Event Notification Report for October 24, 1999

- MANUAL REACTOR TRIP DURING CONTROL ROD WORTH TESTING -

With Unit 1 stable in Mode 2 (Startup) at 10E-8 amps, the licensee was performing control rod worth measurements in accordance with the Initial Criticality and Testing using Advanced Digital Reactivity Computer Procedure under the provisions of Special Test Exception Tech Spec 3.10.1 and 3.10.3 (Shutdown Margin and Physics Tests). Control Bank 'C' control rods were being inserted at maximum speed (66 steps per minute) when the reactor operator noted a discrepancy between the Group 1 and Group 2 step counters. Reactor operators manually tripped the reactor at 1219. All control rods inserted completely. Unit 1 is stable in Mode 3 (Hot Standby). Steam is being dumped to the main condenser and main feedwater is aligned to the steam generators.

The licensee is troubleshooting the rod control problem. Initial investigation revealed a stationary phase failure for Group 1, Control Bank 'C' control rods.

The licensee plans to notify local officials and the NRC Resident Inspector.

INADEQUATE HIGH PRESSURE FIRE WATER SYSTEM INSTALLATION IN THE C-337 BUILDING

"On 10/24/99, at 2250 CDT, the Plant Shift Superintendent was notified that High Pressure Fire Water system D5 in the C-337 building, does not meet NFPA Code 13. During a walkdown of the system, two non-conformances were noted. The spacing between two of the branch lines exceeds the NFPA 13 maximum spacing criteria of 15 feet. It was also noted that the spacing of the sprinkler heads on these two branch lines is between 5 to 6 feet. NFPA 13 requires the heads to be spaced a minimum of 6 feet apart unless baffles have been installed. These heads do not have baffles installed on them. This system was inoperable at the time of discovery, and LCO required fire patrols were being performed.

"It has been determined that this event is reportable under 10CFR76.120(c)(2) as an event in which equipment is disabled or fails to function as designed.

"The NRC Resident Inspector has been notified of this event."


***RETRACTION ON 11/23/99 AT 2328 EST FROM WHITE TAKEN BY MACKINNON****

PGDP Engineering has evaluated this condition and concluded that the spacing of the branch lines on this system (C-337 HPFWS D-5) is such that the sprinkler spray pattern and coverage area is maintained without the need for the center branch line, and the sprinkler can meet its intended safety function. The subject non-conformance did not impact the systems ability to perform its intended function, and therefore, the 10CFR76.120(c)(2) reporting criteria was not met.

The NRC Resident was notified of this retraction by the certificate holder. The R3DO (Ron Gardner) and NMSS EO (Joe Holonich) were notified by the NRC operations officer.

STEAM GENERATOR "2C" CLASSIFIED AS CATEGORY "C-3" DUE TO STRESS CORROSION CRACKING OF > 1% IN-SERVICE TUBES IN THE AREA OF THE HOT LEG SUPPORT PLATE CREVICES.

"ON OCTOBER 24, 1999 THE INSPECTION RESULTS OF THE 2C STEAM GENERATOR DETERMINED THAT MORE THAN 1% OF THE TUBES ARE DEFECTIVE, CONSTITUTING A C-3 CONDITION PER STP TECHNICAL SPECIFICATION SURVEILLANCE REQUIREMENT 4.4.5.2. THE GENERAL AREA OF DEGRADATION IS IN THE HOT LEG TUBE SUPPORT PLATE CREVICES. THE CAUSE OF THE DAMAGE IS THOUGHT TO BE OUTSIDE DIAMETER STRESS CORROSION CRACKING. 100% OF THE IN-SERVICE TUBE-TO-TUBE SUPPORT PLATE INTERSECTIONS ARE BEING EDDY CURRENT INSPECTED BY BOBBIN COIL PROBE. ALL DISTORTED SUPPORT PLATE INDICATIONS WITH BOBBIN VOLTAGE OF OVER 1 VOLT ARE BEING FURTHER EXAMINED BY PLUS POINT PROBE. COMPLETION OF THE
EXAMINATION SCOPE IS IN PROGRESS. THIS REPRESENTS A REPORTABLE CONDITION PER 10 CFR PART 50.72(B)(2) AS DEFINED BY STP TECHNICAL SPECIFICATIONS TABLE 4.4-2."

INSPECTIONS ARE ALSO PLANNED FOR STEAM GENERATORS "2A", "2B" AND "2D." THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR.