ML20090H132
| ML20090H132 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 07/12/1984 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Bishop T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| ANPP-29952-TDS, DER-84-31, NUDOCS 8407260131 | |
| Download: ML20090H132 (4) | |
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'P RECEIVED NRC Arizona Public Service Company O All IG Pfl 2; g 7 July 12,.1.984 SEG!ONV;p ANPP-29952-TDS/TRB l
U. S. Nuclear Regulatory Commission Region V Creekside Oaks Office Park 1450 Maria Lane - Suite 210 Walnut Creek, CA 94596-5368 Attention: Mr. T. W. Bishop, Director Division of Resident Reactor Projects and Engineering Programs
Subject:
Final Report - DER 84-31 A 50.55(e) Reportable Condition Relating To Unsealed Piping Penetrations In The MSSS.
File: 84-019-026; D.4.33.2
Reference:
A) Telephone Conversation between P. Narbut and T. Bradish on May 17, 1984 B) ANPP-29861, dated June 6, 1984 (Interim Report)
Dear Sir:
Attached is our final written report of the Reportable Deficiency under 10CFR50.55(e), referenced above.
Very truly yours, CU._t_
%LL.
O E. E. Van Brunt, Jr.
AFS Vice President Nuclear Production ANPP Project Director EEVB/TRB:dh At tachment ec: See Page Ivo 8407260131 840712 PDR ADOCK 05000528 S
', ' XE-2 7
Mr. T. W. Bishop DER 84-31 Page Two r
cc:
Richard DeYoung, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 T. G. Woods, Jr.
D. B. Karner W. E. Ide D. B. Fasnacht A. C. Rogers j
L. A. Souza D. E. Fowler T. D. Shriver C. N. Russo J. Vorees J. R. Bynum J. M. Allen 1
J. A. Brand A. C. Gehr W. J. Stubblefield W. G. Bingham i
R. L. Patterson R. W. Welcher H. D. Foster D. R. Hawkinson L. E. Vorderbrueggen R. P. Zimmerman S. R. Frost J. Self D. Canady T. J. Bloom Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, GA 30339 i
s FINAL REPORT - DER 84-31 i
DEFICIENCY EVALUATION 50.55(e)
ARIZONA PUBLIC SERVICE COMPANY (APS)
PVNGS UNITS 1, 2, 3
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.I.
Description of Deficiency The Main Steam Support Structure (Systen ZM) Detailed Design Criteria, paragraph 1.5.2, states:
"The portion of the structure below elevation 100 feet - 0 inches shall be designed to be I
watertight both from external sources-of water and int arnal sources above elevation 100 feet - 0 inches." contrary to this criteria, 1
floor penetrations' for piping in the Main Steam Support Structure floor slah at elevation 100 feet are not sealed. The penetration seal schedule for drawing 13-A-ZYD-175, Rev.1 specifically states "no seal required" for penetrations 1 through 13 which are detailed on the floor insert and penetration drawing 13-A-ZYD-485, Rev. O.
II.
Analysis of Safety Implications Safety-related A and B-train Auxiliary Feedwater (AFW) Pumps are 4
located in this structure below elevetion 100 feet.
These pumps are i
required to function under certain accident conditions including feedwater or steam line breaks. For a design basis pipe rupture in this structure, the unsealed floor slab penetrations at elevation 100 feet would expose the AFW pumps to environmental conditions for.
j which they have not been qualified, and the operability of the AFW pumps would not he assured. The resulting loss of auxiliary feed capability could adverse.ly affect the safe shutdown of the reactor.
I This deficiency represents a defect in the design of a structure j
important to hardware safety, which if left uncorrected, could have precluded the safe shutdown of the. reactor; consequently, it is evaluated as reportable under 10CFR50.55(e). Since the subject floor slab penetrations have not been delivered or offered for acceptance it is evaluated as not reportable under 10CFR21.
III. Corrective Action Design Change ~ Packages 1SA-ZM-011, 2SA-ZM-011 and 3CA-ZM-011 i
including revisions to drawings 13-A-ZYD-175 and 13-A-ZYD-096 will be issued to add appropriate seals to the open penetrations through the Main Steam Support Structure floor slab at elevation 100 feet.
The physical modifications will be completed prior to fuel load for i
each unit.
'The requirement to limit the propagation of high energy pipe break temperature, pressure and flooding effects to certain areas within a structure is unique to the MSSS and was not adequately addressed during separation review meetings held during the design of. the MSSS. Correction of this specific design deficiency satisfactorily closes out this issue.
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b Mr. T. W. Bishop ANPP-29952 Page Two A detailed review of penetration seals throughout the plant'is not required as a result of this deficiency in the MSSS. Fire barrier sealing requirements are currently receiving a complete review as part of the project fire protection effort to revise and update the fire hazards analynia and fire protection evaluation report to support fuel load for Unit 1.
This effort includes physical verification of design and as-huilt configuration conformance to licensing requirements and commitments. Incorporation of radiation harrier sealing requirements into the ; physical design has been assured through prior detailed reviews of design drawings by the Nuclear discipline. Bionhield surveys during initial reactor startup and power ascension will confirm the adequacy of the plant.
shielding, including seals. Finally, a substantial design review to identify unsealed conduits and conduit penetrations below grade for protection against simple flooding was conducted as a corrective action for DER 83-41.
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