ML20076C644
| ML20076C644 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 07/12/1991 |
| From: | Shelton D CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 1953, TAC-75234, NUDOCS 9107230001 | |
| Download: ML20076C644 (6) | |
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ENsRGY Donsed C. Shelton-300 Madison Avenue Vice President. Nuclear '.
Toledo, OH 436520001 MBesse (419)249 2300 :
Docket Number 50-346 License Number NPF Serial Number 1953
' July 12. 1991 United States Nuclear Regulatory Commission Document Control Desk Vashington, DC 20555 Subject Request for Exemption from 10CFR20 Appendix A to Allow Credit
.for Use of a Radiolodine Protection Factor for Mine Safety Appliance Company GMR-I Filter Canisters ' TAC No. 75234)
_Ge.n tlemen :
By letter dated December 5, 1989,'(Serial Number 1728) Toledo Edison (TE) requested the= subject exemption-from 10CFR Part 20 to allow credit for a radiciodine protection factor for air purifying respirators to be used at the Davis-Besse Nuclear Power Station (DBNPS). As a result of a-telephone call with the NRC staff,-the follov'ug additional information-is submi_ttei to support review and approval of the request.
10CFR20.103_provides standards relating to the exposure of individuals to concentrations of radioactive materials in air in restricted areas.
-10CFR20.103(b) requires' licensees to use process or othcr engineering controls to.the extent practicable to liuit concentration-of airborne
-radioactivity to levels below those which delimit an-airb.
9 radioactivity. area. Where it is' impracticable for process r other controls to limit airborne concentrations below the level voich delimits an-airborne radioactivity area, 10CFR20.103(b) provides for the use of respiratory protection to maintain exposure of individuals
--as lov as reasonably achievable-(ALARA).
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Docket Number 50-346 License Number NPF-3 Serial Number 1953 Page'2 Respiratory protective equipment used to limit exporure to airborne radioactivity shall be certified or have had certification extended by the National Institute for Occupational Safety and Health / Hine Safety and Health Administration (NIOSH/MSHA).
Additionally, protection factors credited to the use of respiratory protection shall not exceed those specified in 10CFR20 Appendix A.
Currently, Appendix A states that no allowance is to be made for the use of sorbents against radioactive gases or vapors.
However, 10CFR20.103(d) permits the NRC to authorize higher protection factors than those specified where the need for higher protection factors exists and where it is demonstrated that the respiratory protective equipment vill provide the higher pr'oection factors under the proposed conditions of use.
10CFR20.103(e) permits the NRC to authorize the use of respiratory protective equipment which has not been certified or had certification extended by NIOSH/MSHA provided that testing or reliable test information demonstrates that the material and performance characteristic 9 of the equipment are capable of providing the proposed degree of protection under the anticipated conditions of use.
Toledo Edison has requested an exemption from 10CFR20 Appendix A, and authorization to credit a radioiodiae protection factor for the use of Mine Safety Appliance Company (HSA) GMR-I canister (Number 466220).
A NIOSH/MSHA testing and certification schedule for sorbents for ase for protection against radioiodine gases and vapors has not been developed.
In support of this request Toledo Edison referenced test data and canister qualification information provided by MSA and-submitted to the NRC in conjunction with similar exemption requests for Farley 1 and 2 by Alabama Power Company dated January 13, 1984, by Southern California Edison Company for San Onofre Units 1, 2, and 3 dated March 20, 1985 and by Union Electric Company for the Callavay Plant dated October 22, 1985.
The MSA data constitutes reliable test information which demonstrates that the material and performance characteristics of the HSR GHR-I canister are capable of providing the proposed degree of protection under the anticipated conditions of use.
Tb9 test data verifies that the HSR GMR-I. canister vill provide-a proteca ut factor of 50 over a continuous period of eight hours of use.
Testing was conducted under conditions of cyclic flow and under vorst case environmental conditions affecting service life of temperature, relative humidity, challenge concentrrtioc of methyl iodide, which is the most penetrating of the
.hallenge forms. ' Testing was conducted at 110*F.
A challenge concentration of 5 to 10 ppm of methyl iodide was used.
Sample lots of canisters-were tested to break through (1% of the challenge concentration) at 60% and 90% relative humidity.
