ML17222A315

Forwards Responses to NRC 880316 Questions 471.5,471.6, 471.7,471.9,471.11 & 471.12 Re Util 10CFR20,App a Exemption Request for Worker Respiratory Protection Apparatus

ML17222A315
Person / Time
Site:	Saint Lucie
Issue date:	06/23/1988
From:	Conway W FLORIDA POWER & LIGHT CO.
To:	Stello V NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
References
L-88-280, TAC-67138, TAC-67139, NUDOCS 8807010691
Download: ML17222A315 (26)

Text

ACCELERATED DISOIBUTION DEMONSTRCi'ION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR-8807010691 DOC.DATE: 88/06/23 NOTARIZED: NO DOCKET FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335

. 50-389 St. Lucie Plant, Unit 2, Florida Power & Light Co. 05000389 AUTH. NAME AUTHOR AFFILIATION CONWAY,W.F. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION STELLO,V. Ofc of the Executive Director for Operations

SUBJECT:

Responds to Questions 471.5 471.12 re App A exemption request for worker respiratory protection apparatus.

DISTRIBUTION CODE: AOOID TITLE: OR COPIES RECEIVED:LTR (

Submittal: General Distribution ENCL J SIZE: ( g NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 0 PD2-2 PD 5 5 TOURIGNY,E 1 1 INTERNAL: ACRS 6 6 ARM/DAF/LFMB 1 0 NRR/DEST/ADS 7E 1 1 NRR/DEST/CEB 8H 1 1 NRR/DEST/ESB 8D NRR/DEST/RSB 8E NRR/PMAS/ILRB12 OGC 15-B-18 RES/DE/EIB l,l 1

1 1,1 1

1 1

0 NRR/DEST/MTB 9H

-NRR/DOEA/TSB 11 NUDOCS-ABSTRACT 01 1

1 1

1 1

1 1

1 EXTERNAL: LPDR 1 1 NRC PDR ~ 1 1 NSIC 1 1 R

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TOTAL NUMBER OF COPIES REQUIRED: LTTR 28 ENCL 25

P. 0 X 14000, JUNO BEACH, FL 33408-0420

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e JUNE 2 3 1988 L-88-280 10 CFR 20.501 10 CFR 20.7 Mr. Victor Stello, Jr.

Executive Director for Operations U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555

Dear Mr. Stello:

Re: St. Lucie Units 1 and 2 Docket Nos. 50-335 and 50-389 Request for Additional Information 10 CFR 20 Appendix A Exemption Request for Worker Respiratory Protection A aratus TAC Nos. 67138 and 67139 By NRC letter dated March 16, 1988, the Staff requested additional information relating to the above subject for St.

Lucie Plant, Unit Nos. 1 and 2.

The purpose of this letter is to provide the second set of responses. The first set of responses was provided in Florida Power 6 Light Company's letter L-88-209, dated May 5, 1988. This submittal provides responses to Questions 471.5, 471.6, 471.7, 471.9, 471.11 and 471.12.

Should there be further questions, please contact us.

Very truly yours, W. . Con y Senior Vice President Nuclear Enclosures WFC/MSD/gp cc: Dr. J. Nelson Grace, Regional Administrator, Region USNRC II, Senior Resident Inspector, USNRC, St. Lucie Plant goo/

MSDAASS . RAI SS0701069i SS0623 PDR ADOCK 05000335 p DCD an FPL Group company

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QUESTION 473..5 Provide a description of the SCOTT 631-TEDA-H canister including particulate filter, sorbent and percent TEDA.

Address the question of the potential toxic hazard to the respirator user from inhalation of TEDA desorbed from the SCOTT 631-TEDA-H canister. Describe the criteria for use of these SCOTT canisters at St. Lucie (e.g., radioiodine concentration, canister labeling, prevention of canister reuse).

RESPONSE

A. Descri tion of SCOTT 631-TEDA-H Canister The 631-TEDA-H chin style gas mask canister is constructed using a 12 x 20 mesh (U. S. Sieve series) activated carbon, impregnated with 54 by weight triethylenediamine (TEDA), and a high efficiency particulate air (HEPA) filter.

construction.

Figure 1, attached, depicts the canister The sorbent in the canister is batch certified to meet the ASTM D3803 and D4069 radioiodine performance requirements.

The"volume it occupies within the canister"is'340 cc's.

