ML20002A580

Forwards Supplemental Response to IE Bulletin 79-02 Re Pipe Support Base Plate Anchor Designs.Testing Program Ensures That Seismic Category I Sys Will Perform Intended Function

ML20002A580
Person / Time
Site:	Beaver Valley
Issue date:	10/23/1980
From:	Dunn C DUQUESNE LIGHT CO.
To:	Grier V NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
IEB-79-02, IEB-79-2, NUDOCS 8011200179
Download: ML20002A580 (10)

Text

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October 23, 1980

,ws United States Nuclear Regulatory Commission

~

d Office of Inspection and Enforcement

'E_j Atta: Boyce H. Grier, Regional Director Region I N'

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631 Park Avenue

.. j King of Prussia, Pennsylvania 19406 i'

5 Ni e

Reference:

Beaver Valley Power Station, Unit No. 1 M

c7 Docket No. 50-334 9

IE Bulletin 79-02, Supplemental Response

Dear Mr. Grier:

The attached is a Supplemental Response to II Bulletin 79-02 and is to be used in conjunction with the " Final Report - IE Bulletin 79-02, Beaver Valley Power Station, Unit No.

1," dated July 7, 1980.

This infor-mation is being provided in response to a request for additional information from Mr. Howard Wong, Technical Programs, IE, USNRC.

If you have any questions concerning this response, please contact my office.

Very truly yours, f

C. N. Dunn Vice President, Operations Attachment ec:

U.S. Nuclear Regulatory Coc:nission Office of Inspection and Enforcement Washington, D.C.

20555 Mr. D. A. Beck =an, Resident Inspector i

U.S. Nuclear Regulatory Cec:missica Beaver Valley Power Station Shippingport, PA 15077 U.S. Nuclear Regulatory Commission c/'o Document Management Branch Washington, D.C.

20555 8011200/77 O

i SUPPLtW AL.RESPCNSE TO IE BULLETIN 79-02 BEAVER VALLEY PCWER STATICN - UNIT NO. 1 October 13, 1980 The following is provided as a Supplemental Response to IE Bulletin 79-02 and is to be used in conjunction with the " Final Report - IE Bulletin 79-02, Beaver Valley Power Station - Unit 1", dated July 7,1980. This information is being provided in response to a request for additional information from Mr. Howard Wong, Technical Programs, II, USNRC.

SUBJECT:

Additional information concerning common base plate con-figuration for which load factors are applied.

RESPONSE: Attachment SR1-A contains one (1) sample calculation and four (4) examples of common base plate configurations using more than four (4) anchor bolts. Includd with each example are the following:

1)

The base plate configuration sketch which indicates the number, size and type of anchor bolts, the thickness and size of the baseplate and the type, size and location of the attachment to the plate.

2)

The leading conditions (tension and moment) for each plate as applicable.

3)

The maximum calculated anchor bolt loads showing the method used calculate those loads.

SUBJECT:

Additional information regarding " shoulder to cone" ;neasure-ments of shell type anchor bolts.

RESPCNSE: When the test and inspection program for compliance with the requirements of IE Bulletin 79-02 was begun at Beaver Valley Power station, Unit 1, it was felt that measurement of the plug depth for the shell type anchors may be a reliable means for determining the adequacy of the anchor installation. However, the plug depth measurements taken during the initial testing program shewed varying plug depth with no apparent corrella-tion between the position of the plug in the shell and the

]

ability of the shell to withstand the test load. For example, some anchors f ailed to withstand the test load when the plug depth measurement met the specified dimension based on the manufacturer's dimensions for the shell and assumed dimensions

- for the plug, and likewise other anchors failed when the plug depth either exceeded or was less than the specified dimen-sion.

Also for snap-off type self-d rilling anchors, the jagged edge which results when the snap-off is removed could serve to introduce significant error in the plug depth measurement.

For these reasons it was determined that for Beaver Valley Power Station, Unit 1, the only practicable means by which the adequacy of an anchor installation could be determined was by physical testing.

