ML20038B374
| ML20038B374 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 12/02/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8112080086 | |
| Download: ML20038B374 (3) | |
Text
.
1
(.'*
USN TENNESSEE VALLEY AUTHORhf,fR EGl:*m.
's r
- e. ~
4* U b.D
CH ATTANOOG A. TENNESSEE 37401
+
400 Chestnut Street Tower II 9N 3 A 8,. 3 4 December
'/ff, BLRD-50-438/81-54 BLRD-50-439/81-56 3r,e Q
If,[
V
$ WCr ~
b, Mr. James P. O'Reilly, Director I ~f IO8/A 7i Office of Inspection and Enforcement
- d M k'o,y U.S. Nuclear Regulatory Commission 6,
Region II - Suite 3100 t /'
101 Marietta Street ifI l tM Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - STRUCTURAL TUBING EXCEEDING AWS ALLOWABLES - BLRD-50-438/81-54, BLRD-50-439/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector D. Quice on August 13, 1981 in accordance with 10 CFR 50.55(e) as NCR BLN BLP 8121. This was followed by our first interim report dated September 14, 1981. Enclosed is our final report.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY t-L. M. Mill -Manager W
Nuclear Regulation and S
-y N
Enclosure cc:
Mr. Victor Stello, Jr., Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 OTI4CIAL CO[,'
8112080086 811202 d
PDR ADOC.K 05000438 S
ype
$tg i
An Equal Opportunity Employer I
{.
ENCLOSCHE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 STRUCTURAL TUBING EXCEEDING AWS ALLOWABLES BLRD-50-438/81-54, BLRD-50-439/81-56 10 CFR 50.55(e)
FINAL REPORT Description of Condition In the Bellefonte Final Safety Analysis Report (FSAR), Section 3 8.4.2, a commitment was made to use American Welding Standards (AWS) Structural Welding Code, AWS D1.1-72.
This edition of the code provides a punching shear stress check for circular tubular members only. A check for. square and rectangular tubular members was not added to the code until the middle 1970's. At the time design work was in progress on the Control Building cable tray supports, the appropriate stress check was not available.
There are 86 braced cable tray supports in the Control Building which have main vertical members consisting of structural tubing size TS 8" x 8" x.25", TS 8" x 3" x.3125", and TS 8" x 8" x.375".
These supports have been braced with structural tubing whose width is 6 inches or less. At the point where the brace connects to the main vertical member, the punching shear stress in the main vertical member exceeds the -
allowables as specified in ANSI /AWS D1.1-81, part B of section 10.
t Safety Implications By exceeding the punching shear allowables, the effectiveness of the brace could be diminished during a seismic event. This could cause the supports to displace excessively and this, in turn, could damage safety-related cables, etc.
Corrective Action The design drawings (see attachment A) which dictate the configuration of the 86 cable tray supports have been altered. In the design, two 3/8-inch thick wing stiffener plates were added to the connection at the point where the brace connects to the main vertical member. This modification
- will ensure seismic qualification of the supports. In order to complete the required work, Engineering Change-Notice 1320 was issued August 13, 1981. The revised seven drawings showing the cable tray supports were issued November 16, 1981. To prevent recurrence, cable tray supports will be designed according to ANSI /AWS D1.1-31 instead of AWS D1.1-72.
FSAR Section 3.8.4.2 will be revised to include a reference to the applicable c ode,
a
j..
ATTACHMENT A NONCONFORMANCE REPORT BLN BLP 8121 Drawing Nu_mby Support Number Required 4CWO942-X2-7 MK 22 11 MK 22A 1
MK 22B 1
MK 23 12 MK 23A 10 MK 24 2
MK 24A 2
MK 24B 1
MK 25 1
MK 26 3
MK 26A 2
MK 27 4
MK 27A 5
MK 27B 10 MK 38 1
4CWO942-X2-8 MK 32 1
MK 32A 1
MK 33 2
4CWO943-X2-4 MK T/B 5 1
4CWO943-X2-5 MK T/B 23 1
4CWO943-X2-9 MK T/B 14 1
4CWO943-X2-12 MK T/B 3 1
MK T/B 4 1
MK T/B 6 1
MK T/B 7 2
MK T/B 7A 1
4CWO943-X2-13 MK T/B 11 2
MK T/B 11A 4
MK T/B 13 1
Total 86 1