ML13324A577
| ML13324A577 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/20/1985 |
| From: | Medford M Southern California Edison Co |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| TAC-57868 NUDOCS 8503220236 | |
| Download: ML13324A577 (3) | |
Text
Southern California Edison Company P. 0.
BOX BOO 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 M.O.MEDFORD TELEPHONE MANAGER, NUCLEAR LICENSING March 20, 1985 (818) 572-1749 Director, Office of Nuclear Reactor Regulation Attention:
Mr. George W. Knighton, Branch Chief Licensing Branch No. 3 U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket Nos. 50-206, 50-361 and 50-362 San Onofre Nuclear Generating Station Units 1, 2 and 3 Southern California Edison's San Onofre Nuclear Generating Station Unit 3 is scheduled for its first refueling in 1985 and we are anticipating abnormally high airborne levels of radioiodine in the containment building during the initial phases of the outage. Experience with a previous unscheduled maintenance outage indicates that concentrations of airborne iodine can exceed 100 MPC shortly after shutdown. Adequate respiratory protection for radioiodine can be provided for a limited number of workers by air-line supplied or self-contained breathing air. However, use of air purifying respirators will offer sufficient protection for a larger work force while enhancing worker comfort, permitting access to areas within Unit 3 containment otherwise not accessible, and enabling an estimated 30% reduction in time and man-rem exposure to complete tasks requiring respiratory protection.
The Health Physics Program at San Onofre is committed to maintaining exposures to airborne contamination to as low as reasonably achievable.
Engineering controls, such as purging, filtration, and local containments, are used to the extent practicable to limit concentrations of radioactive materials in air to levels below which personnel access is unrestricted.
However, respiratory protection from radiolodine will be required in addition to the above process controls because of high levels of iodine (approximately 0.5 uCl/ml dose equivalent 1-131) in the reactor coolant system.
We are aware that on October 23, 1984, Alabama Power Company was issued an exemption from the requirements of Appendix A to 10 CFR 20 to allow the use of a radiolodine protection factor of 50 for the MSA GMR-I canisters used by workers at their Joseph M. Farley plant. We have reviewed the Farley exemption and the Safety Evaluation and modified certain useage restrictions to agree with our existing respiratory protection program.
8503220236 850320 PDR ADOCK 05000206 CI P
Mr. G.
March 20, 1985 Pursuant to 10 CFR 20.103(e) and 10 CFR 20.501, Southern California Edison hereby applies for exemption to 10 CFR 20, Appendix A, footnote d-2(c),
for San Onofre Nuclear Generating Station, Units 1, 2 and 3, to allow credit for a radioiodine protection factor when using the MSA 466220 GMR-I canister.
Except where reference to an existing respiratory protection procedure number is made, the limitations and usage restrictions noted below agree with the Farley exemption and the recommendations of NUREG-CR 3403.
The following items will apply at San Onofre Nuclear Generating Station.
o A protection factor equal to 50 as a maximum value will be used.
o The maximum permissible continuous use time will be eight hours after which the canister will be discarded.
o Canister allowable service life will be calculated from the time of unsealing the canister, including periods of non-exposure.
o Canisters will not be used in the presence of organic solvent vapors. Painting or the use of organic substances will be prohibited while the GMR-I canister is in use.
o Canisters will be stored in sealed, humidity barrier packaging in a cool, dry environment. The GMR-I canisters will be maintained in Class "A" storage (as defined in ANSI N45.2.2) except for those maintained for ready issue in the respirator issue area.
o Canisters will be used only with a full facepiece proven capable of providing the individual with a protection factor greater than 100 by a quantitative respirator fit test.
o Canisters will not be used in total challenge concentrations of organic iodines and other halogenated compounds greater than 1 ppm, including non-radioactive compounds.
o Canisters will not be used in environments where temperatures exceed 110 0F. Temperatures at work locations where GMR-I canisters are in use will be measured each shift and/or coincidently with operations which heat the work areas to assure that this limit is not exceeded.
o The following program verification measures during initial GMR-I canister implementation will be used:
- a. weekly whole body counts of individuals using the GMR-I canister for radioiodine protection will be performed;
- b. a whole body count will be given to individuals who exceed 30 MPC hours in seven consecutive days prior to their next entry into a radiolodine atmosphere (50123-VII-4.2, "Internal Dosimetry Program");
- c. if an individual measures 35 nCi or greater iodine uptake to the thyroid during a whole body count, the individual will be restricted from further entries into radioiodine atmospheres pending a health physics evaluation (S0123-VII-4.2, "Internal Dosimetry Program"); and
Mr. G.
March 20, 1985
- d. a whole body count survey data base will be compiled to coordinate the results of the program.
In accordance with 10 CFR 170.12, enclosed is the required application fee of $150.00.
If you have any questions regarding this matter, please call me.
Very truly yours, Enclosure cc:
Mr. J. A. Zwolinski, Branch Chief, Operating Reactors Branch No. 5 Mr. W. A. Paulson, NRR Project Manager, San Onofre Unit 1 Mr. H. Rood, NRC (to be opened by addressee only)
Mr. F. R. Huey, Senior Resident Inspector, SONGS Mr. J. B. Martin, Regional Administrator, Region V