ML20024C134
| ML20024C134 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 06/30/1983 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Sternberg D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML20024C135 | List: |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, ANPP-24220-RQT, DER-82-72, NUDOCS 8307120296 | |
| Download: ML20024C134 (4) | |
Text
{{#Wiki_filter:, l Arizona Public Service Company Po. BOX 21666. PHOENIX, ARIZONA 85036 June 30, 1983 ANPP-24220-RQT/BSK U. S. Nuclear Regualtory Commission Region V Creekside Oaks Office Park 1450 Maria Lane - Suite 210 Walnut Creek, CA 94596-5368 Attention: Mr. D. M. Sternberg, Chief Reactor Projects Branch 1
Subject:
Final Report - DER 82-72 A 50.55(e) Reportable Condition Relating To Concrete Void In Unit 2 Containment Exterior Wall File: 83-019-0 26, D.4.33.2
Reference:
A) Telephone Conversation between P. Narbut and G. Duckworth on November 24, 1982. B) ANPP-22591, dated Dec. 23, 1982 C) ANPP-23438, dated April 21, 1983 (Time Extension)
Dear Sir:
/ Attached is our final written report of the Reportable Deficiency under 10CFR50.55(e), referenced above. Very truly yours, %hQQjQ W E. E. Van Brunt, Jr. APS Vice President Nuclear Projects Management ANPP Project Director EEVBJr/RQT:ru Enclosure ec: See Page 2 ,sp -{,j hw ,\\ $ di\\ 8307120296 830630 "A PDR ADOCK 05000529 g PDR ),1 y
-f,.. - ] t. U. S. Nuclear Regulatory Commission Page Two I cc: Richard DeYoung, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 T. G. Woods, Jr. G. C. Andognini J. A. Roedel D. B. Fasnacht A. C. Rogers B. S.'Kaplan W. E. Ide J. Vorees J. R. Bynum P. P. Klute/D. D. Green A. C. Gehr W. J. Stubblefield W. G. Bingham R. L. Patterson R. W. Welcher R. M. Grant D. R. Hawkinson .L. E. ' Vorderbrueggen G. A. Fiorelli S. R. Frost J. Self Records Center Institute of Nuclear Power Operations 1100 circle 75 Parkway - Suite 1500 Atlanta, Georgia 30339 a i p. s d
FINAL REPORT - DER 82-72 DEFICIENCY EVALUATION 50.55(e) ARIZONA PUBLIC SERVICE COMPANY (APS) PVNGS UNIT 2 I. Description of Deficiency Specification 13-CM-158, Revision 9, paragraphs D.8.6.2.5 and D.8.6.2.7 requires that the tendon sheathing be sufficiently leak-tight to hold the sheathing filler material. Subsequent to installation and tensioning of PVNGS Unit 2 Containment Building tendons H32-009 and H32-011, a subcontractor informational air test revealed excessive leakage to the outside face of the conctete. Further inspection revealed a concrete surface irregularity in the exterior Containment wall at the point of air leakage. This condition is documented in nonconformance report CC-3805. A comprehensive investigation of this condition was performed by Bechtel Engineering to determine the characteristics of the leak system between the tendon sheaths and the ultimate exit points at the surface of the Containment wall. Initial chipping of this surface irregularity revealed a crack generally parallel to the concrete surface and located up to 5" from the surface. Extensive air and hydraulic testing of the leak pathways was subsequently performed, resulting in definiton of the characteristics of the leaks, extent of the leak system and volume of the leak system. Results of this testing showed the leaks to be confined to narrow localized pathways and that no large voids were present. This testing also demonstrated that cement grouting of the leak pathways would be an effective repair procedure (see Part III, Corrective Action). Further details of the subject condition and investigation are provided in the attached report " Engineering Evaluation Report: Investigations and Grouting of Leaks Associated with Tendon Sheaths H32-009 and H32-011", dated June, 1983 (Attachment 1). II. Analysis of Safety Implications The function of the sheathing filler (grease) is to provide protection against corrosion of the tendons in the post-tensioning l system. The post-tensioning system ensures the structural integrity I of the Containment structure in a postulated LOCA and/or seismic event. Should the leaks in the subject tendon sheaths have remained uncorrected, uncontrolled escape of sheathing filler could potentially have occurred, resulting in incomplete corrosion protection of the subject tendons. Corrosion of the tendon wires could result in significant degradation of the local prestress ferce due to loss of tendon strength. The subject condition is therefore evaluated as reportable under the requirements of 10CFR50.55(e) since, if left uncorrected, it could have adversely affected the safety of operations of the plant during the lifetime of the plant and it represents a deficiency in construction.
Final Report DER 82-72 Page 2 III. Corrective Action 1. As indicated in " Condition Description", Bechtel Engineering has conducted extensive air and hydraulic testing of the leak pathways in the Containment Building wall. Af ter defining the characteristics, extent and volume of the leak system, a grouting program was conducted to fill the leak paths in the wall and to seal off the leaks in the tendon sheaths. A verification test program confimed that the leaks had been fully repaired by the grouting program. Tendons H32-009 and H32-011 were subsequently reinstalled, stressed, and greased successfully with no uncontrolled escape of grease. Details of the test program, grouting work performed and verification tests are presented in the attached Engineering Evaluation Report. 2. The attahed Engineering Evaluation Report has been reviewed by the Project consultant, Mr. John King. His letter stating his concurrence with the conclusions of the report is provided in. 3. The subject of the strength of the grout used to seal the leaks has been addressed by the consultant, Mr. King. His letter stating his conclusion that the grout strength is adequate for the application is provided in Attachment 3. 4. Nonconformance Report CC-3805 has been dispositioned to have the above described work and testing performed. 5. The subject condition is isolated to Unit 2. Tendon installation and greasing has already been successfully performed for Unit 1. Tendon installation has not yet been initiated for Unit 3. .-,}}