L-04-001, 60-Day Reports Per Bulletin 2004-01 and CAL No. NRR-07-023 Pressurizer Inspection Results for the 2010 Refueling Outage
| ML103500407 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/16/2010 |
| From: | Kirwin T Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BL-04-001, NRR-07-023 | |
| Download: ML103500407 (7) | |
Text
Entergy Entergy Nuclear Operations, Inc.
Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043 Tel 269 764 2000 Thomas P Kirwin Acting Site Vice President December 16, 2010 U. S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555-0001
SUBJECT:
References:
60-Day Reports per Bulletin 2004-01 and CAL No. NRR-07-023 Pressurizer Inspection Results for the 2010 Refueling Outage Palisades Nuclear Plant Docket 50-255 License No. DPR-20
- 1. NRC Bulletin 2004-01: "Inspection of Alloy 82/182/600"Materials Used in the Fabrication of Pressurizer Penetrations an'dtpteam Space Piping Connections at Pressurized-Water Reactors, II dated May 28, 2004
- 2. CAL No. NRR-07-023: "Confirmatory Action Letter - Palisades Nuclear Plant (TAC NO. MD4168)," dated March 29,2007
Dear Sir or Madam:
On May 28, 2004, the Nuclear Regulatory Commission (NRC) issued Bulletin 2004-01 (Reference 1) (ADAMS Accession Number ML041480034). In a 60-day bulletin response letter dated July 26, 2004 (ML042100242), the Nuclear Management Company, LLC (NMC), former holder of the Palisades Nuclear Plant (PNP) operating license, made a series of commitments related to inspection of pressurizer penetrations.
On March 29, 2007, the NRC issued CAL No. NRR-07-023 (Reference 2)
(ML070800449), confirming commitments made in a February 27, 2007, NMC letter, "Supplement to Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt-Welds" (ML070590333). The commitments addressed actions that would be taken regarding pressurizer dissimilar metal butt-welds containing Alloy 82/182/600 material.
Entergy Nuclear Operations, Inc. (ENO) has assumed the commitments made by NMC for the refueling outage inspections of the pressurizer piping connections. In the 2010 refue-ling outage that began on October 3, 2010, and ended on
Document Control Desk Page 2 October 29, 2010, ENO inspected pressurizer heater sleeves and dissimilar metal butt-welds containing Alloy 82/1821600 material in accordance with commitments and qualified procedures. A total of 144 welds were examined: 120 heater sleeves, 13 butt-weld piping connections containing 22 Alloy 82/182/600 butt-welds requiring examination, and two pad repair welds. Based on the results of the examinations performed, ENO has concluded that all pressurizer heater sleeves, Alloy 82/1821600 pressurizer butt-welds, and pressurizer pad repair welds that were returned to service in 2010 were not degraded, and no wastage of the pressurizer occurred.
Summary of Commitments This letter identifies no new commitments and no revisions to existing commitments.
I declare under penalty of perjury that the foregoing is true and correct. Executed on December 16, 2010.
Sincerely, tpk/jlk
Attachment:
- 1. 60-Day Reports per Bulletin 2004-01 and CAL No. NRR-07-023 Palisades Nuclear Plant Pressurizer Inspection Results for the 2010 Refueling Outage cc:
Administrator, Region III, USNRC Project Manager, Palisades, USNRC Resident Inspector, Palisades, USNRC
ATTACHMENT 1 GO-DAY REPORTS PER BULLETIN 2004-01 AND CAL NO. NRR-07-023 PALISADES NUCLEAR PLANT PRESSURIZER INSPECTION RESULTS FOR THE 2010 REFUELING OUTAGE
1.0 INTRODUCTION
On May 28, 2004, the Nuclear Regulatory Commission (NRC) issued Bulletin (BL) 2004-01, "Inspection of Alloy 82/182/600 Materials Used in the Fabrication of Pressurizer Penetrations and Steam Space Piping Connections at Pressurized-Water Reactors." In a 60-day response letter, dated July 26, 2004, the Nuclear Management Company (NMC), former holder of the Palisades Nuclear Plant (PNP) operating license, made a series of commitments related to inspection of pressurizer penetrations.
