Event Notification Report for February 25, 1999

24-HOUR NRC BULLETIN 91-01 REPORT

"Potentially fissile trap media was discovered in an approximately 30 gallon trash can in violation of NCSA GEN-15. NCSA GEN-15 requires that fissile/potentially fissile waste be accumulated in a maximum 5.5-gallon waste drum. The only exception is if the waste is exempted from NCS controls in accordance with requirement 2 of NCSA GEN-15. However, the trap media was not exempted prior to disposal.

"The waste was generated prior to implementation of NCSA GEN-1 5 and is therefore a legacy issue; however, NCSA GEN-15 is the currently approved NCSA for the generation and handling of potentially fissile waste.

"This event is being categorized as a 24-hour event in accordance with Safety Analysis Report Table 6.9-1 Criteria A.4.a and NRC Bulletin 91-01, Supplement 1 report.

"SAFETY SIGNIFICANCE OF EVENTS:

"This violation resulted in the loss of one leg of double contingency. Although double contingency was not maintained, there was not enough material present to result in a critical configuration.

"POTENTIAL CRITICALITY PATHWAYS INVOLVED (BRIEF SCENARIO[S] OF HOW CRITICALITY COULD OCCUR):

The trash can contained approximately 15 gallons of contaminated alumina. Based upon data from KY/S-208, Subcritical Dimensions For Water Reflected UO2F2 and Water Systems at Two Weight Percent Enrichment, at 2.0 wt % U-235, the safe volume of UO2F2 solution is 23 gallons. Additionally, KY/S-208 modeled optimal concentration UO2F2 solution in a spherical geometry reflected with 30 cm of water. The trash can contains trap material intermixed with the UO2F2, and the material is not in the optimum configuration modeled in KY/S-208, therefore, in reality it would take much more than 23 gallons to achieve a critical configuration. Based upon this information, a criticality is not possible.

"In order for a criticality to be possible much more than 23 gallons of the trap material would have to be present In the trash can.

"CONTROLLED PARAMETERS (MASS, MODERATION. GEOMETRY, CONCENTRATION, ETC.):

"Controlled parameters are geometry and spacing.

"ESTIMATED AMOUNT, ENRICHMENT, FORM OF LICENSED MATERIAL (INCLUDE PROCESS LIMIT AND % WORST CASE OF CRITICAL MASS):

"The trash can contained approximately 15 gallons of contaminated alumina at a maximum assay of 1.04 wt % U235.

"In order for a criticality to be possible, much more than 23 gallons of the trap material would have to be present in the trash can.

"The determination that the material in the drum was fissile is based on conservative sample results. Two independent smears and two independent bulk samples were taken and analyzed. One of the bulk sample results indicated an assay of .944% U-235. All of the remaining sample results were below 9%. A .1% error is conservatively applied to lab sample results as a general rule to account for uncertainties. Much lower uncertainties are routinely achieved but have not been established far these samples at this time. This Incident Report conservatively assumes the material in the drum is fissile based on the .1% error applied to the one sample result above .9% U-235.

"NUCLEAR CRITICALITY SAFETY CONTROL(S) OR CONTROL SYSTEM(S) AND DESCRIPTION OF THE FAILURES OR DEFICIENCIES:

"Loss of spacing control. Double contingency control leg was lost since geometry process condition was not maintained.

"CORRECTIVE ACTIONS TO RESTORE SAFETY SYSTEM AND WHEN EACH WAS IMPLEMENTED:

"The trap media will be disposed of in a minimum 5.5 gallon drum in accordance with plant procedure CP2-EW-WM1036.

"A minimum 6 ft. spacing is being maintained between the cold trap and the container of contaminated trap media. A minimum 2 ft. spacing will be maintained between the maximum 5.5 gallon waste drum containing the trap media and all other fissile/potentially fissile material."

The NRC resident inspector has been informed of this notification.

DISCOVERY OF EMERGENCY DIESEL GENERATOR BUILDING TEMPERATURE LESS THAN DESIGN DUE AN ONGOING SEVERE WINTER STORM (Refer to event numbers 33658 and 33938 for previous similar occurrences reported to the NRC Operations Center by Pilgrim 1.)

The design temperature for the building that houses the emergency diesel generators is 60°F. However, at 0805 on 02/25/99, it was discovered that temperature for the area that houses the 'A' emergency diesel generator was 59°F. This was due to an ongoing severe winter storm with winds out of the northeast which introduced cold air to the emergency diesel generator building. Temperature returned to 60°F at approximately 0830, but it is expected that it may decrease below the design temperature throughout the storm as long as the winds are coming out of the northeast.

The licensee stated that this problem has occurred in the past and referenced Licensee Event Report (LER) 98-004-01. Corrective actions for this LER involved changing the emergency diesel generator building design temperature to 40°F. This design change is currently being processed but has not yet been approved.

The licensee currently has an engineering evaluation in place to justify emergency diesel generator operability with building temperatures as low as 40°F. Therefore, both emergency diesel generators are considered to be operable, and the unit is not currently in a technical specification limiting condition for operation as a result of this issue.

The licensee notified the NRC resident inspector.