It is not reasonable to expect that ancho'es installed in permanent plant facilities should be tested to ultimate capacity. Therefore, as stated in the Final Report for IE Bulletin 79-02 for Beaver Valley Power Station, Unit 1, dated July 7, 1980, approximately 91 per cent of the anchor bolts were either torque tested or tension tested to a value at lesst 23 per cent greater than their maximum allowable design bolt loads.

Given the ; strength of the concrete, and centrolling the dimensions of the shell, the plug, and the hole into which the anchor is to be installed and the condition of the bottom of the hole (i.e.,

square bottom, free of debris) prior to installation of a shell anchor, it is reasonable to expect that the ultimate capacity of the 'nstalled anchor could - be predicted with some accuracy. For Beaver Valley Unit 1, the concrete strength was the only one of the above parameters for which there was sufficient documentation from which a value could be assigned.

. Lack of documentation for the other parameters restricted our ability to accurately assess the ultimate capacity of an installed anchor.

This further reinforced our decision to physically test the anchors.

(Later discussions with the anchor bolt manufacturer indicated that the allowable manufacturing tolerances for both the shells and the plugs manufactured at the time of their installation in Beaver Valley, Unit 1, preclude the use of the plug depth measurement as a reliable means of determining the ultimate capacity of an anchor installation.)

l It was further reasoned ' that if it was assumed that the

- manuf acturer's safe working load' recommendation was based on compensation for the variables involved in concrete anchor bolt installation, then the significance of the factor of safety relative to the ultimate capacity of an installed-anchor lessens when the installed anchor is physically testad to a load which is shown to be conservative relat.ive to the maximum anchor bolt lead as determined by analysis.

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The maximum allowable design load for shell anchors, which was used as the basis for the test loads, was -stablished by applying a f actor-of safety of five (5) relative to the anchor manufacturer's published average ultimate loads adjusted to the in-place concrete strength.

This was based on the requirements of the Bulletin and was considered conservative because the standard industry practice, as reccamended by the manuf acturer at the time the anchors were installed and at the time the Bulletin was issued, was to use a safe working load equal to 25% of the ultimate capacity of the anchor [a factor of safety of four (4)]. The conservatism of using the maximum allowable design leads as the basis for the test load is further shown by the fact that results of the plate analysis shows that approximately 50 per cent of the plates analyzed had anchor bolt loads corresponding to a factor of safety relative to the anchor manufacturer's published average ul-timate loads greater than 10 and approximately 80 per cent had anchor bolt leads corresponding to a factor of safety greater than 6.

The acceptance criteria for each plate analyred was that the calculated anchor bolt loads not exceed the maximum allowable design load.

On the basis of the information provided above and that provided as part of the Final Report for IE Bulletin 79-02, there is assurance that the testing program conducted for the concrete expansion anchor bolts ensures that each Seismic Category I system trill perform its intended function.

1 I

1 1

I An Aca c e SRl-A

L A LLU L A 1 IUN M M t:.t. I e.u./c.o./ caLcutATiza mo.

s> cvisi om w.a

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12690.88-EXP CALC r.svicasa / cwecusa / caTe atospt oenT neversta/ cart i

NapAy'a/ nary;I n,- L

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SUBJECT / TITLE Q A CATEGORY / CooE OL ASS BASE PLATE REVIEW IE-79-02 I/NSR J) SAMPLE PROBLEU.

,g r

3,

([PL & ATTACHMENT E

l' 7'

7' I"

ii i i

'2

]l l

]l 2

E,I AI e

E 5

['[)Y (IN 6 RED HEAD SELF

-g 4

CRIU_ING ANCHORS g

m (TYP) e

+

ep J 4 1

4 l

t W6 X 15.5 i

1 PL l'X 17'X 21 i

I 0, t.

il

^

i

_h I

!!uA.

