ML13134A077
| ML13134A077 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 04/26/2013 |
| From: | NextEra Energy Seabrook |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| SBK-L-13062 | |
| Download: ML13134A077 (29) | |
Text
SEABROOK UPDATED FSAR APPENDIX 3G CONTAINMENT LINER ANCHOR LOAD TESTS The information contained in this appendix was not revised, but has been extracted from the original FSAR and is provided for historical information.
SB 1&2 FSAR APPENDIX 3G CONTAINMENT LINER ANCHOR LOAD TESTS 3G-l Amendment 53 August 1984 SB 1&2 FSAR FINAL REPORT CONTAINMENT LINER ANCHOR LOAD TESTS by Edwin G.Burdette February 5, 1981 Tests Performed for United Engineers and Constructors 30 South 17th.Street Post Office Box 8223 Philadelphia, Pennsylvania 19101 Testing Facilities:
Department of Civil Engineering The University of Tennessee Knoxville, Tennessee 37916 Amendment 52 December 1983 Edwin G.Burdette Consultant 3G-2 1.INTRODUCTioN SB 1&2 FSAR Containment Liner Anchor Load Tests by Edwin G.Burdette Amendment 52 December 1983 The containment structure for the Public Service Company of New shire's Seabrook Nuclear Power Station consists'of a right vertical cylin-der, a hemispherical dome, and a thick, flat base.In order to meet leak-tightness requirements for the containment acting.*as a pressure vessel, the entire inside surface of the concrete is covered with a steel liner.This liner is anchored to"the concrete by embedded structural tees, angles, or studs which are welded to the steel liner plate.The containment is designed to resist the high temperature.and pressure associated with the most severe break in a reactor coolant pipe.Under this postulated loading condition, the liner anchors must be adequate to maintain the structural integrity of the system.: In order"to evaluate, analytically, the adequacy of the liner anchors to perform their required function)experimental load-deflection data for individual anchors are needed for shear loads and displace-ments along the surface of the containment wall.The results of load tests on liner anchors have been reported in ences 2, 3 and 4.Of particular interest relative to the tests reported here-in are the results reported in Reference 2 of tests performed at the University of Tennessee.
These test results considerable information on load-deflection behaviot of angles and a smaller amount of data on structural tees, both and tees being to 1/4 inch thick liner plates.The tests reported herein utilized the same test equipment and essentially the same 3G-3 SB 1&2 FSAR Amendment 52 December 1983 procedure as those tests**in Reference 2 and were designed to provide experi-mental data directly applicable to the containment liner at Seabrook.1.1 Objective The objective of the tests aeported here is to obtain the shear load-displacement relationships*for a)the Japanese Tee lOOxlOOmm with 1/4 inch fillet welds which was used to anchor the containment liner at Seabrook and b)for 3/4 inch diameter x 12 inch long studso The boundary support condi-tions for the liner plate test specimens were designed to represent, as near-ly as those existing in the field;if an accurate simulation of field conditions was not practical,.
the support conditions were designed to produce conservative results.1.2 Scope A total of six shear tests were performed.to accomplish the stated ob-jective three tests on the Japanese Tee lOOxlOQmm and three tests on 3/4 inch diameter x 12 inch long studs.Information was obtained in each test to plot the load-deflection curve for the anchor being tested.1.3 Acknowledgment The work reported herein was performed as a part of United Engineers and Inc.,'Purchase Order No.H.O.56971, Change Order No.1.The facilities of the Department of Civil Engineering the University of Tennes-see, Knoxville, were used to perform the tests.A number of Civil Engineering students participated in the performance of the tests, with special commenda-tion due to Steve Stethen, graduate student in and to James Haley*.3G-4 2.TEST SPECnlENS SB 1&2 FSAR Amendment 52 December 1983 All of the test specimens were prepared on'the Seabrook plant site using procedures and materials approved for construction of the containment struc-ture.A complete description of the test specimens with is contained in Reference 1, and a sketch showing the dimensions of the test specimens is shown in Figure I herein.The concrete blocks in which both the tees and the studs were embedded were 3'-4" x 3'-0" x*2'-3",,'ith the lin-er attached to the 3'-4" x 3'-0" top face..The embedded tees were 12 inches long, and the two studs'were spaced 12 inches apart.The\velds for the tees were 1/4 inch continuous fillets on both sides of the The embedded an-chars were located 20 inches from the loaded front face of the test block, a distance equal to the horizont?l spacing of the structural tee anchors.The length of the liner piate beyond the front edge of the concrete test block\Vas determined by the dimensions of the test rig.After the specimens were cast, they were shipped to the University of Tennessee via truck for testing.At the time of casting, concrete cylinders of conc:"ete in each were cast and'stored at the Seabrook site.On the day a particular specimen was tested at the University,-
