ML20323A157
| ML20323A157 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 10/22/2020 |
| From: | NextEra Energy Seabrook |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20323A163 | List:
|
| References | |
| SBK-L-20124 | |
| Download: ML20323A157 (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 Amendment 53 FSAR August 1984 APPENDIX 3G CONTAINMENT LINER ANCHOR LOAD TESTS 3G-1
SB 1 & 2 Amendment 52 FSAR December 1983 FHlAL 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 C~6-~~ Edwin G. Burdette Consultant 3G-2
SB 1 & 2 Amendment 52 FSAR December 1983 Containme nt Liner Anchor Load Tests by Edwin G. Burdette
- 1. INTRODUCTiON The containme nt structure for the Public Service Company of New Ramp-shire's Seabrook Nuclear Power Station consists of a right vertical cylin-der, a hemisphe rical dome, and a thick, flat base. In order to meet leak-tightness requireme nts for the containme nt actin.g .* 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 structura l tees, angles, or studs \vhich are \velded to the steel liner plate. The containme nt is designed to resist the high temperatu re and pressure associate d with the most severe break in a reactor coolant pipe. Under this postulate d loading condition ,
the liner anchors must be adequate to maintain the structura l integrity of the liner-;lin er ~nchor system * . In order to evaluate, analytica lly, the adequacy of the liner anchors to perform their required function, experimen tal load-deflectio n data for individua l anchors are needed for shear loads and displace-ments along the surface of the containme nt wall.
The results of load tests on liner anchors have been reported in Refer-ences 2, 3 and 4. Of particula r interest relative to the tests reported here-in are the results reported in Reference 2 of tests performed at the Universit y of Tennessee . These test results provide considera ble informati on on load-deflectio n behavior of angles and a smaller amount of data on structura l tees, both angl~s and tees being attached to 1/4 inch thick liner plates. The tests reported herein utilized the same test equipment and essential ly the same teqt 3G-3
SB 1 & 2 Amendment 52 FSAR December 1983 ed to provi de exper i-proce dure as those tests in Refer ence 2 and were design at Seabr ook.
menta l data direc tly appli cable to the contai nment liner 1.1 Objec tive the shear load-The objec tive of the tests aepor ted here is to obtain Omm with 1/4 inch displa cemen t relati onshi ps for a) the Japan ese Tee lOOxlO liner at Seabr ook and fille t welds \vhich was used to ancho r the contai nment ary suppo rt condi -
b) for 3/4 inch diame ter x 12 inch long studs . The bound to repre sent, as near-tions for the liner plate test specim ens were design ed accur ate simul ation of ly as practi c.::bl e,* those existi ng in the field ; if an tions were design ed to field condi tions was not pract ical,_ the suppo rt condi produ ce conse rvativ e resul ts.
1.2 Scope the stated ob-A total of six shear tests were perfor med to accom plish three tests on 3/4 inch jectiv e three tests on the Japan ese Tee lOOxlOOmrn and diame ter x 12 inch long studs . Inform ation was obtain ed in each test to plot the load- defle ction curve for the anthe r being tested 1.3 Ackno wledgm ent d Engin eers and The work repor ted herei n was perfor med as a part of Unite
- 1. The Constr~ttors, Inc., Purch ase Order No. H.O. 56971 , Change Order No.
the Unive rsity of Tenne s-facil ities of the Depar tment of Civil Engin eering ~t see, Knox ville, were used to perfor m the tests . A numbe r of Civil Engin eering
, with speci al commenda-stude nts partic ipate d in the perfor mance of the tests and to James Haley .
tion due to Steve Steth en, gradu ate stude nt in charg e, 3G-4
SB 1 & 2 Amendment 52 FSAR December 1983
- 2. TEST SPECIHENS 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 appr~priate drawings is contained in Reference 1, and a sketch showing the dimensions of the test specimens is shown in Figure 1 herein. The concrete blocks in which both the tees and the studs were embedded ~ re 3 1 -4" x 3 1 -0" x *2 1 -3" high ~dth the lin-er attached to the 3 1 -4" x 3 1 -0" top face . . The embedded tees were 12 inches long, and the two studs Here spaced 12 inches apart. The ields for the tees were 1/4 inch continuous fillets on both sides of the ste2. 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 ivas determined by the dimensions of the test rig . After the specimens were cast, they were shipped to the University of Tennessee via flat-bed truck for testing.
At the time of casting, concrete cylinders rep:-esc:tc.tive of t[;e conc:*ete in each specimen 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 with 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 safety measure; if one specimen 3G-S
SB 1 & 2 Amendment 52 FSAR December 1983 ed was damaged in shipmen t or if the results of the first three tests suggest It a revised testing procedu re, the extra specime n would then be tested.
three turned out that there was no reason to test the extra specime ns; thus, tee and three stud specime ns were tested.