Cyclic flow of 64 liters per minute was used for the tests which is at least twice the average breathing rate that could be sustained over an eight hour period.
Statistical analysis of the test results indicate that under the above test conditions and 100% relative humidity that over 99% of GMR-I canisters have a service life of well over eight hours (15.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />).
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Docket Number 50-346 License Number NPF-3 f
Serial Number 1953 Pege 3 The conditions, limitations, and restrictions on the use of GMR-1 canisters proposed by Toledo Edison in the December 5, 1989 request for exemption are conservative relative to the test results.
These conditions, restrictions, and limitations on the use of GMR-I canisters vill be iuplemented through a planned revision to Radiological Controls Procedure DB-HP-01315, Respiratory Protection Permit.
Respiratory Protection Permits issued for the use of GMR-I canisters wills o
Limit the radiciodine protection factor to a maximum of 50.
o Require that canisters be used only with full face piece masks proven capable of providing the individual vith a protection factor greater than 100 by a quantitative respirator fit test.
Limit the maximum permissible use time to less than eight hours o
after which the canister vill be discarded. The use time vill begin when the canister is unsealed and vill include periods of non-exposure.
o Prohibit the use of GMR-I canisters in areas where temperature exceeds 110'P.
Temperatures at work locations where GMR-I canisters are in use vill be measured each shift and/or coincidentally with operations which heat the work areas to assure that the 110'F limit is not exceeded.
o Prohibit the use of GMR-I canisters in the presence of organic solvent vapors or in areas where the total challenge concentrations of organic iodines and other halogenated organic compounds (including non-radioactive compounds) greater than 1 ppm.
DBNPS administrative procedure NG-HS-00505 " Controlled Materials Program" preclude the indiscriminate use of organic solvent containing materials on site.
Materials used on site are evaluated for both personnel hazards and effects on station equipment be' ore being authorized for use on site under the controlled matet_ ls program.
Operating procedures for safety related ventilation systems such as the Emergency Ventilation System and Control Room Emergency Ventilation System which co,,tcy charcoal filters include precautions and restrictions i Ma.ing to use of paint and organic vapor producing processes. Tw existing controls on the use of organic vapor producing solvents and enemicals in conjunction with the requirements of DB-HP-01315, provide adequate restrictions to assure that GMR-I canisters vill not be used in organic vapor environments.
Since radiolodine breakthrough is not directly detectable by the user, Toledo Edison recognizes its responsibility to assure the quality and performance of MSA GMR-I canisters.
Prior to crediting an iodine protection factor for MSA GMR-I canisters, Toledo Edison vill verify that the MSA GMR-I canisters vill meet the standards for quality assurance and quality control which are recognized by NIOSH
Docket Number 50-346 I
License Number NPF-3 Serial Number 1953 Page 4 (i.e. Hil-STD 414).
Specifically this includes a 1% Acceptable Quality Limit (AOL) in a 5 to 10 ppm challenge concentration of methyl lodide, 90% relative humidity, 110'F, 64 LPH cyclic flov, for a service life of eight hours or more at a penetration equal to 1% of the challenge concentrations.
Prior to NIOSil certification of MSA GMR-I canisters this verification vill be made through Toledo Edison acceptance and periodic review of the HSA 04 controls for the CMR-1 canisters.
Prior to use, canisters purchssed from MSA, vill be stored in sealed humidity barrier packaging in a cool dry environment. Canisters vill be maintained in Class "A" stornge (as defined by ANS1 N45.2.2) In accordance with DBNPS procedure EM-DP-00070 except for those maintained in the respirator issue area for ready issuance.
MSA test results submitted to the NRC by Union Electric (August 29, 1986) in support of the Callaway Plant exemption request, demonstrate that the canister seals provide an effective barrier against any adverse effects of temperature / humidity in storage. These measures ensure that the canisters vill perform as required during use.
Toledo Edison's December 5, 1989 exemption request included program veritication measures to be used during the initial implementation of HSA GMR-I canisters.
These measures i.ncluded veekly whole body counts; whole body counts at 30 MPC hours in the seven consecutive days prior to next entry into a radiolodine atmosphere; health physics evaluation of individuals whose whole body count indicates a thyroid uptake of 35 nci or greater of iodine; and, compilation of whole body count data to assess the effectiveness of the program.
