ML20215F739
| ML20215F739 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 10/01/1986 |
| From: | Papanic G YANKEE ATOMIC ELECTRIC CO. |
| To: | Mckenna E Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20215F740 | List: |
| References | |
| RTR-NUREG-0825, RTR-NUREG-825, RTR-NUREG-936, TASK-03-06, TASK-3-6, TASK-RR 86-152, FYR-86-093, FYR-86-93, NUDOCS 8610160355 | |
| Download: ML20215F739 (21) | |
Text
-
-)
Tel: phone (617) 872-8100 TWX 7103807619
' YANKEE ATOMIC ELECTRIC COMPANY WL 1671 Worcester Road, Framingham, Massachusetts 01701 65-152
. ANKEE 2.C2.1 October 1, 1986 FYR 86-093 United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
hs. Eileen McKenna PWR Project Directorate No. 1 Division of PWR Licensing-A
References:
(a) License No. DPR-3 (Docket No. 50-29)
(b) Letter, USNRC to YAEC, " Yankee Nuclear Power Station -
NUREG-0825, Sections 4.5, ' Wind and Tornado Loadings,'
4.8,
' Tornado Missiles,' and 4.1,
'Celsmic Design Considerations'," dated June 6, 1986
Subject:
Response to Questions Relating to Masonry Wall Seismic Evaluation
Dear Ms. McKenna:
Enclosed please find Yankee Atomic Electric Company's (YAEC's) response to the NRC's questions relating to masonry wall seismic evaluation as presented in Enclosure 1 of Reference (b). to this letter contains the responses to questions in Reference 1 regarding masonry wall evaluation criteria. Enclosure 2 contains the response to questions concerning the modifications at the PAB north wall, Upper Pipe Chase, and Cable Spreading Room. contains the responses to questions regarding the modifications to masonry walls inside the Turbine Building.
At the conclusion of the May 1986 YAEC-NRC Meeting, the following questions were considered resolved:
Ila(i), (ii); Ilb; Ile; Ile; Ilg; Ilh; Ii(i), (ii), (iii),(iv); I2b; I2c; 12d; I2e; 12f(i), (ii), (iii), (v); I2g(i), (ii), (iii), (iv); I2h; 12i(i), (ii), (iii), 12j; I2k(ii), (iii); 121; I3a; I3c; I3d; I3e; and I3g.
i 8610160355 861001 0gl PDR ADOCK 05000029 i
P PDR
(
\\
L
United States Nuclear Regulatory Commission October 1, 1986 Attention:
Ms. Eileen McKenna Page 2 FYR 86-093 All responses incorporate the comments and the additional information requested by the NRC during the May meeting.
We believe the attached enclosures provide sufficient information to resolve all of your questions concerning the seismic evaluation of masonry walls.
Further, we believe this information is sufficient to enable the NRC to prepare a safety evaluation of the masonry walls which will be included in the SER for SEP Topic III-6.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY G. Pap ic, Jr.
Senior Project Engineer, Licensing CP/dps Enclosure o
A
r i
I l
ENCLOSURE 1 Masonry Wall criteria
ENCLOSURE 1 Page 1 of 8 RESPONSE TO OUESTIONS ON MASONRY WALL CRITERIA
- QUESTION I.1.a Item a of Section 7.3:
(i) Provide the definition of " diverse wall strengthening materials," (ii) provide examples on permitting cracking of the masonry wall where the application of diverse wall strengthening materials requires the allowable masonry stresses to be exceeded, and (iii) provide
-analysis methodology to calculate the cracked masonry wall section.
RESPONSE
(1)
Diverse wall strengthening materials refers to the various alternative materials which may be used to upgrade a block wall (i.e., reinforcing with miscellaneous structural steel shapes, grouting reinforcing steel, post-tensioning, etc.).
(11) Design calculation examples illustrating permitted horizontal cracking of unreinforced masonry walls when reinforced with structural steel members spanning vertically are contained in the calculation sets which were made available for NRC audit during the May meeting.
