NG-13-0274, License Renewal Commitment Changes
| ML13254A150 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 09/06/2013 |
| From: | Richard Anderson NextEra Energy Duane Arnold |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NG-13-0274 | |
| Download: ML13254A150 (7) | |
Text
NEXTera ENERG-7Y6 September 6, 2013 NG-1 3-0274 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Duane Arnold Energy Center Docket No. 50-331 Renewed Op. License No. DPR-49 License Renewal Commitment Changes
References:
- 1) NUREG-1955, "Safety Evaluation Report Related to the License Renewal of Duane Arnold Energiy Center," dated November 30, 2010 (ML103070013)
Revision 2, December, 2010 In Reference 1, the NRC Staff documented their safety review of the renewal of the Duane Arnold Energy Center (DAEC) Operating License. Included in this review were a number of commitments requiring NextEra Energy Duane Arnold, LLC, hereafter NextEra Energy Duane Arnold, to implement aging management programs. These commitments were subsequently incorporated into the NextEra Energy Duane Arnold Updated Final Safety Analysis Report (UFSAR) in accordance with 10 CFR 50.71(e).
The Staff has updated the generic guidance for aging management as reflected in Reference 2. NextEra Energy Duane Arnold has identified several instances where the existing commitments in the NextEra Energy Duane Arnold UFSAR either require clarification to ensure proper implementation, or warranted updating to reflect later guidance contained in Reference 2. These changes have been evaluated in accordance with our commitment control procedures and in accordance with 10 CFR 50.59.
The enclosure to this letter provides a summary of these commitment changes.
NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA52324 NEfu XIJV[X'-'
Document Control Desk NG-13-0274 Page 2 of 2 If you have any questions or require additional information, please contact Ken Putnam at 319-851-7238.
- ichard L. Andke Zso Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC Enclosure cc: Regional Administrator, USNRC, Region III Resident Inspector, USNRC, Duane Arnold Energy Center Project Manager, USNRC, Duane Arnold Energy Center
Attachment to NG-1 3-0274 Summary of Commitment Chanqes to the Aqingi Management Programs Required Per NUREG-1955 4 pages follow
Enclosure to NG-1 3-0274 Commitment 36: Thermal Aging and Neutron Irradiation Embrittlement of Cast Austenitic Stainless Steel (CASS) Program, XI.M13 Existing Commitment:
Implement a Thermal Aging and Neutron Irradiation Embrittlement of Cast Austenitic Stainless Steel (CASS) Program.
Reason for Commitment Change:
Generic Aging Lessons Learned (GALL) Rev.1 included a program for Thermal Aging and Neutron Irradiation Embrittlement of Cast Austenitic Stainless Steel, XI.M13. GALL Rev. 2 incorporated into the XI.M9, BWR Vessel Internals Program inspections for degradation of wrought and cast reactor vessel internal components due to neutron and thermal embrittlement using VT-1 inspections.
The inspections of the susceptible Cast Austenitic Stainless Steel components will be performed under the Augmented ISI Program. Previous inspections of these components were limited to the weld area. The first exams fully consistent with the enhanced program will be performed during the 2014 refueling outage. A standalone CASS Program will not be implemented as the inspections are performed under another aging management program.
Revised Commitment:
Enhance the Augmented Inspection procedures for the BWR Vessel Internals Program implementing procedures to include inspection for thermal and/or neutron embrittlement in susceptible Cast Austenitic Stainless Steel (CASS) components.
Commitment 52: Buried Piping and Tanks Inspection Program, XI.M34 Existinq Commitment:
Enhance the Buried Piping and Tanks Inspection Program to include inspection of at least a minimum number of pipe segments in each material group (one stainless steel, two carbon steel, one cast iron, and two ductile iron) prior to entry into the period of extended operation and each ten-year period after entry into the period of extended operation.
Where torsional guided wave data indicates significant susceptibility, inspections will be performed on associated locations. The sample locations for directed inspections will preferentially select higher risk locations. Piping that normally contains hazardous materials will be prioritized in the inspection location selection process. The diesel fuel oil piping will be inspected prior to entry into the period of extended operation. These directed inspections will be performed
Enclosure to NG-1 3-0274 with sufficient excavation to expose at least ten linear feet of piping as practicable, including the pipe bottom. Inspections of coated carbon steel piping will include the coating and backfill in the vicinity of the piping for material that could cause coating damage. The uncoated stainless steel, ductile iron and cast iron piping will be externally inspected for corrosion, and the fill in the vicinity of the piping will be inspected for material that could cause external damage to the stainless steel, ductile iron or cast iron pipe.
Reason for Commitment Changqe:
The applicable section of GALL Rev. 2, under the XI.M41, Buried and Underground Piping and Tanks allows the inspection of buried and underground piping and tanks to be hydrostatically tested or examined internally by a method capable of determining pipe wall thickness instead of excavation of 10 linear feet of piping. The alternate inspection methods ensure piping is capable of performing its intended function without the need for extensive excavation and backfill and may be a more appropriate inspection for some piping.
Revised Commitment:
Enhance the Buried Piping and Tanks Inspection Program to include inspection of at least a minimum number of pipe segments in each material group (one stainless steel, two carbon steel, one cast iron, and two ductile iron) prior to entry into the period of extended operation and each ten-year period after entry into the period of extended operation.
