Medical Isotopes Studies

Judah Friese, Rosi Payne

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The views expressed here do not necessarily reflect the views of the United States Government, the United States Department of Energy, or Pacific Northwest National Laboratory.

Medical Isotope ProductionMo-99 fission production process emits 109-1013 Bq of Xenon-133 and other isotopes per batch

About as much or more emitted from an underground nuclear explosionXe ratios from medical isotope production can look similar to that of a weapon due to the production processWhile this can be discriminated via isotope ratios, it is better to not have the signal

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Date /Time

7:39 8:40 9:40 10:41 11:41 12:42 13:42 14:43 15:43 16:44 17:44 18:45 19:46 20:46 21:47 22:47 23:48 0:48 1:49 2:50 3:50 4:51 5:51

TimeXe 133 (5.3d) Kr 85m(4.5h) Kr 88(2.8h) Xe 135(9.2h) Kr 87(76m) Xe 135m(15m)

Global Production of Mo99/Tc99m

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Primary production mode is through fission of uranium

Current Producers Future Producers

Medical Isotope Production Xe Background

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The CTBT International Monitoring System (IMS) detects emissionsSituation will worsen; red areas are where current isotope production has the greatest effect on measurable backgroundsCalculations are incomplete and will change as production expands

Red locations arefrom the “Big Four”

Achim , Gross, Le Petit, Taffary, CEA, DAM, DIF, F-91297 Arpajon, France

From Noble Gas Monitoring and IMS Radionuclide Laboratories, November 1-5, 2010, Buenos Aires, Argentina

Medical Isotope Production Particulate Background?

Nuclide Level 4 CountNa-24 1760Co-60 634Cs-137 518I-131 205

Tc-99m 169Sb-122 87Zn-69m 65

Y-91 59Zn-65 54I-133 38Y-88 35

Mn-54 29K-42 27

Co-58 24Pd-112 22Ru-103 22

Nuclide Level 5 CountCs-137 27Co-60 19Na-24 13I-131 11

Tc-99m 11Sb-120 3

Y-91 3I-133 3

Ru-103 2Sb-122 2Rb-86 1Zr-95 1

Ru-106 1Mn-54 1

Pm-151 1Eu-152 1

• Nuclides Causing the Most Level 4 and 5 Event Classifications

• Event data for radionuclide stations (particulate, IMS)

• Date range: Jan. 1, 2005 through March 9, 2010

• Top three detects are cosmogenic/fallout

• Not of concern

• 131I and 99mTc

• relevant to medical isotope production

MI Production PathwayEnvironmental Issues

Chemical separation produces:Waste productsGaseous productsMo/Tc product

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Chemistry Method Influences Emissions

Dissolution chemistriesAcidic chemistry

Volatizes iodine. Relies on engineered barriers to stop Iodine, acts as a Xe source

Alkaline chemistryEasier to capture iodine because it stays in solutionCurrent ‘method of choice’ for new producers

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A Producer Prospective

Most producers are commercial entities, which means they are in the production business for profit

All producers are currently meeting their particular countries health and safety regulations

Don’t want more restrictive regulations

Producers may not be interested in improved monitoringBetter monitoring will detect emissions

Detected emissions are required to be reported

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Concerns for Moly Producers

Monitoring data accessibility

Proprietary information involvedAmount of product producedWhen product is producedRegulatory limits

Changing a process costs time and $$Any process change to reduce emissions may add significant cost

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Motivations for Moly Producers

Desire to be good environmental stewards

Desire good public relationsThis is especially important during off normal eventsWant to be viewed as being proactive on limiting emissions

Desire to be world leaders in moly production

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Possible Path forward from a Producers View

Technology developed and deployed at each production site

Stack monitoring that measures the isotopes of interestNear real timeInvolves upgrading many facility systems

Data is available upon request from CTBTO for understanding IMS detections

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Summary

Medical isotopes can provide a challenging signal to discriminate from Treaty-relevant signalsThe scientific possibility is there to eliminate this problem.

Organize communityReduceMonitorAdd tracers

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“Workshop on Signatures of Medical and Industrial Isotope Production”

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• Radionuclide monitoring technologies relevant to medical and industrial isotope production

• Measurement of medical and industrial isotopes related background; background inventories for particulate and gaseous effluents

• Correlation of gaseous and particulate releases with specific isotope production processes

• Plans, ideas, and concepts for reducing emissions of medical and industrial isotopes

• Plans for the future in medical isotope production

June 13-17, 2011