ML20195C458
| ML20195C458 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 08/19/1978 |
| From: | Broehl D PORTLAND GENERAL ELECTRIC CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| TAC-07551, TAC-08348, TAC-7551, TAC-8348, NUDOCS 8811030113 | |
| Download: ML20195C458 (17) | |
Text
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I" PouTLAxn OsNERAL ELac rnic COMPANY tats.W SALuoN St a c t?
PonTLANo.OREcoN 97204
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August 19, 1978 Trojan Nuclear Plant Docket 50-344 License NPF-1 bgl()D Director of Nuclear Reactor Regulation ATTN:
Mr. A. Schwancer, Chief Operating Reactors Branch #1 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Sir:
Attached are "NRC Staff Questions and Licensee Responses, August 4 through 17, 1978" based on information provided by Bechtet in confirmation of telephone conversations between Portland General Electric Company (PCE), Bechtel and the NRC's Kan Herring on August 4, 7, 8, 9, 10, 16 and 17, 1978.
This letter and attachments are being served on the Atomic Safety Licensing Board ( ASLB) and all parties to the Control Building Hearings.
Sincerely, l
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Pk11030113700019 ADOCK 05000344
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UNITED STATUS OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
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Docket 50-344 PORTIAND GENERAL ELECTRIC COMPANY,
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(Control Building Proceeding)
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(Trojan Nuclear Power Plant)
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CERTIFICATE OF SERVICE I hereby certify that on August 19, 1978, a lettet of the same date from the Licensee to the Director of Nuclear Reactor Regulation with attached "NRC Staff Questions and Licensee Responses, August 4 through 17, 1978" has been served upon the persons listed below by depositing copies thereof in the United States mail with proper postage af fixed for first class mail.
Marshall E. Miller, Esq., Chairman Atomic Safety and Licensing Board Atomic Safety and Licensing Board Panel U. S. Nuclear Regulatory Commission U. S. Nuclear Regulatory Consission Washington, D. C.
20555 Washington, D. C.
20555 Dr. Kenneth A. McCollon, Dean Atomic Safety and Licensing Appeal Division of Engineering, Board Architecture and Technology U. S. Nuclear Regulatory Commission Oklahoma State University Washington, D. C.
20555 Stillwater, Oklahoma 74074 Robert M. Johnson, Esq.
i Dr. Hugh C. Paxton Assistant Attorney General 1229 - 41st Street 100 State Office Building Los Alamos, New Mexico 97544 salem, Oregon 97310 t
Joseph R. Gray, Esq.
Robert Lovenstein, Esq.
1 Counsel for NRC Staff Lowenstein, Newman, Reis & Axelrad i
U. S. Nuclear Regulatory Commission Suite 1214 l
Washington, D. C.
20555 1025 Connecticut Ave., N. W.
Washington, D. C.
20036 Columbia County Courthouse i
Law Library, Circuit Court Room Mr. Eugene Rosofie St. Helens, Oregon 97051 Coalition for Safe Power 215 S. E. 9th Avenue Ms. Nina Bell Portland, Oregon 97214 l
2018 N. W. Everett $201 t
Portland, Oregon 97209 Mr. Stephen M. Willingham
$55 N. Tomahawk Drive Columbia Environmental Council Portland, Oregon 97217 P. O. Box 611 St. Helens, Oregon 97051 John H. Socolofsky, Esq.
Assistant Attorney General i
i Mr. John A. Kullberg Of Attorneys for the 9 tate of Oregon Route 1, Box 250Q 100 Stste office Building Sauvie Island, Oregon 97231 Salem, 0:egon 97310 i
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CERTIFICATE OF SERVICE (Concluded)
Mr. David B. McCoy Gregory Kafoury, Esq.
348 Hussey Lane Counsel for Columbia Environmental Grants Pass, Oregon 975'6 council 202 Oregon Pioneer Building Ms. C. Cail Parson 320 S. W. Stark 800 S. W. Creen #6 Portland, Oregon 97204 Portland, Oregon 97205 William Kinsey, Esq.
Docketing and Service Section Bonneville Power Administration Office of the Secretary P. O. Box 3621 U. S. Nuclear Regulatory Commission Portland, Oregon 97208 Washington, D. C.
20555 2
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,4+-<.4l f, g f.l Ronald W. Johnson Attorney for the Licensee Dated:
Au-st 19, 1978
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S NRC STAFF QUE.'TIONS AND LICENSEE RESPONSES, AUGUST 4 THROUCH 17, 1978
- 1) Question Verify that the steel strain limits in calculating moment capacities wer1:
a) 2c for walls with only uniform steel.
