ML101660166

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

ML101660166
Person / Time
Site:	Columbia
Issue date:	07/13/2010
From:	Gettys E License Renewal Projects Branch 1
To:	Oxenford W Energy Northwest
Gettys E, NRR/DLR, 415-4029
References
Download: ML101660166 (10)

Text

1 July 13, 2010 Mr. W.S. Oxenford, Vice President Nuclear Generation and Chief Nuclear Officer Columbia Generating Station Energy Northwest MD PE08 P.O. Box 968 Richland, WA 99352

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION, LICENSE RENEWAL APPLICATION

Dear Mr. Oxenford:

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 by e-mail at evelyn.gettys@nrc.gov.

Sincerely,

/RA/

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

ML101660166 OFFICE LA:DLR PM:RPB1:DLR BC: RPB1:DLR PM:RPB1:DLR NAME SFigueroa EGettys BPham w/edits EGettys w/comments DATE 7/8/10 6/21/10 7/13/10 7/13/10

COLUMBIA GENERATING STATION LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION RAI B.2.6 - BWR Feedwater Nozzle Program Issue:

LRA Section B.2.6 includes a statement indicating the use of enhanced in-service inspection (ISI) for the feedwater (FW) nozzles in accordance with American Society of Mechanical Engineers (ASME) Code,Section XI requirements and the recommendations of General Electric (GE) document NE-523-A71-0594. LRA Section B.2.6 also states that the detection and sizing of FW nozzle cracks at Columbia is conducted in accordance with the ASME Boiler and Pressure Vessel Code,Section XI requirements and GE NE-523-A71-0594. The NRC staff notes that the above statements in LRA Section B.2.6 are consistent with the corresponding FW nozzle program elements described in the GALL Report,Section XI.M5.

Request:

The NRC staff requests that Columbia confirm whether the implementation of the GE NE-523-A71-0594 recommendation results in plant-specific FW nozzle inspection requirements that are augmented with respect to the baseline AMSE Code,Section XI requirements for FW nozzle inspections (e.g., are Columbias plant-specific FW nozzle inspection criteria in full compliance with ASME Code,Section XI requirements, with the GE NE-523-A71-0594 FW nozzle inspection recommendations implemented at Columbia?).

Does Columbia use ultrasonic (UT) examination systems, techniques, personnel, and procedures that are qualified in accordance with the AMSE Code,Section XI, Appendix VIII Performance Demonstration Initiative (PDI) criteria when performing UT examinations of the FW nozzles?

Issue:

LRA Section B.2.6 states that Columbia operating experience shows that Columbias BWR FW nozzle program is effective in managing aging effects in that no FW nozzle cracking has been observed and that previous inspections of the FW nozzles found no unacceptable indications.

Request:

Please indicate whether this statement applies just to the FW nozzles or to other FW system components in the reactor, such as the FW spargers. The NRC staff recognizes that FW spargers are nonsafety-related components.

RAI B.2.8 - BWR Stress Corrosion Cracking Program Please describe the overall scope of the BWR stress corrosion cracking (SCC) Program at Columbia, as follows:

a. Does this particular program address SCC of reactor coolant pressure boundary (RCPB) piping alone, or does it address SCC for any other structures, systems, or components (SSCs) other than RCPB piping?

b. Does the BWR SCC Program at Columbia address only ASME Code,Section XI, ENCLOSURE

Class 1, Examination Category B-J and B-F components; only Class 1 components (regardless of ASME Code,Section XI Examination Category); or does this AMP address SCC in components irrespective of ASME Code Class or Examination Category?

c. Is the overall scope of components covered by the BWR SCC Program at Columbia identical to the scope of components covered by Generic Letter (GL) 88-01, as modified by Columbias current implementation of BWRVIP-75; does the BWR SCC Program at Columbia cover components beyond the scope of GL 88-01; or does the scope of components covered by the BWR SCC Program at Columbia not include all of the components addressed in GL 88-01?

Issue:

The LRA Section B.2.8 program description for the BWR SCC Program states that Columbia mitigates aging by maintaining reactor coolant system (RCS) water chemistry in accordance with the current BWRVIP guidelines, as detailed in the BWR Water Chemistry Program and that Columbia has implemented hydrogen water chemistry (HWC) and noble metal chemical application (NMCA) to mitigate SCC.

Request:

Does Columbia formally credit the use of HWC and/or NMCA in establishing plant-specific piping inspection sampling, sample expansion, and frequency requirements based on the criteria of NUREG-0313, Rev. 2; GL 88-01 and its Supplement 1; and BWRVIP-75?

