IR 05000362/1987013

Insp Rept 50-362/87-13 on 870508-14.No Items of Noncompliance Noted.Major Areas Inspected:Evaluation of Licensee 870507 Revised Rept of Exposure to Hand of Worker Apparently in Excess of Regulatory Limit

ML20214X246
Person / Time
Site:	San Onofre
Issue date:	05/28/1987
From:	Russell J, Yuhas G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
Shared Package
ML20214X221	List: IR 05000362/1987013 ML20214X218
References
50-362-87-13, NUDOCS 8706160393
Download: ML20214X246 (5)

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.U.S. NUCLEAR REGULATORY COMMISSION

REGION V

Report No.: 50-362/87-13 Docket No.: 50-362 License No.: NPF-15 Licensee: Southern California Edison Company 2244 Walnut Grove Avenue Rosemead, California 91770 Facility Name: San Onofre Nuclear Generating Station - Unit 3 Inspection at: San Onofre Nuclear Generating Station Inspection Conducted: May 8-14, 1 Inspector: i c .rf-X 7 J. Sussell, Radiation $pecialist Date Signed Approved By: kle G. P.(YDhts, Chief E/2R/T7 Ddte Signed Facilft g Radiological Protection Section Summary:

Inspection on May 8-14, 1987 (Report No. 50-362/87-13)

Areas Inspected: This was a special, in-office inspection'to evaluate.the licensee's May 7, 1987, revised report of an exposure to the hand of a worker apparently in excess of the regulatory limi The inspection included a presentation of the revision highlights by licensee representatives at the NRC regional office, in-office review, and independent technical evaluation by a NRC consultan Inspection procedures 30703 and 90712 were addresse Results: No items of noncompliance were identified in the areas examine PDR ADOCK 05000362 G PDR

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DETAILS 1. Persons Contacted Licensee Personnel P. Knapp, Health Physics (HP) Manager R. Waldo, Computer Engineering E. Medling, Nuclear Engineering Safety and Licensing Licensee Contractors J. A. Auxier, International Technology Corporation P. F. Braunlich, International Sensor Technology, In NRC Contractor F. Attix, Consulting Physicist, Department of Medical Physics, University .

of Wisconsin NRC Representatives J. B. Martin, Regional Administrator R. A. Scarano, Director, Division of Radiation Safety and Safeguards F. A. Wenslawski, Chief, Emergency Preparedness and Radiological Protection Branch G. P. Yuhas, Chief, Facililties Radiological Protection Section S. Block, Health Physicist J. Russell, Radiation Specialist All the above individuals were present at the meeting on May 11, 198 . Background Previously developed information on the potential-512 rem exposure, including the licensee's initial investigation and NRC inspections and evaluations relative to the event, is contained in Inspection Report No. 50-362/86-3 As a result of this report and of the management meeting held at the Region V offices on April 10, 1987; the licensee committed to revise their evaluation of the potential overexposure in -

order to accommodate comments noted in the NRC report and to incorporate new information which was then being developed by the licensee. The revised report, Evaluation of the Reported High' Exposure to Extremity TLD No. 80365 in October 1986 Revision 1, was received at the NRC Region V office on May 8, 1987, and a NRC licensee technical meeting was subsequently held on May 11, 1987, at which licensee management representatives and consultant experts presented the highlights of the revised report and the licensee's concluding position. The licensee's concluding position was:

"It has not been possible to determine whether or not an extremity exposure in the amount reported occurred. SCE believes, based on all the data developed in our investigation, that the exposure probably did not occu i ~ -

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'lNotwithstanding SCE's belief.that such an exposure probably did not

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occur, tan evaluation of the dose equivalent. associated ~with such an ~

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. exposure has been performed.' It has been concluded.that the-best

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estimate of the dose.equiv'alent_in_this instance,is 5.6 res." ,

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y _ Licensee Reevaluation-

The' highlights of-the licensee's reevaluation.are described hereafte The licensee

revised their conclusions relative to the medical i examinations and stated, " Medical evidence to_ support or refute an .

excessive extremity exposure was inconclusive because.the anticipated

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effects would be minor or un-observable if a small area.of a finger received about'500 to 600 rad,' and because the best time to observe such an effect was missed."