On March 29,2007, the NRC issued CAL No. NRR-07-023, "Confirmatory Action Letter - Palisades Nuclear Plant (TAC No. MD4168)," confirming commitments made, in a February 27,2007, NMC letter "Supplement to Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt-Welds." The commitments addressed actions that would be taken regarding pressurizer dissimilar metal butt-welds containing Alloy 821182/600 material.
Entergy Nuclear Operations, Inc. (ENO), as the PNP license holder', ~as assumed the commitments made by NMC for the refueling outage inspections of the pressurizer piping connections. In the 2010 refueling outage that began on October 3, 2010, and ended on October 29, 2010, ENO inspected pressurizer heater sleeves and dissimilar metal butt-welds containing Alloy 82/182/600 material in accordance with commitments and qualified procedures. A total of 144 welds were examined: 120 heater sleeves, 13 butt-weld piping connections containing 22 Alloy 82/182/600 butt-welds requiring examination, and two pad repair welds.
2.0 DESCRIPTION
OF INSPECTION METHODS Performance Demonstration Initiative (PDI)-qualified ultrasonic examinations were performed by qualified non-destructive examination (NDE) personnel using qualified procedures to inspect two spray line safe end butt-welds to elbow and nozzle, and three pressurizer safety valve mounting flange-to-nozzle butt-welds.
Bare metal, direct visual examinations were performed by qualified NDE personnel to inspect 100% of all 120 unmitigated Alloy 82/1821600 pressurizer heater sleeves, 16 unmitigated one-inch level tap safe end butt-welds to piping and nozzles, and one unmitigated surge line safe end to nozzle butt-weld. Bare metal, direct visual examination also was performed by qualified NDE personnel to inspect two temperature element nozzle pad repair welds performed in 1995.
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3.0 COMMITMENTS AND RESULTS In 2004, NMC made four commitments for PNP in response to Bulletin 2004-01. Three of the commitments remained open in 2010. ENO actions and results during the 2010 PNP refueling outage are described below for heater commitments one, two, and three. Commitment four was completed in 2006.
Additionally, in February 2007, NMC made a total of eight new and revised commitments for PNP in regard to Alloy 82/182/600 pressurizer butt-welds that were confirmed in CAL No. NRR-07-023. Of these eight commitments, commitments one through four do not apply to outage activities.
Commitments five and six were completed during the 2007 PNP refueling outage. ENO actions and results during the 2010 PNP refueling outage are described below for butt-weld commitments seven and eight.
Heater Commitment 1 :
NMC [ENO] will perform a bare metal visual inspection of 100 percent of al/
pressurizer heater sleeve locations, in a manner that visual access td the bare metal 360 degrees around each sleeve can be attained during each outage at Palisades Nuclear Plant.
Results for Commitment 1 :
During the 2010 refueling outage, a bare metal visual examination of all 120 pressurizer heater sleeves (J-groove welds) was performed. This examination included 360 degrees around each sleeve. There was no accumulation of boric acid in the vicinity of the penetrations. All visual examinations of the penetrations had acceptable results.
Heater Commitment 2:
NMC [ENO] will perform non-destructive examination (NDE) capable of characterizing crack orientation of al/ sleeves for which visual inspection shows evidence of leakage at Palisades Nuclear Plant. The NDE will be performed prior to any repairs.
Results for Commitment 2:
No action was required since the visual examination did not show any evidence of leakage.
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Heater Commitment 3:
NMC [END] will notify the NRC immediately if the NOE defines the flaw as potential circumferential primary water stress corrosion cracking (PWSCC) in either the pressure boundary or non-pressure boundary portions of any locations covered under the scope of BL 2004-01 for the PNP. An appropriate inspection plan will be developed, which will define additional sleeves to be inspected by NOE, sufficient to determine the extent of condition commensurate with the characterization of the flaw.
