted.

Issue That staff noted that the Diesel Systems Inspection or the Diesel-Driven Fire Pumps Inspection Programs (i.e., One-Time Inspection Programs) are not used to verify the effectiveness of an AMP as recommended by GALL Report. The staff further noted these programs to provide

- 6 assurance that aging that has not yet manifested or that the evidence of aging is so insignificant that an AMP is not warranted. However, the applicant has not indicated that corrosion of the diesel exhaust piping, piping components, and piping elements has not previously occurred.

Request Provide additional information on the operating experience of the diesel exhaust piping, piping components, and piping elements indicating if corrosion has been observed in the past. If operating experience does reveal corrosion of the diesel exhaust piping, piping components, and piping elements, provide additional information on why the Diesel Systems Inspection or the Diesel-Driven Fire Pumps Inspection Programs are appropriate to manage the aging of these components.

RAI 3.5.2.1-1

Background

In LRA Table 3.5.2-1, row number 9, the applicant states that stainless steel drywell sump liners exposed to raw water are being managed for loss of material by the Structures Monitoring and BWR Water Chemistry Programs. The AMR line item cites generic note J and plant specific note 0508, which states that, in addition to the Structures Monitoring Program as the applicable AMP, the BWR Water Chemistry Program is also credited with the elimination of excessive chlorides and sulfates from the water. In LRA Section 2.4.1, the applicant also states that it has two drywell sumps; one for unidentified leakage, and one for identified leakage. The applicant further states that the floor drain sump collects unidentified leakage from sources within the drywell, such as valve stem, and control rod drive (CRD) leakage; and the drywell equipment drain sump receives identified reactor coolant leakage from the reactor vessel head flange vent and pump seal leak-off lines.

The staff notes that the applicant's BWR Water Chemistry Program includes monitoring and control of contaminants, such as chlorides and sulfates, in primary and secondary water in accordance with Electrical Power Research Institute water chemistry guidelines. However, the staff also notes that water collected by the drywell sumps include normal leakage which could have been exposed to contaminants in the drywell as it drains from the leak point to the drywell sump. The staff further notes that closed cooling water leakage from the drywell cooling units, which is not monitored by the BWR Water Chemistry Program, could also enter the drywell sumps.

Issue The configuration of the floor drain and drywell equipment drain sumps do not prevent the intrusion of water that was part of the primary water system but has been exposed to contaminants or water from the closed cooling water system that is not monitored by the BWR Water Chemistry Program. It is unclear to the staff how the BWR Water Chemistry Program is being used to reduce chlorides and sulfates in the water being collected by the drywell sumps in order to manage loss of material for the drywell sump liners.

Request Explain how the BWR Water Chemistry Program is being used to manage loss of material for the drywell sump liners.

-7 RAI B.2.43-3

Background

SRP-LR, Appendix A.1.1.2.3.5, states that monitoring and trending activities should be described and should provide predictability of the extent of degradation in order to effect timely corrective or mitigative actions. It also states that the methodology for analyzing inspection results against acceptance criteria should be described.

Issue The Potable Water Monitoring Program's "monitoring and trending" program element provides information on monitoring activities for water quality; however, there is no description of monitoring or trending activities associated with the planned enhancement to the program for periodic inspection activities.

Request Provide information regarding monitoring and trending activities associated with the planned program enhancement for periodic inspection activities, or provide a basis for not monitoring and trending these periodic inspection results.

RAI B.2.43-4

Background

SRP-LR, Appendix A.1.1.2.3.1 0 states that operating experience information, including past corrective actions which result in program enhancements, should be considered. It continues by stating this information can show where an existing program failed to intercept aging degradation in a timely manner, resulting in appropriate program enhancements, and the information should provide objective evidence to support the conclusion that the effects of aging will be managed so that intended function(s) will be maintained.

The Potable Water Monitoring Program's "detection of aging effects" element states that based on operating experience, it is necessary that inspections be conducted at least one every 5 years, and to include components in the potable cold water, potable hot water and reactor building outside air systems. The program's "operating experience" element states that there have been recurrent problems mainly related to PVC piping, which are not in-scope for license renewal and that none of the leakage problems have occurred where they could have affected safety-related equipment due to leakage or spray. However, based on the staff's onsite review of operating experience involving corrosion or indications of corrosion, even though these components may not have been in-scope for license renewal, they are indicative of corrosion occurring in both copper and iron alloys in the potable water system. It was not clear to the staff if the operating experience provides objective evidence to support the conclusion that the effects of aging will be managed adequately by a periodic inspection of the potable water system every 5 years so that intended function(s) will be maintained.

Request Provide additional information on the technical basis for conducting periodic inspections at 5 year intervals; including relevant operating experience for components that have the same

-8 material, environment, and aging affects, consistent with the in-scope components in the potable water system.

September 16,2010 Mr. S.K. Gambhir Vice President Technical Services Columbia Generating Station Energy Northwest MD PE04 P.O. Box 968 Richland, WA 99352-0968

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION, LICENSE RENEWAL APPLICATION (TAC NO. 3058)

Dear Mr. Gambhir:

By letter dated January 19, 2010, Energy Northwest submitted an application pursuant to Title 10 of the Code of Federal Regulations Part 54 (10 CFR Part 54), to renew operating license NPF-21 for Columbia Generating Station, for review by the U.S. Nuclear Regulatory Commission (NRC or the staff). The staff is reviewing the information contained in the license renewal application and has identified, in the enclosure, areas where additional information is needed to complete the review. Further requests for additional information may be issued in the future.

Items in the enclosure were discussed with Abbas Mostala and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me at 301-415-4029 or bye-mail at evelyn.gettys@nrc.gov.

Sincerely, IRA!

Evelyn Gettys, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-397

Enclosure:

As stated cc w/encl: See next page DISTRIBUTION:

via listserv ADAMS Accession No'.. ML102450727 OFFICE LA:DLR PM:RPB1 :DLR !C: RPB1:DLR PM:RPB1 :DLR NAME IKing EGettys BPham wlcomments EGettys wlcomment DATE 9/9/10 9/10/10 9/11110 9/16/10 OFFICIAL RECORD COpy

Letter to S.K. Gambhir from E. Gettys dated September 16, 2010

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION, LICENSE RENEWAL APPLICATION (TAC NO. 3058)

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