ML19298C368
| ML19298C368 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 10/21/1985 |
| From: | Baer R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | Ronald Bellamy, Dan Collins, Shafer W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML19298C372 | List: |
| References | |
| NUDOCS 8510250278 | |
| Download: ML19298C368 (4) | |
Text
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'o UNITED STATES 8'
1, NUCLEAR REGULATORY COMMISSION g
W ASHINGTON, D. C. 205S5
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OCT 211%5 MEMORANDUM FOR:
Ronald R. Bellamy, Chief Emergency Preparedness and Radiological Protection Branch, R1 Douglas M. Collins, Chief Emergency Preparedness and Radiological Protection Branch, RII Wayne D. Shafer, Chief Emergency Preparedness and Radiological Protection Branch, RIII Ramon E. Hall, Chief Radiological and Safeguards Programs Branch, RIV Frank A. Wenslawski, Chief Emergency Preparedness and Radiological Protection Branch, RV FROM:
Robert L. Baer, Chief Engineering and Generic Conmunications Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
SUBJECT:
CLOSE0VT ON STUCK CAllBRATION SOURCE EVENT A Region III inspection report documented a stuck calibration source problem at the Quad Cities Station. When EGCB became aware of this event, we contacted the source vendor to determine how many end-users were affected, and to obtain documentation of the reported vendor user notification and corrective action.
During our discussion with the vendor, we learned that only a few Series 28 sources with this type of timing-latching mechanism had been sold, and the vendor had telephoned all affected users (as noted in the attached Rlll re-port). We have attached the vendor service advisory, vendor rationale for determining the end-users affected and the list of affected users notified.
Contact:
James E. Wigginton, IE (301)492-4967 8510250278 851021 IE ADOCK 05000254 CF
Multiple Addressees Since the vendor reports that all customers have been notified and has issued a service advisory to correct the problem, IE plans no further action on this matter.
If you have any questions concerning this matter, call Jim Wigginton or me.
Robert L. Baer, Chief Engineering and Generic Communications Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
Enclosures:
As stated DISTRIBUTION JMTaylor RHVollmer ELJordan SASchwartz RLBaer DPAllison JEWigginton JGPartlow BKGrimes GGZech LCobb LCunningham VMiller, NMSS RGreger, RIII JLShepherd EWBrach, EDO DCS DEPER R/F EGCB R/F JWigginton R/F j
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aa D NER:IE DEPER:IE DEPER:IE Wi inton DPAllison RLBaer
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85 10/,/85 10/;j/85 l t-
pT {XEVf Followup of Stuck Calibration Source During liarch 1985 the licensee informed NRC Region III that a Shepard calibrator, used to irradiste dosimetry devices, had stuck in the open (source exposed) position while in use. The licensee stated that a timer mechanism was designed to automatically return (drop) the source to its shielded position. The licensee used an override to manually return the source to its shielded position.
The calibrator contains a 20 curie Cs-137 source. To place the source in the exposed position, a timer is set and the source rod is manually lif ted to a position where an electric solenoid latch holds it in place.
The timer releases the electric power to the solenoid and a spring releases the latch. The licensee has installed an electric eye system that also terminates power to the solenoid if a person walks toward the exposed source beam.
The licensee contacted the vendor concernina the stuck source incident.
Af ter investication, the vendor prescribed a lubricant for a nortion of the unlatchina mechanism. The licensee applied the lubricant and no further problems have been encountered.
According to a vendor representative contacted by the inspector, all owners of this model calibrator were subsequently contacted and instructed to apply the lubricant to the uniatching mechanism. The vendor is also i
I revising the technical manual for this model calibrator.
l No violations or deviations were noted.
Reports No. 50-254/85019(DRSS); 50-265/85021(DRSS)
Docket Nos. 50-254; 50-265 Licenses No. DPR-29; DPR-30 Licensee:
Commonwealth Edison Company P. O. Box 767 Chicago, IL 60690 Facility Name:
Quad Cities Nuclear Power Station, Units 1 and 2 Inspection At:
Quad Cities Site, Cordova, IL Inspection Conducted:
June 24-28, 1985
d ankCh110 dales U-740 Salem Street, Glendale, California 91203 213/245-0187 Irradsation & Cahbration Equipment Lead Shiciding Nuclear Applications SERVICE ADVISORY SERIES 28 CALIBRATOR WITH PRESET TIMER OPTION On the Series 28 Calibrator, the source is held in the "ON".-
position by a solenoid operated latching arm which is activated when the source is raised to the fully exposed position.
This arm is held in place by a shoulder bolt which threads into the upper horizontal plate of the drive assembly.
An internal rad-ial bearing and two thrust bearings are incorporated.
At six month intervals, this bearing assembly should be lubricated with dry graphite WD40 or a light oil (10 weight).
CAUTION:
Extreme caution should be taken, that no lubricating material so is allowed to fall into the source tube.
This would cause the source to stick.
The lock nut, which is above the horizontal plate which locks the shoulder bolt in place should, also, be checked for tight-ness at this time.
Access to the locking arm assembly is avail-able by removing the flat vertical plate from the tower assembly.
This plate faces the beam port.
- 1. Lock nut-5/16-18 t'
- 2. 3/8 shoulder bolt
- 3. Top tower plate (3 j g/
4.
Aluminum spacer
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- 5. Bronze thrust bearing 6.
Latching arm t t
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- 7. Radial bronze bearing Y
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