ML20080P491
| ML20080P491 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 09/21/1983 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Sternberg D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, ANPP-27864-BSK, DER-83-41, NUDOCS 8310070006 | |
| Download: ML20080P491 (5) | |
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s September 21, 1983-ANPP--2 7864-BSK/R' 'T' "
- Q U. S. Nuclear Regulatory 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 83-41 A 50.55(e) Reportabic Condition Relating To Flooding In The Control Building
'3' Train Rooa File:
83-019-026; D.4. 3 3. 2.
Reference:
(A) Telephone Conversation between A. D'Angelo and R. Tucker on June 29, 1983
Dear Sir:
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Attached is our final written report of the Reportable Deficiency under._
10CFR50.35(e), ref erenced above.
Very truly you
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p GLL E. E. Van Brunt, Jr.
APS Vice President, Nuclear Projects Management ANPP Project Directcr EEVBJr/RQT:sn Attachment cc: See Attached Page 2 s
8310070006 030921 s
PDR ADCCK 05000529 i
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i Mr. D. M. Sternberg DER 83-25 Page 2 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 D. D. Green /P. P. Klute 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 D. Canady Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway - Suite 1500 Atlanta, Georgia 30339
o FINAL REPORT - DER 83-41 DEFICIENCY EVALUATION 50.55(e)
ARIZONA PUBLIC SERVICE COMPANY (APS)
PVNGS UNIT 1 I.
DESCRIPTION OF DEFICIENCY On June 3,1983, at 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br />, it was discovered that the circulating water intake canal was overfilled. This condition resulted in flooding the control building 74' elevation. The "B" train room was flooded to a depth of 7 inches and the "A" train room to a depth of 1 inch. The path of the flow was an open conduit running between the intake area and the control building.
At the cine of the incident the station was in the process of precore start up testing. The initiating condition was caused by an abnormal system alignment aggravated by confusion during testing and miscommunication between the outside area and control room operators.
During the event, the intake canal water level continued to rise above the normal operating level to the maximum high water level where water then passed through an unsealed pipe penetration to flood the circulating water pump pit area.
An unused (awaiting cable pulling) below grade conduit runs between the circulating water pump pit and the corridor building. Since the corridor building is connected to the control building below grade, a leakage path existed to the area containing safety related equipment. Figure A provides an overall perspective of the flood path.
II.
ANALYSIS OF SAFETY IMPLICATIONS No safety related components or circuits are located in the vacinity of the circulating pump pit area and therefore flooding of the pit itself did not present a significant safety hazard.
The control building 74' elevation is divided into two safety related equipment areas, each provided with its own drainage system. The areas are divided by a non watertight masonry wall with the door opening being provided with a 7-1/2" high curb. The curb functions, in the event of a flooding condition, to contain the
.uater in one area such that the leak can be detected and isolated prior to flooding presenting a significant hazard to both equipment areas.
Flooding from outside areas had been evaluated from both a ground water and a fluid system standpoint; however, flooding from an outside source through a below grade conduit was not previously evaluated. Even though this specific incident occurred prior to cable pulling through the conduit, the same event could have occurred at some later time if no corrective action were taken.
e DER 83-41 Page 2 This incident is evaluated as reportable as defined by 10CFR50.55(e) since the passive flooding protection features provided for the control building 74' elevation were not adequate to preclude flooding of both trains of safety related equipment.
III. CORRECTIVE ACTION
- 1. The pipe penetrations between the circulating water intake canal and pump pit (shown in elevation A on Dwg. 13-C-CWS-285 Rev. 13,
" Intake Structure Sections Sheet 2") will be sealed to limit the leakage rate into the pump pit to within the capacity of the pit drainage systen. This will prevent flooding of the area in the event the canal is overfilled at some later time.
- 2. The seven (7) below grade electrical duct bank penetrations of each power block facility (shown on Dwgs. 13-E-ZVU-006 Rev. 18, 007 Rev.16, " Underground Electrical Duct Layout Plot Plan Sheets 1, 2 and 3") will be scaled to block the below grade moisture instrusion paths.
Dug. 13-E-AVU-014 Rev. 8 " Underground Electrical Installation Notes, Symbols and Details" will be revised to define where and how internal conduit passages are to be sealed.
- 3. Dwg. 13-A-ZJD-509 Rev. 8, " Control Building Concrete Block Plans at E1. 74'-0, 100'-0 and Wall Elev." and 13-A-ZJD-510 Rev. 7,
" Control Building Concrete Block Wall Elevations and Sections" will be revised to require that all joints in the masonry wall separating the control building elevation 74' Train "A" and Train "B" equipment areas are to be sealed. Sealing will be required to a height of at least 7-1/2".
This corresponds to the curb height in the door opening through the wall.
- 4. To preclude recurrence of a flooding condition in all three units, the following Design Change Packages will be issued by 10-1-83 to incorporate the above modification. They are as follows:
ISE-ZY-121 ISA-ZJ-105 2CE-ZY-121 2SA-ZJ-105 3 CE-ZY-121 3CA-ZJ-105
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