three corresponding cyl-inders were tested at Seabrook to obtain the compressive strength of the concrete.Four specimens were cast with embedded tees and four embedded studs.The test plan called for the testing of three specimens of each type.The fourth specimen of each type was cast"as a saf ety measure;if one specimen 3G-S SB 1&2 FSAR Amendment 52 December 1983 was damaged in shipment or if the results of the first three tests suggested a revised testing procedure, the extra specimen would then be tested.It turned out that there was no reason to test the extra specimens; thus, three tee and three stud specimens were tested.3*r-1ETHOD OF TESTING.3.1 Test Apparatus The concrete biock with the liner*plate anchored to its top face was re-strained by bearing against an abutment beam.The liner plate was fastened to a moveable head beam which was driven by two, 200kip capacity hydraulic rams.The driving of this head beam produced tension in the liner plate and, in turn, a shear load in the anchor.A hydrocal cap was placed between the leading top edge of the concrete block and the top 3 inches of the abutment beam.Calibration curves for the two load cells are included in Appendix c.The test instrumentation consisted of the following key elements: 1.An LVDT was attached to the liner plate in the vicinity of the anchor.In the first test the LVDT was located behind the anchor-that is, on the side away from the applied load-but the rotation of the anchor and the re-suIting uplift of the plate behind the anchor caused some inaccuracies in LVDT readings at deflertions beyonrl peak Joad (see Plates Bl and B2).Thus, for all later tests the LVOT was attached to the liner plate several inches in front of the anchor where there'was no vertical movement of the liner plate (see Plate B8).2.A Gilmore console was used to control the closed loop testing system.A voltage input at the console causes the pump to drive the hydraulic ram until a voltage output from the LVDT sends a feedback signal that precisely matches 3G-6 SB 1&2 FSAR Amendment 52 Decemb.er 1983 the input signal, at which point the system is in equilibrium.
3.Load cells are attachedlto the head beam which pulls the plate in such a way that the rams act..directly against the cells.The signal from the load cells is transmitted to.a digital strain indicator which is calibrated to read the load directly in kips.4.An Al plotter is keyed into the system in such a way that it receives signals from both the LVDT and the load cells.These tlvO signals cause the XY plotter to prodpce a continuous plot of load versus deflection a test is in progress.3.2 Test Procedure The tests proceeded as follows: 1.A small input voltage, corresponcing to a small deflection,\'las"dialed in" at the console.The pumps then drove the rams until sufficient movement of the anchor resulted in an output voltage from the which matched the input vol-tage.The°lo?d required to produce that deflection was read and recorded, and the XY plotter made a continuous record of load and deflection to that point.2.The procedure just described was repeated for increments of deflection small enough to obtain an accurate plot of the measured data.tleasurernent of load and deflection continued until the full 0.5 inch travel of the LVDT was reached or failure of the anchor occurred.For those tests where failure had not Occur-red at the limit of travel 6f the the LVDT was disconnected from the specimen, and the test was continued to failure to observe the mode of fail-ure of the embedded anchors..A dial gage was attached to the specimen to pro-vide a check on the deflections measured by the LVDT.3G-7 SB 1&2 FSAR 3.3 General Comments Two aspects of the testing procedure merit special comment: Amendment 52 December 1983 1.The load was applied to the anchors in the tests through a pull on the plate rather than.a push on the plate as used in*the tests in Reference 4. type of load application obviated the need for any bending stiffeners on the liner plate, permitting a realistic representation of the rotation of the liner plate at the anchor.However, the fact that tpe unloaded end of the liner plate was unrestrained permitted it to lift off the test block as a result of the.anchor rotation.In an actual liner-liner anchor system, this lift-off would be restrained by another embedded tee or rov]of studs, restraint that would add to the stability of the system.This effect is par-important in the tee tests.Therefore, the method of testing these specimens was such that the load-deflection curve obtained for an anchor would be a conservative representation of the actual load-deflection relationship for an anchor in an actual field installation.