The HEPA filter is a radially pleated high efficiency filter with greater than 99.97% removal efficiency against a 0.3 micrometer dioctylphthalate (DOP) aerosol.

Canisters are 1004 tested for DOP removal efficiency at the time of manufacture per NIOSH respirator certification requirements of 30 CFR Part 11.

B. Potential Hazard from Desor tion of TEDA Studies have been performed on the desorption characteristics of TEDA from impregnated activated carbons. It has been found that the desorption rate of TEDA is not a function of the linear flow rate or sorbent bed depth within the canister. However, desorption rates are linearly related to temperature on a semi-log plot.

At 48.9'C (120'F) a maximum TEDA desorption rate of approximately 2 mg/m has been measured (1) .

There 's no toxicological data available for TEDA, however, there are similarities between other amine type compounds. A sample of several compounds and their threshold limit values are given below (2):

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(mg/m3) (ppm)

Ethylamine 18 10 Diethylamine 30 10 Triethylamine , 40 10 Ethylenediamine "'25 10

'iethylene/triamine 4 1 The 2 mg/m, desorption value at 48.9'C is 'well below the lowest threshold limit 'value for similar',type substances and therefore should not present a toxic hazard to the user.

C. Use of SCOTT Canisters at St. Lucie FPL does not plan to reuse the canisters after initial use. All canisters will be removed after use and discarded to prevent any further use. The canisters will not be used when the radionuclide concentrations of radioiodines, particulates or a combination of each exceed 50 times the applicable limit for the radionuclides in question in 10 CFR 20 Appendix B, Table I Column 1 as described in 10 CFR 20.103.c.1. FPL does not plan on any labeling outside the labeling required to show compliance to NIOSH/MESA requirements.

QUESTION 471.6 The FPL submittal includes tabular summaries of test conditions and test results provided by SCOTT for the SCOTT 631-TEDA-H canister but contains no other information on these tests or on the means for ensuring the reliability of the tests and test results. Provide a complete description and discussion of the test program (including apparatus used), the means for ensuring the reliability of the tests and the test results, and the basis for your acceptance of the test results. Include the complete name and address of the manufacturer (SCOTT) and the identification of the organization or group that actually performed the tests, other than SCOTT.

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RESPONSE

A. Canister Test S stem Descri tion A sketch depicting the test system used to determine the performance of the SCOTT 631-TEDA-H canisters against methyl iodide is shown in Figure 2. The primary MSDAASS.RAI

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components and key features. of the system include:

~ Detection S stem:

Gas chromatograph equipped with an electron capture detector for measuring methyl iodide concentrations in the canister effluent. The chromatograph is calibrated against CH3I using two independent techniques. The first technique employs a permeation tube while the second technique was by volume dilution. Excellent agreement between the two methods was realized.

~ Tem erature Humidit Flow S stem:

A modified Miller-Nelson (MN-301) airflow, temperature and humidity controller is employed for generation and control of the humidified air. The MN-301 unit delivers air at the desired temperature and flow rate to a humidity vessel.'s" ,the air passes through the water vapor laden headspace of the vessel, air-stream humidification and final air heating is accomplished.

The temperature and humidity of the air stream is monitored using an optical dew point hygrocomputer.

The hygrocomputer is located in the thermal enclosure for monitoring the air immediately prior to entering the canister inlet.

~ Meth l Iodide Generation:

A syringe pump is used to generate the methyl iodide challenge concentrations of interest. Capability for generating challenge concentrations using this method was verified using a Miran 1A infrared analyzer and the gas chromatograph. Concentrations generated throughout the test program are verified using volumetric displacement measurement techniques and by use of the chromatograph.

~ Challen e Atmos here Deliver Due to the high temperature and water vapor concentration of the airstream, in-line condensation in the transfer tubing was eminent unless appropriate measures were taken to prevent this condition. A heated enclosure was utilized to contain the canisters, the stream selector valve (which selected the appropriate air stream to be sampled) and the hygrocomputer.

Temperature of the enclosure is set and controlled to the same temperature as the challenge airstream (i.e.

120 F or 100'F). Water vapor condensation is thereby eliminated. No temperature gradients were observed in the thermostated enclosure. A radial manifold is used MSDAASS.RAI

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for distribution of the flow to the test canisters.