Where torsional guided wave data indicates significant susceptibility, inspections will be performed on associated locations. The sample locations for directed inspections will preferentially select higher risk locations. Piping that normally contains hazardous materials will be prioritized in the inspection location selection process. The diesel fuel oil piping will be inspected prior to entry into the period of extended operation. These directed inspections will be performed with sufficient excavation to expose at least ten linear feet of piping as practicable, including the pipe bottom. Inspections of coated carbon steel piping will include the coating and backfill in the vicinity of the piping for material that could cause coating damage. The uncoated stainless steel, ductile iron and cast iron piping will be externally inspected for corrosion, and the fill in the vicinity of the piping will be inspected for material that could cause external damage to the stainless steel, ductile iron or cast iron pipe.
As alternatives to direct external inspections involving excavation, the buried piping inspections may be performed by a hydrostatic test on at least 25% of the code class/safety-related or hazmat piping or both constructed from the material under consideration on an interval not to exceed 5 years. Or, similarly, at least 25% of the code class/safety-related or hazmat piping or both constructed from the material under consideration will be internally inspected by a method capable of precisely determining pipe wall thickness on an interval not to exceed 5 years.
Enclosure to NG-13-0274 Commitment 55- One-Time Inspection Program, XI.M32 Existinq Commitment:
The sample selection for the DAEC One-Time Inspection program will include a representative sample of approximately 20% of the population (defined as having the same material environment combination) or a maximum of 25 components with the exception of carbon steel and cast iron in a fuel oil environment. Existing maintenance records that document component condition will be used as part of the sample.
Reason for Commitment Change:
During implementation of the One Time Inspection Program it was recognized that there was ambiguity in the commitment with respect to what constituted a separate grouping of material and environment combinations with respect to calculating the sample size of required inspections for aging. The following commitment change eliminates that ambiguity. The specified number of required inspections is consistent with a target of approximately 20% of the population (defined as having the same material environment combination) or a maximum of 25 components with the exception of carbon steel and cast iron in a fuel oil environment. The table clarifies the separate environmental groupings and material combinations with respect to selecting the sample of required inspections for aging that will be used. Since the aging effects of Carbon Steel and Stainless Steel are the same in Sample Group 3 and Sample Group 4 the required number of inspections for both groups were added together totaling 57.
Revised Commitment:
The sample selection for the DAEC One-Time Inspection program will include a representative sample of the population. Existing maintenance records that document component condition will be used as part of the sample. The material environment combinations and the number of required inspections for the sample group will be as shown in the following table:
Sample Group Materials in the Sample Group Environment Number ofRequired Environment Inspections.
Sample Group 1- Carbon Steel and Cast Iron 6 Fuel Oil Stainless Steel Sample Group 2- Aluminum alloy 38 Lube Oil Carbon Steel and Cast Iron Copper Alloy including Admiralty Brass Stainless Steel including Cast Austenitic Stainless Steel Sample Group Copper Alloy, Copper, Admiralty Brass, Brass 57 3/4-Steam and Carbon Steel, Low Alloy Steel and Cast Iron Treated Water, Stainless Steel Including Cast Austenitic Reactor Coolant Stainless Steel Stainless Steel Cladding of Low and Sodium Alloy Steel with Carbon Steel and Nickel Alloy Pentaborate I
Enclosure to NG-13-0274 ATTACHMENT 1 (Revised Commitments for Table 18-1 of UFSAR)
Item No.1System7, Component or :.. Commitment. Section Schedule:
Program
- 36. (Thermal Aging Implement a Thermal Aging and Neutron Irradiation 18.1.38 Prior to the and Neutron Embrittlement of Cast Austenitic Stainless Steel period of Irradiation (CASS) Program. extended Embrittlement of operation Cast Austenitic [Revised in DAEC letter NG-09-0764 in response to Stainless Steel New Program Commitment RAI]
(CASS) Program)
- 52. (Buried Piping Enhance the Buried Piping and Tanks Inspection 18.1.7 Prior to the and Tanks Program to include inspection of at least a minimum period of Inspection number of pipe segments in each material group extended Program) (one stainless steel, two carbon steel, one cast iron, operation and two ductile iron) prior to entry into the period of extended operation and each ten-year period after entry into the period of extended operation. Where torsional guided wave data indicates significant susceptibility, inspections will be performed on associated locations. The sample locations for directed inspections will preferentially select higher risk locations. Piping that normally contains hazardous materials will be prioritized in the inspection location selection process. The diesel fuel oil piping will be inspected prior to entry into the period of extended operation. These directed inspections will be performed with sufficient excavation to expose at least ten linear feet of piping as practicable, including the pipe bottom.
Inspections of coated carbon steel piping will include the coating and backfill in the vicinity of the piping for material that could cause coating damage. The uncoated stainless steel, ductile iron and cast iron piping will be externally inspected for corrosion, and the fill in the vicinity of the piping will be inspected for material that could cause external damage to the stainless steel, ductile iron or cast iron pipe.
[Added in letter NG-10-0383]
[Revised in letter NG-10-0427]
- 55. (One-Time The sample selection for the DAEC One-Time 18.1.32 Prior to the Inspection Inspection program will include a representative period of Program) sample of the population. Existing extended maintenance records that document component operation condition will be used as part of the sample.
[Revised in DAEC letter NG-09-0764 in response to New Program Commitments RAI]