ML19257C492

LER 80-010/01T-0:on 800111,during Review for IE Bulletin 79-14,S&W Found Stress on Vertical Rod Hangers SW-H-162A & SW-H-160A to Be Over Design Allowable.Caused by Incorrect Valve Weights Used in Pipe Support Design Calculations

ML19257C492
Person / Time
Site:	North Anna
Issue date:	01/24/1980
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19257C480	List: ML19257C479 ML19257C491 ML19257C492
References
IEB-79-14, LER-80-010-01T, LER-80-10-1T, NUDOCS 8001290228
Download: ML19257C492 (2)

Text

NRC FORM 366 U. S. NUCLE AR REGULATORY COMMISSION (7 77)

LICENSEE EVENT REPORT CONTROL ULOCK: l l l l l l l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 1 O o 1 l Vl A n [ A j S 114 @l 0 ] 0 l - l 0 0 0 0 0 l- 0 0hl@l 164 1ll CENSE l1 l1l1l@l TYPE JO $1 C A I $8 l@

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MX l@l015l0 0j0 60 61 3 3 81@l0111111 64 63 EVENT DATE 8 0!@l 01 11 74 15 21 4l 8l Ol@

HEPORT DATE B0

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DOCKET NUMBER EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h o 2 l On January ll, 19 80, during the review for IE Bulletin !9-14 Stone & Webster o 3 l discovered the stress on vertical rod hangers SW-H-162A and SW H-160A to be over I o 4 ldesiga allowable. The hangers support the discharge piping of screen wash pumps I o s I l-SW-P-2 and 2-SW-P-2 respec t ively. The health and safety of the general public were 1 0 6 l not af fected by this event. Reportable pursuant to T.S. 6. 9.1. 8.1. l 0 7 l l 0 8 l  !

7 8 9 80 SYSTEM CAUSE CAUSE CoVP. VAL'JE CCOE CODE SU8 CODE COYPONEN T CODE SU8 CODE SUSCODE o 9 l W l A l@ [Bj@ l A l@ l S l Ul P l 0 l R l T l@ l A l@ y @

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,_ SEQUEN TI AL OCCURRENCE HEPOHT REVISION LE R RO ELENT YE AR REPOHT NO CODE TYPE NO.

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_ 21 22 23 26 21 23 29 3J 31 TAKE A T ON O PLANT 1 T HOURS 22 S B IT D FOR1 UB. UPPLIE MANUFA TURER I33Fj@34 Zl g l Zlg 3a l Zlg 36 l 0l 0l 0l Ul 3/ 40 lYg 43 l N lg l Alg lGl2l5l5l@ 47 42 43 44 CAUSE DESCRIPTICN AND CORRECTIVE ACTIONS i o j The hangers were overstressed because incorrect valve weights were used in the pipe l li j i i support design Calculations. Both vertical rod hangers have been modified by replacing I gg the rod with a strut for reinforcement. l 11 131 I l 11 1411 I 7 8 9 80 STA S 80AER OTHER STATUS blSCO RY DISCoV ERY DESCRIPTION lil5l 9 @ l 0l 0l 0l g NA l lD[gl Notification from A/E l ACTIVITY CO TENT OF pe AYOUNT OF ACTIVITY LOCATION oF RELEASE -

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7 8 9 11 12 13 80 PERSONNEL 1%uHiES NU'RER DESCRIP TION 0

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Virginia Electric and Power Company North Anna Power Station, Unit #1

Attachment:

Page 1 of 1 Doc ke t No. 50-333 Report No. LER 80-010/01T-0 Description of Event On January 11, 1980, during the review for IE Bulletin 79-14, Stone & Webster discovered vertical rod hangers SW-H-162A and SW-H-160A to be stressed over the design allowable. The hangers support screen wash pump dishcarge lines 6"-WSSW-1-151-Q3 and 6"-WSSW-401-151-Q3, respectively.

Probable Consequences of Occurrence Because the hangers were overstressed, it was possible that the discharge piping of both the Unit 1 and Unit 2 screen wash pumps could have failed in the event of a seismic occurrence. The health and safety of the general public were not af fected by this event. No generic iraplications exist for this occurrence.

Cause of Event The hangers were stressed over design allowable because incorrect valve weights were used in the design calculations of the supports. The we igh t of the gate valve, immediately downstream of each pump, changed from 215 lbs. to 202 lbs.

Immediate Jorrective Action Both vertical rod hangers have been reinforced by replacing each hanger's tod with a strut.

Scheduled Corrective Action No scheduled corrective action is required.

Actions Taken to Prevent Recurrence No further actions are required.

1840 061'