Three solenoid valves controlled by an electronic timer unit allows for 192 lpm airflow delivery to each canister for 0.82 seconds and 0 lpm flow for 1.64 seconds (equivalent to a 64 liter minute volume). A pressure vs. time history of each flow segment is used to verify system pressure symmetry (i. e. flow), correct operation of the solenoid valves and "squareness" of the pulsed waveform. A fast response pressure transducer is used for these pressure measurements.

~ S stem Control:

The "brain" of the system is the computing integrator which controls information flow in the instrument network loop (INET). A basic program was written and loaded into the integrator for control of the INET system operation. The program dictates which canister is to be sampled and at what. time. The sampler event control module positions the stream selector valve to the appropriate location for canister effluent sampling.

After the sample is processed by the chromatograph, the integrator computes the amount of methyl iodide in the air and stores the information. At the end of the test, the stored data is loaded into the IBM PC/AT for further analysis, presentation and storage.

B. Discussion of the Test Pro ram As a result of the symmetry in the pulsed cycle (flow for 0.82 seconds, no flow for 1.64 seconds), this pattern lends itself to simultaneous testing of three canisters.

In some instances, data from one or more of the test stations (i.e. number 1, 2 or 3) is not reported in the data tabulations as they related to either empty stations or stations which were used to evaluate prototype product.

Another important feature of the test program was that the detector in the chromatograph was calibrated routinely to monitor and correct for deterioration of the cell. The cell deterioration is caused by oxygen present in the sampled air stream from the canister effluent.

C. Reliabilit of Test Results Data on the performance characteristics of various air purifying respirator cartridges or canisters for methyl iodide exists (3,4). However, data on the performance of the SCOTT 631-TEDA-H canister at the test conditions of interest has not been previously reported. Therefore by comparison of the data enclosed in this exemption request with previously published data, a correlation can be MSDAASS.RAI

established which substantiates the SCOTT results. These conclusions are summarized below:

~ Test data on the SCOTT P/N 600252-75 canister which contained 305 cc of 8 x 16 mesh, 5% TEDA carbon, tested with air at 64 lpm constant flow, 25'C, 974 R.H. was greater than 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to 14 penetration.

The SCOTT 631-TEDA-H canister with 340 cc of 12 x 20 mesh, 54 TEDA carbon provides 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> duration to 14 penetration. Test conditions were 64 lpm constant flowi 48 ' Ci 904 R H.

Due to the increased sorbent volume and smaller sorbent particle size distribution, improved canister performance has been realized in the 631-TEDA-H canisters.

~ It has been reported in the published data that service life of air purifying canisters decrease with increased relative humidity of the air stream. Performance of the 631-TEDA-H canister was 13.7 hrs. at 904 R.H and 23.9 hrs. at 60% R.H. (48.9'C, pulsed flow conditions, Co =

10 ppm). This trend is also consistent with the published data.

~ Under steady flow conditions, time to a 1: penetration fraction is greater than under cyclic (pulsed) flow conditions for equivalent minute volumes. For the 631-TEDA-H canister, steady flow conditions provided times approximately 2 times greater than pulsed flow tests.

This result is also consistent with the published data.

~ Other tests were performed by SCOTT (not reported in the exemption request) under steady flow conditions, with various methyl iodide challenge concentrations and with a 60 cc sorbent bed volume. The test results demonstrated that for steady flow, removal efficiency was independent of the challenge concentration.

Penetration fractions with time remained identical over the 0.5 3.0 ppm concentration range of interest.

This result has also been previously reported in the literature.

Therefore, by correlation of SCOTT test results with previously reported data, reliability of the SCOTT results has been demonstrated.

D. Test Location All the methyl iodide tests were performed by SCOTT Aviation, 225 Erie Street, Lancaster, NY 14086.

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QUESTION 471.7 Describe how the quality and function of the SCOTT 631-TEDA-H canisters will be verified by Florida Power & Light Company (FPL). It is the utility s responsibility to ensure that canister performance and quality are fully adequate through such measures as verification of vendor quality assurance/quality control (QA/QC) and through development of utility/site QA/QC procedures which provide a continuing assurance of canister quality. (a) Include a general discussion of any vendor audits performed, or outline the basis for, your acceptance of, vendor QA/QC controls for the SCOTT 631-TEDA-H, canisters. (b) Cite general controls and procedures related to SCOTT 631-TEDA-H canister QA/QC to be utilized at St. Lucie by FPL. (c) Clarify the "Equilibration" entry for the "SCOTT RADIOIODINE PROPOSAL" in Table A of Attachment 1 of the FPL submittal. Clarify how and by whom the "Quality Control Lot Acceptance Plan..."

