ML19291C458
| ML19291C458 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/22/1980 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Rubenstein L Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001240453 | |
| Download: ML19291C458 (4) | |
Text
.
TENNESSEE VALLEY AUTHORITY CHATTANCOGA. TENNESSEE 374ot 400 Chestnut Street Tower II January 22, 1980 Director of Nuclear Reactor Regulation Attention:
Mr. L. S. Rubenstein, Acting Chief Light Water Reactors Branch No. 4 Division of Project Management U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Rubenstein:
In the Matter of the Application of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 As requested by H. Asher in a telephone conversation on January 7, 1980, enclosed is information on the number of 3/8-inch and 1/4-inch expansion anchors installed at Sequoyah Nuclear Plant (SNP) and information on the number of supports at SNP designed before issuance of TVA Civil Design Standard DS-C6.1.
The enclosed information was delivered to C. Stahle on January 15, 1980.
If you have any questions, please get in touch with D. L. Lambert at FTS 854-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure gg(,
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$ 6,.,1 1794 223:
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au ENCLOSURE SEQUOYAH NUCLEAR PLANT RESPONSES TO H. ASHER'S QUESTIONS (JANUARY 7,1980)
Question 1.
How many 3/8-and 1/h-inch expansion anchors were used at Sequoyah? Identify the systems or features in which they were used.
Response
TVA utilized 1/h-and 3/8.ach anchor bolts in some minor support designs. The followin6 is a list of the systems and typical drawings utilizing these anchor bolts.
I.
Piping and Conduit Supports (All.3/8-inch anchors)
Number of Percent System Drawing Surport Types of D'egs 1.
Fuel Pool 47A454 2
1%
Cleaning - #78 2.
ERCW - #67 47A450 40 8%
3 Component h7A464 15 10%
Cooling - #70 h.
2" and under 47A053 8*
1%
piping - Typical 5
Scmpling Lines 47A052 9'
23%
6.
Sensing Lines 47A051 6*
12%
- Each support could have been used more than once.
The factors of safety for 1 through 6 range from a minimum of h.6 to a maximum of 106.
II.
Cable Tray, Main Steel, and Miscellaneous Steel Areas Fourteen 1/4-inch anchors (drawing hSn1231-1) were utilized in three supports in the auxiliary building in the referenced areas.
A minimum factor of safety of 40 exists with respect to the actual anchor loads.
In the centrol building and diesel generator buildings 3/8-inch anchors were utili cd in approximately eleven supports. The factors of safety rance frca a minimum of 6.67 to a maximum of 100.
The factors of safety for I and II above do not take into censideration actual concrete strengths. A minimum increase of 29 percent in the factors of safety would result if actual concrete strengths were considered.
./.
2 1794 224
un question 2.
How many supports utilizing expansion anchors were designed prior to the issuance of TVA Civil Design Standard DS-C6.17 Utilizing a sampling technique, determine the minimum factors of safety used in the designs on a system by system basis.
Restonse TVA performed some designs prior to the issuance of DS-C6.1.
The following is a list of systens and typical drawings which were not designed by DS-C6.1:
I.
Piping and Conduit Supports Number of Percent System Drawing Support Types of Dwgs 1.
2" and under 47A053 1*
.1%
piping - Typical 2.
Sampling Lt,r s 47A052 1*
2%
Typical 3
Conduit Supports 47A056 10 8%
4.
Duct Support 15 33%
Control Building
- Each support could have been utilized more than once.
Eleven supports were selected en a random basis to be investigated for actual safety factors.
Cne support had a safety factor of 4.62.
The others all had safety factors above 5 with the maximum being 106.
II.
Cable Tray, Miscellaneous Piping, Equipment, and Mail Steel Supports Number of
% of Supnorts Surrorts 1.
Cable Tray Supports 150 9
2.
Miscellanecus Steel 33 76 Pipe Supports 3
Miscellaneous Equipment 30 15 Supports 4.
Miscellaneous SteeI 2
Less than 1 Supports 5
Main Steel 46 100 f.
1794 225 -
2 A random sample of the above supports was evaluated to determine actual safety factors for the maximum loading condition. Emphasis was placed on items 2 and 5 The minimun factor of safety found was 4.6 while the maximum was 58. The main steel supports had a miriisum factor of safety of 4:6 and a maximum of h.8.
The factors of safety in I and II do not consider actual concrete strengths.
If actual concrete strengths were considered, the factors of safety could be increased by 29 percent.
O e
9
/-
17N.226 '