7 b) c for walls with bundles of bars in outer edges.
y Include justification that 0.81, is representative of the effective depth of members in calculation of their shear capacities.
Response
a) The shear force capacities due to pier bending have been eval-usted with the ascuaption that strain ductility y = h = 2.
Y The controlling shear force is either the shear force due to pier bending or the shear force evaluated from contribution of concrete and steel, whichever is less.
Therefore, in those members controlled by pier bending steel e < 2c for vertical steel.
b) Due to compatibility, members with bundles of bars tn outer edges are assumed to reach 2 c,, also (when shear force due to pier bending capacity control's).
According to ACI 318-71, Section 11.16.1, "the nominal shear Vu stress, v where d shall be :aken equal to 0.81,.
A
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larger value of d, equal to the distance from the extreme compression fiber to the center of force of all reinforce-ment in tension, may be used when determined by a strain compatibility analysis".
On Pages 615 and 616 of Reinforced Concrete Struc tures by Park and Paulay (John Wiley, 1975), it is mentioned that "the ef fective depth of a rectangular shear wall section is
affected by the arrangement of the vertical section.
In applying the appropriate equations for nominal shear stress, the effective depth d need not be taken as less than 0.81,".
It is also mentioned that this gives a conservative estimate of the shear strength.
- 2) Question Provide a table which illustrates the noment-controlled and shear-controlled capacities for the various elements between elevations for a representative shear wall system.
Re s p> ns e Table 2-1 illustrates the moment-controlled and the shear-controlled capacities for the various elements between floor Elevations 45 f t and 61 ft in the N-S direction of the Control Building and part of the Auxiliary Building as shown in Figure 2-1.
Reinforcing steel development details were investigated to assure that appropriate end conditions were used in the analysis, and it was demonstrated that the tabulated capacities could be developed.
The amount of capacity contributed by shear-controlled and moment-contro11c; elements is typical of other locations.
- 3) Question Verify that overturning and tor,ional moments were considered.
Out-line how they were considered atd why they were within acceptable limits.
This will substantiate that the lateral force resistance capacity was the only capacity af fected by the errors such t at it is the only nonconformance with the appropriate FSAR criteria.
Response
The gross bending moment and the torsional response of the struc-tural system was considered in the evaluation of the Control Building.
The lateral shear in t'ie Control Building obtained from the original TABLE 2-1 (f = 6(00 psi, f = 45 ksi) y Y
Y shear budig eontrolling DOWEL CAPACITY (KIPS)
, MEMBER (KIPS)
(KIPS)
(KIPS)
EL. 45' EL. 59' R(q 83 1A 1426 1767 1126 2/74 1793 0.795 IB 1176 *I 3661 1176 2027 1046 *I 1.124 I
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ICI 2
903 466 *I 466 1569 425 1.096 3
873 487 *I 487 1455 474 1.027 I
ICI 4A 522 *I 602 522 1077.6 0.485 I
4B 731
- 998 731 1479.4 0.494 5A 244 222[a]
222 753.8 0.306 5B 395 359 *I 359 903.3 0.495 I
6 785 *I 1335 785 1977 1977 0.397 I
7A 1375 *I 2297 1375 2297 2297 0.599 I
7B 1093 3741 1093 3741 3741 0.292 I
I IdI 7108 *I 1534 *I 8642 15035.5 82.2%
17.8%
[a] Controlling capacities are summed.
[b] These columns refer to Question 5.
(c) Dowel capacity less than controlling shear.
[d] Smaller of either column summed.
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seismic analysis is influenced by the gross torsional response and therefore the torsional response is included directly.
In consider-ing the gross bending moment, the Control and Auxiliary Buildings were considsted to act as beams with the walls parallel (side walls) to the seismic forces carrying all the shear, and the walls perpen-dicular (end walls) to the seismic forces prim 4rily carrying the bending moment.
In order for this type of behavior to develop, it is necessary for vertical shear to develop at the ends of the side walls.
The required shear capacity can be developed by the dowel action of the reinforcing steel in the block and the beam-to-column connections.
On the tension side, this vertical shear at the end of the side walls is resisted by a combination of the dead load in the column at the intersection of the side and end walls, and the dead load of the end wall itself.
The dead load of the end wall is engaged by a combination of dowel action of the reinforcing steel in ti.e block and the beam-to-column connections.
On the compression side of the structure, the vertical shear is transferred to the columns and end wall by the same mechanism.
