NL-04-1801, Application for License Renewal - Request for Additional Information
| ML042670361 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 09/15/2004 |
| From: | Stinson L Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-04-1801 | |
| Download: ML042670361 (6) | |
Text
L M. Stinson (Mike)
Vice President Southern Nuclear Operating Company, Inc.
40 Inverness Center Parkway Post Office Box 1295 Birmingham, Alabama 35201 Tel 205.992.5181 Fax 205.992.0341 September 15, 2004 SOUTHERN A COMPAY Energy to Serve Your World' NL-04-1801 Docket Nos.:
50-348 50-364 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk x
Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant Units I and 2 Application for License Renewal - Reauest for Additional Information Ladies and Gentlemen:
This letter is in response to your letter dated September 14, 2004, requesting additional information for the review of the Joseph M. Farley Nuclear Plant, Units I and 2, License Renewal Application. The response to this Request for Additional Information (RAI) is provided in the enclosure.
Mr. L. M. Stinson states he is a vice president of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and to the best of his knowledge and belief, the facts set forth in this letter are true.
If you have any questions, please contact Charles Pierce at 205-992-7872.
Respectfully submitted, SOUTHERN NUCLEAR OPERATING COMPANY L. M. Stinson Sworn to and subscribed ormethis \\S day 2004.
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U. S. Nuclear Regulatory Commission NL04-1801 Page 2
Enclosure:
Joseph M. Farley Nuclear Plant, Units I and 2 Application for License Renewal - Response to Request for Additional Information cc:
Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. D. E. Grissette, General Manager - Plant Farley Document Services RTYPE: CFA04.054; LC# 14137 U. S. Nuclear Regulatory Commission Ms. T. Y. Liu, License Renewal Project Manager Dr. W. D. Travers, Regional Administrator Mr. S. E. Peters, NRR Project Manager - Farley Mr. C. A. Patterson, Senior Resident Inspector - Farley Alabama Department of Public Health Dr. D. E. Williamson, State Health Officer
NL-04-1801 ENCLOSURE Joseph M. Farley Nuclear Plant Units 1 and 2 Application for License Renewal Response to Request for Additional Information E-i
Enclosure NL-04-1801 RAI 3.2-8 FNP's six charging/high head safety Injection pumps are susceptible to loss of material due to clad cracking and subsequent corrosion In the carbon steel base metal. The applicant stated that the pump casing Inspections are existing periodic tasks that manage loss of material in the carbon steel base metal resulting from boric acid corrosion at locations of clad cracking.- Inspections Include periodic non-intrusive ultrasonic testing (UT) exams of accessible areas of the pump casings to detect through-clad cavities (loss of material) In the carbon steel base material. Visual testing (VT) examination of the Internal surface of the pump casings Is performed any time a rotating assembly Is removed during pump maintenance. To further evaluate the aging management program for the pumps, the staff requests the applicant to provide the following Information:
- a. The applicant stated that pump 2A casing received a VT-I for clad cracking during Inspection of the rotating assembly; however, It Is not clear if the other five pumps received VT-I Inspections. Explain If VT-I Inspections for clad cracking have been performed (or are scheduled to be performed) for the IA, 1B, 1C, 2B, and 2C pumps.
Are all Internal cad surfaces of the pump casing Vr-I Inspected? Will VT-1 inspections be performed during the period of extended operation?
- b. The applicant stated that UT Inspections will be performed to detect loss of material In the carbon steel base material of the pump casings. Since the loss of material is not limited to a specific location, describe the process used to ensure that the UT inspection methodology (including sample size) will detect the loss of material In the pump casings.
- c. NUREG-1800, Section A.1.2.3.1 recommends that the scope of the aging management program Include the specific structures and components of which the program manages the aging. The applicant is requested to Include the charging/high head safety injection pumps In the scope of the program for Periodic Surveillance and Preventive Maintenance Activities.
- d. NUREG-1800, Section A.1.2.3.5 recommends that monitoring and trending activities be described, and they should provide predictability of the extent of degradation and thus affect timely corrective actions. Plant-specific and/or industry operating experience may be considered In evaluating the appropriateness of the technique and frequency.
The applicant Is requested to describe the monitoring and trending process for the Periodic Surveillance and Preventive Maintenance Activities.