6 i

@ LOADS AT BASE PLATE: F=

1943 M = i2196 0' M;=

350dO*

y x

@ ANCHOR TENSION BY COMMON BASE PLATE CONFIGURATION PROCEDURE WHICH DETERMINES LOAD FACTORS C LFT & LFM )

Mz 6 3 35000 (10 )

Pmz _ N i f(tNa %=

- 100 6 2(3')2 +3(10')2 P

Mx Ph 21960 C 12")

Ni &+ N2 %

2(3')2 + 3(12')2 - 585 6 mx 4

R,. = Fy _1943 - 242.9 NT if,j fD FACTCR TABLE N>4 LOAD FACTORS-L){ = 7K =7.5 FROM LOAD FACTOR TABLE LFT = 1.6 MAX ANCHOR TENSION ( FACTORED)

Pmax = LFM C Pmz +Pmx ) + LFT C P 3

T.

e n

= 1.25 C I 100.6 -5e5.6 ) + l.6 C 242.9)= 2496.4 - MAX ANCHCR FCRCE i

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CALCULATION SHEET J.G./U.Q. / CAL.CULAf teJ CJ, kEvtSt02 W.et 12690.68-SC 33-24 CC2-F 0

me.,

enspanen/oAre yvir.wsm /Cu cuan / oaf t inose morgT =cviewen/oaTe T J. HAA/A--

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\\.O.' W SUSJECT/ TITLE QA CATEsORY / CooE CL ASS BASE PLATE PEVIEN IE-79-02 I/NS R REE CALC. 440.55-SCS-24cC'2 F (D LINE*24-CC-2 -151-03 q=q q 4.qn. zn H-64

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1 1

l 7

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7 i.J_

i

2 jl l

l l

ll 2

3 ? PED HEAD m

A A

I A

b 4 SELF DRILLING W

ANCHOR (TYP) s s

g E'

s o

R44XI2'X24" Y/

l

=

c OUT:

s I

h iI l~

I'

\\

f na I

i<

l l

l 77 l

cLi) tX W6 X 25 ( BEVELED e 45 J.

USE 9' DEEP)

~4 5698"4

@ LOADS AT BASE P:

F=

5 2 53* M =

20M6 M3=

y x

ANCHOR TENSION SY COMMON SASE PLATE CONFIGURATION PROCECURE WHICH DETERMINES LOAD FACTORS C LFT a.LFM )

Pma = 5698.*

X 7.5 4 X.C 7.5')2 = 190 p

20146 X 15 21 mx = 2 X (15')2+ 2 X (832 +2 X C l')2

=

Lg = 15/f= 20 < 24 7

LOAD FACTORS ~

LFM = l.95 P

5253, T=

= 657 Lg =7-75=10 < 20 8

LFT = 1.85 a

+

a t

Pmax =l.85(657 ) + l.95 C 521 +l90) = 2602 = MAX ANCHOR FORCE

~ ~ " ' ' " ~ ~ ~ ~ ~ ~ ~ ~ ~ " ~ " " " " "

CALCULATION SHEET J.".;./'.f.O. / C ALCULAT3,,J t#J.

k Eyl31 L; pa4E j

12690.88-S(6)-2 4CC 2-J O

P;EPAIEJ/ D ATE LEVIE :E;J / C4ECKE;3 / D ATE IZ O E P EIdE",7,4 EV4 E L E J /

T.a M4 aer lio-r.=,

T.Or m )n 10/2/60 T.

u;T-h c

SUSJECT/ TITLE QA CATEGQRY / CQOE CL ASS j

BASE PLATE REVIEW IE 79.02 I/NS R RE.C. CALC. F2690.88-O LIN E NO. 2 4-C C 151-Q 3 H-69 ggv. t s go.So AY l"

3 1"

a 2

12 lg g

RED HEAD SELF I

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DRILLING ANCHOR (TYP) 11Nt I

1 i/

3 f g 2. g x 15 x 17 t

' 4N o

i v

Sg f(X(IN)

N 4

=

I

(

? -- --*-E k

W4 x 13

.P I

?

i i

s

-im +

t 9-

-f 1

r

@ LOADS AT BASE P "-

Fx=0 M = ! 149 8 8 "*

M=0 y

z

@ ANCHOR TENSION BY. COMMON BASE P.

