ML20036C178
| ML20036C178 | |
| Person / Time | |
|---|---|
| Issue date: | 11/12/1991 |
| From: | Glenn J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Cline W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML20036C177 | List: |
| References | |
| HPPOS-280, HPPOS-302, NUDOCS 9306150138 | |
| Download: ML20036C178 (5) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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WASHINGTON. D.C. 20555
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i w MEMORANDUM FOR:
William E. Cline, Chief Nuclear Material Safety and Safeguards Branch, RII FROM:
John E. Glenn, Chief Medical, Academic, and Commercial Use Safety Branch Division of Industrial and Medical Nuclear Safety, NMSS
SUBJECT:
TECHNICAL ASSISTANCE REQUEST DATED JULY 17, 1991 CLARIFICATION 0F 10 CFR 35.50(b)(1)
This memorandum responds to your request dated July 17, 1991, for clarification 1
of the performance of dose calibrator constancy checks as described in 10 CFR 35.50(b)(1).
Specifically, "is it appropriate for a licensee to perform this test on the cobalt-57 setting although technetium-99m is the most frequently used isotope?" Based on the information submitted, the following guidance is given.
Although this issue is not addressed in the Statements of Consideration for either the proposed or final rule on 10 CFR Part 35, effective April 1, 1987, we believe that the rule is intended to assure that the licensee determine the constancy of the dose calibrator, on each day of use, under the actual conditions of use.
Since most medical licensees use techetium-99m for patient dosage administrations more frequently than any other isotope, such licensees must check the technetium-99m setting, on each day of use, with a dedicated check source.
If the licensee frequently uses the technetium-99m setting to measure patient dosages but only performs a constancy check on the cobalt-57 setting, it appears appropriate to cite against 10 CFR 35.50(b)(1) unless the licensee can demonstrate that the cobalt-57 setting is frequently used to measure patient dosages.
It is recommended that cobalt-57 be used as a standard to measure the constancy of the technetium-99m setting because of the close proximities of the energies.
Cobalt-57 has principal energies of 122 and 136 kev and technetium-99m has a principal energy of 140 kev.
We also recommend that dose calibrators having pre-calibrated settings or potentiometers be tested on both the cobalt-57 and technetium-99m settings because discrepancies or fluctuations have been observed between the two settings when tested for constancy with the same check source.
If such discrepancies are observed, it could indicate that there is a problem with one or both of the settings.
9306150138 911112 PDR ORG NRRB
William E. Cline N'A 2 1891 Inspectors should encourage licensees to perform a daily constancy check on all commonly used isotope settings, not only technetium.99m, to assure the accuracy of all acministerea patient dosages.
This issue will te clarified in the next revision to Regulatory Guide 10.8.
Additional information regarding this issue may be directed to Janet Schlueter, of this staff cn FTS:
492-0633.
- -- - A s)e d By f John E. Glenn, Chief Medical, Academic, and Commercial Use Safety Branch Division of Industrial and Medical Nuclear Safety, NMSS DISTRIBUTION %
Region NRC File Center TAR r/f JEGlenn RECunningham JGreeves IMNS Central File PCVacca RRBellarry, RI WECline, RII JGrobe, RIII RJPate, RV MShanbacky, RI JKinneman, RI PSwetland, RI CHosey, RII GMMcCann, RIII BPrange, RV SLBaggett, IMAB MLamastra RFonner, OGC EMcAlpine, RII L. J. Callan, RIV VLMiller, GPA/SP WFisher, RIV JRicci, AEOD/TTC CCain, RIV LWCarrper, IMAB INAB r/f '
JPiccone, IMAB LFranklin, RII JJohansen, RI NMSS r/f STreby fc)(dd4rh 4 s,a s yamoa cc,Mtsupy t 0FC :IMAS
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s William E. Cline Inspectors should encourage licensees to perform a daily constancy check on all commonly used isotope settings, which would include technetium-99m, in most cases.
If the licensee adequately performs a constancy check on the cobalt-57 setting, it appears appropriate to cite against 35.50(b)(1) unless the licensee can demonstrate that the to alt-57 setting is frequently used to measure patient dosages. This issue wil be clarified in the next revision to Regulatory Guide 10.8.
Additional information rega ding this issue may be directed to Janet Schlueter, of this staff on TS:
492-0633.
John E. Glenn, Chief Medical, Academic, and Commercial Use Safety Branch Division of Industrial and Medical Nuclear Safety, NMSS DISTRIBUTION Region NRC File Cente TAR r/f JEGlenn RECunningham JGreeves IMNS Central File PCVacca RRBellamy, RI WECline, RII JGrobe, RIII RJPate, RV MShanbacky, RI JKinneman, RI PSwetland, RI CHosey, RII GMMcCann, RIII BPrange, RV SLBaggett, IMAB MLamastra RFonner, 0GC EMcAlpine, RII L. J. Callan, RIV VLMiller, GPA/SP WFisher, RIV JRicci, AE0D/TTC CCain, RIV LWCamper, IMAB IMAB r/f JPiccone, IMAB LFranklin, RII JJohansen, RI NMSS r/f STreby n
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DATE :09 f(;/91
- 09/lb/91
- 09/ /91
- 09/
/91 OFFICIAL RECORD COPY TAR 35.50 s
Licensee:
9se NO. m i
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.DATEf July 9, 1991 TO:
John E. Glenn S
, Chief,
_demic and Comercial i Use Safety Branch, IMS ^
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, Chief, Nuclear Materials Safety Section FROM$
WilliamE.Clineh iL, m,,
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i DRSS, Region II
SUBJECT:
REQUEST FOR TECHNICAL ASSISTANCE Control No.
(enclosed) letter dated (enclosed)
Suggested change in licensing procedure (enclosed)
X Other (See remarks)
Requested Action:
Custom source / device review X
Review and comment X
Provide policy guidance Other (See remarks)
Remarks:
(SEE ENCLOSED REMARKS) i To Be Completed by NMSS DATE:
The above request has been received by IMAS/IMNS and assigned to (name) l Please contact this individual for a status report if (phone number) j response is not received by (date) i
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Signature:
IMAB/IMS Branch Chief Revised January 25, 1989
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ENCLOSUPE TECHNICAL ASSISTANCE REQUEST DATED JULY 9, 1991 (REGION II)
REMARKS:
Medical licensees are required to perform a dose calibrator daily constancy check.
10 CFR 3 5. 50 (b) (1) requires, in part, that a licensee check each dose calibrator for constancy with a dedicated check source at the beginning of each day of use, and that the test be done on a frequently used setting.
Based on numerous nuclear medicine inspections in Region II, the most frequently used setting is technetium-99m.
Based on the requirements of 10 CFR 3 5. 51 (b) (1),
licensees who use technetium-99m more frequently should perform this test on the technetium-99m setting with a dedicated sealed source (which is usually cobalt-57).
- However, some licensees perform this test on the cobalt-57 setting and not on the technetium-99m setting.
Please clarify if it is appropriate for a licensee to perform this test on the cobalt-57 setting although technetium-99m is the most frequently used setting.
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