ML20154J211
| ML20154J211 | |
| Person / Time | |
|---|---|
| Site: | 05000187 |
| Issue date: | 02/28/1986 |
| From: | Berkow H Office of Nuclear Reactor Regulation |
| To: | Benveniste J NORTHROP CORP. |
| References | |
| NUDOCS 8603100517 | |
| Download: ML20154J211 (5) | |
Text
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NUCLEAR RE'IULATORY COMMISSION oI 3.,
WASHINGTON, D. C. 20665
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- February 28, 1986 Docket No. 50-187 i
Dr. Jack Benveniste Chairman Corporate Radiation Committee Northrop Research & Technology Center Northrop Corporation L
One Research Park Palos Verdes, California 90274
Dear Dr. Benveniste:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION ON NORTHROP CORPORATION'S REACTOR FACILITY DECOMMISSIONING PROGRAM Northrop Corporation's (NC) final report on the facility decommissioning program has been reviewed by the Headquarters staff and a site survey of the decontaminated facility has been conducted by the Region V staff.
Our review and the site survey have identified the need for additional information, as discussed below.
(1) Radiation measurements were obtained by NC using a sodium fodide crystal which is calibrated for a certain source type and strength.
The methods and standards used for calibration of this survey instrument were not specified in the final report. Please provide a detailed description of your calibration procedure and justify use of a scintillation detector, which is an energy dependent instrument, to measure dose rate with reasonable accuracy (e.
wide range of energies expected in your surveys. g.120%) over the (2) Your report indicates that your survey of the Exposure Room was hampered by the small dimensions of the room, which resulted in your providing 4 pi readings versus measurements which would directly demonstrate satisfaction of the requirements of 5 pR/hr.- at one meter from any planar surface. Your calculations indicated that the readings were close to background. However, because of the geometry problem, you dismantled the room and placed the resulting biological shield concrete rubble in a pile.
Your survey of this pile also indicated readings close to background. However, during its final survey of your facility, the Region V staff found that the configuration of the concrete rubble pile precluded their obtaining
.the required final survey measurements with the available instrumentation.
0603100517 e60228 ADOCK0500g7 DR
. Accordingly, we request that NC:
(a) provide all the readings that were taken of the Exposure Room walls prior to dismantling, with and without shielding, (b) discuss the method used to determine
" background" radiation and provide the respective data, (c) show from your measurement techniques and data that the contribution of dose rate from the surrounding walls could be subtracted from the relevant planar wall to provide the "close-to-background" dose rate from the planar wall (d) physically redistrihota the concrete rubble pile into a homogeneous configuration with as uniform and even a surface as possible and not more than about 1 foot deep.
Measure the radioactive contamination levels at the surface and the radiation levels at one meter from the surface at a suitable number of locations.
Following receipt of the above fnformation, we will complete our safety
~
evaluation of your facility decommissioning. Should you have any questions, please contact Harold Bernard at (301) 492-8529.
Sincerely, d
Herbert N. Berkow, Director Standardization and Special Projects Directorate Division of PWR Licensing-8, NRR cc: See next page
Northrop Corporation Docket No. 50-187 cc: Director Energy Facilities Siting Division Energy Resources Conservation &
. Development Commission 1516 - 9th Street Sacramento, California. 95814 California Department of Health ATTN: Chief, Environmental Radiation Control Unit Radiologic Health Section 714 P Street, Room 498 Sacramento, California 95814 Attorney General 555 Capitol Mall Sacramento, California 95814 i
Fcbruary 28, 1986
. Accordingly, we request that NC:
(a) provide all the readings that were taken of the Exposure Room walls prior to dismantling, with and without shielding, (b)-discuss the method used to determine
" background" radiation and provide the respective data, (c) show from your measurement techniques and data that the contribution of dose rate from the surrounding walls could be subtracted from the relevant planar wall to provide the "close-to-background" dose rate from the planar wall, (d) physically redistribute the concrete rubble pile into a homogeneous configuration with as uniform and even a surface as possible and not more than about 1 foot deep.
Measure the radioactive contamination levels at the surface and the-radiation levels at one meter from the surface at a suitable number of locations.
Following receipt of the above information, we will complete our safety evaluation of your facility decommissioning. Should you have any questions, please contact Harold Bernard at (301) 492-8529.
Sincerely, Original signed by Herbert N. Berkow, Director Standardization and Special Projects Directorate Division of PWR Licensing-8, NRR cc: See next page DISTRIBUTION:
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- SEE PREVIOUS CONCURRENCE SHEET
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, Accordingly, we request that NC:
(a) provide all the readings that were taken of the Exposure Room walls prior to dismantling, with and without shielding, (b) discuss the method used to determine
" background" radiation and provide the respective data, (c) show from your measurement techniques and data that the contribution of dose rate from the surrounding walls could be subtracted from the relevant planer wall to provide the "close to background" dose rate from the planer wall, (d) physically redistribute the concrete rubble pile into a homogeneous configuration with as uniform and even a surface as possible and not more than about I foot deep.
Measure the radioactive contamination levels at the surface and the radiation levels at one meter from the surface at a suitable number of locations.
Following receipt of the above information, we will complete our safety evaluation of your facility decomissioning. Should you have any questions, please contact Harold Bernard at (301) 492-8529.
Sincerely, Herbert N. Berkow, Director Standardization and Special Projects Directorate Division of PWR Licensing-8, NRR cc: See next page DISTRIBUTION:
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