Toledo Edison has reassessed these verification mearures in view of differences with verification measures employed in conjunction with similar exemptions at other plants. The revised following program verification measures vill be used during initial canister implementation:
a.
Veekly whole body counts of individuals using the GMR-I canister for radiolodine protection vill be performed; b.
A whole body count vill be given to individuals who exceed 10 MPC hours in seven consecutive days prior to their next entry into a radiolodine atmosphere; c.
If an individual measures any iodine uptake to the thyroid during a whole body count following use of GMR-I canisters, the individual vill be restricted from further entries into radiofodine atmospheres pending a health physics evaluation; d.
A whole body count survey data base vill be compiled to evaluate the results of the program.
'fter an adequate data base has been accumulated to support the effectiveness of the GMR-I canisters, these verification measures vill be reviewed and if supported by the data, relaxed accordingly.
The verification measures described above vill be implemented through a planned revision to DBNPS Radiological Controls Procedure DB-HP-00002, Internal Exposure Control Program.
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e.
Docket Number 50-346 License Number NPF-3
.Sorial Number 1953-Page 5 Toledo Edison requested the exemption to permit the use of air purifying respirators as another means of maintaining personnel exposure _as lov as reasonably achievable.
Although Toledo Edison has not identified specific tasks it is expected that the use of air purifying respirators in lieu of air line supplied or self-contained breathing apparatus can reduce personnel exposure on the order of 25 percent. The use of air purifying respirators provides increased worker comfort and mobility. The corresponding increase in efficiency
- and decrease in exposure time on the job can result in averall dose savings.
During Cycle 7 operation the need for this exemption has increased.
Increased levelsaof reactor coolant system (RCS) activity have beer.
experienced due to a small number of leaking fuel rods in the reactor core.
In addition, a small primary to secondary leak and small RCS-to-coeponent cooling water (CCV) system leak have resulted in increased levels of activity in these systems.
As a result of these increased levels of activity, respiratory protection may be required to support work on these systems during the upcoming seventh refueling cutage (7RFO).
Toledo Edison plans to inspect fuel assemblies which are to be reinserted into the reactor during the 7RF0 to identify leaking fuel rods. -Toledo Edison has requested NRC approval of a license amendment to permit reconstitution of affected fuel assemblies to eliminate leaking fuel pins from the reactor core.
In order toLensure fuel cladding integrity, Toledo Edison audits the Babcock & Wilcox (B&V) fuel fabrication quality assutance program, and performs receipt fuel inspections at the DBNpS.
DBNPS operating procedures' include restrictions on rate of power changes in accordance with B&V guidelines to reduce the potential for fuel degradation.
In addit. ion to maintaining fuel integrity, Toledo Edison employs other practices to reduce the levels of airborne radiciodine.
During plant cooldown for refueling, the containment is purged as soon as permitted by Operating License Appendix A Technical Specifications to reduce airborne contamination as much as practical.
Other areas such as mechanical penetration rooms are normally purged continuously during plant operation.
During plant cooldown, the makuup and purification system removes contaminants from the RCS.
During cooldown for the 7RF0,-Toledo Edison plans to chemically-induce a crud burst in the RCS to maximize the removal of contaminants from the RCS by the makeup and purification system during cooldovn.
ALARA planning is an integral part of outage planning at the DBNPS.
Radiological Controls-procedure DB-HP-01800, ALAPA Job Reviev,.provides for job planning to -maintain exposure ALARA. The ALARA job review considers the needs for engineering controls, such as portable HEPA filters and temporary containments, to reduce airborne contamination j
levels as lov as practical.
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Docket Number 50-346
+
License Number NPF-3
. Serial Number 1953 Page 6 Toledo Edison considers that approval of the requested exemption vill further enhance the effectiveness of Toledo Edison's radiological controls program. Toledo Edison requests approval of the exemption by September 1, 1991, so that it may be utilized during the upcoming refueling outage.
If you have any questions regarding the information provided by this let ter, please contact Mr. R. V. Schrauder, Manager - Licensirig at (419) 249-2366.
Very truly yours, d)
/
h, PVS/a cci P. H. Byron, NRC Region III, DB-1 Senior Resident Inspector A. B. Davis, Regional Administrator, NRC Region III J. B. Hopkins, NRC/NRR DB-1 Senior Project Manager Utility Radiological Safety Board
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