ML20247H726

Safety Evaluation Re Use of Radioiodine Protection Factor for Sorbent Canisters

ML20247H726
Person / Time
Site:	Hatch
Issue date:	03/16/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20247H571	List: ML20247H567 ML20247H726
References
TAC-71145, TAC-71146, NUDOCS 8909200080
Download: ML20247H726 (5)

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UNITED STATES NUCLEAR REGULATORY COMMISSION r,, j WASHWGTON, D. C 20655 7

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE USE OF A RADIOI0 DINE PROTECTION FACTOR FOR SORBENT CANISTERS AT EDWIN 1. HATCH NUCLEAR PLANT, UNITS 1 AND 2 DOCKET WOS. 50-321 AND 50-366 INTRODUCTION By submittal dated October 25, 1988, as supplemented January 12, 1989, Georgia '

Power Company, et al., (the licensee) requested an exemption to 10 CFR Part 20, Appendix A, footnote d-2(c), and for authorization to use equipment which nas not been certified by NIOSH/MSHA. The licensee submitted this request in accordance with 10 CFR Parts 20.501 and 20.103(e).

Test data ano canister qualification information have been provided by the licensee. The exemption and authorization would allow the use of MSA GMR-I rotection factor of 50 at the Edwin I. Hatch canistersPlant, Nuclear with aUnits radiciodine 1 and 2 p(Hatch 1 and 2). Criteria and background information useo for our evaluation include 10 CFR Part 20.103; 10 CFR Part 19.12; Regulatory Guide 8.15 " Acceptable Programs for Respiratory Protection;"

Regulatory Guide 8.20, " Applications of Bioassay for I-125, and I-131;"

NUREG/CR-3403, " Cartridges and Test Methods for Certifying Air Purifying Respirator Cartridges and Canisters Against Radiciodine," and Regulatory Guide 8.8, "Information Relevant to Ensuring That Occupational Radiation Exposures at Nuclear Power Stations Will Be At low As Is Reasonably Achievable."

DISCUSSION AND EVALUATION Since a NIOSH/MSHA testing and certification schedule for sorbents for use for protection against radiotodine gases and vapors has not been developed, the NRC staff has evaluated the licensee's request and verified that the licensee has demonstrated through reliable test data and adequate quality assurance measures that the material and performance characteristics of the MSA GMR-I canister can provide the proposed degree of protection (i.e., a protection factor of 50) under the anticipated conditions of use, as required by 10 CFR Part 20.103(e),

for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. We considered canister efficiency and service life, and the effects of temperature, poisons, relative humidity, challenge concentration and i breathing rates on canister efficiency and service life. The programmatic evaluation considered quality control / quality assurance, and radiation protection /

ALARA considerations, including task preparation and planning, on-the-job and post-task evaluations, use of engineering controls, radiological surveillance, and radiological training.

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The licensee has provided reliable test information which verifies that the MSA GMR-I canister will provide a protection factor of 50 over a period of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of continuous use, provided that the total challenge of radioactive and non-radioactive iodine and other halogenated compounds does not exceed 1 ppm, and temperature does not exceed 110'F, or up to 120*F provided the dewpoint does not exceed 107*F. The data provided by MSA showed the breakthrough point to be well beyond 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

Testing has been conducted under acceptable conditions of cyclic flow, and under worst case conditions for those environmental factors affecting service life: temperature, relative humidity, and challenge concentration of CH I (methyliodide/ methyl radiciodide), which is the most penetrating of the 3 challenge forms. DC.a provided from MSA indicate that the MSA GMR-I canisters perform adequately under the acceptable test conditions. These conditions - the criteria and test methods - are consistent with those derived for the canisters by the NRC steff from NUREG/CR-3403, and are acceptable.

The licensee, through acceptance of MSA QA controls, has provided commitments that the MSA GMR-I canisters will meet standards for quality assurance and quality control which are recognized by NIOSH, compatible with NRC staff and are therefore acceptable. This standard is met by demonstrating positions a 1% AQL (Acceptable Quality Limit) in a 5 to 10 ppm challenge concentration, of CH,1, 90% relative humidity,110 F, 64 LPM cyclic flow, for a service life j of 8 Hours or more, at 1% of the challenge concentration penetration, with a

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QA/QC program comparable to that described in M1LSTD-414. Testing data provided by the licensee demonstrated that performance (i.e., service life) of canisters et 100% relative humidity is acceptable.

1 Coupled with the use of a full facepiece with the capability of providing a fit factor equal to or greater than 500 by quantitative fit test, the protection factor of 50 is acceptable. Canister efficiency will be retained for the radioiodine gas or vapors of interest (CH I,1, HOI) for this time period.

Toprecludeaging,servicelifewillbecalculatedfromunsealingtime, 2

including periods of non-use, and the canister will not be used in the presence of organic solvents or in temperatures in excess of 107'F dewpoint. Canisters will be stored in sealed humidity-barrier packaging in a cool, dry environment, and discarded after the 8-hour use period to prevent reuse. Through usage restrictions and air sampling, the licensee will preclude exposures to organic vapors and chemicals (such as decontamination compounds, lubricants, volatized paint, alcohols, freon) which could cause aging, poisoning or desorption of the '

adsorbed radiciodines.

i Certain limitations and precautions based on NUREG/CR-0403 guidance are necessary for utilization of the sorbent canisters. We agree with the following limitations and usage restrictions as proposed by the licensee:

1. Protection f actor equal to 50 as a maximum value.

2. The maximum permissible continuous use time is eight hours after which the canister will be discarded.

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3. Canisters are not to be used in the presence of organic solvent vapors.

