ML19345D807
| ML19345D807 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 10/30/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Withers B PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 8012170415 | |
| Download: ML19345D807 (1) | |
Text
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- p. ~ c <,9,,g UNITED STATES g '
3..,gf g NUCLEAR REGULATORY COMMISSION 5.'
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j REGION V O
1990 N. CALIFORNI A COULEVARD N *#
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SUITE 202, WALNUT CREEK PLAZA h,
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WALNUT CREEK. CALIFORNI A 94596 Cctober 30, 1930 Docket No.50-34a Portland General Electric Company 121 S. 11. Salmon Street Portland, Oregon 97204 Attention:
Mr. Bart D. Withers Vice President liuclear Gentlemen:
This Information i40tice is forwaraed to provide a notification of a potential source of degradation that mignt occur in a safety related component over long term operation. No specific action or written response to this Information Notice is equired at this time.
If you have any questions related to this matter, please contact this office.
Sincerely, (c 'e p n.;.e l ; ~
P.. M. Engelken Director
Enclosures:
1.
IE Information f'otice No. 80-38 2.
List of Recently Issued IE Information Motices cc w/ enclosures:
C. P. Yundt, PGE J. 11. Durham, Esq., PGE 8 01217e 5
SSIftS flo. : 6835 Accession flo. :
UtlITED STATES 8008220180 flUCLEAR REGULATORY COMMISS10fl Ift-80-38 OrlCE OF IflSPECTIO!1 AtlD EtlFORCEtiEtlT HASHINGTON, D.C.
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October 30, 1980 IE Inforration f!otice fio. 80-33:
CPACKIflG IN CHARGIt!G PUMP CASIrlG CLADDIflG Description of Circunstances:
In January 1980 Commonwealth Edison Company (Ceco) reported to the flRC that a radiographic examination had revealed crack indications in the cladding on the suction end plate of the 1A charging pump at Zion Unit 1.
This cen-trifugal charcing punp 1A is one of two punns installed in Zion Unit l' for high head safety injection of borated water to the reactor locos.
These pumps are additionally utilized as charging pumps durina normal operation. ASME Section XI inservice inspection rules referenced in the plant technical specification reouires pump examination only once during the 10 year service interval and this pump had been in service about 7 years.
The cumps are 2-1/2 inch, 11 stage, Type IJ manufactured by the Pacific Pumps Division of Dresser Industries. The pump casing end assembly in the area of interest, Figure 1, consists of a suction end plate of A515 grade 60 carbon steel plate welded to the casing barrel forging of A266 class 1 carbon steel using an Inconel weldment. The entire inner surface is clad with type 308 stainless steel applied by submerged arc welding.
An in-situ ui.rasonic examination conducted in late April confirmed clad cracking indications a: the barrel case to end plate inner radius for approximately 330 l
degrees arouno the circumference and that the cracking possibly extended into the cump base material in the botton 130 degrees of the assembly. A review of the original radiographs revealed crack like indications in the clad overlay, however, not to the extent observed during this examination.
Subsecuently, the entire suction end of the pump was removed and cross sections metallographically examined tc further evaluate the nature and extent of the cracking.
It was determined that initiation and propagation of the clad cracks probably resulted from stress concentration and dilution effects in the initial corner bead pass due to the difficult access and bead sequencing required by the fairly sharp corner geometry.
Extension of the cracks at the base metal-clad interface ranged to a depth of 1/16 inch maximum in the 1-1/2 inch thick base material.
These crack tip areas were well blunted and slichtly cavitated from corrosion effects due lengthy exposure to the localized boric acid attack.
Examination of the crack morphology revealed that the clad cracking essentially arrested at the base metal-clad interface and that base metal corrosion progres-sed at a relatively slow rate.
The 1A charging pump was replaced with a new pump provided with a casing con-structed entirely of stainless steel. The licensee is currently developing improved fide procedures for examination of the three remaiM9 pumps at the next refueling outage.
Further, the licensee and pump manWturer are develooing repair procedures in the event cracks are discovered in the remaining pumps.
L
IN-80-33 October 30, 1980 Page 2 of 2 A corrosion evaluation nrovided Ceco by Hestinchouse indicates the corrosion rate of carbon steel subject to environmental conditions typical of the installed pumps is on the crder of E-1/2 to a nils per month.
Additionally, a stress analysis of the puro casing by the ranufacturer usinn ASME Section III, Subsec-tion NC rules, indic3tes that at design c ditions a flew with death of 0.763 inches could be tolerated.
Based on the available information no immediate safety concern is indicated.
However, the observed conditions reveal a potential source of pump degradation over long tern operations. Therefora, to assure maximum availability, it appears crudent to cerfarn a nondestructive exanination of this puno type at the earliest cractical time durina tr.e first code recuired in-service inspection interval and if crackinc is ccnfirred, take aoprooriate corrective actions per the. rules of ASME Section XI BP&V Code.
This Information Notice is provicea as a notificaton of a potential source of degradation of a safety related conconent tnat is still uncer review by the llRC staff.
It is expectec tnat recipients will review the infornation for possible applicability to their facility.
No specific action or response is requested at If you ' ave any auestions regarding this matter, please contact the this tire.
n Director of the a>prooriate JRC Regional Office.
Enclosure:
Figure 1 l
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FIGURE
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y SUCTION END PLATE j
j
( ASIS GR. 60 )
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1 i
i j
SUCTl')N x
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[ CLADDING (TroE 300 ST ST) i ~'.D Pi AT E
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zous as
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CASING BARREi_
( A 266 OL.1 )
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o IN 30-38 Cctober 30, 1980 DECENTLY ISSUED IE I" FOP"ATICN NOTICES Inferration
- ate of Notice '!c.
Sub.i ec t
!ssue Issued to 80-37 Containment coolar leaks 10/24/C0 All nuclear cower and reacter cavity facilities holding
- 1cedino at Indian Point cower reactor OLs Unit 2 or cps 80-36 Failure of Steam 10/10/80 All nuclear oower rererater Succort Poltino reactor facilities holdina power reactor OLs or cps 80-35 Leakina and disloaced 10/10/80 All catecories G and Iodine-12a inolant seecs G1 nedical licensees 80-34 Coron dilution of reactor 9/26/80 All pressurized water cociant during steam reactor facilities generator cecontamination holding power reactor OLs 80-33 Determination of teletherapy 9/15/80 All teletherapy
- 'rer accuracy (G3) licensees 80-3?
. '>rification of certain C/12/00 All 1RC and agreement renairer ents or Exclu-state licensees
^
sive-use shipments of radioactive materials 80-31
'aloneration of Could-8/27/30 All light water reactor Brown Boveri Tyce 430 facilities holding OLs volt Mme K-6005 and or cps
- -EON 6005 circuit breakers 80-30 Potential fcr unaccept-5/19/80 All boiling water reactor able interaction between facilities holding power l
the contrc'
'd drive scran reactor OLs or cps.
function anu non-essential control air at certain GE BUR facilities i
30-29 Proken studs en Terry 8/7/80 All light water reactor l
turbine steam inlet facilities holding flange power reactor OLs or cps *
- Operating Licenses or Construction Permits l
i