ML20081F261
| ML20081F261 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/03/1991 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9106070259 | |
| Download: ML20081F261 (2) | |
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BALTIMORE GAS AND ELECTRIC CHARLES CENTER
- P.O. BOX 1475
- BALTIMORE. MARYLAND 21203 1475 n E.DENTON I
OLNI RAL t.8AN AGE R CAiv(R1 Cliffs June 3,1991 U.S Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Document Contial Desk SUlljECT:
Calvert Cliffs Nuclear Power Plant Unit No. 2; Docket No. 50 318 Reactor Vessel Leve: hionitorine Sygem (RVI.MS)
Gentlemen:
Per the requirements of Technical Specification 3.3.3.6, Table 3.310, Item Number 14, we hereby submit the following Special Report concerning an inoperable Channel A RVLMS probe.
Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very trul > yours,
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RED /DWM/SCM/bjd gg &
At'.achment cc:
D. A.13 rune, Esquire J. E. Silberg. Esquire R. A. Capra, NRC D. G. Mcdonald, Jr., NRC T. T, Martin, NRC L. E. Nicholsott, NRC R. I. McLean, DNR J. II. Walter, PSC
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UNIT 2 REAC' LOR VESSEL LEVEL MONITORING SYSTEM, CilANNEL A SPECIAL REPORT llACKGROUND On hiay 3,1991, Calvert Cliffs Unit 2 received spurious trouble alarms on Channel A of the Reactor Vessel Level hionitoring System (RVLhtS). Plant Engineering investigated the problem and found four error. codes present on the channel digital display. These codes were associated with high Delta.Ts at the 29-and 50-inch locations and ar. open heated junction thermocouple at the 50-inch k3 cation.
Following the investigation, the 50-inch sensor location wa: declared out of senice. The 29-and 71 inch locations had previously been declared out of senice. This rendered RVLMS Channel A inoperable since three of the lower five sensor krations were unavailable.
EFFECT ON OPERATIQ_N At 2:45 a.m. on May 3,1991, Channel A of the Unit 2 RVLMS was removed from senice and Unit 2 Technical Specification 3.3.3.6, Table 3.3-10, item Number 14, Action Statement 34 was entered. A Field Engineering Change was processed to installjumpers to clear the hanging trouble alarm.
The Unit Technical Specifications and the System Operating Instruction 11 were reviewed to see if any remedial actions were required for single channel failure. There were no requirements. Channel B of the Unit 2 RVLMS is operable.
PLANS AND SCIIEDULES The inoperable Channel A RVLMS probe will be replaced and the channel restored to operable status during the next Unit 2 Refueling Outage, scheduled for Spring of 1993.
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