ML20059E917

SER Supporting Util 890928 Request for Exemption from 10CFR20,App a & Authorizing Use of Radioiodine Protection Factor for Sorbent Canisters

ML20059E917
Person / Time
Site:	Vogtle
Issue date:	08/31/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20059E912	List: ML20059E909 ML20059E914 ML20059E917
References
NUDOCS 9009110003
Download: ML20059E917 (5)

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UNITED sT ATEs NUCLE AR REGULATORY COMMISSION

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE USE OF A

_RA010100lNE PR,0TECTICN FACTOR FOR SORBENT CANISTERS l l

AT V0GTLE ELECTRIC GENERATING PLANT, UNIT 2 1

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1 DOCKET NO. 50-425 INTRODUCTION  ;

l i By submittal dated September 28,1989(ELV-00902),GeorgiaPowerCompany, et al., (the licensee) requested an exemption from 10 CFR Part 20, Appendix A, footnoted-2(c),andauthorizationtouseequipmentwhichhasnotbeen  ;

certified by NIOSH/MSHA at Vc9tle Electric Generating Plant, Unit 2. The lie nsee submitted this request in accordance with 10 CFR Parts 20.501 and 2(a03(e). A similar exemption from 10 CFR Part 20 was granted to Vogtle Electric W.erating Plant, Unit 1, on October 27, 1988, and subsequently amended on February 23, 1990.

l Test data and canister qualification information have been provided by the licensee. The exemption and authorization would allow the use of a radiciodine protection factor of 50 for MSA GMR-! canisters at Vogtle Electric Generating

! Plant, Unit 2 (Vogtle 2). Criteria and background inforsetion used for our evaluation include 10 CFR Part 20.103; 10 CFR Part 19.12; Regulatory Guide l 8.15. " Acceptable Programs for Respiratory Protection;" Regulatory Guide P ^0, '

" Applications of Bioassay for 1-125, and 1-131;" 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 As Low As is Reasonably Achievable."

01500SS10N AND EVALVATION Since a NIOSH/MSHA testing and certification schedule ~for sorbents for use for

• protection against radioiodine 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 neasures that the raterial and performance characteristics of the MSA GMR-1 canister can i provide the proposed degree of protection (i.e., a protection factor of 50) l under the anticipated conditions of use, as required by 10 CFR Part 20.103(e),

l 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 i of temperature, poisons, relative humidity, challenge concentration and breath-ing rates on canister efficiency and service life. The programmatic evaluation considered qu6lity coutrol/ quality assurance, and radiation protection /ALARA considerations, including task preparation and planning, on-the-job and post-task evaluations, ese of engineering controls, radiological surveillance, and radiological trainin1 9009110003 900831 PDR ADOCK 05000425 P PDC

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l The licensee has provided reliable test information which verifies that the MSA GMR-! 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 usa, provided that the total challenge of radioactive and non-radioactive 100" bd other halogenated compounds does not exceed I 1 ppm, and temperature o a 1 )t exceed 110'F, or up to 120*F provided the dewpoint does not exceed d/*F. The data provided by MSA demonstrate 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 CH31 (methyliodide/methylradiciodide),whIchisthemostpenetratingofthe challenge forms. Data pN.Yided from MSA indicate that the MSA GMR-! canisters perform adequately under the acceptable test conditions. These conditions - the criteria and test methods - are sonsistent with those derived for the canisters by the NRC staff 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 positions, and are therefore acceptable. This includes a commitment by MSA to establish a 1% AQL (Acceptable Quality Limit) in a 5 to 10 ppm challenge concentration of CH 3 1, 90% relative humidity, 110*F 64 LPM cyclic flow for aservicelifeof8hoursormoreatpenetrationequ, alto 1%ofthechallenge concentration. Testing data referenced by the licensee demonstrated that performance (i.e., service life) of canisters at 100% relative humidity is acceptable.

Coupled with the use of a full facepiece with the capability of providing a protectioh 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 radiciodine gas or vapors of interest (CH 1. I 2 H01 for this time period.

Toprecludeaging,servicelifewillbecalculatedfromu)nsealingtime, 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. Through usage restric-l tions and air sampling, the licensee will preclude exposures to organic vapors andchemicals(suchasdecontaminationcompounds, lubricants,volatilizedpaint, alcohols. Freon) which could cause aging, poisoning or desorption of the absorbed radioiodines.

l l The licensee a submittal provided a letter from the Mine Safety Appliances Company (MSA; which contains a summary of test results which form the basis for MSA and the licensee's conclusion that Class C storage is acceptable. The i

' test summary discussed accelerated storage tests, Class B storage tests, and a moisture permeation study of the bottom seal.