(Attachment 3 of the FPL submittal) has been and is to be used; verify that only the SCOTT 631-TEDA-H canisters from lots accepted under this MIL-STD 414 acceptance plan will be used at St. Lucie by FPL.

RESPONSE

A. ualit Control Lot Acce tance Plan The Q.C. lot acceptance plan will be employed by SCOTT Aviation on each manufacturing lot of 631-TEDA-H canisters produced. Therefore, all canisters consumed by FPL will have been tested per the requirements of the Q.C. plan.

MIL-STD-414, level II, AQL 14 the number of canisters needed will be used to determine for testing based on lot size with acceptability criteria based on canister performance results. The canister test conditions would be as follows:

Air Temperature, 4 Relative Humidity 120F /904 R. H.

Airflow rate conditions 192 lpm for 0.82 seconds 0 lpm for 1.64 seconds Contaminant/Concentration CH3I/10 ppm Test Duration 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Performance Criteria 14 maximum penetration An improved test procedure and lot acceptance plan is MSDAASS.RAI

0 being investigated. The improved test procedure will be devised with the intent of being capable of verifying the acceptability of a manufacturing lot of canisters.

However, the test conditions will not be as severe as the qualification test . conditions. Future work will be directed toward constant flow and high methyl iodide challenge concentrations. Correlation between the qualification test results and the new test condition results will be accomplished.

B. A C General Controls FPL will accept only those canisters that have been certified by SCOTT as meeting the acceptance criteria of the MIL-STD 414 acceptance plan. FPL will perform a receipt inspection of each shipment of the canisters to verify lot number, expiration date of the canisters and physical integrity of the canisters. SCOTT will be required to provide to FPL the results of the acceptance testing for each lot of the canisters that FPL purchases from SCOTT. 'I lt C. Equilibration The SCOTT test program tested canisters without pre-conditioning air flow through the canister.

QUESTION 471.9 The FPL submittal states that the SCOTT canisters are to be stored in sealed, humidity barrier packaging, but does not specify whether the canisters are hermetically sealed nor does it specify the conditions of storage. Specify whether or not the canisters are to be stored in hermetically sealed packaging. Identify the specific procedures that will be used to control canister storage, indicate the range of temperature and relative humidity allowed in the storage area(s), and describe where these canisters will be stored at St. Lucie. Specify the shelf life of the canisters and testing to verify shelf life.

RESPONSE

A. Humidit Barrier Packa in The 631-TEDA-H line canisters are sealed at time of manufacture using a paper backed, heat sealable, aluminum foil laminate. The seals when applied to the canisters, produce an essentially hermetic seal which inhibits water MSDAASS.RAI

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vapor transmission through the seals. Once the seals are removed by the user, they cannot be reinstalled.

t B. Shelf Life of Canisters The manufacturer of the TEDA carbon sorbent used in the 631-TEDA-H canister suggests a shelf life in excess of 3 years under normal room temperature storage conditions in sealed containers. The 631-TEDA-H canister with the foil-lined hermetic seals provides such a satisfactory container. A product shelf life under room temperature storage conditions is therefore taken to be 3 years.

Methyl iodide removal efficiency tests performed on 631-TEDA-H canisters stored in a 70-75'F, 30-70% R.H.

environment for 6 month periods displayed no performance degradation characteristics. Studies are underway to better define high temperature storage conditions on product shelf life.

C. Stora e of Canisters at St. Lucie Health Physics Procedure HP-62 "Inspection, Maintenance, and Quality Assurance of Respiratory Protection Equipment" will be used to control canister storage. Long term storage of large quantities of the canisters will be in one of the plant store rooms. The environmental conditions found in the store rooms to be used for canister storage is that normally found in an air conditioned office type of environment. The general temperature ranges are from approximately 70-80 F with a relative humidity of 30-804.

Short term storage of the canisters will also be in an air conditioned environment in the plant's respiratory protection equipment issue rooms. This short term storage is designed to maintain a stocking level adequate to meet the immediate needs of ongoing work in the plant.

Environmental conditions in the equipment issue rooms are generally the same as the plant store rooms. There may be instances when the temperature may reach 85'F for short periods of time, however, should not affect the performance of the cartridges.