2.The tests were controlled by deflection rather than by load.The input voltage corresponded to a deflection and the rams acted to produce this de-flection;the load required to produce this deflection then read from the multirneter.
This method of controlling the.tests permitteddefinition of the descending portion of the load-deflection curve for an anchor.4.TEST RESULTS The test results are summarized in Tables 1 and 2, and load-deflection curves are shown in Figures 2 and 3.Original data t including XY p10tst are included in Appendix C.Selected photographs are presented in Appendix B to 3G-a SB 1&2 FSAR Amendment 52 December 1983 illustrate the testing operations and the mode of failure of the anchors.4.1 Discussion of Results The irregularities present in the load-deflection curves shown in theplots in Appendix C are due, for the most part, to relaxation of the concrete causing a reduction in load under a constant deflection. the test was stopped to take readings or, for that matter, when the person dialing in the voltage hesitated a bit, the system responded by maintinaing constant de-flection; the load required to maintain this deflection immediatelycreased. lC2c-deflection curves for the tees, sho\*m in Figure 2, drop off sharply after peak load is reached.At peak load the rotation of the tee in the concrete a crack on the back side of the flange of the tee.The local instability of the anchor results in a sharply reduced load-carrying capacity;in fact, the only load-carrying capacity remaining is-that required to fail the concrete wedge directly in front of the embedded tee.The drop-off in load beyond the peak t-las so sudden for T-I.and T-3, the testing equipment was incapable of tracking it accurately.
The sud-den load instability of the concrete around the tee would permit the anchor to move too far forward,"overshooting" the dialed in voltage.The rams would then try to rectify the situation by retracting; however, the rams were not connected to the head beam, so their retraction allowed the load to go to zero.This situation is illustreted by the load-deflection curves obtained from the XY plotter and included in Appendix c...This loss of load presented no partic-ular problem;a new, higher voltage was d1aled in, the test was continued, and 3G-9 SB 1&2 FSAR a continuation of the load-deflection curve was obtained.Amendment 52 December 1983 In an actual con-tainment liner-liner anchor system, the restraint provided by an adjacent anchor would almost certainly reduce the sharpness of the drop-off of the load-deflection curve and enhance the ductility of the tee anchors.The distinctly different-shapes of the load-deflection curves for the tees and for the studs reflect the different modes of failure for the two anchor systems.The fillet welds joining the tee's to the liner plate were of sufficient strength to prevent a failure of the steel-embedment; thus, the shear stren 6 th of the anchor was limited by concrete tension acting to resist the rotation of the tee produced by the.applied shear.Ductility of the ern-bedded tees resulted from-the development of a secondary mode of failure, namely, the diagonal tension failure of the wedge of concrete directly in front of the tee.Conversely, the strength element in a stud test was the shear strength of the studs.In ea6h case the studs sheared just below the weld which attached them to the liner*plate.The resulting load-deflection relationship resembles the stress-strain curve for steel, with a corresponding high degree of ductility.
Interestingly, the maximum shear stress in the studs fat an average of the"three'tests was 60 ksi.5.CONCLUSIONS The load-deflection curves shown in Figures 2 and 3 represent, in the op-inion of this a reasonable description of the shear load-deflection behavior of the anchors tested.Because of the absence of any hold-down re-straint on the free ends of the liner plates in the tests, the descending por-tions of t*he curves for the tees.should be somewhat higher.-Thus*, the curves in 3G-IO SB 1&2 FSAR Amendment 52 December 1983 Figure 2 may be thought of as reasonaole but somewhat conservative represen-tations of the behavior of actual embedded tee anchors.3G-ll SB 1&2 FSAR REFERENCES Amendment 52 December 1983 1.Ga1unic, Branko,"Procedure for Containment Liner Anchor Load Test", United Engineers and Constructors, Inc., Philadelphia, PA 19101 t Revised August 25, 1980 (attached to Purchase Order No.H.O.56971, Change Order No.1)..2.Burdette, Edwin G.and Rogers,.Larry W.,"Liner Anchorage*
Tests",nal of the Structural Division, ASeE, Vol.101, No.ST7, Proc.Paper 11432, July 1915, pp 1455-1468.
3.Lee, T. Gurbuz, 0.,"Assessment of Behavior and Designing Steel Liners for Concrete Reactor Vessels", Final Report, Engineering Research Institute, Iowa State University, Ames, Iowa, Nov.1973 (prepared for the u.s.Atomic Energy Commission Under No.AT(11-1)-2267).