(iii) For unreinforced masonry, the allowable mortar tensile stress is 14 psi normal to the bed joint and 41 psi parallel to the bed joint. Because of the substantially greater mortar tensile stress allowable in the horizontal direction, structural steel spanning vertically is NRC questions are based on review of Section 7.0, Masonry Wall Performance Criteria, of Document DC-1 (Reference 1-1).
4961R
ENCLOSURE 1 Page 2 of 8 generally provided to reinforce the masonry walls. When cracking occurs in the horizontal direction (i.e., the mortar tensile stress of 14 psi normal to the bed joint is exceeded resulting in zero moment capacity), the masonry spans horizontally between the vertical structural steel supports.
In effect, the structural steel reinforcement is designed to carry the lateral load into the supporting structure. Additionally, deflections of the steel reinforcement is limited to 1/720 of its span, thus insuring wall integrity.
OUESTION I.l.b Item f of Section 7.3: Clarify the " miscellaneous steel shapes required to support the masonry block walls".
RESPONSE
Miscellaneous steel shapes refers to mircellaneous structural steel shapes (i.e., W shapes, angles, plates, etc.) used to reinforce the masonry block walls.
QUESTION I.1.c Item b of Section 7.6: Provide the detail information on how the effects of heavy equipment and/or attachments will be superimposed on a representative uniformly loaded area of the wall, also define "a representative uniformly loaded area".
4961R
ENCLOSURE 1 Page 3 of 8
RESPONSE
Where equipment and/or attachments (i.e. conduits, piping) exist on the block walls, the mass of such items was included in the computer analysis by combining the item mass with the mass of the.CMU wall. This was accomplished-by distributing the item weights over the surface area wf finite element plates at their respective locations. Examples were provided for NRC review during the May meeting.
QUESTION I.1.d Item e of Section 7.7:
Provide justification of the allowable in-plane strain, Y = 0.001, for confined walls. This allowable only applies to in-plane strain, how about out-of-plane analysis and criteria?
RESPONSE
The allowable in-plane strain for confined walls is based on the recommendations of " Recommended Guidelines for the Reassessment of Safety Related Concrete Masonry Walls", prepared by Owners and Engineering Firms Informal Group on Concrete Masonry Walls, dated October 6,1980.
Out-of-plane analysis was performed and the acceptance criteria is presented in Table 7-2, Allowable Stresses in Unreinforced Masonry, and Table 7-3, Allowable Stresses in Reinforced Masonry contained in Document No. DC-1 (Reference 1-1).
OUESTION I.1.e Item (2) of Section 7.8:
Provide the justification not to include other loads such as pipe reaction, jet impingement loads, etc. in the load combination.
4961R
r1 ENCLOSURE 1 Page 4 of 8
RESPONSE
There were no jet impingement loads delivered to the masonry walls evaluated.
The pipe jet impingement plate in-the Turbine Building adjacent Col. G-10 was designed to span between structural steel framing floor levels Elevation 1037'-2 1/2" and Elevation 1052'-2 1/2".
Where piping was supported by a masonry wall, the pipe reactions were added to the other equipment / attachment loadings on the wall. By way of clarification, Section 7.8, Load Combinations, of Document No. DC-1 will be revised to include pipe reaction / impingement loadings. A marked-up copy of Section 7.8 is included in -1.
QUESTION I.1.f (i) Item a of Section 7.9, Tables 7-2 and 7-3 are for existing masonry walls.
What are the allowables for modifications?; (ii) Tables 7-2 and 7-3 are based on ACI 531-79 allowables for the " inspected masonry" category. Was special inspection program implemented during the construction of the existing wall?
If so, the inspection program needs to be reviewed.
RESPONSE
(1)
Tables 7-2 and 7-3 have been modified to clarify the masonry wall allowables. A marked-up copy of Tables 7-2 and 7-3 is included in -1.