There is adequate capacity from dowel action of the block reinforcing steel and beam connections, considering the initial dead load reac-tions, to resist the vertical shear.
The gross bending of the Control Building is resicted in this manner.
- 4) Question Verify that steel yielding, not concrete crushing, governs the moment behavior of all members.
Response
In all bending members, when under-reinforced (o < o;) steel yields first, concrete crushing does not take place.
The members fail in tension.
Reinforcement acting in compression does not alter the behavior.
All of the shear walls have reinforcement p'rcentages less than their respective balanced reinforcement pe rc ent ag e.
For J
example, for the 4 f t 8 in. Long and 34 in. thick wall on Line N at 45 ft elevation of the Control Building, o = 6.2 percent while the b
existing steel o = 0.4 percent (approximately).
This is typical of all members.
- 5) guestion that percentage of the walls had dowel capacities which were in excess of the capacities governed by either shear or bending?
What were the lowest and average ratios of:
Shear or Moment Coverned Capacity Dowel Capacity Also, what percentage of member capacities governed by shear had moment-governed capacities i 2 times the shear capacity and i 1-1/2 times the shear capacity?
Response
Dowel capacities calculated according to Vdm1 = 0.7A,f are tabu-y l
laced in Table 2-1.
Accordingly, all the walls (except for 15, 2 l
and 3) have dowel capacities exceeding the shear capacities controlled by either shear or bending.
This constitutes 75.4 percent (6513 kips)
I of the 8642 kips total capacity.
i Ratio R in Table 2-1 refers to:
ear r M ment Verne
- Pacity R=
l Dowel Capacity i
i l
The lowest R value is 29.2 percent while the average R value is 57.5 percent based on total shear or moment controlled capacity divided by the sum of the smaller dowel capacitier corresponding t
l to each wall in Table 2-1.
I The percentages of member capacities as governed by shear had:
i 6-i
68% for
- **"" < 2 38% for
- "" 1 1.5 shear shear
- 6) Question What was a representativa load va deflection curve, calculated under the assumption of elasto plascia member (wall) behavior, be.tveen ele-
'ations of the building? At each point at which a given percentage of members reached their capacity, indicate the percentages of wall r.spacity governed by both shear and bending which are "yielding".
How could this curve be affected by inelastic behavior?
Compare this to the elastic resistance used in the dynamic analysis.
Piscuss why this is representative of other building shear wall systems. Also, provide an upper bound for the rebat strain at the required capacity limit.
Response
A simplified shear load capacity vs deflection curve is developed for the major structural elements between Elevations 45 f t and 61 f t in the N-S direction of the Control Building and the Western half of the Auxiliary Building.
The development of this curve was based on an elssto plastic load vs deflection relationship (Figure 6-1) for the individual members. The elastic stiffness is based on uncracked sections including bending and shear deformation.
The capacity of each member is that determincd by shear or moment con-sideraticas as discussed previously.
The limiting deflection is defined by the capacity of the member divided by its elastic stif f-ness.
The shear load capacity change against deflection (N-S, Elevation 45 ft-61 ft) is given in Figur2 6-2.
The capacity of the walls in the Auxiliary Building neglected in the original design are not included in the total capacity shown in Figure 6-2.
The capacities of these walls were conservatively determined from dowel action at the top of t' e wall-slab interf ace.
The capacities of these walls were included in the complete evaluation..
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In Column 1 of Table 6-1 in given the percent of the total capacity of the system evntributed by "yielded" members.
The percents given are for a load slightly less than the load at the change in slope.
Columns 2 and 3 give the percent of the capacity contributed by "yielded" member controlled by moment and shear, respectively.
For example, at a load slightly less than 7391 kips, (Point C), the only members that have yielded are controlled by bending.
The stiffness of the system has not decreased significantly over most of the loading range as is indicated by the slope of the load-deflection curve. This indicates the system has considerable stiff-ness af ter the first few elements have "yielded" and that the major contributors to the overall capacity do not have to go beyond the deflection associated with the limiting load significantly in order for all the members to reach their capacities.
For this particular wall system, the maximum strain experienced by the reinforcing steel is approximately 3 to 4 times yield.
This type of behavior is typical for other locations in the critical levels of Elevations 45 ft-61 ft and 61 ft-77 ft within the struc-tural complex, ie, the more significant walls reaching their capa-cities in the final stages of daformation.
As an indication of how l
typical this behavior is of other locations, the same type of curve io showa in Figure 6-3 for the Control Building at Elevation 61 f t-77 ft due to East-West motion.
This curve was developed for a yield strength of stee; equal to 40 ksi and a compressive strength of con-crete of 5000 psi.
