ML19269C194
| ML19269C194 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 12/11/1978 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML19269C191 | List: |
| References | |
| NUDOCS 7901290304 | |
| Download: ML19269C194 (2) | |
Text
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SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 s street, Box 15830, Sacramento, California 95813; (916) 452-321 December 13, 1978 A.
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R. H. Engelken, Director 0 g Division of Inspection & Enforcement, Region V y
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l'. S. Nuclear Regulatory Commission Walnut Creek Plaza, Suite 202 1990 North California Boulevard Walnut Creek, California 94596 Re:
November 21, 1978, Letter of R. H.
Engelken to J. J. Mattimoe NRC Inspection 78-19 Sir:
A Notice of Violation, Docket No. 50-312, has been received by the District as a result of an audit performed by Region V on October 26, 27 and 30, 1978.
Three items are listed as infractions, all related to a District-reported technical overexposure incident on October 23, 1978.
Item A indicates that an individual received an exposure to the head, unper trunk and lens of the eye of 3.45 Rem during removal of a prefilter in the Miscellaneous Liquid Waste System.
The District Joes not disagree with this statement, but would point out that the lens of the eye is the critical organ in this incident, and that the " head and trunk," as a different category of critical organs per 10 CFR 20.101, vould not be expected to have received as much exposure.
Dasimetry was used at the forehead in recognition that the eye lens would be the critical organ.
Item B states that contrary to Technical Specification 6.13.la, the welder working in the cubicle, a high radiation area, was not provided with a radiation monitoring device which would continuously indicate the radiation dose rate in the work area.
It has been an industry standard for many years for health physics personnel to control exposures by making surveys of radiation fields in proposed work areas and use estimat s of the allowablt times in zones to control worker exposure; this practice is frequently the od y acceptable technique for control-ling exposure, especially in high radiation areas, as in this instance. Knowing that the lens of the eye was the critical organ, and having made,;ood curveys of the anticipated zones of occupancy, the HP controller proceeded with his responsi-bility of exposure control by taping dosimeters to the forehea1 of the welder and providing stopwatch control on the period of work.
The Technical Specification states that access control to a high radiation area must assure that a worker or workers be provided witt. a continuous-indicating dose rate instrument.
Two such continuous-indicating survey instruments were in the custody of the HP controller at the job location, but or:e was not in the work area during the welder's operation.
The District will commit to additional training and discussion of this citation and the necessity of having instrumentation in the radiation field during any high radiation work.
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Mr. R. II. 'Engelken Page 2 December 11, 1978 Item C indicates that a survey was not made as necessary to prevent the technical overexposure.
This must be an unavoidable po'sition when almost any part of 10 CFR 20 requirements are not met, i.e.,
survey information was
" inadequate." In fact, several complete surveys were made prior to initiation of work, and initial portions of the job were completed with workers receiving exposures very close to the predicted levels.
Unanticipated changes in physical position of components resulted in the welder positioning his head much closer to the work than planned; in this regard, an adequate resurvey was not perforned.
In order to prevent changing conditions during work causing unplanned exposures, the District will commit to an evaluation of various kinds of equipment and practices that will aid the detection and control of such changing conditions.
This evaluation will include integrating alarn exposure devices, audio communica-tion devices and visual communicative techniques, among others.
Sincerely, h < LYN ct J.f J. Mattimoe Assistant General Manager and Chief Engineer JJM: RJR: RIM:j im