ML20011A626

Final Deficiency Rept Re Failure of Tack Welds on safety- Related Automatic Air Dampers Supplied by Pacific Air Products,Initially Reported 800912.Cause Determined to Be Vendor Matl or Welding Inadequacy.Dampers Repaired

ML20011A626
Person / Time
Site:	Grand Gulf
Issue date:	10/19/1981
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, AECM-81-412, NUDOCS 8110290199
Download: ML20011A626 (5)

Text

.

MISSl%A

', 1 ' if@H'elping Build Mississippi @$VER Eiibhihididd5 P. O. B O X 16 4 O. J A C K S O N. Ml S SIS S iP PI 3 9 2 O 5 i31 gT ?.6 a10 . O

1. $UE,UN[d',jR October 19, 19El h

Office of Inspection & Enforcement 'o U. S. Nuclear Regulatory Commission Regi.on II g, Q OOx [\Tg 101 Marietta Street, N. W. -

>g '@O ,  ;,

Suite 3100 g d) 1 Athata, Georgia 30363 b U Attention: Mr. J. P. O'Reilly, Director

'g/ , _ ,o'

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File: 0260/15525/15526 PRD-80/57, Final 2eport, HVAC Automatic Air Dampers AECM-81/412

Reference:

1) AECM-81/270, 7/29/81

2) AECM-81/41, 1/23/81

3) AECM-80/254, 10/13/80 On September 12, 1980, Mississippi Power & Light Company notified Mr. M.

Hunt of your office of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns the failure. of tack welds on safety related automatic air dampers supplied by Pacific Air Products Company.

Working with our Constructor we have determined that this deficiency, had it remained uncorrected, could have affected the safety of operations of the nuclear power plant and theretore is reportable under the provisions of 10CFR 50.55(e). It is not reportable per 10CFR21 as explained in our attached report.

Yours truly, J. P. McGaughy, Jr. g'J 7 Attachment 5 cc: See Page 2

[

8110290199 811019 PDR ADOCK 05000416 Member Middle South Utilit es System 8

S PDR

. m Mr. J. P. O'Reilly AECM-81/412 NRC Page 2 cc: Mr. N. L. Stampley Mt. . B. McCchee Mr. T. B. Conner Mr. Victor Stello, Directcr Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P.O. Box 1589  ;

Hattiesburg, MS 39401 l

4 e... - - - . - - - , -n. ,..-, -

w - , - ~

• a -

bec: . Mr. D. C. Lutken Mr. J. Leatherman ,

Dr. D. C. Gibbs Manager of BWR-6 Licensing Mr. J. N. Ward '

General Electric Company Mr. J. P. McCaughy, Jr. - 175 Curtner Avenue Mr. J. D. Heaton San-Jose, Ca. 55125 . -

Mr. R. S. Trickovic Mr. J. W. Yelverton Mr. L. F. Dal.e Mr. D.-M. Houston Mr. C. K. McCoy U. S. Nuclear-Regulatory Commission Mr. T. H. Cloninger Division _of Licensing Mr. R. A. Ambrosino Washington, D. C. 20555-Mr. R. C. Iron Mr. G. B. Rogers Mr. S. H. Hobbs Mr. J. Matore Mr. L. E. Ruhland U. S. Nuclear Regulatory Commission Mr. D. L. Hunt Division of Licensing Mr. A. G. Wagner Washington, D. C. 20555 Mr. P. A. Taylor -

PRD File File Mr. Bruce J. Cochran Cochran Consulting-Company -

P.O. Box 270503 Tampa, Florida 33688 e

- M.-

.. . . _ _ . _ . . .._._ .. _ ._. . ... c -.. .._ ..a..._._.....w_...___~-,_wo -

b

- wge - ,

, r, ,.w-- - .-v, , ,os p,y,- .- , - -+,-p, . --v-- ---ne + y - 5 g

Attachment to AECM-81/412 P ga 1 of 2 F$,' 1.

FINAL REPORT for PRD-80/57 Description of the Deficiency The tack welds connecting the shaft to the damper blades on two safety related automatic air dampers failed during an attempt to open the blade.

The dampers are QlX77F001A-A and Q1X77F003-C in the Diesel Generator HVAC System (X77). These dampers are supplied by Pacific Air Products Company (PAPCO). When failuras were noted in these dampere, our Constructor undertook investigative action which identified other similar failures. The condition haa now been determined to be generic in nature.

Systems affected in addition to the Diesel Generator HVAC (X77) are the Standby Service Water Building HVAC (Y47), Control Room HVAC (Z51), Safeguard Switchgear and Battery Room HVAC (Z77), and Standby Gas Treatment Systen (T48). Several other non-safety-related systems are also affected. The deficiency is applicable to both Unit 1, Unit 2, and Common. It is not applicable to the NSSS vendor. -

II. Analysis of Safety Implications The failure of the welds could caase the respective damper blades to be inoperative. Failure of the dampers to perform in accordance with design requirements could cause malfunction of equipment due to inadequate cooling in the above interfacing systems. Inadequate environmental control in the Control Room could result due to loss of function of the Control Room Ventilation System (Z51).

Failure of the dampers associated with the safety related equipment to fully open when required could result in temperatures above design limits, loss of Control Roon environmental control, and could hazard safety-related equipment and operating personnel.

Therefore, this deficiency is reportable under the provisions of 10CFR50.55(e). It is not reportable under 10CFR21 because any affected systems that had been turned over to MP&L had the deficiencies identified prior to turnover.

III. Corrective Actions Taken Mississippi Power & Light and our Architect / Engineer have determined that the cause of the deficiency is the inadequacy of the material (ASTM-A-108 12L14) utilized by the vendor for the damper shafts and/or use of inappropriate welding procedures for welding this type of material.

. . i '* -

Attachment to AECM-81/412 Pagn 2 cf 2 4 9

- However, the vendor (Pacific Air Products Co., Santa Ana, California) disagrees with our determination of-the cause. The vendor contends that

. during installation, he failure to set the limit switches on the actuaturs' caused over-torquing on the. entire damper causing the. tack welds to break.

Irrespective of either cause noted above, the corrective actions outlined below will correct the deficiency. .

The vendor has provided:a thru-bolt mechanical connection between the damper blade bracket and the drive shaft, eliminating,the design requirement for'a

. tack weld.

,Th e rework and repair of all' installed dampers has been completed. The. Unit 2 dampers'will be repaired by our Constructor after resumption of Unit 2 work. This is being tracked on Condition Report (CR) 7482.

Since all defective dampers at GGNS will be replaced, these actions will~

serve to preclude recurrence. a 3

e J

t 4

f p

4 h

h

. .. . _, . ,_. , , .. _ _ _ . , - - - , , _ ,_. ..,. _ _ _.-._ ~. ._ ._, . . _ . _ , , _ _ . _ . - _

. .