Stresses in existing masonry walls, with or without modifications, are limited to the allowables of Tables 7-2 and 7-3 for existing masonry. Where new masonry is used to replace existing masonry, stresses are limited to the allowables in Tables 7-2 and 7-3 for new masonry.
(11) The use of ACI 531-79 allowables for " inspected masonry" is based on the following information.
4961R
(;
ENCLOSURE 1 Page 5 of 8 (a) The requirements of the original construction specification (Stone and Webster Specification No. YS-1028) meet or exceed the inspection requirements of ACI 531-79.
YS-1028 is included as Attachment 1-2.
(b) Memo, D. E. Nichols (NEES) to D. R. LeFrancois (YAEC), dated November 3, 1983.
Mr. Nichols was present during the construction of the plant. He verified that the construction of the walls was carefully supervised and performed by skilled craftsmen.
(c) Test reports, dated September 14, 1984 and July 1986. The blocks tested were chosen from interior and exterior blocks which were removed during modifications to the block walls. Mortar cubes were also tested.
In all cases, the block and mortar properties (m,
f,) were greater than those assumed in calculating the allowables in Tables 7-2 and 7-3.
The test reports are included as -3.
(d) Field inspection of the block walls performed as part of gathering information for the wall evaluations found the existing walls to be in very good condition.
QUESTION I.1.K Items (d) and (e) of Section 7.12: define the equivalent earthquake loadings; "How are they derived from the dynamic analysis results and how are they applied to the static analysis?"
4961R
(
l ENCLOSURE 1 Page 6 of 8
RESPONSE
Equivalent earthquake loadings were determined by selecting an appropriate spectral acceleration value from the applicable ARS curve, and then multiplying the wall mass by the selected acceleration (g) and a modal participation factor of 1.3 or greater when applicable. The resulting equivalent earthquake loadings (F, F, F ) were'then accounted for in x
y z
the STRUDL static analysis. These calculations were available for NRC audit.
QUESTION I.1.h Define I in Table 7-1, and provide an explanation why I
=I yy xx yy
RESPONSE
The masonry block moment of inertia calculation considers only the face shell areas (the web areas are neglected). Therefore, I (bending about the vertical axis) is equal to I (bending about the horizontal axis).
QUESTION I.1.1 Section 7.12:
(i) Provide details of hybrid element of McAUTO STRUDL code; (11) first paragraph states that the initial wall models shall include
" preliminary.
.", what did the final wall models include? (iii) provide a description of how horizontal seismic loadings are combined with vertical seismic loading, (iv) how dynamic analysis was performed for vertical amplified floor response spectra?
4961R
(
ENCLOSURE 1 Page 7 of 8
RESPONSE
(1)
McAUTO STRUDL details and documentation for the hybrid element were made available for NRC audit in May.
See also the response to Question I.2.F in Enclosure 2.
(ii) The final wel). computer models included the design fixes / modifications approved *nd released for construction.
Section 7.12 will be modified i
to reflect this. The marked-up section is included in Attachment 1-1.
(iii) The resulting stresses (axial, bending and shear) due to-the E-W and N-S seismic loadings were combined by " square root sum of the square" (SRSS) method. The vertical stresses due to vertical seismic loading were then added to the SRSS stresses to produce governing design stress. Section 7.12 will be modified to reflect this. The marked-up page is included in Attachment 1.1.
(iv) Vertical seismic effect in the plane of the wall was accounted for by multiplying wall mass by an appropriate acceleration value selected from the applicable vertical ARS curve, and combining the resulting stress with those stresses of other applicable loads to obtain governing design stress.
OUESTION I.1.]
Section 7.1: The criteria were specifically spelled out for a seismic event based on the Yankee Composite Spectra (YCS).
Provide justification for not including seismic event based on NRC loading.
I 4961R
f.
