L-2003-118, Inservice Inspection Plan Second Ten-Year Interval Relief Request 37 - Supplement 1
| ML031270216 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 05/04/2003 |
| From: | Jefferson W Florida Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-2003-118 | |
| Download: ML031270216 (6) | |
Text
0 Florida Power & Light Company, 6501 S. Ocean Drive, Jensen Beach, FL 34957 FPL May 4, 2003 L-2003-118 10 CFR 50.4 10 CFR 50.55a U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Re:
St. Lucie Unit 2 Docket No. 50-389 Inservice Inspection Plan Second Ten-Year Interval Relief Reauest 37 - Supplement 1 By letter L-2003-116 dated May 1, 2003, Florida Power and Light Company (FPL) requested, pursuant to 10 CFR 50.55a(a)(3)(i), approval of Relief Request 37, Altemative Examination Of Class 3 Piping Base Metal Weld Repairs. The request is to eliminate the requirement for radiography of Class 3 lined carbon steel piping base metal repair welds when repair welds are greater than 10 in2 in area. The subject piping is on the intake cooling water (ICW) system. Based on a conference call between the NRC and FPL on May 2, 2003, the attached revised relief request provides the clarifications requested by the NRC reviewer.
The revised relief request proposes an alternate that results in repair welds receiving a degree of examination equivalent to that imposed on pipe welds during the construction period. Therefore, this alternate provides an acceptable level of quality and safety.
Please contact George Madden at 772-467-7155 if there are any questions about this submittal.
William J rson Vice President St. Lucie Plant Attachment an FPL Group company
St. Lucie Unit 2 Docket No. 50-389 L-2003-118 Attachment Page 1 10 CFR 50.55a ST. LUCIE UNIT 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 37, Revision I Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(i)
Alternative Provides Acceptable Level of Quality and Safety "EXAMINATION OF ST. LUCIE UNIT 2, INTAKE COOLING WATER CLASS 3 LINED CARBON STEEL PIPING BASE METAL WELD REPAIRS"
- 1. ASME Code Component(s) Affected All St. Lucie Unit 2 Intake Cooling Water (lCW) ASME Class 3 lined carbon steel piping and components: such as shown on FPL Drawing 2998-G-082 Sheet 2, Revision 48, "Flow Diagram Circulating & Intake Cooling Water System"
2. Applicable Code Edition and Addenda
ASME B&PV Code, Section Xl, 1989 Edition (Applicable Inservice Inspection Requirements)
3. Applicable Code Requirement
ASME B&PV Code, 1989 Edition, Section Xl, Article IWD-4000, "Repair Procedures," Paragraph IWD-4100, "Scope," states: The rules of IWA-4000 apply.
Article IWA-4000, "Repair Procedures", Paragraph, IWA-4120, "Rules and Requirements" states:
"(a) Repairs shall be performed in accordance with the Owner's Design Specification and the original Construction Code of the component or system.
Later Editions and Addenda of the Construction Code or of Section III, either in their entirety or portions thereof, and Code Cases may be used..........
ASME B&PV Code, 1980 Edition, Section 1II, Subsection ND, Paragraph ND-4130 "Repair of Material" states:
"Material originally accepted on delivery in which defects exceeding the limits of ND-2500 are known or discovered during the process of fabrication or installation is unacceptable. The material may be used provided the condition is corrected in accordance with the requirements of ND-2500 for the applicable product form, except: (1) the limitation on the depth of the weld repair does not apply; and (2) the time of examination of the weld repairs to weld edge preparation shall be in accordance with ND-5120.
However, radiography is not required for welded
St. Lucie Unit 2 Docket No. 50-389 L-2003-118 Attachment Page 2 10 CFR 50.55a ST. LUCIE UNIT 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 37, Revision I repairs in material used in components provided that the welded joints in these materials are not required to be radio raphed, the extent of the welded repair does not exceed 10 sq in. (6540 mm ) of the surface area, and the magnetic particle or liquid penetrant examination of the repair is made as required by ND-2539.4."
4. Reason for Request
Repairs are to be made to ICW lined carbon steel pipe that has suffered damage during service. Damage can be internal or external, localized or widespread.
Such repairs are made in accordance with the requirements of ND-4130.
An example would be the repair of external corrosion on a 30-inch diameter pipe.
The surface area of a full penetration circumferential butt weld in a 30-inch diameter pipe could be 95 in2 and the weld would not require radiography.
Should external corrosion occur on this pipe, a repair weld would be a partial thickness weld and if the corroded area was greater than 10 in2, radiography would be required. The 95 in2 of full penetration weld is considered acceptable for use without radiography while an adjacent weld of approximately half the thickness and one tenth of the area is not considered suitable unless the more stringent examination method is used. The requirement for radiography when the repair is more than 10 in2 area is more stringent than the original construction requirements.
The additional radiography is an involved process that is in excess of the original design and construction requirements and does not necessarily provide greater assurances of quality and safety.
This request is to eliminate the requirement for radiography of lined carbon steel ICW piping base metal repair welds when repair welds are greater than 10 in2 in area and circumferential butt welds in the piping were not examined by radiography.