Issue:

While BWRVIP-75 is an NRC Staff-approved document, the implementation of BWRVIP-75 modifications to the piping inspection criteria of GL 88-01 at plants may result in the establishment of plant-specific inspection sampling and frequency criteria that are less comprehensive than those required by the ASME Code,Section XI, Examination Categories B-J and B-F for RCPB piping. Therefore, the staff position on the plant-specific implementation of BWRVIP-75 for Examination Category B-J and B-F components is that licensees must submit to the NRC a request for alternative to the ASME Code,Section XI requirements, in order to implement the BWRVIP-75 modifications to the piping inspection criteria of GL 88-01 and obtain NRC authorization for this alternative under 10 CFR 50.55a(a)(3)(i).

Request:

Is Columbia currently operating with an NRC-approved alternative, granted under 10 CFR 50.55a(a)(3)(i), authorizing the implementation of the alternative inspection criteria of BWRVIP-75 for the current (third) 10-year ISI interval program at Columbia? If so, please indicate the ASME Code,Section XI, Examination Categories (e.g. Examination Category B-J, B-F, etc.)

that this alternative covers. If Columbia does not currently have this alternative authorized, please indicate whether or not Columbia currently meets all ASME Code,Section XI requirements for ASME Code,Section XI, Examination Category B-F components.

(Note: The staff recognizes that the implementation of other NRC-authorized alternatives and reliefs from ASME Code,Section XI requirements for Examination Category B-J components may be applicable to Columbia and allow for a more limited inspection scope than that delineated in the ASME Code,Section XI, Table IWB-2500-1, for certain Examination Category B-J components.)

Issue:

LRA Section B.2.8 describes Columbia operating experience with the BWR SCC Program and inspection results for the program. It states that one relevant indication (e.g., flaw) was identified in stainless steel (SS) recirculation system piping-to-valve weld 20RRC(6)-8 in 1991.

Columbia states that this indication has been monitored for 10 years and has shown no identifiable growth. The weld with the indication was examined in 2001 using EPRI PDI qualified techniques and systems, and it was determined that the indication was not caused by IGSCC. Consequently, the GL 88-01-based categorization for the weld with the indication was changed to Category B.

Request:

The staff requests that Columbia provide the following additional information concerning this indication:

a. Is this indication located in the actual weld metal or is it located in the base metal heat affected zone (HAZ) adjacent to the weld?

b. Is this a surface-breaking indication or a sub-surface indication?

c. LRA Section B.2.8 states that this indication was determined to be acceptable for continued operation without repair. How did Columbia arrive at this determination?

Was this flaw screened using the ASME Code,Section XI, IWB-3500 Acceptance Standards. What were the results of this screening? If this flaw did not pass the IWB-3500 acceptance standards, did the flaw receive an analytical evaluation in accordance with IWB-3600? If so, what were the results of this analytical evaluation? Was the analytical evaluation of this flaw submitted to the NRC? If so, please provide a reference to the report documenting the analytical evaluation of this flaw. If not, please provide the actual flaw evaluation report.

d. Is this weld with the indication still currently designated a Category B weld? Has the NRC been notified of and concurred with Columbias determination that this weld may be designated a Category B weld? If the NRC has not concurred with Columbias determination that this weld may be designated a Category B weld, please provide technical justification as to how and why Columbia determined that this welds categorization could be changed from Category E to Category B.

e. If Columbia determined that this flaw was not caused by Intergranular Stress Corrosion Cracking (IGSCC), then please discuss whether this flaw is considered a fabrication flaw or a service-induced flaw. If Columbia believes that this is a service-induced flaw, please discuss the aging affect or mode of degradation that Columbia believes may have caused this flaw to form.

Does Columbia use UT examination systems, techniques, personnel, and procedures that are qualified in accordance with ASME Code,Section XI, Appendix VIII PDI criteria when performing UT examinations of pressure boundary piping?

RAI B.2.10 - BWR Vessel Internals Program

Background:

The staff notes that LRA Section B.2.10 includes a statement indicating that the BWR Vessel Internals Program at Columbia incorporates all of the BWRVIP guidance documents, including

those specifically called out in GALL Report,Section XI.M9. B.2.10 also states that augmented inspections (beyond the ASME Code,Section XI requirements) required by the BWRVIP program documents are performed by Columbias BWR Vessel Internals Program, and that the program implements all BWRVIP requirements for the reactor internals components.

Columbias plant-specific commitments to specific BWRVIP programs are documented in Appendix C of the LRA through their responses to specific license renewal applicant action items for each BWRVIP document.

