ML13330B542
| ML13330B542 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/01/1991 |
| From: | Rosenblum R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9108050211 | |
| Download: ML13330B542 (2) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 R. M. ROSENBLUM TELEPHONE MANAGER OF August 1, 1991 (714) 454-4505 NUCLEAR REGULATORY AFFAIRS U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Thermal Shield Support System Replacement Project Dosage San Onofre Nuclear Generating Station, Unit 1 The enclosure to this letter provides the radiation exposure received during each task and the total radiation exposure received during the replacement of the thermal shield supports. You requested this final information during a thermal shield meeting in your offices on October 3, 1990. The collective dose was approximately 95 person-rem during a total project time of 66,843 hours0.00976 days <br />0.234 hours <br />0.00139 weeks <br />3.207615e-4 months <br />. In our letter dated May 24, 1990, we estimated the total dose would be 86 rem over an estimated project time of 27,454 hours0.00525 days <br />0.126 hours <br />7.506614e-4 weeks <br />1.72747e-4 months <br />.
The total project person-hours exceeded the estimate due to additional hours expended to modify the premanufactured support components to fit field conditions. However, the actual total dose received was not much greater than our original estimate. This was due to the lower than estimated dose rate emitted from the core barrel, our effort during the project to keep exposures as low as reasonably achievable, and the fact that the majority of the additional work was not performed in areas of high radiation.
If you have any questions, please do not hesitate to call.
Very truly yours, Enclosure cc:
J. B. Martin, Regional Administrator, NRC Region V George Kalman, NRC Senior Project Manager, San Onofre Unit 1 J. 0. Bradfute, NRC Project Manager, San Onofre Unit 1 C. W. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2&3 910S0i 1CS0 21 05000206 PDR -ADOCK PDR0)
THERMAL SHIELD OVERVIEW EXPOSURE ESTIMATE 86.040 PERSON-REM ACTUAL EXPOSURE 94.839 PERSON-REM ESTIMATED PERSON-HOURS 27454 PERSON-HOURS ACTUAL PERSON-HOURS 66843 PERSON-HOURS ESTIMATED EFF. EXPOSURE RATE 3.13 mREM/HR ACTUAL EFF. EXPOSURE RATE 1.42 mREM/HR EXPOSURES BROKEN DOWN BY SPECIFIC JOBS Person-Rem Time MACHINE THERMAL SHIELD TOOLING 0.000 63.24 REMOVAL OF TRI-NUKE FILTERS 0.195 49.77 THERMAL SHIELD REPAIR ACTIVITIES 47.994 28937.90 THERMAL SHIELD REPAIR WITH BUBBLEHOOD, 0.569 397.57 THERMAL SHIELD REPAIR VISUAL INSPECTION 11.195 10273.79 THERMAL SHIELD REPAIR SUPPORT ACTIVITIES 15.478 14448.61 HP SUPPORT FOR THERMAL SHIELD REPAIR 13.690 10897.13 RMC SUPPORT FOR THERMAL SHIELD REPAIR 0.343 408.57 CORE BARREL LIFT 1.951 559.71 INSPECTION THIMBLE GUIDE 0.010 6.83 MEASUREMENTS ON IRRADIATED SUPPORT BLOCKS 0.165 34.74 REMOVE DEBRIS FROM REFUELING POOL AND TRANSFER TO HIC 0.784 221.59 RETRIEVE SUPPORT BLOCK BOLTS FROM HIC 0.305 48.62 SURVEILLANCE CAPSULE WORK STATION 1.916 435.48 SURVEILLANCE CAPSULE SUPPORT WORK 0.154 41.18 FOREIGN MATERIAL EXCLUSION NET REMOVAL 0.020 5.13 CLEAN AND INSPECT CORE BARREL 0.070 12.94 TOTAL 94.839 66842.70