4."Liner Plate Anchorage Tests", Bechtel Corporation, San Francisco,ifornia, for*Arkansas Nuclear One, Arkansas Power and Light Co., April 18, 1969.3G-12 SB 1&2 FSAR APPENDIX A TABLES AND FIGURES 3G-13 Amendment 52 December 1983 SB 1&2 FSAR Table 1 Test Data for Tee Specimens Amendment 52 December 1983 f Concrete Peak Peak Defl.Peak Load at Age f'Load Load Load 6=0.25 in.c Specimen (Davs)(psi)(k/in)(ins)(kips)T-I 20 152 12.67 0.070 36 T-2 24 156 13.0.0.070 34 T-3 28 5,950 144 12.0 0.060 32 Avg.
150.7 12.6 0.067 34 Table 2 Test Data for Stud Specimens , Concrete Peak Peak Defl.at Load at Age ft Load Load Peak Load 6=0,.25 in.c Specimen (Davs)(psi)(kips).(k/stud)(Ins.)(kips)5-1 42 6,100 51.5 25.8 0.390 48 S-2 56 6,060 54.B-27.4 0.620 46 5-3 67 6,500 52.5 26.3 0.395 49 Avg.6,220 52.9 26.5 0.468 47.7 3G-14
(\NS.')-0..L.__
o Z.LOAD-DE"FL-EC\"\ON CUR.VE-"3......TSE-SP=CIMl:1JS
.....JAPA1-!';:'3ETE.\;
)00)(
"'I'14'WELDS-3G-16 SB 1&2 FSAR Amendment 52 December 1983..--so (0
\f\\(l..40-)1"-'D 4 S 70 rJU1:l 2.0o o 0.\0 0.20 O.?O 0,4-0., o.so Fc=.;DR.-S 3 eo
-
CU'KVE.5-v S-rUD
-2}"'3/4'4>"\'2" STuDS-3G-17 SB 1&2 FSAR APPENDIX B PHOTOGRAPHS 3G-18 Amendment 52 December 1983 SB 1&2 FSAR Amendment 52 December 1983 Plate Bl: Specimen T-l.Test Assembly at Start of Test.. Plate B2: Specimen T-l.Plate Deformation During Final Stages of Testing 3G-19 SB 1&2 FSAR Amendment 52 December 1983 Plate B3: Specimen T-l.Concrete Surface After Removal of Liner Plate Plate B4: Specimen T-l.Liner Anchor (Tee)After Test 3G-20 SB 1&2 FSAR Amendment 52 December 1983 Plate B5: Specimen T-2.Liner Deformation at End of Test Plate B6: Specimen T-2.Top of Concrete at End of Test 3G-21 SB 1&2 FSAR Amendment 52 December 1983 Plate B7: Specimen T-2.Liner and Tee at Elld of Test*......................
- ...:.:.*.Plate B8: Specimen T-3.Instrumentation at Start of Test 3G-22 SB 1&2 FSAR Amendment 52 December 1983 Plate B9: Specimen T-3.Concrete Surface After Removal of Liner Plate Plate BIO: Specimen T-3.Liner and Tee After Removal of Liner Plate 3G-23 SB 1&2 FSAR Amendment 52 December 1983 Plate B11: Specimen S-l.Start-up of Test Plate B12: Specimen S-l.Studs in Concrete After Shear Failure 3G-24 SB 1&2 FSAR Amendment 52 December 1983 Plate B13: Specimen S-I.Detail of Sheared Stud in Plate Plate B14: Specimen S-I.Detail of Sheared Stud in Concrete 3G-25 SB 1&2 FSAR Amendment 52 December 1983 Plate B15: Specimen S-2.Concrete Surface After Failure of Studs Plate B16: Specimen S-2.Liner After Stud Failure 3G-26 SB 1&2 FSAR Amendment 52 December 1983 Plate B17: Specimen S-2.Detail of Sheared Stud in Concrete Plate B18: Specimen S-2.Detail of Sheared Stud in Plate 3G-27 SB 1&2 FSAR Amendment 52 December 1983 Plate B19: Specimen S-3.Sheared Studs in Concrete After Test Plate B20: Specimen S-3.Sheared Stud in Plate After Test 3G-28