ML20010F526
| ML20010F526 | |
| Person / Time | |
|---|---|
| Issue date: | 08/24/1981 |
| From: | Book H, Riedlinger B, Thomas R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML20010F518 | List: |
| References | |
| NUDOCS 8109100318 | |
| Download: ML20010F526 (5) | |
Text
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U.S. iiUCLEAR REGULATORY C0"filSS!0fl
- .FICE OF Ii!SPECTIO:1 AtlD E!!FORCEMErlT REGION V Reper: "o.81-01 License Mo53-03694-01.Oriority 7
Category G2 Licensee: W. T. Minatoya, M. D.
1003 Pensacola Street Honolulu, Hawaii 96814 Facility :ame:
Inspection at:1003 Pensacola Street, Honolulu, Hawaii Inspection Concuctea: July 22, 1981 Inspectors: 8t7,N//Si/ht)
Th//T/
B. A. Riedlingeg Radiation Special1st Dat'e signea Approved by:
/
R. D. Thomas, Chief, Materials Radiological C/te Si fned f
P ction Se ion.
2/h CrtM Approved by:
H. E. Bdok, Chief Date Signed Fuel Facility and Materials Safety Branch This special inspection was conducted as a follow-up on information first received by Region V on June 15, 1981 in a letter from Dr. W. T. Minatoya.
Dr. W. T. Minatoya reported that a badge had received an exposure of 26R for the April 15 - May 14,1981 badge period. He stated that the badge was inadvertently left next to the case containing the strontium-90 beta applicator for three days.
Since the film badge report for the 4/15/81 - 5/14/81 badging period indicated that the 26R exposure was a beta exposure received with tha badge in a i
fixed position, it was concluded that the badge reading % not represent l
an exposure to an individual.
l l
RV From 219 (1) 8109130318 810824 NMC, LfC30 1
53-03694-01 PDR
J t
4 DETAILS Persons Contacted 4
Dr. W. T. Minatoya, Authorized User Dr. H. K. Minatoya, Employee Mr. E. Kuramoto... Hawaii State Department of Health Mr. G. Yamane, Hawaii. State Department of Health
Background
i i
I On June 15, 1981 Region. V received a letter (dated June 12,1981) from W. T. Minatoya, M.D., stating that a film badge of one of his employees rec.eived a reported exposure of 26R for the period of April 15 - May 14, 4
1981. The letter further stated that the badge had been inadvertently left next to the case containing the strontium-90 app 11cator for three days, and there had been no overexposure to personnel.
Inspection i
A.
Genera,l_
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A special follow-up inspection was conducted on July 22, 1981 of records relating to the reported exposure of 26R and of activities conducted under NRC License 53-03694-01 since the last inspection on February 27, 1964, t
B.
Examination of Film Badge Reports Film badges are issued by Radiation Detection Company.
Dr. W. T. Minatoya j
stated that film badges were not used prior to June 15, 1980. This fact was substantiated by a review of the records. In a letter dated August l
30, 1977, which is referenced in License Condition 15., Dr. W. T. Minatoya stated that, " Film badges are worn for determination of exposure to extremities of user." The failure teewear film badges was identified as an item of noncompliance.
The film badge report for the period April 15, 1981 to May 14, 1981 l
indicated the following:
26000 beta millirem l
Individual A O millirem Individual B Radiation Detection Company added a note stating that the reported overexposure was due to beta radiation and that the badgc was in a fixed location during the exposure. This indicates that the exposure was to the badge and not to an individual.
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. Dr. W. T. Minatoya keeps both film badges in his desk drawer and takes one out and puts it on when he is going to use the eye applicator.
He said that it was too difficult to look and see which badge he was wearing. The inspector informed Dr. Minatoya that this defeats the purpose of the film badge.
The film badge report for the period ending July 14, 1981 showed the following year-to-date totals:
non-penetrating penetrating Individual A 26170 millirem 0 millirem Individual B 360 millirem 30 millirem C.
Identification of Radiation Source The radiation source currently possessed by the licensee is an NEN Beta Therapy Sourco, Model NB-1. Serial Number 0325. The radiation source had an activity of 102 m1111 curies in November 1979, with a surface dose rate of 65.2 rads /second.
D.
Evaluation of Dose-Rates Near Storage Boxes The beta eye applicator is stored inside two wooden boxes which are maintained on the floor of the treatment room. The area is posted,
" Caution, Radioactive Material," and a Form NRC-3 is posted with a notice describing the location of the regulations and operating and emergency procedures.
The licensee does not have a survey instrument.