- 3. HETHOD OF TESTING.
3.1 Test Appara tus re-The concre te biock with the liner plate anchore d to its top face was straine d by bearing against an abutme nt beam. The liner plate was fastene d to a moveab le head beam which was driven by t'>vO, 200kip capacit y hydrau lic rams. The driving of this head beam produce d tension in the liner plate and, in turn, a shear load in the anchor . A hydro cal cap \vas placed bet\veen the nt leading top edge of the concre te block and the top 3 inches of the abutme beaffi. Calibra tion curves for the two load cells are include d in Append ix C.
The test instrum entatio n consist ed of the followi ng key elemen ts:
- 1. An LVDT '>vas attache d to the liner plate in the vicinit y of the anchor.
on the In the first test the LVDT was located behind the anchor - that is, the re-side a\vay from the applied load - but the rotatio n of the anchor and in LVDT sulting uplift of the plate behind the anchor caused some inaccu racies reading s at deflert ions beyonrl peak Joad (see Plates Bland B2). Thus, for all in front of later tests the LVDT was attache d to the liner plate several inches (see Plate B8).
the anchor where there was no vertica l movement of the liner plate A
- 2. A Gilmore console was used to contro l the closed loop testing system ~
ram until voltage input at the console causes the pump to drive the hydrau lic ly matche s a voltage output from the LVDT sends a feedbac k signal that precise 3G-6
SB 1 & 2 Amendment 52 FSAR December 1983 the volt~ge input signal, at which point the system is in equilibrium.
- 3. Load cells are attached ~to 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
~ead the load directly in kips.
- 4. An XY plotter is keyed into the system in such a way that it receives signals from both the LVDT and the load cells . These t\vo signals *c ause the Ary plotter to prodpce a continuous plot of load versus deflection while a test is in progress.
3.2 Test Procedure The tests ptoceeded as fbllows :
- 1. A small input voltage, corresponC.ing to a small deflection, Has "dialed in" at the console. The pumps then drove the rams until sufficient movement of the anchor resulted in an output voltage from the L\~T which matched the input vol-tage. The *load required to produce that deflection was read and recorded, and the XY plotter made a continuous record of load and deflection t.:p 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. Heasurement 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 of the LVDT , 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 .
SB 1 & 2 Amendment 52 FSAR December 1983 3.3 Gene ral Comments ial comment:
Two aspec ts of the testi ng proce dure merit spec throu gh a pull on the
- 1. The load was appli ed to the ancho rs in the tests the tests in Refer ence 4.
plate rathe r than a push on the plate as used in' for any bendi ng stiff ener s This type of load appli catio n obvia ted the need senta tion of the rotat ion on the liner plate , perm itting a reali stic repre fact that the unloa ded end of the liner plate at the ancho r. Howe ver, the to lift off the test block of the liner plate was unres train ed perm itted it l liner -line r ancho r syste m, as a resu lt of the .a nchor rotat ion. In an actua ded tee or rov7 of studs ,
this lift- off would be restr ained by anoth er embed syste m. This effec t is par-restr aint that would add to the stab ility of the ticular~y impo rtant in ~he tee tests . There fore, the metho d of testi ng these obtai ned for an ancho r would speci mens was such that the load- defle ction curve defle ction relat ionsh ip for be a conse rvati ve repre senta tion of the actua l load-an ancho r in an actua l field insta llatio n.
by load. The input
- 2. The tests were contr olled by defle ction rathe r than de-volta ge corre spond ed to a defle ction and the rams acted to produ ce this ction was then read from the flect ion; the load requi red to produ ce this defle perm itted the defin ition of multi mete r. This metho d of contr ollin g the . tests for an ancho r.
the desce nding porti on of the load- defle ction curve
- 4. TEST RESULTS 2, and load- defle ction The test resu lts are summ arized in Table s 1 and inclu ding XY plots , are curve s are shown in Figur es 2 and 3. Orig inal data, B to inclu ded in Appen dix C. Selec ted photo graph s are prese nted in Appe ndix 3G-B
SB 1 & 2 Amendment 52 FSAR 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 the h~
plots in Appendix C are due, for the most part, to relaxation of the concrete causing a reduction in load under a constant deflection. \fuen 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; ~nd the load required to maintain this deflection immediately d~-
creased.
T-he lc?..d-deflection curves for the tees, shm*m in Figure 2, drop off sharply ia~ediately after peak load is reached. At peak load the rotation of the tee in the concrete produces 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 'tvedge directly in front of the embedded tee.