ENCLOSURE 1 Page 8 of 8 1
RESPONSE
Masonry walls evaluated for a YCS seismic event to the Section 7.0 criteria will function under an NRC seismic event. This will be verified by the confirmatory analysis of the north wall of the PAB.
QUESTION I.1.k 0
Provide the basis for material properties, f ' = 600 psi and M = 750 psi.
m o
RESPONSE
The original Masonry Specification, YS-1028 (Attachment 1-2) required ASTM C-90, Grade A and C-129 hollow concrete masonry blocks. Minimum mortar compressive strength per ASTM C-270 was specified as 750 psi.
Based on YS-1028, M was set equal to 750 psi. The value for f '
o m
(600 psi) was based on the ASTM C-129 strength requirements.
The values of f ' and M are conservative. The test results (Attachment 1-3) show that M is, at minimum, 1,226 psi.
f ', based on Table 4.3 of ACI 531 using Type N mortar, is as a minimum 760 psi. The test results included interior and exterior, and 8" and 12" blocks. These blocks tested were chosen from those removed during modifications to the masonry walls.
REFERENCES 1-1.
Cygna Energy Services, Document No. DC-1, Revision 3 (Draft), Seismic Re-evaluation and Retrofit Criteria for Yankee Nuclear Power Station.
4961R
(
ENCLOSURE 1 ATTACHMENT 1-1 Mark Ups - Section 7.0 of DC-1 4961R
Enclosura 1 Att chment 1-1 P ga 1 of 8 Linear interpolation may be used to determine relative displacements c.
at elevations other than those already developed.
d.
In-plane strain analysis applies to the following:
(1) Full story height walls restrained at top and bottom.
(2) Full story height walls restrained at all four sides by the building structure.
(3) All partial height walls restrained at the bottom and both sides.
Allowable in-plane strain shall be Y =0.001 (for confined walls).
e.
e 7.8 Loaddom51 nations a.
For Masonry Design Load combinations for masonry design shall be:
i I
d (0 D+W (2) D+ E '
(3 D+ W i
( ) D+ Yj+ E '
l Where D = gad loadM&h_w s weight of any equipment attached P
Ya2C y
QJ Pi 6 3"PPor l
W = wind load (exterior walls only) per SEP Topic III-2.
E'= loads due to seimic event based on Yankee Composite Spectra.
~_
Yj
- 100d5 due $O llaldjb impingemen
~
w Yankee Nuclear Power Station 37 Seismic Reevaluation Criteria g
[
t i 80023/81060/81061/86064 Doc. No. DC-1; Rev. 3, ORAFT 1111lll11llllllllllllllll1llll
r j
Enclosurm 1
/ -1 Paga 2 of 8 W
= loads due to tornado winds, tornado generated AP and tornado t
missiles per SEP Topic III-2.
b.
For Steel Design Load combinations for steel design shall be:
(1) D+W (2) D + E' 3
0+
(4) D+ Y + E '
Where D, { P are defined in Paragraph 7.8.a.
c.
For Concrete Design load combinations for concrete design shall be in accordance with ACI 349-76, Ref. 3(k).
7.9 Allowable Stresses a.
For Masonry Design Allowable stresses for inspected masonry per ACI 531-79, Ref.
3(o).
For load combinations (2) and (3) of Paragraph 7.8.a., the allowabl e stresses may be increased by factors in NRC Standard Review Plan 3.8.4, Appendix A [Ref. 3(z)], except that no factor shall be applied to masonry tension perpendicular to bed joint.
Allowable stresses in unreinforced masonry and reinforced masonry are summarized in Tables 7-2 and 7-3, respectively.
