ML20086E169
| ML20086E169 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 04/10/1974 |
| From: | Swart F, Warembourg D PUBLIC SERVICE CO. OF COLORADO |
| To: | Gilbert W NRC |
| Shared Package | |
| ML20086E172 | List: |
| References | |
| AO-50-267-74-5A, NUDOCS 8312060227 | |
| Download: ML20086E169 (6) | |
Text
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O O
Y ABNORMAL OCCURRENCE X DATE:
' April 10, 1974 i
FORT ST.'VRAIN NUCLEAR GENERATING STATION l
PUBLIC SERVICF COMPANY OF COLORADO P. O. BOX 361 PLATTEVILLE, COLORADO 80651 f
REPORT NO. 50 -267/74/5A Interim Final X
IDENTIFICATION OF OCCURRENCE:
This report is issued to finalize Int eris-Report 50-267/74/5 dated February 25, 1974, concerning the failure of the orifice valve assembly of Control Rod Drive Serial No. 30, to properly engage and seat 'in the metal clad top reflector elements.
This event is considered to be an abnormal occurrence as defined i
in The Technical Specifications, paragraph 2.1C.-
i CONDITIONS PRIOR TO OCCURRENCE:
Steady State Power.
Routine Shutdown i
I Hot Shutdown -
Routine-Load' Change Cold Shutdown X
Other (specify)
Refueling Shutdown-Low Power Physics Tests Routine Startup in Arr The major plant parameters at the time of the event were as follows:
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-i Power RTR.
N/A Eth
'I ELECT.-
N/A'
~we j
Secondary Coolant Pressure
/N/A psig
~
' Temperature
'N/A
- F-831'2060227 74041'O pDR ADOCK 05000267 Flow.
N/A.
f/hr.
S PDR
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50-267/74/3A Paga 2
.f Primary Coolant Pressure N/A psig 0
Temperature N/A F Core Inlet N/A 0F Core Outlet Flcw
-N/A f/hr.
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DESCRIPTION OF OCCURRENCE:
About 4:00 A.M., Monday, January 14, 1974, during inspection of~
the metal clad keyed top reflector elements, we found that there were burrs on some of the drilled holes in the bottom distribution plate and machining chips in the plenum area between the graphite box portion and the lower dis-tribution plate of some of these elements in the warehouse. One of the chips found was about 1" in diameter, large enough to plug a coolant passage.
See Attachment "A."
APPARENT CAUSE OF OCCURRENCE:
Design Unusual Service Cond.
Including Environ.
Manufacture I
Component Failure.
Installation /Const.
Other (specify)
Operator
-I Procedure t
i ANALYSIS OF OCCURRENCE:
The apparent cause of the incident was a deficiency in the QA/QC inspection and/or inspection procedure for_the subject plenum elements during fabrication and prior to shipping to the site. Evaluation of the documents
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50-267/74/3A Page 3 used'in the manufacture of the Keyed Plenum Elements'and Keyed Control
-Reflector Elements revealed that:
Drawings required deburring of these components.
Manufacturing travelers required appropriate cleaning, deburring and inspection of operations to be accomplished; however, the. final traveler operation did not require particular manufacturing or inspection attention to these items.
Cleaning, deburring and inspection operations.were not signed off in all cases on the inspection and manufacturing travelers.
- The traveler was inadequate in that it called for a' genera 11 inspection of c all parts 100%. As a result, it appears that the specific check for deburring and for. chips did not receive the detailed attention that it J
should have received. These inspection steps should have been specifically.
defined at the end of all manufacturing operations.
l Specific instructions have now been established to require 100%
inspection of this type of discrepant condition as a final' step.in the-manufacturing process.
Changes have been made to the GA Quality Assurance Manual to require final review and approval of travelers by Component Quality Engineering prior to implementation.
Organization changes have been made that place Component Quality-Control and Component Quality Engineering within the GA organization under-the same administrative management'..-
CORRECTIVE ACTION:.
At the time of the occurrence 28 elements had been inspected, seven of which had been installed in the~ reactor. These.seven,(7) elements-were removed from the reactor andfound'to be free of foreign material or-
- debris._
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l A procedure was developed for inspection and removal of burrs and/or other foreign material. The elements were given a 100% inspection audited by both PSC and GA QA.
The procedural and organizational changes initiated by GA should prevent recurrence of the problem in the future.
Since these reflector elements are not normally replaced in future fuel reloads at Fort St. Vrain this problem is not a matter of continuous concern. The implications of the problem as they affect QA/QC in other areas appear to be adequately resolved by the proposed GA procedural and organizational changes.
FAILURE DATA /SIMILAR REPORTED OCCURRENCES:
No occurrences of this type have previously been experienced.
PROGRAMMATIC IMPACT:
A slight delay was experienced due to necessity to reinspect elements previously inspected and to develop procedures to facilitate close element internal inspection and cleaning.
CODE IMPACT:
No codes involved' Approved:
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Prepared by:
1)Eederic E. Sway Superintendent, Fort St. Vrain Nuclear d 71 mM Generating Station Don Warembourg Director, Quality Assurance
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ATTACID{ENT "A" 50-267/74/3A O
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P. O. Box 361, Platteville, Colorado 80651 L_ l:.
J April 24, 1974 Mr. William Gilbert 7920 Norfolk Avenue Bethesda, Maryland 20034 REF: Eacility Operating License No. DPR-34 Docket No. 50-267 Gentlemen:
Enclosed please find 1 copy 600fkiWk) of Abnormal Occurrence Reports, Nos. 50-267/74/1A, 50-267/74/2A, 50-267/74/3A, 50-267/74/4A, and 50-267/74/5A, submitted to the Directorate of Licensing, for your information.
Very truly yours, o
L E42 Frederic E. Swart Superintendent Fort St. Vrain Nuclear Gererating Station FES/alk Q
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3745 COPY SENT REGION
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