Considering the other locations, at least 70 to 75 percent of the total capacity is obtained before a major shear wall reaches its capa-city, 80 to 85 percent would be an average percent of total capacity.
Some additional information concerning the breakdown of member capa-cities are:
i a) At Elevation 45 ft-61 ft in the N-S direction, the shear in the concrete contributes 61 percent and the steel contributes 39 percent.
TABLE 6-1 1
2 3
Location
% Yielded I Noment I Shear Controlled (b)
Controlled (c) on Curve Members A
0.0 0.0 0.0 5
5.4 100.0 0.0 C
11.0
'00.0 0.0 D
40.1 62.1 37.9 E
88.3 17.1 82.9 I
l F
97.3 17.8 82.2
[a] Percent of total capacity contributed by yielded sesbers.
(b) Percent of capacity from yielded members controlled by moment.
(c] Percent of capacity from yielded members controlled by shear. _
V (X/f5) 5769 1104 M-peg M-m.
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(inches)
FIGURE 6-3: SHEAR ts. OsnKC,Doh REuhnoNSHIP (E-W, El, Git '7 7 ')
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b) At Elevation 61 ft-77 ft, shear-controlled members and bending-controlled members cootribute 90 percent and 10 percent respectively for the N-S direction, and 93 percent and 7 percent respectively for the E-W direction.
The contribution of the walls au.he Auxiliary Building not included in the original design have not been included in the load deflection curves presented here.
The contribution of these walls is small compared to the required capacity, and therefore, will not cause a significant change in the curves.
Response
The base shear forces for the 0.15g OBE and 0.25g SSE are given in Table 4-1 of the May 24, 1978 submittal to the NRC.
- 8) Question Tor the SSE resnalysis, provide a brief outline of how the "new" numbers were derived from the original numbers and analysis.
Response
The "SRSS" results used in the evaluation were obtained from the results of the original analysis which used an absolute sum com-bination of the modal res ponses.
When the modal reponses from the original analysis are combined on an SRSS basis, most results show a 25 percent reduction in response but a few show only about 20 percent reduction. The 20 percent reduction was, therefore, 1
l conservatively used for all responses. l f
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9)
Question Refer to Attachment 3 to "NRC Summary of the Site Visit and Meeting Held on July 6, 1978, at the Trojan Site to Discuss the Trojan Control Building".
Provide a comparison of material properties used in the above-referenced Attachment 3 tests for the HCBL with the material properties for the Trojan Control Building block walls.
Response
Trojaa type wall material properties are swamarized in Table 9-1.
One important chcracteristic is the height / length ratio.
The Berkeley HCBL tests are 1:1 ratio while the majority of the Trojan valls have 0.5 ;( height / length i 1.
As are shown by the test data, this is a very important characteristic. Also, the Trojan vs.11 blocks have approximately 50 percent net area while the Berkeley specimens have 58 percent net area which ef fectively provides for more cell grout area (>6000 psi) in Trojan valls.
If one single vythe concrete block is considered, the reinforcement ratios in the Trojan valls for 7-5/8 fr. thick block vythe vary from 0.0024 (#6/24 in.) to 0.0048 (2-#6/24 in.) for horizontal steel, and from 0.0017 (#5/24 in.) to 0.0024 (#6/24 in.) for the vertical steel.
These are within the ranges used for the Berkeley tests.
Some of the Berkeley test specimens (those with lower nominal shear stresses) are partially grouted, meaning that grout is placed only in those cells where reinforcement in placed. The Trojan walls are fully grouted with >6000 psi concrete.
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! L'4E/ c rw 66. 582
9 TABLE 9-1 MATERIAL STRENCTN COMPARISONS Trojan Walls Specified Average Strength Minimum Value Item Parameter Notation Value (In-Place)
Serkeley NCEL Testa tal e
Heavyweight Masonry compressive f
2000 4100 3000 concrete blocks strength (psi) tal Lightweight Masonry compressive f.
2000 2700 concrete blocks strength (psi) 1 E
Mortar Mortar compressive f
2000 3500 2500 (ASTM Type M) strength ('28-day 8
psi) ibl Icl e
Cell Grout Concrete compressive f
5000
>6000 4000 (Grout:
IC:35:2C) strength (psi)
Ibl Core fill Concrete compressive f*
5000
>6000 conc re t e strength (psi)
Reinforcing Yield' stress (ksi) f 40
>45
>45 steel I
lal Based on net cross-sectional area.
lbl 28-day compressive strength.
Icl Based on 90-day compressive strength.
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