Yankee Nuclear Power Station 38
= = = - -
YYi Seismic Reevaluation Criteria d [d,I 80023/81060/81061/86064 Doc. No. DC-1; Rev. 3, DRAFT 4
llilllllllllllilllllllllllllli
Enclosura 1 Att.chment 1-1 Piga 3 of 8 Steel :
ASTM A7 (Fy = 33 ksi) - existing ASTM A36 (Fy = 36 ksi) - modifications Welding:
E70XX Electrodes - modifications Bolting:
ASTM A325F - existing and modifications 7.12 Computer Static and Dynamic Analysis The proprietary computer program package MCAUTO STRUDL [ Appendix K(16)] shall be used to analyze designated walls for both static and dynamic loadings. The block walls shall be modeled as grids on hybrid (plane stress - plate bending) finite elements in combination with beam elements.
The initial wall models sha nelude " r iminar fix mod ns" as a priate I W G Il models shall Inc a e design i mah tons as approvedkrconskaction Static analyses will be performed to account for the following loadings:
(a) dead load (b) wind load (c) tornado AP (d) equivalent earthquake (vertical direction)
(e) equivalent earthquake (horizontal direction: N-S A E-W)
(f) interstory displacements (N-S A E-W)
Dynamic analyses will he performed using STRUDL DYNAL to account for the following horizontal seismic loadings:
(a) amplified floor response spectra (N-S)
(b) amplified floor response spectra (E-W)
DYNAL will perform a modal extraction and apply the N-S and E-W amplified floor response spectra individually to the finite element / beam model.
Equipment and/or wall attachment masses, as appropriate, shall be considered in the dynamic analysis.
Damping values shall be in accordance with Yankee Nuclear Power Station 40 p=9@y'ijgm Seismic Reevaluation Criteria
- g*g[d 80023/81060/81061/86064 Doc. No. OC-1; Rev. 3, ORAFT lll111llllllllll11111llll11111
Enclosura 1 -1 Pagn 4 of 8 Section 7.10 herein.
Stresses resulting from horizontal seismic loadi ngs conbin Stresses shal hlthe s g t con of the s uar s SS) tothe SRSS resa.thnq Trvm the vertical seismoc loadsng wo be f thekri200tal seLsmic loadingsw tresses resulting from Tne static and dynamic loadings shall be combined in accordance with the design load combinations of Section 7.8.
The resulting combined stresses shall be equal to or less than the allowable stresses permitted in Section 7.9.
The combined stresses may he calculated manually where appropriate.
m=== _-. Yankee Nuclear Power Station 41
- g ( d l ((Y Seismic Reevaluation Criteria
.M Z:W 80023/81060/81061/86064 Doc. No. DC-1; Rev. 3, ORAFT g
lll1111111111lll11111111111lll
Enclosurn 1 -1 Paga 5 of 8 TABLE 7-2 ALLOWABLE STRESSES IN UNREINFORCEO MASONRY hw Masorid &
, & q & (1,7)
Description S allow.
S max.
S allow [
ow. (3)
Compressi_ ve Axial (H 0.22f',
1000 132 330 1200 198 495 F1exural 0.33f'm B:aring On full area 0.25f',
900 150 375 1200 225 562 On one-third area or less 0.375f'm Shear Flexural members (5,6) 1.1 F 50 27 35 m
34 22 29 Shear walls (5) 0.9 {
a T:nsion Normal to bed joints Hollow units 0.5 (m 25 14 14 9
Solid or grouted
- 1. 0 (m 40 27 27 Parallel to bed joints (6) 50 27 41 Hollow units 1.0 (m,
80 41 62 Solid or grouted 1.5 (m,
Modulus of Elasticity (Em) 1000 f'm 2.5 x 10
.810 x 106 810 x 106 6
6 Modulus of Rigidity (Ev) 400 f',
1.0 x 106
.375 x 106 375 x 10 NOTES (Cont'd Next Page) 46 bs3NAS Yankee Nuclear Power Station
'fj Seismic Reevaluation Criteria r
80023/81060/81061/86064 00c. No. OC-1; Rev. 3 111ll11:111111111111111lll111
Enclosura 1 -1 Pagn 6 of 8
. NOTES (1) Based f', = 600 psi and mo = 750 psi (inspected masonry) for exterior 2
- talls (C-90) and interior walls (C-129). Units are 1bs/in.