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The1 licensee provided extensive new information on the production of~

false'thermoluminescent dosimeter (TLD)' readings by contamination of TLD chips:with particles of fibrous material, such as those'found on the cardboard ring' storage tubes used by the licensee's dosimetry vendo '

-This included a report by?a licensee contractor involving experiments

. conducted on the contractor's laser TLD reader. The. licensee and their

' contractor demonstrated that very high false thermoluminescent (TL)

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outputs can be produced by fibrous contaminants on TLD chips by the contractor's system. When the licensee's experiments were performed-'on

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their' vendor's system the maximum TL output on the first read was equivalent' to approximately 14 rem. . The licensee was able to' produce ari output equivalent to approximately 256 rem on the vendor's system on a third reread, with no annealing, of one contaminated chip. In all tests by the licensee-on.the vendor's equipment, the contaminant, according to-the licensee representative, was glued to the' chi The licensee provided calculations and their interpretation of their dosimetry vendor's quality control procedures and concluded that it

= was unlikely that the vendor's system could have been under-heating

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chips;on the. day in questio The licensee provided a revised fuel fragment cen' sus which included

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fragments found in the fuel handling buildin The licensee also revised their. position from the contention that radiation and contamination surveys would have detected such'a highly radioactive particle to recognize that the surveys were not extensive enough'to provide full assurance such a particle was not presen .

The licensee provided a reassessment of the " dose equivalent" which they' feel should be assigned to the worker based on their interpretation of Publication 26 of the-International Commission on Radiological Protection (ICRP) and supported by their expert consultant. The figure which they state:should be entered on the worker's record is 5.6 rem, which the licensee determined by averaging the dose over 100 square centimeters and adding in an estimate of the gamma componen '

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' NRC Evaluation L

'The NRC staff noted that the information on fibrous contamination of TLD chips, while demonstrating that false TL outputs can be obtained, failed to show that an output similar in magnitude'to the 512 rem seen on the first read of the chip in question could be produced on the vendor's TLD system during an initial read. Additionally, even these outputs required quantities of_ contaminant on the chips'which a technician migh reasonably have been expected to notic The NRC staff's understanding of the vendor's quality control program did not ceircide wi..i that of the licensee. The staff's understanding of the vendor's program indicates that the vendor's system could have easily missed a 10% variation in output as a result of under-heating on the day of the even The NRC consulting physicist made another visit to the facility of the licensee's dosimetry vendor on May 8,1987. The consulting physicist found no basis for changing his conclusion that the TLD reading was most probably due to radiation exposur The NRC staff noted that the requirements of 10 CFR 20 and NRC policy require that the dose at 7 mg/cm2 to the most highly exposed area

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averaged over 1 cm2 be entered on the worker's recor The licensee's presentation regarding " dose equivalent" was presented to the NRC Office of Nuclear Reactor Regulation for revie . Exit Meeting The Director, Division of Radiation Safety and Safeguards, stated that, now that SCE seemed to agree the TLD reading could not be discredited and that circumstances existed which would make the overexposure possible, appropriate attention should be brought to bear on the identified deficiencies in the radiation protection progra Specifically: The licensee's program must be able to promptly identify potential high exposures so that appropriate actions can be initiate The program must be able to control radioactive materials sufficiently to prevent their release from the sit The program must be able to control occupational exposure of personnel and identify work place hazard Health Physics Technician training must provide sufficient information to enable the technicians to deal with the unique problems presented by irradiated fuel fragments and require their dedication to scrupulous adherence to established procedure The Director asked the SCE representatives if there was any disagreement with these programmatic necessities. The Health Physics Manager responded in the negativ . _ > .m -.

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I The NRC Region.V Administrator met with the licensee' representatives

> -denoted in Paragraph 1 at the conclusion of the May 11, 1987, meetin The Regional Administrator stated that there appeared to.be no great chazard relative to the health of the worker in this instance but '

emphasized the concern that such problems must be promptly identified in

. order that appropriate action can be taken and that the licensee's program must effectively control radioactive materials in general and frradiated fuel fragments specifically in order to prevent possible future hazards to both their staff and the public.

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