Event Notification Report for October 17, 2000
U.S. Nuclear Regulatory Commission
Operations Center
Event Reports For
10/16/2000 - 10/17/2000
** EVENT NUMBERS **
37432
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|Power Reactor |Event Number: 37432 |
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| FACILITY: CLINTON REGION: 3 |NOTIFICATION DATE: 10/16/2000|
| UNIT: [1] [] [] STATE: IL |NOTIFICATION TIME: 12:43[EDT]|
| RXTYPE: [1] GE-6 |EVENT DATE: 10/16/2000|
+------------------------------------------------+EVENT TIME: 09:21[CDT]|
| NRC NOTIFIED BY: JIM SCHOTTEL |LAST UPDATE DATE: 10/16/2000|
| HQ OPS OFFICER: STEVE SANDIN +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |ROGER LANKSBURY R3 |
|10 CFR SECTION: | |
|ARPS 50.72(b)(2)(ii) RPS ACTUATION | |
| | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1 M N 0 Refueling |0 Refueling |
| | |
| | |
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EVENT TEXT
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| MANUAL SCRAM INSERTED PRIOR TO REACHING AUTOMATIC SCRAM SETPOINT FOLLOWING |
| REPLACEMENT OF ATWS POWER SUPPLIES |
| |
| "Clinton Power Station is currently in day 3 of refueling outage RF-7. At |
| 09:20 I&C Technicians were performing PMs (PCIMSA017 and PCIMSA019) which |
| replaced power supplies in the Anticipated Transient Without Scram system |
| (ATWS). During reenergization of the ATWS system, the ARI (Alternate Rod |
| Insertion) initiation alarm occurred. The 'A' RO observed Scram Discharge |
| Volume Vents and Drains closing and a rising level in the Scram Discharge |
| Volume (SDV). At 09:21 a manual scram was inserted at approximately 11 |
| gallons SDV level prior to reaching the automatic scram setpoint of 19.6 |
| gallons Scram Discharge Volume level. |
| |
| "Prior to this event Reactor Water Level was at 195 inches. The extra input |
| of water into the reactor due to this scram caused a level rise to 200 |
| inches. The Reactor Operators raised Reactor Water Cleanup letdown rate from |
| the RPV to bring level back to the preferred range of 190 - 200 inches. |
| |
| "Investigation has revealed that reenergizing the ATWS instrumentation |
| causes actuation of the ATWS trip system." |
| |
| There was no rod motion since all rods were fully inserted prior to the |
| event. The licensee informed the NRC resident inspector. |
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