ML20072J498
| ML20072J498 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 06/20/1983 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8306300122 | |
| Download: ML20072J498 (3) | |
Text
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SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OPPICE M4 COLuualA. SOUTH CAROLINA 29218 co DC
- o. w. DixoN. JR.
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VICE PRESIDENT June 20, 1983 wuctuan o aariO~.
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Mr. James P. O'Reilly W
09 Regional Administrator
$7 U.S. Nuclear Regulatory Commission E'
Region II, Suite 2900 101 Marietta Steeet, N.W.
Atlanta, Georgia 30303 l
SUBJECT:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 i
Special Report
Dear Mr. O'Reilly:
Please find attached a Special Report for Virgil C. Summer Nuclear Station.- This fourteen day report is required by Technical Specification. 6.9.2 as a result of entry into Action Statement 30 of. Technical Specification 3.3.3.1 (Table 3.3-6, Item d.i.),
" Radiation Monitoring Instrumentation," on June 8, 1983 Should there be any questions, please call us at your convenience.
Ver trul you l
, - /g O. W.
1 CJM:0WD/meb Attachment cc:
V. C. Summer C. L. Ligon (NSRC)
E. H. Crews, Jr.
G. J. Braddick T. C. Nichols, Jr.,/0. W. Dixon, Jr.
J. C. Miller E. C. Roberts J. L. Skolds H. N. Cyrus J. B. Knotts, Jr.
Group / General Managers I&E (Washington)
O. S. Bradham Document Management R. B. Clary Branch C. A, Price INPO Records Center A. R. Koon NPCF D.
A. Lavigne File (Lic./Eng.)
OFFICIAL copy 8306300122 830620 0500039 7
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5 Mr.' James'P. O'Reilly Special Report Page Two June 20, 1983 ACTION TAKEN At_0700 hours on June 8, 1983, with the plant in Mode 1, Main Plant Vent Radiation Monitor RM-A13 was declared inoperable when the channel began to indicate high radiation as compared to the Main Plant Veat Exhaust Radiation Monitor RM-A3.
RM-A13 is required to be operable while in Modes 1 through 4, therefore, Action' Statement 30 of Technical Specification 3.3.3.1 applies.
Maintenance personnel investigating the problem on the morning of June-8 determined that the operation of RM-A13 was normal with the exception of an inoperable check source.
The high radiation reading previously observed by Operations personnel was not present.- The check source is an integral part of the detector for RM-A13, therefore, the detector assemb:;( must be replaced in order
' to effect repairs to the check source.
The preplanned alternate methoa of monitoring was implemented on June 10 in accordance with Action Statement 30 since a replacement detector assembly was not immediately available for installation.
The new detector was received on June 16 and maintenance personnel were subsquently directed to complete repairs on RM-A13.
Personnel performing the repair discovered that the cover for the reed switch housing on one of the preamplifier circuit boards had come off and was in contact with the electronic components.
The cover was re-installed and an Isotopic Calibration was performed with satisfactory results.
The check source was then verified to be operational, with the original detector installed, during the performance of an Operation Test with the appropriate surveillance tesc procedure, o
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. 4 s.
- Mr. James P.
O'Reilly Special Report Page.Three June 20, 1983
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CAUSE OF THE OCCURRENCE
~The cause of the occurrence is attributed to a loose cover on the x
reed switch-housing of-the preamplifier circuit board.
The cover
.for the housing is normally removed to facilitate the calibration of.the radiation monitor.- It is believed'that this cover was not
~
properly re-installed upon completion ot a previously performed Channel. Calibration and was dislodged by personnel performing repairs to the roof of the Control. Building at the time of the occurrence.
The loose cover in contact.with the electronic circuitry of the preamplifier circuit! boards apparently caused the
' erroneous high' radiation _ reading and check source inoperability cbserved on June 8.
The satisfactory results obtained on Channel Operational: Tests previously_ performed on a monthly basis provides assurrance that the operation of RM-A13 was normal prior to June 8, 1983.
PLANS AND SCHEDULE FOR RESTORING TO OPERABLE STATUS RM-A13 was returned to operable status at.1640 hours0.019 days <br />0.456 hours <br />0.00271 weeks <br />6.2402e-4 months <br /> on June 16, 1983; The licensee plans.no-additional action in regards to this event-unless warranted by a similiar occurrence in the future.
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