Event Notification Report for June 04, 1999

STOLEN CPN MOISTURE DENSITY GAUGE

A CPN moisture density gauge was stolen from a work site in Puerto Rico. The gauge was stolen at approximately 11:00 a.m. on 6/4/99. A report has been filed with the police. The gauge contains 10 mCi Cs-137 and 50 mCi Am-241. The gauge was a model MC-1DR-P82, serial number MD71003957.

(Call the NRC Operations Center for a licensee contact telephone number.)

REACTOR TRIP DUE TO SPURIOUS SIGNAL DURING POWER RANGE CALIBRATION

During the performance of power range calibration of N42, with a trip signal in, a spurious signal from N43 was received which completed the 2 of 4 coincidence for a reactor trip on high flux. The reactor tripped, all rods inserted and all systems functioned as required.

This event is being investigated and the plant will remain in Hot Standby until the cause is determined and corrected. The plant is presently stable with auxiliary feedwater supplying water to the steam generators and the steam dumps exhausting to the main condenser.

The licensee notified the NRC Resident Inspector.

OFFSITE NOTIFICATION DUE TO EXCESSIVE CHLORINE IN DISCHARGE

The licensee notified the Kansas Department of Health and Environment due to exceeding the residual limit of 0.2 ppm chlorine in the Circulating Water discharge. The highest observed reading was 1.6 ppm. A mechanical failure in the sodium hypochlorite feed pump is suspected. An investigation is in progress and the system is isolated until corrected.

The licensee notified the NRC Resident Inspector as well as the State of Kansas and local county authorities.

* * * UPDATE AT 2243 EDT ON 6/4/99 BY STEVE HEDGES TO FANGIE JONES * * *

After subsequent evaluation of sodium hypochlorite release volumes, the licensee determined that the release limits of 40 CFR 302 of 100 pounds was exceeded. The calculated release was 1694 pounds. The licensee notified the National Response Center (report # 486-281).

The licensee notified the NRC Resident Inspector. The Headquarters Operations Officer notified the R4DO (Linda Howell).

REACTOR BUILDING EMERGENCY COOLING SYSTEM OPERABLE BUT DEGRADED

"At 1717 hours on June 4, 1999, GPU Nuclear determined that a condition that is outside the plant design basis may exist at TMI-1 due to potential degraded performance of the Reactor Building [RB] Emergency Cooling System. Measurements of indirect system performance parameters for the TMI-1 Reactor Building Emergency Cooling System indicate that the air flow through the system may be less than that assumed in the plant design basis.

"Specifically, air flow in the RB Normal Cooling system, that utilizes duct work and a flow damper common to both the RB Normal cooling system and the RB Emergency Cooling System, has been found to be below previous air flow measurements. The air flow reduction may be indicative of a reduced air flow that would occur in the RB Emergency Cooling system if it was called upon to function in the event of a design basis accident. The design basis flow for the RB Emergency Cooling System is 25,000 CFM with the RB cooling fans in slow speed. Engineering judgement is that the current flow rate may be below 25,000 CFM if the system was called upon to function, hence the identification of a condition outside the plant design basis.

"Engineering judgement is that: the Reactor Building Emergency Cooling System remains operable but may be degraded. The judgement that the system is operable with degraded air flow is based on the difference between conservative assumptions in environmental temperatures in the plant design basis analysis and current environmental conditions and in view of the fact that the environmental conditions within the Reactor Building in the design basis accident should enhance the current potential degraded system air flow. A formal internal justification of continued operation (JCO) will be prepared to document the basis for the engineering judgement and will be provided to the site NRC resident inspectors office.

"Because GPU Nuclear has classified this condition as being potentially outside the design basis of the plant, GPU Nuclear is notifying the NRC Operations Center in accordance with 10 CFR 50.72(b)(1)(ii)(b). This notification will be followed with a 30 day LER in accordance with 10 CFR 50.73.

"GPU Nuclear will document this condition in its 10 CFR 50 Appendix B corrective action program and this potential non-conformance is being addressed in accordance with the guidance provided in NRC Generic Letter 91-18, Rev 1."

The licensee notified the NRC Resident Inspector.