Results for Commitment 3:
No action was required since the visual examination did not show any evidence of leakage.
Butt-Weld Commitment 7:
NMC [END] will inspect the Alloy 8211821600 pressurizer butt-welds per MRP-139, ("Materials Reliability Program: Primary System Piping Butt Weld..fnspection and Evaluation Guidelines") on a frequency of at least every four ye'8r~,. until the Alloy 8211821600 pressurizer butt-welds are mitigated or removed at PNP. NMC
[END] will notify the NRC in writing, prior to making any changes to this commitment.
Results for Commitment 7:
All existing Alloy 82/1821600 pressurizer butt-welds were examined in accordance with MRP-139 within the last four years, during the spring 2009 and fall 2010 refueling outages.
During the 2010 refueling outage, PDI-qualified ultrasonic examinations were performed to inspect two MRP-139 Category D unmitigated spray line safe end butt-welds to elbow and nozzle, and three MRP-139 Category D unmitigated pressurizer safety valve mounting flange-to-nozzle butt-welds.
The examination results indicated these butt-welds were not degraded.
These welds had previously received ultrasonic examinations during the 2007 PNP refueling outage, and MRP-139 Category J visual examinations during the 2009 PNP refueling outage.
During the 2010 refueling outage, MRP-139 Category J bare metal, direct visual examination was p~.rformed to inspect one MRP-139 Category D unmitigated surge line safe end to nozzle butt-weld. The examination results indicated this weld was not degraded. This weld had previously received POI-qualified ultrasonic examination during the 2009 PNP refueling outage, Page 3 of 5
and MRP-139 Category J visual examination during the 2007 PNP refueling outage.
During the 2010 refueling outage, one MRP-139 Category C Alloy 82/182/600 pressurizer surge safe end to pipe elbow butt-weld, which was mitigated in 1995, and was last ultrasonically examined in 2009, did not require examination.
The only other MRP-139 pressurizer butt-weld, a Category A power operated relief valve line connection, was mitigated by (eplacement with stainless steel and Alloy 690/52/152 material in 1995, and did not require examination in 2010.
There has been no change to the commitment.
Butt-Weld Commitment 8:
NMC [ENO] will provide results of future inspections, including inspections on unmitigated welds and any corrective or mitigative actions taken on the pressurizer surge, spray, safety, or relief nozzle and safe end welds' co"taining Alloy 8211821600 material, within 60 days of the end of the station refueling outage during which the inspection was performed, until the Alloy 8211821600 pressurizer butt-welds are mitigated or removed at PNP. NMC [ENO] will notify the NRC in writing, prior to making any changes to this commitment.
Results for Commitment 8:
During the 2010 refueling outage, other Alloy 82/182/600 pressurizer welds were examined as required by ASME Section XI Code Case N-722. Bare metal, direct visual examinations were performed to inspect 16 unmitigated one-inch level tap safe end butt-welds to piping and nozzles, and two temperature element nozzle pad repair welds performed in 1995. The examination results indicated the 16 butt-welds and two pad repair welds were not degraded. Similar examinations were last performed in 2007 and 2009.
PNP returned to operation from its most recent refueling outage on October 29, 2010. This 60-day report describes inspections and their results for pressurizer surge, spray, safety and relief nozzle, safe end, heater, and temperature element nozzle repair welds containing Alloy 82/182/600 material.
There has been no change to the commitment.
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4.0 CONCLUSION
S ENO has complied with commitments described in Bulletin 2004-01 and CAL No. NRR-07-023 for the PNP 2010 refueling outage. Based on the results of the examinations performed, ENO has concluded that all pressurizer heater sleeves, Alloy 82/182/600 pressurizer butt-welds, and pressurizer pad repair welds that were returned to service in 2010 were not degraded, and no wastage of the pressurizer occurred.
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