' 4. -The allowable service life for sorbent canisters is to be calculated from the time of unsealing the canister, including periods of non-exposure.

5. Canister is to be used with a full facepiece capable of providing a fit factor equal to or greater than 500.

6. Canisters are not to be used in total challenge concentrations of organic iodines and other halogenated compounds greater than 1 ppm, including nonradioactive compounds.

7. Canisters are not to be used in environments where temperatures are greater than 110* or up to 120 F, if the dewpoint is equal to or less than 107 F.

In addition to the liraitations and usage restrictions noted above, the following additional controls will be utilized by the' licensee:

1. Temperatures will be measured prior to and/or during the use of GMR-1 canisters to assure that work temperatures are within limits.

2. Air samples will be taken prior to and during any activities that involve the use of the GMR-I canister for protection against radioactive iodine.

3. A GMR-I canister found to have exceeded 3 years from date of manufacture will not be used for protection against radioactive iodine.

4 In the initial implementation of the GNR-I program, the following verification measures will be in effect:

a. Whole body counts for individuals using the GMR-I canisters for radiciodine protection will be performed at the end of each job.

b. A whole body count for individuals that exceed 10 MPC in a week and used the GMR-I canister for respiratory protection in that period.

c. Anyone that measures 70 nC1 or greater iodine uptake to the thyroid during a whole body count will be restricted from entering a radiciodine atmosphere pending Health Physics evaluation.

d. The radiological survey and whole body count information will be compiled to evaluate the effectiveness of the program.

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l . -4 l 5. Hatch 1 Technical Specification 3/4.7.B and Hatch 2 Technical l Specification 3/4.6.6.1 define the availability and surveillance requirements related to the emergency Standby Gas Treatment System (SGTS) for containment atmosphere control. These requirements are used to deaunstrate system operability with respect to HEPA and charcoal filters. Additionally, the plant procedures governing the operability and functioning of the charcoal beds are in compliance with Regulatory Guides 1.140 and 1.52 for design, testing and maintenance of filtration systems. Since GMR-I canisters will most likely be used in the same areas served by the SBGT, assurance of continuing operability of the SBGT will provide assurance of the proper environment (i.e., no organic vapors or chemicals) for GMR-1 canister use.

6. Specific plant procedures will incorporate the limitations and usage restrictions, listed as 1 through 7 above, prior to GMR-I anister use. Additionally, training of workers on the proper use and the limitations of the GMR-I canisters will be perfomed prior to canister issuance.

The licensee will ensure that the MSA GMR-I canisters meet standards for quality control by use of a procedure or instruction requiring verification that for each canister used: (1) the seal is intact, (2) the canister shelf life has not expired, and (3) the following MSA label is attached to the canister: ,

"This cenister meets the NRC Quality Assurance Specification Required for Radioiodine Protection Factor Credit, in addition to the NIOSH/MSHA Requirements. Credit may only be taken by licensees who have been granted a NRC Exemption."

In addition, onsite QA audits and surveillance of the Respiratory Protection Program will be expanded to include GMR-I canister use and associated procedures and controls.

The primary bases for the licensee's request for exemption are the potentials for both increased worker safety and dose reduction. The utilization of air purifying respirators in lieu of air-supplied or self-contained apparatuses, where possible, can result in person-rem reductions estimated to be in a range of from 25% to 50%. The lightweight, less cumbersome air purifying respirators (i.e., sorbent canisters) can provide increased comfort and mobility in most cases, and result in increased worker efficiency and decreased time on-the-job.

Other actions taken by the licensee to assure that exposures to radiciodine are as low as is reasonably achievable (ALARA) are: radiciodine air sampling before and during activities involving the use of sorbent canisters for radiciodine protection; engineering controls such as degasification of the primary coolant; area decontamination to control contamination levels; maintenance planning allowing for radioiodine decay times, where practical, prior to breaching primary systems. Whole body counts will be conducted routinely, radiological cate will be evaluated, an evalus. tion level for radioiodine uptakes has been

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I' established (at 70 nC1); training of werkers and health physics technicians in the use and restrictions for the use of sorbent canisters for radiciodine protection will be conducted prior to their use; and procedures iterating the controls, restrictions, and requirements will be developed and implemented. The licensee's efforts to keep exposure ALARA are consistent with staff positions in Regulatory Guide 8.6 and are acceptable.

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SUMMARY

The NRC staff review of the licensee's proposal indicates that the actions proposed by the licensee can result in significant dose savings over alternative methods while still providing effective protection. This exemption would enable the licensee to use a protection factor for air purifying radiciodine gas and vapor respirators in estimating worker exposures from radioiodine gases and vapors. The licensee has provided usage restrictions and controls which can assure an effective radioiodine protection program. The proposed criteria and test methods for verifying the effectiveness and quality of GMR-I canisters are consistent with our criteria. The licensee's proposed exemption, with the controls and limitations Review Plan (NUREG-0800), meets the NRC

, NUREG/CR-3403 and staff's positions Regulatory Guidein theand 8.8, Standard is acceptable. The actions proposed b the licensee are consistent with the i requirements of 10 CFR Part 20.103(y),

e ano form an accepttble bauis to authorize the use of equipment (MSA GMR-I canisters) in accordance with 10 CFR 20.103(e) and to authorize the granting of an exemption in accordance with the provisions of 10 CFR Part 20.501.

Principal Contributor: Lawrence P. Crocker, PDII-3/NRR Dated: March 16, 1989

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