IR 05000295/1986017

Insp Repts 50-295/86-17 & 50-304/86-16 on 860716-18.No Violation or Deviation Noted.Major Areas Inspected: Resolution of IE Bulletin 79-02, Pipe Support Baseplate Design Using Concrete Expansion Anchors

ML20203J389
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	07/30/1986
From:	Danielson D, Norton J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20203J388	List: IR 05000295/1986017 ML20203J383
References
50-295-86-17, 50-304-86-16, IEB-79-02, IEB-79-2, NUDOCS 8608050258
Download: ML20203J389 (4)

Text

.

b U.S. NUCLEAR RESULATORY COMMISSION

REGION III

Reports No. 50-295/86017(DRS);50-304/86016(DRS)

Docket Nos. 50-295; 50-304 Licenses No. DPR-39; DPR-48 Licensee: Coninonwealth Edison Company P.O. Box 767 Chicago, IL 60690 Facility Name: Zion Station, Units 1 and 2 Inspection At: Zion Site, Zion, IL Inspection Conducted: July 16-18, 1986

'* *

.

Inspector: B~J. F. Norton 1 /40/ %

Date Approved By: D. H. Danielson, Chief _]

Date 3 (5 Materials and Processes Section Aspection Summary Inspection on July 16-18, 19_8_6 JReportsNo. 50-295/86017]Ir~e~soliition of TEDRSJ;50-30

~- ~ ~ ~

Areas Inspected:_ heutine, unannounced lnspectlisIFTFe

. 'Biifletin No. 79-02 " Pipe Support Baseplate Design Using Concrete Expansion Anchors."

Results: No violations or deviations were identified, e600050208 e6073o PDR G

ADOCK 05000295 PDR .

--

.

.

DETAILS 1. Persons Contacted Commonwealth Edison Company (CECO)

• G. Plim1, Station Manager

• E. Fuerst, Superintendent, Production

• T. Rieck, Superintendent, Services

• R. Budowle, Assistant Station Superintendent, Technical Services

• C. Schultz, Regulatory Assurance Administrator

• W. Stone, Quality Assurance Supervisor

• E. Campbell, Master Instrument Mechanic

• A. Rasmussen, Maintenance Staff B. Majhi, Maintenance Staff K. Cichon, Maintenance Staff U.S. Nuclear Regulatory Commission

• M. Holzmer, Senior Resident Inspector

• L. Kanter, Resident Inspector

• Denotes those present at the exit intervie . Licensee Action on IE Bulletins

, (Closed) IE Bulletin No. 79-02 (295/79-02-BB, IB; 304/79-02-BB, IB): IE Bulletin No. 79-02 " Pipe Support Baseplate Design / Construction Using Concrete Expansion Anchor Bolts." Background IE Bulletin No. 79-02 addresses the design and construction of pipe support baseplates with concrete expansion anchors. The Bulletin was issued March 3,1979, and supplemental revisions were issued July 21, August 20, and November 8, 1979. The primary purpose of the bulletin was to assure that licensees had appropriately considered baseplate flexibility and its potential effects on anchor load Testing Program (1) Commonwealth Edison Company (CECO) committed to perform static,

.

'

dynamic and relaxation testing of expansion anchors to verify that the static and dynamic characteristics and capacities of the anchors conform to IE Bulletin No. 79-02. (CECO letter Cordell Reed to J. G. Keppler, dated July 5, 1979). A summary report entitled, " Static, Dynamic and Relaxation Testing of Expansion Anchors in Responses to NRC IE Bulletin No. 79-02,"

was issued July 20, 198 _ _ _ _ _ _ _ __ .

.

.

(2) The purpose of the test program was to supplement previous responses which had referred to these tests. The specific items addressed by the tests were ultimate static capacities of various types of expansion anchors; load-displacement relationships for these anchors; behavior of expansion anchors subjected to simulated seismic events and other cyclic loads; baseplate flexibility and its effect on anchor loads; and the phenomenon of relaxation (loss of anchor preload) with tim (3) These tests were divided into four phases (A through D), and provided a clear understanding of anchor behavior under a wide range of static and dynamic loadings and the effect of various parameters on that behavio (a) Phase A involved static tension tests of single anchors and provided an understanding of individual anchor behavio This series of tests proved that the level of preloading of the anchor at the time of testing does not affect the ultimate capacity of the ancho (b) In Phase B type tests, wedge, sleeve, and shell type anchored plate assemblies were cyclically loaded to simulate seismic or pipe transient type loadings. These tests were performed in reinforced concrete and concrete blocks walls, and confirmed that anchors embedded in concrete block and mortar can withstand cyclic load levels of at least 25% of the anchor ultimate static capacity. Tests in reinforced concrete demonstrated that anchors could withstand cyclic loads up to 50% of the anchor ultimate static capacit Also, it was determined that preload was not a determining factor as far as capacity of the anchor was concerne (c) Phase C tests were static tests on anchored baseplate assemblies for purposes of determining the effects of prying action on flexible plates. The results of these tests revealed that prying action is on the order of 15%

to 20% of the applied load. This increase was lower than originally anticipated due to the lower stiffness modulus of expansion anchors installed in concret (d) Phase D tests were run to determine the amount of relaxation of load that occurs in an anchor after it has been preloade After the cyclic tests were completed, which demonstrated that preload is not required to withstand cyclic loading, it was subsequently determined that the relaxation phenomenon is not of significant concer (4) A major finding resulting from the testing is that loss of preloading in an anchor does not affect the static ultimate load capacity of the anchor, nor is preload required for an anchor to withstand cyclic loading l l

~-

B

.

(5) The licensee field tested anchor installations at Zion Station as follows:

Load Test 850 tested 11 failures Thread Engagement 2596 tested 117 failures Shell Projection 2458 tested 2 failures Angularity 3244 tested 234 failures This data represents a 95% confidence level. This is consistent with CECO's commitments to the NRC regarding the "95-5" criteria presented in D. L. Peoples letter to J. G. Keppler, dated February 19, 198 Conclusion All expansion anchors which did not meet inspection criteria were modified or replaced. Modifications were accomplished in accordance with licensee engineering and QA/QC requirements. The NRC inspector reviewed quality records on several of the anchor installations. No QA/QC deficiencies were discerne The NRC inspector, based on this review, concluded that the actions set forth in IE Bulletin 79-02 have been complied with at Zion Station, Units 1 and . Exit Meeting The inspector met with licensee representatives (denoted under Persons Contacted) at the conclusion of the inspection on July 18, 1986. The inspector summarized the purpose and findings of the inspection. The licensee acknowledged the findings as reported herein. The inspector also discussed the likely informational content of the inspector's report with regard to documents or processes reviewed by the inspector during the inspection. The licensee did not identify any such documents / processes as proprietar _ _