QUESTION 471.11 The FPL submittal states that the canisters are not to be used in challenge concentrations of total organic iodide, including "nonradiometric" (nonradioactive?) iodide, greater than 1 ppm. Describe the methods and particular procedures that will be applied to prevent the use of the SCOTT

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canisters in the presence of challenge concentrations of MSDAASS.RAI

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total organic iodides and other halogenated compounds greater than 1.0 ppm, including nonradioactive compounds.

RESPONSE

There are no known sources of nonradioactive organic iodides or halogenated compounds to which the canisters would be exposed, either in storage or during use. The only other source of exposure of the canister to organic iodides would be the exposure to the radioactive iodides while the canister is in use. Calculations have been performed for selected radioiodines found in the reactor coolant system to determine the atmospheric concentration equivalent to 1.0 ppm of the radioiodines. The results of the calculations indicate that the atmospheric concentrations would be in excess of 1.0 E+09 times the maximum permissible concentrations listed in 10 CFR 20 Appendix B. These atmospheric concentrations are far in excess of the limitations of the respirators which provide a protection factor of 50 times the 10 CFR 20 Appendix B concentrations. The calculations are contained in Attachment 1~

QUESTION 471.12 The FPL submittal states that the SCOTT canisters are not to be used in environments greater than 120'F but does not provide a limit on the relative humidity. Specify a limit on the relative humidity for canister use and provide the basis for this limit. Specify how compliance with the limits for temperature and humidity will be demonstrated.

RESPONSE

A. Maximum Conditions of Use The performance of the 631-TEDA-H canister has been characterized at various conditions which include 37.8'C/48.9'C temperatures and 60/90% relative humidity.

The ability to extrapolate test results from one set of humidity conditions to another humidity level has been demonstrated (3). Using data at the 48.9'C temperature, a log-log plot of breakthrough time vs.  % relative humidity has been prepared and is shown in Figure 3. Using a linear extrapolation, canister service life to a 14 methyl iodide penetration value is projected to be 12.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />.

Use of the 631-TEDA-H canister in a saturated air stream MSDAASS.RAI

at 48.9'C (120'F) should provide a nominal 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> duration to a 14 methyl iodide penetration.

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REFERENCES:

(1) Wood, G. 0.: Desorption of TEDA from Impregnated Respirator and Absorber Charcoals, Am. Ind. Hyg. Assoc.

J 45: 622-625 (1984)

(2) American Conference of Governmental Industrial Hygienists: Threshold Limit Values and Biological Exposure Indices for 1987 1988, ACGIH, Cincinnati, OH (1987)

(3) Wood, G.O., F. 0. Valdez, V. Gutschick, "Criteria and Test Methods for Certifying Air Purifying Respirator Cartridges and Canisters against Radioiodine", NRC FIN No. A 7041, Los Alamos National Laboratory, August, 1983.

(4) Wood g G ~ 0 ~ g "Respirator Canister Testing for Radioiodine", Am. Ind. Hyg. Assoc. J. 42: 570-578 (1981)

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FIGURE SCOTT Ghl -TEDA- H CAN l5TER OUTLET GASKET FOIL LINED SEAL PLASTIC COVER SEALANT ALUMINUM SHELL HOUSING 5% TEDA CARBON CANISTER SORBENT STOCK MASER RETENTION FILTERS 65I- TEDA PERFORATED PLATE HE PA FI LT ER FO I L L I NE D S E A L I NHALAT ION CHECK VALVE INLET

FIGURE 2 METHYL tODIDE TEST SYSTEM WATER HOMIDIFICATIOSI HEATER ONTIIOLL VESSEL VENT TEMP SENSOR AIR AIR FLOW ELECTROI4IC AND TIMER TEMPERATURE COI4TROLI ER

+5 t

RH TEMP HYGRO l~

I I RECORDER qc I I SENSOR COMPUTE l I I I I I

I I THERMAL RADIAL MANIFOLD I I I I

ENCLOSURE r

I r J I

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CI CE. CS

'I 5M PC/AT PRKSSU COMPUTER TRANS-RECORDER OUCER SEQUENCE EVENT INTEgggOR CONTROL MODULE SSV I I I

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EXHAUST I I

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I PURIFI ED FLOW GSV ECD VENT Np CARRIER GAS SEI4SOR GAS CHROMATOGRAPH WITH ELECTRON CAPTURE DETECTOR SSV = STREAM SELEC'TOR VALVE G SV = GAS SAMPLING VALVE COLUMN ECD= ELECTRON CAPTURE DETECTOR