5. Proposed Alternative and Basis for Use
The proposed alternative is to inspect weld repairs to base metal in St. Lucie Unit 2 ICW Class 3 lined carbon steel piping systems in accordance with ASME B&PV Code, Section Xl, 2001 Edition, Paragraph IWA-4520(a)(1) which states:
"Welding or brazing areas and welded joints made for installation of items shall be examined in accordance with the Construction Code identified in the Repair/Replacement Plan with the following exceptions:
St. Lucie Unit 2 Docket No. 50-389 L-2003-118 Attachment Page 3 10 CFR 50.55a ST. LUCIE UNIT 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 37, Revision 1 Base metal repairs on Class 3 items are not required to be volumetrically examined when the Construction Code does not require that full penetration butt welds in the same location be volumetrically examined."
In accordance with the proposed alternative, repair welds in St. Lucie Unit 2 ICW Class 3 lined carbon steel piping will receive a final surface examination, but not radiographic examination, regardless of the surface area of the weld repair.
Additionally, when the repair does not penetrate through the piping, the repair excavation area will receive a surface examination prior to welding. Also, where the repair penetrates through the piping, the root pass of the repair weld will receive a surface examination when required to comply with the conditions of Regulatory Guide 1.147 and Code Case N-416-1 (Reference 1). All of the Class 3 piping welds at the St. Lucie Unit 2 plant received a final surface examination during construction; the welds were not radiographed.
The final surface examination was in accordance with the governing Construction Code requirements.
The proposed alternative results in repair welds receiving a degree of examination equivalent to that imposed on pipe welds during the construction period.
The requirement for imposing radiography on weld repairs with surface area greater than 10 in2 is a common requirement from base material specifications.
The requirement is to insure that the final product meets uniform expected properties. The material manufacturer works to a set of specific requirements, not knowing the exact use of the product, fabricating material for stock and subsequent delivery to end users. The requirement for radiography on weld repairs with surface area greater than 10 in2 is appropriate for a material manufacturer. Once an item is installed, it exists in a specific environment and the universal nature of stock products is inappropriate. Accordingly, the controls to insure universality are no longer appropriate or meaningful after installation.
The proposed alternative will be employed starting with the current St. Lucie Unit 2 outage.
In conclusion, the proposal to examine St. Lucie Unit 2 ICW Class 3 lined carbon steel piping base metal weld repairs in a manner equivalent to examination of circumferential butt welds in the piping is an alternative to the requirement to radiograph base metal repairs that have a surface area greater than 10 in2 in piping that is not subject to radiographic examination. The alternate provides a degree of quality and safety equivalent to the Construction Code requirements, and has been approved by the ASME Code.
St. Lucie Unit 2 Docket No. 50-389 L-2003-118 Attachment Page 4 10 CFR 50.55a ST. LUCIE UNIT 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 37, Revision 1
6. Duration of Proposed Alternative
The proposed alternative will be applicable to any base metal repairs in St. Lucie Unit 2 ICW Class 3 lined carbon steel piping for the remainder of the second interval for Unit 2.
- 7. Additional Design Information The following provides additional design information for the St. Lucie Unit 2 ICW System lined carbon steel components, as requested by the NRC for evaluation of the proposed relief.
Material Specifications:
Piping:
Welded plate pipe per ASTM A-155 Grade KC-65, Class 1, Firebox Quality Seamless Carbon Steel pipe per ASTM A106 Grade B ASTM A-672 Grade C65 Class 22 or 42 Fittings:
ASTM A-234, Grade WPB or WPBW ASTM A-216 Grade WPC ASTM A-216 Grade WCB ASTM A-352 Grade LCB ASTM A-350 Grade LF2 ASTM A-105 Grade II Flanges:
ASTM A-105 Grade II ASTM A-216 Grade WCB ASTM A-350 Grade LFI ASTM A-352 Grade LCB ASTM A-181 Grade II ASTM A-181 Class 70 ASTM A-105 For St. Lucie Unit 2, materials were specified to the corresponding ASME SA material where required by Section III of the ASME B&PV Code.
Design Pressure/Design Temperature:
90 psig/1 250F upstream of the component cooling water heat exchanger 90 psig/1 500F downstream of the component cooling water heat exchanger
St. Lucie Unit 2 Docket No. 50-389 L-2003-118 Attachment Page 5 10 CFR 50.55a ST. LUCIE UNIT 2 SECOND INSPECTION INTERVAL RELIEF REQUEST NUMBER 37, Revision 1 Pipe Schedule/Thickness:
3/8 inch wall for piping 14 inches and larger 2 % -12 inches - Schedule 40 Pipe Lining: Cement lining, or approved alternate coating
- 8. References
- 1) ASME Boiler and Pressure Vessel Code, Code Case N-416-1, "Alternative Pressure Test Requirements for Welded Repairs or Installation of Replacement Items by Welding, Class 1, 2, and 3, Section Xi, Div. 1" as accepted by Regulatory Guide 1.147.
- 2) ASME Boiler and Pressure Vessel Code, Section Xi, "Rules for Inservice Inspection of Nuclear Power Plant Components," 2001 Edition.
- 3) ASME B&PV Code,Section III, Subsection ND, "Nuclear Plant Components -
Class 3 Components," 1980 Edition (in accordance with the provisions of the Repair/Replacement Program).