The drop-off in load beyond the peak was so sudden that, for T-1 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 AppendixC. .This loss of load presented no partie-ular problem; a new, higher voltage 't.;ras d'ialed in, the test was continued, and 3G-9
SB 1 & 2 Amendment 52 FSAR December 1983 a continuation of the load-deflection curve was obtained. 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 t~o anchor syste~s. 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~tli of the anchor was limited by concrete tension acting to resist the rotation of the tee produced by the applied shear. Ductility of the em-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 limiting strength element in a stud test was the shear strength of the studs. In each 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 wr.iter, 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 the curves for the tees should be somewhat higher. *Thus, the curves *in 3G-10
SB 1 & 2 Amendment 52 FSAR December 1983 Figure 2 may be thought of as reasonaole but somewhat conservative represen-tations of the behavior of actual embedded tee anchors.
SB 1 & 2 Amendment 52 FSAR December 1983 REFERENCES
- 1. Galunic, Branko, "Procedure for Containment Liner Anchor Load Test",
United Engineers and Constructor s, Inc., Philadelphi a, PA 19101, 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", Jour-nal of the Structural Division, ASCE, Vol. 101, No. ST7, Proc. Paper 11432, July 197.5, pp 1455-1468.
- 3. Lee, T. ~md Gurbuz, 0., "Assessment of Behavior and Designing Steel Liners for Concrete Reactor Vessels", Final Report, Engineering Research Institute, Iowa State University, Ames, Iowa, Nov. 197.3 (prepared for the U.S. Atomic Energy Conunission Under Contract No. AT(ll-1)-22 67).
- 4. "Liner Plate Anchorage Tests", Bechtel Corporation , San Francisco, Cal-ifornia, for *:\rkansas Nuclear One, Arkansas Po\oJer and Light Co., April 18, 1969, 3G-12
SB 1 & 2 Amendment 52 FSAR December 1983 APPENDIX A TABLES AND FIGURES 3G-13
SB 1 & 2 Amendment 52 FSAR December 1983 Table 1 Test Data for Tee Specimens I Concrete Peak Peak Defl. Peak Load at Age £' c Load Load Load !::. = 0.25in.
Specimen (Davs) (psi) (kin~) (k/in) fins ) (kins)
T-1 20 5,710 152 12.67 0.070 36 T-2 24 5,770 156 13.0 .0.070 34 T-3 28 5,950 144 12.0 0.060 32 Avg. 5,810 150.7 12.6 0 . 067 34 Table 2 Test Data for Stud Specimens I
Concrete Peak Peak Defl . at Load at Age fI Load Load Peak Load !::. = 0 . 25 in.
c Specimen (Davs) (psi) (kips) * (k/stud) (Ins.) (kips.)
S- 1 42 6,100 51.5 25.8 0.390 48 S-2 56 6,060 54.8
- 27.4 0.620 46 S-3 67 6,500 52.5 26.3 0.395 49 Avg. 6,220 52.9 26.5 0.468 47 . 7 3G-14
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SB 1 & 2 Amendment 52 FSAR December 1983 APPENDIX B PHOTOGRAPHS 3G-18
SB 1 & 2 Amendment 52 FSAR December 1983 Plate Bl: Specimen T-1. Test Assembly at Start of Test
.II Plate B2: Specimen T -1. Plate Deformation During Final Stages of Testing 3G-19
SB 1 &. 2 Amendment 52 FSAR December 1983 Plate B3: Specimen T -1. Concrete Surface After Removal of Liner Plate Plate B4: Specimen T-1. Liner Anchor (Tee) After Test 3G-20
SB 1 & 2 Amendment 52 FSAR December 1983 Plate BS: 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 Amendment 52 FSAR December 1983 Plate B7: Specimen T -2. Liner and Tee at End of Test Plate B8: Specimen T -3. Instrumentation at Start of Test 3G-22
SB 1 & 2 Amendment 52 FSAR December 1983 Plate B9: Specimen T-3. Concrete Surface After Removal of Liner Plate Plate BlO: Specimen T-3. Liner and Tee After Removal of Liner Plate 3G-23
SB 1 & 2 Amendment 52 FSAR December 1983 Plate Btl: Specimen S-1. Start-up of Test Plate B12: Specimen S-1. Studs in Concrete After Shear Failure 3G-24
SB 1 & 2 Amendment 52 FSAR December 1983 Plate B13: Specimen S-1. Detail of Sheared Stud in Plate Plate B14: Specimen S-1. Detail of Sheared Stud in Concrete 3G-25
SB 1 & 2 Amendment 52 FSAR 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 Amendment 52 FSAR 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 Amendment 52 FSAR 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