FIGURE 3 RELATIVE HUMIDITY vs. BREAKTHROUGH TIME FOR THE SCOTT 631-TEDA-H CHIN CANISTER 100 90 80 70 60 50 40 RELATIVE HUMIDITY 30 10 10 80 30 40 50 60 70 80 90 100 BREAKTHROUGH TIME (hour s) 624. 16367NXww (-0. 737711)

TEST CONDITIONS:

CHALLENGE CONCENTRATION - 10 ppm METHYL IODIDE BREAKTHROUGH CONCENTRATION 0. 1 ppm PULSED FLOW ( 192 LPM FOR 0.82 sec., 0 LPM FOR 1.64 sec.)

TEMPERATURE 48 . 9 C, VARIABLE Fo RELATIVE HUMIDITY

ATTACHMENT 1 ATMOSPHERIC CONCENTRATIONS EQUIVALENT TO 1.0 ppm OF RADIOIODINES j

'w A

In order to'etermine the atmospheric concentration of the radioiodines at 1.0 ppm equivalent, a two step approach is necessary. The first step is to determine the specific activity of each radioiodine. The second step is to determine the mass of each radioiodine that is equal to 1.0 ppm and to determine the concentration in uCi/ml from the specific activity and the mass. The calculations are as follows:

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SPECIFIC ACTIVITY Specific Activity = SpA = X XN / 3.7 E10 = Ci/gm where X = 1n 2 = 0.693 Tl/2 Tl/2 N = 6.023 E+23 atoms/gram atomic mass Ci = 3.7 E10 dps Tl/2 I-131 = 6.96 E+05 sec Tl/2 I-132 8.14 E+03 sec Tl/2 I-133 7.31 E+04 sec Tl/2 I-134 3.12 E+03 sec Tl/2 I-135 2.40 E+04 sec I-131 SpA = 0.693 X 6.023 E+23 X 1 Ci 6.96 E05 131 , 3.7 Elo 1.24E05 Ci/gm I-132 SpA = 0.693 X 6'.023 E+23 X 1 Ci 8.14 E03 132 3.7 Elo 1.05 E07 Ci/gm I-133 SpA = 0.693 X 6.023 E+23 X 1Ci 7.31 E04 133 3.7 Elo 1.16 E06 Ci/gm I-134 SpA = 0.693 X 6.023 E+23 X 1Ci 3.12 E03 134 3.7 Elo 2.7 E07 Ci/gm I-135 SpA = 0.693 X 6.023 E+23 X 1Ci 2.40 E04 135 3.7 Elo

= 3.47 E06 Ci/gm MSDAASS. RAI

0 t 1'

CONCENTRATION EQUIVALENT TO 1.0 ppm IN AIR The next step after the determination of the specific activity of the radioiodines is to determine the mass equivalent of 1.0 ppm in 1 ml of air and using that mass equivalent and the specific activity to determine the concentration in air.

Molecular iodine exists as I2 in the elemental 1 gram mole of I2 contains 6.023 E+23 molecules state 1 mole of air occupies 22.4 liters at STP 1 mole of air contains 6.023 E+23 molecules of air 8.93 E-11 gm/ml = conversion factor SpA = specific activity 6.023 E23 molecule air X 1 molecule I2 X 1 22.4 liters air 1.0 E06 molecule air 1000 ml X ~2m I2g 8.93 E-11 gm/ml

6. 023 E23 molecule Concentration Calculation uCi/ml = 8.93 E-11 gm/ml X SpA Ci X Atomic Wt X 1.0E06 uCi gm Ci I-131 8.93 E-ll gm/ml X 1.24 E05 Ci/gm X 131 X 1.0 E06 uCi/ci

= 1.45 E+03 uCi/ml I-132 8.93 E-ll gm/ml X 1.05 E07 Ci/gm X 132 X 1.0 E06 uCi/ci

= 1.24 E+05 uCi/ml I-133 8.93 E-11 gm/ml X 1.16 E06 Ci/gm X 133 X 1.0 E06 uCi/ci

= 1.38 E+04 uCi/ml I-134 8.93 E-11 gm/ml X 2.70 E07 Ci/gm X 134 X 1.0 E06 uCi/ci

= 3.23 E+05 uCi/ml I-135 8.93 E-ll gm/ml X 3.47 E06 Ci/gm X 135 X 1.0 E06 uCi/ci

= 4.18 E+04 uCi/ml MSDAASS.RAI