Issue:

The staff notes that Appendix C of the LRA contains no reference to several BWRVIP documents. Furthermore, the staff cannot locate any statement anywhere in the LRA indicating that Columbias BWR Vessel Internals Program commits to and implements the programs described in these BWRVIP documents for the following components:

i. Core Shroud - BWRVIP-76, BWR Core Shroud Inspection and Flaw Evaluation Guidelines ii. Steam Dryer - BWRVIP-139, Steam Dryer Inspection and Flaw Evaluation Guidelines iii. Access Hole Covers - BWRVIP-180, BWR Access Hole Covers Inspection and Flaw Evaluation Guidelines Request:

For each of the above reactor internal components, please provide a statement indicating whether Columbia commits to programs described in the BWRVIP document for the components and whether Columbias BWR Vessel Internals Programs implements all the requirements of these BWRVIP documents.

Please provide a brief description of the reactor coolant system (RCS) water chemistry conditions that are used for mitigating cracking and other forms of aging and degradation in the reactor internal and pressure boundary components at Columbia, including whether hydrogen water chemistry is implemented and noble metal chemical additions are implemented. Also, please state the BWRVIP programs (by BWRVIP document number and/or title) that Columbia implements for managing RCS Water Chemistry.

Issue:

LRA Section B.2.10 provides information on Columbias plant-specific operating experience for the reactor internal components. With respect to nondestructive examination (NDE) inspection results, LRA Section B.2.10 describes indications in several reactor internals components, including cracking of the core shroud, cracking of the steam dryer, gaps on the jet pump set screws, and wear of the jet pump wedges.

Request:

The staff requests the following additional information concerning the reactor internals indications discussed in B.2.10:

a. Please state whether there were ever any other flaws or relevant indications discovered in any reactor internal component, covered under B.2.10, other than the indications cited above.

b. Please state whether the reactor internals indications discussed in B.2.10 were documented in Columbias site condition reports, action requests, or a similar site condition reporting program.

c. Please discuss how the reactor internals indications discussed in B.2.10 are being tracked and monitored, including whether Columbia is monitoring these indications in accordance with the inspection and evaluation (I&E) guidelines of applicable BWRVIP documents for the reactor internals components with indications.

Please identify the materials from which the core shroud is fabricated, including both welds and base metal (e.g., 304 stainless steel (SS), 304L SS, any nickel alloys, etc.). Identify the core shroud designation at Columbia (e.g., Category A, B, or C) based on BWRVIP-76 core shroud designation criteria.

Issue:

LRA Section B.2.10 includes a brief statement indicating that Columbia has found indications of cracking of the core shroud.

Request:

The staff requests the following additional information concerning these indications of cracking in the core shroud:

a. Please identify where the core shroud cracking indications were found: Were the indications of cracking found in the core shroud welds, base material, and/or heat affected zone? If cracking indications were found in or near shroud welds, identify which welds were found to have indications of cracking, based on the BWRVIP-76 nomenclature.

b. Please provide a brief description of the nature of these indications, including the overall number of shroud cracking indications, the length of the indications (expressed as a percentage of total weld length or shroud height/circumference), and the orientation of the indications (e.g., axial or circumferential flaws).

Have there been any other aging effects (other than SCC) identified for the core shroud at Columbia? Does the implementation of the BWRVIP-76 I&E guidelines provide adequate aging management for all potential forms of degradation that are applicable to the core shroud, including pitting, crevice corrosion, and cumulative fatigue damage?

Please state whether Columbia has implemented any tie rod repairs or other repairs to the core shroud. If no tie rod repairs or other repairs have been implemented, please state whether Columbia has current plans to implement tie rod repairs or other repairs to the core shroud in the future. If there are no current plans to implement tie rod repairs or other repairs to the core shroud in the future, please discuss the reasons for not implementing repairs, such as the extent of shroud cracking implementation of BWRVIP-76 I&E guidelines that would be sufficient to manage aging effects for the core shroud without implementing tie rod repairs.

For the core shroud, please state whether Columbia follows the guidelines of BWRVIP-100-A pertaining to the updated fracture toughness assessments for neutron-irradiated SS in the core shroud.

Please provide the following additional information concerning the NDE inspection/examination volume for the jet pump holddown beams at Columbia:

a. State whether the locations designated in BWRVIP-41 as BB-1 and BB-2 are inspected using UT with high priority, according to BWRVIP-41 guidelines.

b. State whether the taper region of the holddown beams is inspected for cracking or other degradation. Note that the holddown beam taper region is the location of the jet pump holddown beam failure at Oyster Creek in 2002.

c. State whether the jet pump holddown beams at Columbia are of the same, similar, or different design from the Oyster Creek jet pump holddown beams.