CONFIGURATION PROCEDURE WHICH DETERMINES LOAD FACTORS (LFT & LF M).

-_ 14988 x 8 _6 2 o_g p

3 x (8)2 my P

=0 P : O*

L2/t : 9/.75 212 < 2 4-mz T

LFM 1.25 -LOAD FACTOR L ft = 6. 5/. 7 5 = 8. 7 i

4 Pma x = l. 2 5 (6 2 5) = 7 81.3=M A X ANCHOR TEN 5!CN 1

CALCULATION SHEET

• '"". /U. O. / C A LC 4 LAfl0 ) 760.

l J.O k E VISI T;4 Pl.SE e,..,

12 6 90. 8 8 -S(B)- 24-C C 2 2-A TC E PX E.2 / 0 AT E L Evi EO 2/CMEC EJ / D ATE fr0EPE DEllT CEviE0E12/DATE i

TJ M A b> w s i, o. z.__g o T.

C to 30 T. /46.-

\\o r-90 SUBJECT / TlTLE QA CATESQRY / CODE CLA3S BASE PLATE REVIEW IE 79-02 I/N S R g

RE.CA.LC. 390.88 55) ?GC'~- A

@ LINE 2 4 - C C 151 -Q 3 H -18 2Ev /2 s.r~ Ao h@ RED HEAD SELF Y

iu i <<

l2 7

A 7,,

I I DRILLING ANCHOR I

(TYP)

-ft

%t 5(IN)

{

4

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Q s

X=

Sf,,

I

+

1 A

e

-fi

~

4 s

i L P_1 xlOxl7" I

I 4

,(

\\N 6 x 15,5

@ LOADS AT B AS E R. :

M = ! 24 0"~# M = r i l 22"'#

Fe = i4164

• x y

@ ANCHOR TENSION SY COMMON BASE P CONFlGURATlON PROCEDURE WHICH DETERMINES LOAD FACTORS (LFT & LFM),

P*

• 24 0 x 6. 53 x (6.5) 2 12g ll 2 2 x 10 4'

o 52 Y~ 2 x(3)2 x 2 (IO)2 P

4164/6 r 694 T

L2/T 210 /.75 : 13. 3 < 24 LFMr1.4 LOAD FACTORS L i / T = 5.5 /. 7 5 = 7.3 < 2 0 LFT= 1. 6 P

= l. 4 (12 + 5 2) 1.6 (694) = 12 00 MAX ANCHOR FORCE max

C A LGU L A I IO N SHEET

,,2,,,,,,, c, g e o g,,,,, a,

,,y,,,,,

.. w m.,

12690.88 -SCB)-24CC22-A O

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t o.1. C-o SUSJECT/ TITLE QA CATEGORY / 000E ~L ASS BASE PLATE REVIEW IE-79-02 I/ NS R

,%{[ N (D LIN E *24-C C i SI-Q EE N 3

y, H -18 Y4 7"

7" g'

, 3" a

i

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l

-r

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I 1

1 1I'&"

7 M

ro a

.~

i z

i 9

N 4[(IN) l 6 RED HEAD SELF 4

0 DRILLING ANCHOR X

l l>

(TYP)

's i

i I

l TI - fN f

PLfX17fX17f

^

,I T

\\-

7

,e i

i ro e 31

.,__fL W10 X49 (Li )'

@ LOADS AT BASE P-:

F = t. 5619* M =

16 7 8Y% My=2 2899!

3 x

ANCHOR TENSION BY COMMON BASE PLATE CON FIG U R ATION PROCEDURE WHICH DETERMINES LOAD FAC T O RS (LFT &

LFM) p 16787 X 12 2 X C 5 ')2+3(1252 LN " 12[75 =l6 < 24 mx-LOAD FACTORS-LFM =1.625,

1 28991X12

^

my = 2 X (5')a +3 C l2.)2 = 722 Lgt =3.7f = 5 <- 2 0 P

.75 L F T=1.325 5619* = 702 PT=

l 8

+

a Pmax = l.625 C 722 + 418)+l.325( 702) = 2783 = MAX ANCHOR FORCE