The accelerated storage tests consisted of 24 canisters after 4 months' storage being exposed to a 10 ppm methyliodide concentration for 480 minutes, three canisters after 6 months' storage being exposed to a 5 ppm methyliodido con-centration for 480 minutes, and one canister af ter 1 year's storage being exposed to an 8 ppm methyliodido concentration for 480 minutes. In all cases,

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methyliodide penetration was below 0.5%. In addition, the three canisters tested after 6 months' storage had their testing continued to a 15 break-through of methyliodide. The average time to a 1% breakthrough was 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br />.

The Class B storage tests consisted of samples drawn at 3- and 4-year storage intervals and tested. Test penetrations were at or below initial inspection results for the canister lot.

The moisture permeation study on the canister bottom seal was conducted at 100*F and 100% relative humidity. MSA found the moisture incursion to be insignificant.

Certain limitations and precautions based on NUREG/CR-3403 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 factor equal to 50 :s s m:ximum 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. Canisters are to be stored in a Class C or better environment as defined in ANSI N45.2.2.

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

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

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

8. 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 j less than 107*f.

In addition to the limitations 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.

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

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

a. Weekly whole body counts for individuals using the GMR-I canisters for radiciodine protection.

l b. A whole body count for individuals that exceed 10 MPC in a week .

and used the GMR-1 canister for respiratory protection in that period.

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

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

5. Vogtle Technical Specification 4.7.7, " Piping Penetration Area Filtration and Exhaust System," defines the availability and sur-veillance requirements related to the auxiliary building radiation i

area filter exhaust and continuous exhaust system. The containment i

purification and cleanup system and the auxiliary building radiation area filter exhaust and continuous exhaust system plant procedures, governing the operability and functioning of charcoal beds, are in compliance with Reculatory Guides 1.140 and 1.52 for design, testing, and maintenance of' filtration systems. These requirements are .

utilized to demonstrate system operability with respect to HEPA and charcoal filters. Since GMR-I canisters will be in the same areas served by these systems, assurance of continuing operability of these systems will provide assurance of a 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 8 above, prior to GMR-1 canister use. Additionally, training of workers on the proper use and the limitations of the GMR-I canisters will be performed prior to canister issuance.

7. Existing licensee engineering controls to relieve the needs for respiratory protection as required in 10 CFR 20.103(b)(1) will still apply. These measures include but are not limited to, degasification of the reactor coolant system,. crud burst cleanup, process to confine or eliminate airborne radioactivity, delay breaches of primary systems to allow decay of radioisotopes and area decontamination to decrease possibilities of generating airborne radioactive material.

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

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~5-purifying re nin tors in lieu of air-supplied or self-contained apparatuses, where possible, can result in person-rem reductions estimated overall at 301 l for tasks requiring radiciodine protection, in a range of from 25% to 50% for several major tasks. The light weight, less cumbersome air purifying respira- l tors (i.e., sorbent canisters) can provide increased comfort and mobility in moet 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 rcisonably achievable (ALARA) are: radioiodine air sampling before l

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 data will be evaluated, an evaluation level for radioiodine uptakes has been established (at 70 nCi); training of workers 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 8.8 and are acceptable.

CONCLUSION The NRC staff review of the licensee's proposal indicates that the actions proposed by the licensee can result in significant dose savings ove alterna-tive methods while still providing effective protection. This en:nktion would enable the licensee to use a protection factor for air purifying radiciodine gas and vapor respirators in estimating worker exposures from radiciodine gases r.nd vapors. The licensee has provided usage restrictions and controls which can assure an effective radiciodine protection program. TM proposed criteria and test rethods for verifying the effectiveness and pHty of GMR-! aanisters are consistent with our criteria. The licensee s proposed i

exemption, with the controls and limitations, meets the NRC staff's positions in the Standard Review Plan (NUREG-0800), NUREG/CR-3403 and Regulatory Guide 8.8 and is acceptable. The actions proposed b the requirements of 10 CFR Part 20.103(e) andy the formlicensee are consistent an acceptable basis to with authorize the use of equipment (MSA GMR-1 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: Timothy A. Reed, PDII-3/DRP-l/II Dated: August 31, 1990 l

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