NRC BULLETIN 91-01 24 HOUR REPORT

"ON 6/4/99 AT 0725 HRS. OPERATIONS PERSONNEL DISCOVERED THAT REQUIREMENT #5 OF NUCLEAR CRITICALITY SAFETY ANALYSIS (NCSA) PLANT_003.A01 WAS NOT BEING MET. THE REQUIREMENT, MONITORING SURGE DRUM PRESSURE ONCE EACH SHIFT WAS BEING PERFORMED WITH THE INSTALLED PRESSURE INDICATOR WHICH WAS ISOLATED ON 5/20/99 TO ALLOW MAINTENANCE TO CALIBRATE. WHEN THE INDICATOR COULD NOT BE CALIBRATED IT WAS LEFT ISOLATED AND OPERATIONS WAS NOT MADE AWARE THAT OF THIS CONDITION. SINCE THE LINE WAS VALVED OFF THE DRUM PRESSURE WAS NOT MEASURED AS REQUIRED, THIS IS A LOSS OF A SINGLE CONTROL (CONCENTRATION) OF THE DOUBLE CONTINGENCY PROGRAM. THE SECOND CONTROL (MODERATION) WAS MAINTAINED THROUGHOUT THE EVENT. THE PRESSURE INDICATOR WAS VALVED IN AT 0905 HRS. ON 6/4/99. PREVIOUS MAINTENANCE IN THE CASCADE REGARDING SURGE DRUM CALIBRATION MAY HAVE RESULTED IN A SIMILAR SITUATION.

"THE 'X' BANK SURGE DRUM WAS EVACUATED AND TAGGED OUT OF SERVICE FOR MAINTENANCE.
THEREFORE, THE SURGE DRUM IS CONSIDERED EMPTY. ON 5/20/99 MAINTENANCE VALVED OFF THE DRUM TO DO WORK ON THE PRESSURE SENSOR. THE DRUM REMAINED VALVED OFF UNTIL 6/4/99. WHEN THE DRUM WAS VALVED BACK IN THE DRUM WAS STILL EVACUATED. THIS INDICATED THAT THE NCSA PRESSURE LIMIT WAS NEVER EXCEEDED (i.e., WET AIR IN-LEAKAGE DID NOT OCCUR), THEREFORE, THE SAFETY SIGNIFICANCE OF THIS EVENT IS LOW AND A CRITICALITY WAS NOT POSSIBLE.

"FOR CRITICALITY TO OCCUR THE SURGE DRUM WOULD HAVE TO HAVE MATERIAL IN IT AND THE MATERIAL WOULD NAVE TO BE MODERATED BY WET AIR IN-LEAKAGE. THIS WAS EXPECTED TO OCCUR IN THIS CASE BECAUSE THE DRUM WAS HOLDING ITS PRESSURE BEFORE MAINTENANCE CALIBRATED THE PRESSURE SENSOR, AND THE FACT THAT OTHER SURGE DRUMS IN THE SAME ROOM WERE OPERATING AND THE ROOM TEMPERATURE WAS GREATER THAN 140°F.

"THE ESTIMATED AMOUNT OF MATERIAL IN THE DRUM IS LESS THAN 600 gms. U-235 (A SAFE MASS AT 10% ENRICHMENT) DUE TO THE FACT THAT THE DRUM WAS EVACUATED PRIOR TO MAINTENANCE. WHEN THE PRESSURE SENSOR WAS VALVED BACK INTO THE DRUM, THE DRUM WAS STILL AT A VACUUM (NOTE: THE NCSA PRESSURE LIMIT ON THE DRUM IS 17 psia). THE MAXIMUM ENRICHMENT IN THIS DRUM IS 10%. THE FORM OF THE MATERIAL IS EITHER UF6 OR UO2F2.

"THE MAINTENANCE PROCEDURE REQUIRES THE PRESSURE INDICATOR TO BE ISOLATED FOR CALIBRATION. THIS WAS DONE ON 5/20/99. WHEN THE SENSOR COULD NOT BE CALIBRATED, THE LINE WAS LEFT VALVED OFF AND OPERATIONS DID NOT KNOW THIS. THE NCSA REQUIRES THE PRESSURE ON THE DRUM TO BE MONITORED AND RECORDED EACH SHIFT, OPERATIONS WAS READING THE MT&E SENSOR INSTALLED. HOWEVER, SINCE THE LINE WAS VALVED OFF THE DRUM PRESSURE WAS NOT MEASURED AS REQUIRED.

"THE RESIDENT NRC INSPECTOR HAS BEEN NOTIFIED."

* * * UPDATE AT 2120 EDT ON 6/4/99 BY ERIC SPAETH TO FANGIE JONES * * *

Clarification: the normal pressure indicator is read in the control room. That indicator is still not calibrated and a local calibrated pressure gauge was valved in for indication on 6/4/99 and is read locally each shift.