A survey of the beta eye applicator storage boxes was conducted by the inspector with NRC instrument 009163, a Keithley Model 36100 X-Ray /
Gamma Radiation Survey Meter with a recalibration due date of September 1, 1981. The maximum dose-rate on the surface of the inner box was 29 millirem per hour. The maximum dose rate on the top of the outside box was 2 millirem per hour with an average of 1.2 to 1.3 millirem per hour.
According to Dr. W. T. Minatoya's June 12, 1981 letter, the badge in question was left on the eye-applicator box (the outer box) for three days.
Since the maximum dose rate on the outer box was 2 millirem per hour, the resulting dose would have been (2%)(h)(3da)=144mr.
,, Dr. W. T. Minatoya stated that he did not drop his film badge in the box with the eye applicator and that there were no unusual circumstances involved in the patient treatment on May 12, 1981.
Dr. W. T. Minatoya said that be thought that the film badge supplier made some kind of mistake.
E.
Demonstration of Source Use, Dr. W. T. Minatoya demonstrated the way he treats a patient and then cleans the eye applicator prior to storage. The maximum dose rate to Dr. Minatoya's whole-body film badge (clipped onto his laboratory coat) during this procedure was about 500 millirem per hour. This dose rate occurred during source cleaning, and the exposure time lasted only a few seconds.
It should be noted that Dr. Minatoya was moving with respect to the source during this time and that bremsstrahlung exposure would have been the major dose contribution.
F.
Discussion of Patient Treatments The inspector asked abwt the number of patients treated during the calendar quarter involving the overexposure. The followin9 infonnation was provided: April 1981 - no patients treated; May 12,19 and 27, 1981 - one patient treated each day; June 16, 1981 - one patient treated; and July 8,1981 - one patient treated. Dr. W. T. Minatoya treated all of these patients. Dr. H. K. Minatoya stated that his father has always conducted the activities with the eye applicator. He stated that he may have observed his father treat a patient or two.
Dr.
W. T. Minatoya stated that he thought h's son had treated one patient in 1980.
Dr. W. T. Minatoya stated that he has ancther son who will be entering the practice soon. The inspec+or cociner.ted that a license amendment should be submitted, as Dr. W. T. Minatoya is currently the only authorized user (see License Condition 12.).
G.
Source Receipt and Transfer Records Dr. Minatoya disposed of an eye applicator and purchased a new one since the last inspection on February 27, 1964. He could not locate disposal rtcords during the inspection, but he forwarded them to Region V with a letter dated July 24, 1981.
Nuclear Sources and Services, Inc., Houston, Texas, disposed of a strontium-90 eye applicator on January 15, 1980.
He procured the new source between August and December of 1979.
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4 H.
Discussion of Previous Items of Noncompliance There were three Iten.s of noncompliance during the last inspection which was conducted on February 27, 1964:
- 1) Dr. Minatoya collected leak tests, but he was not authorized to do so, 2) No leak tests were performed between June of 1961 and May of 1963, 3) The eye app 11cator box was not labeled, " Caution, Radioactive Material."
During this inspection, it was found that Dr. W. T. Minatoya collects leak tests which are analyzed by LFE.
In a telephone conversation on August 5,1981. Joe Delmedico. Licensing, stated that this procedure was in compliance with License Condition 13D., which states that, " Tests for leakage and/or contamination shall be performed by persons specifically authorized by the Comission or an Agreement State to perform such services." This item is considered closed.
Since the last inspection, leak tests have not been conducted at six month intervals. The licensee was cited because leak tests were not conducted during the following periods: July 1966 to February 3, 1967; August 1968 to February 20, 1969; March 1970 to January 1972; February 1973 to January 1974; July 1974 to February 26, 1975; and August 1975 to April 1977. The last leak test was conducted on March 12, 1981.
This is a repetitive item and is considered as being an open item for future inspections.
The eye applicator box is properly labeled with " Caution, Radioactive Material" and a complete description of the source. This item is considered closed.
I.
Results of the Inspection Since the film badge report for the April 15, 1981 - May 14, 1981 badging period indicated that the 26R exposure to one badge was due to beta exposure with the badge in a fixed position, it was concluded that the badge reading does not represent an exposure to an individual.
An individual's exposure would have had a bremsstrahlung component and would have indicated movement during exposure.
It is the inspector's opinion that the film badge was probably temporarily misplaced near the strontium-90 source.
If Dr. Minatoya had dropped his badge in the storage box, attempted to store the applicator, and then discovered the film badge, the 26R exposure would not be difficult to explain. Dr. Minatoya, however, stated that he "could not have i
done anything so stupid."
As a result of the inspection two items of noncompliance were identified.
One item was repetitive in nature and involved failure to conduct leak tests at six month intervals (see Report Section H). The second item identified was that film badges were not being worn as required by the license application (see Report Section B.).
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