PNO-IV-99-029, on 990625,female Licensee Employee Was Discovered Contaminated in Facial Area.Licensee Convened Incident Investigation Team to Assess Event.Worker Received Total Effective Dose Equivalent of Approx 7 Mrem

PNO-IV-99-029:on 990625,female Licensee Employee Was Discovered Contaminated in Facial Area.Licensee Convened Incident Investigation Team to Assess Event.Worker Received Total Effective Dose Equivalent of Approx 7 Mrem

ML20196G686
Person / Time
Site:	Wolf Creek
Issue date:	06/28/1999
From:	Brockman K, Graves D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-99-029, PNO-IV-99-29, NUDOCS 9907010245
Download: ML20196G686 (2)

V e~ Jun3 28,1999 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE

.PNO-ly-99-029 e .

This preliminary notification constitutes ~EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by Region IV staff in Arlington, Texas on this date.

Facility - Licensee Emeroency Classification Wolf Creek Nuclear Oper. Corp. Notification of Unusual Event Wolf Creek 1 Alert Burlington, Kansas Site Area Emergency Dockets: 50-482 General Emergency e X Not Applicable

Subject:

WOLF CREEK GENERATING STATION PERSONNEL DOSE MISCALCULATION On June 25,1999, while decontaminating equipment within the Boron Thermal Regeneration System (BTRS), a female licensee employee was discovered to have become contaminated in the faciai area. After completing personal decontamination actions, the worker was given a whole body count, as is required by plant procedures. Using the results of the whole body count, the licensee calculated that the worker had received a Committed Effective Dose Equivalent of 14.5 REM; the exposure was attributed to Co-58. The limit for Total Effective Dose Equivalent, which is the sum of the Committed Effective Dose Equivalent and the Deep Dose Equivalent exposures, is 5 REM / year. The licensee notified  ;

the NRC as required by 10 CFR 20.2202. The licensee also notified the state of Kansas '

and issued a press release. The licensee convened an incident Investigation Team to assess the event.

The licensee' included a verification of the results of the dose calculation as part of the incident investigation Team's assessment. This was due, in part, to the fact that the licensee's portal monitors, which are calibrated to detect intemal contamination of this type,

~ did not alarm; additionally, the job planning for this activity did not identify or account for the

' levels of activity that would be necessary for this degree of exposure. After further review, the licensee determined that incorrect data from the whole body count results had been used to perform the dose calculations; specifically, the licensee selected the wrong value from the whole body count results for input to the dose calculation. The licensee reperformed the calculations and determined that the worker received less than 5 MREM Committed Effective Dose Equivalent. The worker received a Total Effective Dose Equivalent of approximately 7 MREM.

The licensee also submitted the whole body count results to the Oak Ridge National Laboratory for confirmatory calculations. The independent calculation results agreed with

. the licensee's revised dose estimates. The licensee also discussed the calculation input with s health physics specialists at another reactor site. They concurred with the licensee's selection of input data for the revised dose calculation. The licensee's incident Investigation Team will continue to review the contamination event and dose miscalculation issue.

The licensee contacted the NRC and state of Kansas to retract the notification. The licensee also issued a followup press release.

(

9907010245 990629 PDR 18 E \

PNO-IV-99-029 PDR Ch<Q2 L

. . - , ,v PNO-IV-99-029 fteg. log IV received the initial notification of the occurrence by telephone from the Wolf

, Creek Plant Manager at approximately 5 p.m. (CDT) on June 25,1999. Region IV received i the retraction notification at 4:40 p.m. (CDT) on June 27,1999. Region IV has informed the

[ Offices of the Executive Director for Operations, Nuclear Reactor Regulation, and Public Affairs.

This'information has been discussed with the licensee and is current as of 3:45 p.m. CDT, June 27,1999.

Contact:

Ken BrockmanDavid Graves (817)860-8248(817)860-8141 1