ML070430247
| ML070430247 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 01/14/2007 |
| From: | Mauldin D Arizona Public Service Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 102-05629-CDM/SAB/RJR, EA-03-009 | |
| Download: ML070430247 (3) | |
Text
EA-03-009 David Mauldin Vice President Mail Station 7605 Palo Verde Nuclear Nuclear Engineering Tel: 623-393-5553 PO Box 52034 Generating Station and Support Fax: 623-393-6077 Phoenix, Arizona 85072-2034 102-05629-CDM/SAB/RJ R January 14, 2007 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Unit 2 Docket No. STN 50-529 APS' 60-Day after Plant Restart Letter in Response to First Revised NRC Order EA-03-009, Item IV.E - U2R13 First Revised NRC Order EA-03-009, dated February 20, 2004, Item IV.E requested that a report detailing the inspection results of the reactor pressure vessel (RPV) head be submitted to the NRC within 60 days of returning the unit to operation. Arizona Public Service Company (APS) completed Unit 2's 1 3 th refueling outage (U2R13) on November 14, 2006. The effective degradation years (EDY) calculated at the start of U2R1 3 were 13.85 EDY.
Results of the Inspection Required by the First Revised NRC Order, EA 009 Section IV.C.(5)(a) Bare Metal Visual Examination Results This examination was conducted in accordance with the requirements of the First Revised Order with no relaxations. No cleaning of the RPV head was necessary during U2R13. The visual examination of the "bare-metal" surface of the reactor head found no evidence of boron or corrosion.
Section IV.C.(5)(b) Nonvisual Nondestructive Examination (NDE) Results:
Nonvisual NDE was performed in accordance with the requirements of the First Revised NRC Order EA-03-009 Section IV.C.(5)(b) and approved relaxations and commitments.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak 0 Diablo Canyon 0 Palo Verde
- South Texas Project 0 Wolf Creek J
U. S. NRC Attn: Document Control Desk Page 2 APS' 60-Day after Plant Restart, U2R13 First Revised NRC Order EA-03-009 Reactor Head Vent Nozzle:
As reported in APS letter 102-05299, Licensee Event Report (LER) 50-529/2005-001-00, dated June 20, 2005, and letter 102-05311, dated July 18, 2005, two (2) axial indications were confirmed on the vent ID surface.
The axial indications were repaired by grinding the indications to an acceptable condition prior to Unit 2 resuming power operation from the 1 2 th refueling outage (U2R12).
During this outage (U2R1 3), APS found unacceptable indications at or near the same area as those repaired in U2R12. These were reported in APS letter 102-05599, LER 50-529/2006-005-00, dated November 21, 2006. The vent line was repaired by excavating the vent line J-weld, a portion of the vent pipe and some base material. The j-weld was replaced and the excavated surface was overlayed. Both the j-weld and overlay were welded using Inconel 52 weld material. These indications were characterized as axial, estimated less than 0.025 inch deep, approximately 0.2 inch long. The indications were not through-wall and there was no evidence of RCS pressure boundary leakage.
Control Element Drive Mechanism Nozzles:
The minimum required inspection coverage was obtained for all nozzles using ultrasonic and eddy current examination. No flaws were identified.
Section IV.D. Visual Inspection Results:
APS personnel performed a Boric Acid Walkdown (BAW) for the U2R1 3 refueling outage using Work Order 2804344. Potential boric acid leak sites from pressure retaining components above the RPV Head were examined using PVNGS procedure 70TI-9ZC01, Revision 5, Boric Acid Corrosion Prevention Program.
No indication of previously unreported leakage was identified. The two sites identified in APS letter 102-05361, Special Report # 2-SR-2005-002 (Versa Vents), dated October 18, 2005, were cleaned and reworked during this outage.
No new commitments are being made to the NRC by this letter. Should you have any questions, please contact Thomas N. Weber at (623) 393-5764.
Sincerely,
U. S. NRC Attn: Document Control Desk APS' 60-Day after Plant Restart, U2R1 3 First Revised NRC Order EA-03-009 Page 3 cc:
B. S. Mallett M. B. Fields M.T. Markley G. G. Warnick NRC Region IV Regional Administrator NRC NRR Project Manager NRC NRR Project Manager NRC Senior Resident Inspector for PVNGS