SOURCE DRAWER FAILURE ON AN ATC Co-60 MACHINE

THE METCALF INSTITUTE OF RADIATION AT THE HOSPITAL CENTER AT ORANGE LOCATED IN ORANGE, NJ, REPORTED AN INCIDENT WHERE A PATIENT WAS EXPOSED FOR 15 TO 20 SECONDS WHEN THE SOURCE DRAWER ON AN ATC Co-60 MACHINE FAILED. SEVERAL ATTENDING PERSONNEL ALSO WERE EXPOSED FOR 5 TO 10 SECONDS. THE SOURCE STRENGTH WAS 6,000 CURIES. NO DOSAGE CALCULATIONS HAD BEEN PERFORMED AT THE TIME OF THIS EVENT NOTIFICATION.

A SIMULATION FILM WAS BEING TAKEN IN PREPARATION FOR A TREATMENT ON THE PATIENT. THE SOURCE FAILED TO RETURN TO THE SHIELDED POSITION EVEN WHEN THE EMERGENCY STOP WAS ACTUATED. THE ROOM WAS SEALED AND LOCKED, AND THE SOURCE DRAWER WAS THEN CLOSED REMOTELY. ALL OPERATIONS WITH THIS MACHINE HAVE BEEN SUSPENDED.

THE LICENSEE NOTIFIED NRC REGION I (DR. NEELAM BHALLA) AND PLANS TO SUBMIT A WRITTEN REPORT TO THE NRC.

(CALL THE NRC OPERATIONS CENTER FOR A LICENSEE CONTACT TELEPHONE NUMBER.)

10 CFR PART 21 REPORT REGARDING FAULTY RESISTANCE TEMPERATURE DETECTORS (RTD)

The following text is a portion of a facsimile received from PYCO, Inc.:

"A deviation has been detected in that a limited number of 200 OHM DUPLEX RTD assemblies have been fabricated by PYCO using THIN-FILM RTD sensors instead of the WIRE-WOUND RTD sensors specified for the assembly. RTD assemblies fabricated using wire-wound sensors have been tested and qualified by PYCO for nuclear use under our nuclear qualification test program. RTD assemblies fabricated using thin-film sensors have not been tested by PYCO to IEEE-323 and IEEE-344 requirements."

"Externally, thin-film and wire-wound RTDs have the same physical appearance, shape, and electrical characteristics. Both the wire-wound and thin-film sensors meet the requirements of the International Industrial Standard IEC-751, 'Industrial Platinum Resistance Thermometer Sensors'."

These RTDs have been sold to Carolina Power and Light and South Carolina Electric and Gas for use at the Robinson, Brunswick, and Summer plants.

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

* * * UPDATE 1256EDT ON 7/28/00 TO S. SANDIN * * *

The following is a summary of the corrective actions completed:

"PYCO has completed all corrective action activities for NCR Event# 35406. All affected Power Utilities have completed an 'Operability Evaluation and Determination of Acceptance' for potential thin-film RTD's in-service.

"PYCO has completed an x--ray evaluation of all returned in-service or in-stock assemblies and identified those containing the incorrect thin-film sensor.

"Assemblies found to have been manufactured with the correct wire-wound sensor were inspected, calibrated and returned to the utilities. Any assemblies found to contain the incorrect thin-film sensor were scrapped, and replacement assemblies containing the correct sensor were manufactured and shipped to the utilities.

"As required by 10CFR Part 21, the following information is to provide notification of CORRECTIVE ACTION COMPLETION in connection with certain 200 OHM duplex Resistance Temperature Detectors (RTD's) supplied to Carolina Power & Light - Robinson Plant and Brunswick Plant and South Carolina Electric & Gas - V.C. Summer Station."

Notified R1DO(Shanbaky), R2DO(Cahill) and NRR(Hodge via fax).

PRESSURIZER NOZZLE LEAKAGE DISCOVERED DURING REFUELING OUTAGE

During a visual inspection, evidence of reactor coolant system leakage was found on two inconel instrument nozzles located on the top head of the pressurizer. The leakage was in the annulus area where the nozzle penetrates the pressurizer head. The nozzles are welded on the inner diameter of the pressurizer and are joined to instrument valves RC-310 and RC-311.

The NRC resident inspector has been informed of this notification by the licensee.

* * * UPDATE AT 2251 ON 02/27/99 FROM DAVID LITOLFF TAKEN BY STRANSKY * * *

"On 02/25/99 a 4-hour report to the NRC was made per 10CFR50 72(b)(2)(i) for evidence of Reactor Coolant System Leakage on two pressurizer instrument nozzles. The purpose of this report is to update the 02/25/99 report for additional Reactor Coolant System instrument nozzles which have been identified as having evidence of RCS leakage. On 02/27/99, evidence of boric acid leakage was found on one Hot Leg 1 Inconel Alloy 600 instrument nozzle. Potential leakage was also found for one steam generator instrument nozzle and the pressurizer side shell nozzle. Any further evidence of leakage found in subsequent inspections will be included in the 30-day Licensee Event Report."

The NRC resident inspector will be informed of this report by the licensee. The NRC Operations Officer notified the R4DO (Chuck Cain).