(2) For normal and. severe environmental loads. Allowables are not factored.
e (3) For abnormal and extreme environmental load lowables are factored in accordance with Table 7-4 h
(4) Multiply values by ( 1- ( 4
)3) for significant vertical load.
(5) Use net bedded area with these stresses.
(6) For stack bond construction, use 2/3 of specified values.
(7) Refer to Figure 7-3 for illustration of stresses.
= M n-9fM Yankee Nuclear Power Station 47 bg i f q Seismic Reevaluation Criteria JL A 80023/81060/81061/86064 Doc. No. DC-1; Rev. 3 L
111lllllllll1111lllll11111111!
- ,=---r-e
..ev y
7 eey.--r-m--
rw-y---
- -r--
w
-v-
-g-y
Enclosuta 1 R tac t 1-1 ALLOWABLE STRESSES IN REIWORCED MASONRY 5
nokt2So (I)
S al1 N Y 6 N 11ow. (3)
SE S max.
Description Compressive Axial t*/
0.22f',
1000 132 330 1200 198 495 Flexural 0.33f',
Bearing On full area 0.25f',
900 150 375 1200 225 562 On one-third area or less 0.375f'm Shear _
No Shear Reinforcement 50 27 35 Flexural Members 1.1 {
Shearwalls 34 22 29 M/Vdal 0.9 {
M/Vd<1 2.0 {
(5)
(5)
(6)
Reinforcement taking entire shear 150 73 110 Flexural Members 3.0 {
Shearwalls 75 37 48 M/Vd>l 1.5 {
M/Vd(1
- 2. 0 {
(5)
(5)
(6)
R?inforcement Bond (7) 60 60 80 Plain Bars 140 140 186 Deformed Bars Tension 20,000
.9 Fy Grade 40 24,000
.9 Fy Grade 60
.5 Fy or
.9 Fy Joint Wire 30,000 4 Fy
.9 Fy Compression 6
6 810 x 106 l
Modulus of Elasticity (Em) 1000 f'm 2.5 x 10 810 x 10 6
6 6
Modulus of Rigidity _ (Ev) 400 f'm 1.0 x 10
.375 x 10 375 x 10 NOTES (Cont'd Next Page)
I 48 Yankee Nuclear Power Station rQH ' f j Seismic Reevaluation Criteria killlillilill1YlilllillIll 80023/81060/81061/86064 Doc. No. DC-1; Rev. 3 I
}
,--,-.,.,-,,--.,r
-m,,.--,.-.--,,
--~,.,..~,,--.-,.wn_..-..-,..,,--..n,v.--,
--,._,,,n,--.-gn__-n.,
ww w-. - -
--,,,r, e,wn--,
.r---
.,,-,--n--
Enclosura 1 Attrchment 1-1 Paga 8 of 8 NOTES (1) Based f 'm = 600 psi and mo = 750 psi (inspected masonry) for exterior walls (C-90) at Non-radioactive Pipe Tunnel. Units are 1bs/in2, (2) For normal and severe environmental loads.
Allowables are not factored.
(3) For abnormal and extreme environinental load lowables are factored in accordance with Table 7-4 (4) Multiply values by ( 1-(
)3) for significant load.
(5) Refer to ACI 531, Table 10.1 for allowable stresses.
(6) Factor allowables in accordance with Table 7.4.
(7) From Ref. 3(aa).
g=
E=gggg Yankee Nuclear Power Station 49
=---e Seismic Reevaluation Criteria
[*h L d 2 f l 80023/81060/81061/86064 Doc. No. DC-1; Rev. 3, ORAFT i
11llll11111111llllllI!ll111111
ENCLOSURE 1 j
ATTACHMENT 1-2 j
Stone and Webster Specifications YS-1028 1
i 4961R