LIVE TURTLE FOUND IN INTAKE STRUCTURE

The licensee notified the Florida Department of Environmental Protection regarding the discovery of a live Loggerhead Turtle on the intake bar racks. The turtle was removed and transported to the mariculture center. The NRC resident inspector has been informed of this notification by the licensee.

- MANUAL REACTOR TRIP FROM 48% POWER DUE TO 4 CONTROL RODS DROPPING INTO THE CORE -

AT 0313 ON 06/04/99, WHILE PERFORMING TROUBLESHOOTING ACTIVITIES ON UNIT 2 CONTROL ELEMENT DRIVE SYSTEM FOLLOWING A CONTROL ROD DROPPING INTO THE REACTOR CORE ON 06/02/99 (REFER TO EVENT #35785), FOUR CONTROL ELEMENT ASSEMBLIES (SHUTDOWN GROUP 'B' - SUBGROUP 21) FELL INTO THE REACTOR CORE FOR UNKNOWN REASONS. CONTROL ROOM OPERATORS MANUALLY TRIPPED UNIT 2 FROM 48% POWER. ALL CONTROL RODS INSERTED INTO THE CORE COMPLETELY. STEAM IS BEING DUMPED INTO THE MAIN CONDENSER. UNIT 2 IS STABLE IN MODE 3 (HOT STANDBY).

THE LICENSEE IS CONTINUING TO INVESTIGATE THE CAUSE(S) OF THE DROPPED CONTROL RODS.

THIS EVENT HAD NO EFFECT ON UNIT 1 WHICH IS OPERATING AT 100% POWER.

THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR.

LOSS OF TWO 500- µCi STRONTIUM-90 SOURCES DUE TO A HELICOPTER CRASH IN FAYETTEVILLE, NORTH CAROLINA (24-HOUR REPORT)

A representative from Bolling Air Force Base (located in Washington D.C.) reported that a helicopter from Hurlburt Field (located in Mary Esther, Florida) crashed at 2300 on 06/02/99 while performing a night training exercise at Pope Air Force Base (located in Fayetteville, North Carolina). Each helicopter blade contained an in-flight blade inspection system (IBIS) source with 500 µCi of Strontium-90, and it is currently believed that the helicopter had four blades. Two of the four IBIS sources have been identified and recovered by the pope Air Force Base Accident Response Team. These devices have been bagged and will be checked for contamination. Pending the completion of the crash investigation, the licensee plans to search for the remaining IBIS sources with survey equipment.

This event was reported to Bolling Air Force Base at 0630 on 06/04/99.

Five individuals survived the crash, and there was one fatality.

The limit referenced in 10 CFR Part 20, Appendix C, for Strontium-90 is 0.1 µCi.

The licensee plans to notify the NRC Region 4 Office. (Call the NRC Operations Center for a licensee contact telephone number.)

***Update on 07/28/99 at 1215 ET by Major Hicks (USAF) taken by MacKinnon***

All IBIS sources from the Helicopter crash were recovered as of 29 Jun 99. R4DO (Bill Jones), R2DO (Haag) and NMSS (Scott Moore) notified.

ALTERNATE COOLING SYSTEM DECLARED INOPERABLE

"Following a question raised by an NRC Resident Inspector at VY, an Event Report was submitted due to a lack of sufficient analysis to determine if procedural guidance was adequate for operation of the Alternate Cooling System (ACS). VY declared the ACS inoperable at 2110 on 6/3/99 and entered a 7 day LCO [3.5.d.3] per the plant Technical Specifications. Based on further evaluation, Operations and Engineering Personnel concluded that current VY procedures may not provide the specific information necessary to ensure that ACS Design Bases 1 & 2 above, would have been met. Engineering and Licensing evaluations of ACS design and performance requirements continue.

"VY is currently developing procedural enhancements that will ensure that the operating crews are provided with the guidance necessary to ensure that ACS would be operated in the manner necessary to achieve its safety design bases. It is expected that the necessary procedural guidance will be developed and issued prior to the
expiration of the cited 7 day LCO."

The licensee notified the NRC Resident Inspector and the State of Vermont.

* * * RETRACTION 1635 6/29/1999 FROM BROOKS TAKEN BY STRANSKY * * *

"Subsequent to [the original notification], Engineering and Licensing have determined that the design basis criteria for the subject design basis event is that the plant must be maintained in Hot Shutdown condition with a pool temperature maintained with adequate margin to the boiling point. In addition, adequate procedural guidance existed to assure that the design objectives would have been satisfied. Thus the event was not reportable."

The licensee will inform the NRC resident inspector of this retraction. Notified R1DO (Doerflein).