- e. NUREG-1800, Section A.1.2.3.6 recommends that acceptance criteria and its basis be described. The applicant Is requested to describe the UT acceptance criteria and its basis for the Periodic Surveillance and Preventive Maintenance Activities.
- f. NUREG-1800, Section A.12.3.10 recommends that the operating experience provide objective evidence to support the conclusion that the effects of aging will be managed adequately so that the Intended function will be maintained during the period of extended operation. The applicant is requested to provide plant-specific and/or industry operating experience for corrosion of the pump casings to support the conclusion that the aging effects will be adequately managed by the Periodic Surveillance and Preventive Maintenance Activities.
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Enclosure NL-04-1801 BesDonse
- a. Visual examinations of the Internal surfaces of the pump casings (with the rotating assemblies removed) have been performed on four charginglhigh head safety injection (HHSI) pumps at Farley Nuclear Plant, Units I and 2 (IA, IC, 2A, and 2C).
Indications of base metal corrosion due to cladding cracks have only been found in the 2A pump casing. The Internal surface of the casings for the remaining two pumps (lB and 2B) will be visually examined (VT-1) in conjunction with the upcoming replacement of their rotating assemblies. The replacement of the 1 B and 2B charginglHHSI pumps rotating assemblies Is currently scheduled to occur during equipment outages scheduled for the Fall of 2004 and 2005, respectively.
All Intemal clad surfaces of the pump casing are VT-I inspected. The visual examination Is performed with the rotating assembly removed to permit access to all Internal clad surfaces. The requirement to perform the VT-I Inspection of the casing whenever a rotating assembly is removed Is Incorporated into the charging/HHSI pump maintenance procedure and will be continued during the period of extended operation.
- b. The ultrasonic testing (UT) inspection of the charginglHHSI pump casing is performed over all accessible areas of the pump casing. A sampling approach is not used. Inaccessible locations are the result of the physical configuration and geometry of the pump assembly.
- c. SNC has included the charginglHHSI pumps In the scope of the program for Periodic Surveillance and Preventive Maintenance Activities.
- d. SNC letter NL-04-1594 dated August 31, 2004, described the monitoring and trending activities. UT examination of the chargingtHHSI pump casings is currently performed on an 18 month frequency for the 2A pump, and on a 36-month frequency for the other five pumps. VT-1 examination of the internal surface of the pump casing Is performed any time a rotating assembly is removed during pump maintenance.
Any Indications or relevant conditions of degradation are evaluated, Including relative changes to any previously Identified indications. The frequency of inspection is subject to modification based on the observed degradation and any trend from prior Inspections.
- e. The objective of the pump casing's UT examination procedure is to detect loss of material (e.g., "cavities") In the carbon steel base metal that may result from a clad crack with resultant exposure to borated water. Examination techniques include straight beam (0 degree) and angle beam (45 degree) examinations. Any indications or relevant conditions of degradation detected are evaluated. The specific pump drawings are reviewed, and any Indications not representative of the pump casing's geometrical design are reported. Relative changes In any previously identified Indications are also reported. Reported conditions are then evaluated under the corrective action program.
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Enclosure NL-04-1801
- f. Periodic non-Intrusive UT examinations and Internal surface visual examinations with the rotating assembly removed during pump maintenance have proven successful at FNP In detecting and managing this aging effect with no loss of intended function.
Visual examination of the Internal surface of the pump casing (with the rotating assembly removed) has successfully Identified corrosion of the base metal due to cladding cracks. In the 2A charging pump, an Internal surface visual examination readily detected Indications of base metal corrosion due to cladding cracks.
UT examination has been shown to be a reliable technique for monitoring wall thickness (loss of material) In components. Non-Intrusive UT examination has successfully monitored the FNP charging pump casings for Indications of loss of material In the base metal. For the 2A charging pump Indications, the periodic UT examinations have confirmed the actual material loss Is progressing at a very slow rate. The frequency of Inspection assures that the wall thickness will not exceed ASME code requirements.
There has been no loss of Intended function In any charging/HHSI pump as a result of this aging effect. The operating experience demonstrates the program activities are adequate to detect and manage loss of material In the charging/HHSI pump casings due to clad cracking, such that the components Intended function will be maintained during the period of extended operation.
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