Please state whether neutron fluence values for the core shroud were calculated using an NRC-approved fluence methodology that is consistent with Regulatory Guide 1.190.

RAI B.2.15 - CRDRL Nozzle Program Please list the materials for the Control Rod Drive Return Line (CRDRL) Nozzle welds and base metal.

Does Columbia use UT examination systems, techniques, personnel, and procedures that are qualified in accordance with the ASME Code,Section XI, Appendix VIII Performance Demonstration Initiative when performing UT examinations of CRDRL Nozzle?

RAI B.2.52 - Thermal Aging and Neutron Embrittlement of Cast Austenitic Stainless Steel (CASS) Program Will the component-specific evaluations required by this aging management program (AMP) use neutron fluence values calculated using an NRC-approved fluence methodology that is consistent with Regulatory Guide 1.190?

Issue:

GALL Section XI.M13, Thermal Aging and Neutron Embrittlement of Cast Austenitic Stainless Steel (CASS), Element 6, Acceptance Criteria, states that flaws detected in CASS components are evaluated in accordance with the applicable procedures of IWB-3500.

Request:

Although the staff states that Columbia has no pressure boundary components within the scope of this AMP, the staff requests that Columbia provide further explanation as to why the description of acceptance criteria in LRA Section B.2.52 does not directly reference the applicability of ASME Code,Section XI, IWB-3500 acceptance criteria for flaws detected in CASS components at Columbia.

Issue:

The staff notes that certain GALL screening criteria for determining the susceptibility of CASS components to thermal aging (based on ferrite content, molybdenum content, and casting method) do not apply if the CASS components are fabricated from materials that are alloyed with Niobium.

Request:

Does Columbia have any CASS components fabricated from materials that are alloyed with Niobium? If so, please verify whether such Niobium-containing CASS components will be evaluated for susceptibility to loss of fracture toughness on a case-by-case basis.

Issue:

LRA Section B.2.52 states that Columbia has no CASS reactor coolant pressure boundary (RCPB) components that are exposed to high levels of neutron radiation; therefore, there are no pressure boundary components addressed by this program.

Request:

Please state whether there are any CASS RCPB components at Columbia, regardless of exposure to neutron radiation. If there are any CASS RCPB components at Columbia (regardless of exposure to neutron radiation), please provide justification as to why these components will not be screened for susceptibility to reduction in fracture toughness due to thermal aging (even if neutron embrittlement is not an issue for such CASS RCPB components).

Provide an estimate of the projected neutron fluence (if negligible, state this) to which these CASS RCPB components may be exposed through the end of the period of extended operation.

Please state the timeframe, relative to end of the current licensed operating period (e.g., within 5 years of the end of license (EOL), within 10 years of EOL, etc.), when Columbia plans to have completed activities associated with CASS component screening, component-specific susceptibility evaluation, augmentation of the inservice inspection (ISI) program or BWRVIP programs, and the addition of supplemental inspections to Columbias 10-year ISI Program Plan.

Letter to W.S. Oxenford from E. Gettys dated June 13, 2010

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE COLUMBIA GENERATING STATION, LICENSE RENEWAL APPLICATION DISTRIBUTION:

HARD COPY:

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EGettys DDoyle FLyon WWalker, RIV RCohen, RIV LSubin, OGC

Columbia Generating Station cc:

Mr. J.V. Parrish, Chief Executive Officer EFSEC Manager Energy Northwest Energy Facility Site Evaluation Council MD 1023 P.O. Box 43172 P.O. Box 968 Olympia, WA 98504-3172 Richland, WA 99352-0968 Mr. Abbas Mostala Mr. S. K. Gambhir Energy Northwest Energy Northwest PO Box 968 MD PE04 MD PE 29 P.O. Box 968 Richland, WA 99352-0968 Richland, WA 99352-0968 Mr. Douglas W. Coleman, Manager, Regulatory Programs Energy Northwest P.O. Box 968 MD PE20 Richland, WA 99352-0968 Mr. William A. Horin, Esq.

Winston and Strawn 1700 K Street, NW Washington, DC 20006-3817 Chairman, Benton County Board of Commissioners P.O. Box 190 Prosser, WA 99350-0190 Mr. Richard Cowley Washington State Department of Health 111 Israel Road, SE Tumwater, WA 98504-7827 Mr. Ron Cohen U.S. Nuclear Regulatory Commission P.O. Box 69 Richland, WA 99352 Regional Administrator U.S. NRC Region IV Texas Health Resources Tower 612 E. Lamar Boulevard, Suite 400 Arlington, TX 76011-4125