05000321/FIN-2010002-01
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Review Licensee\'s EPD Calibration Methodology |
| Description | The inspectors reviewed calibration records for EPDs at the licensees facility. The licensees EPDs were found to be capable of measuring Deep Dose Equivalent (DDE) and Shallow Dose Equivalent (SDE). The SDE feature was disabled and not used during routine radiological monitoring. EPDs were primarily used to estimate worker exposure for DDE, but were also used as a method of controlling worker exposure for entries in High Radiation Areas in accordance with TS 5.7.1b.The inspectors identified three different methods used to calibrate EPDs. New EPDs purchased directly from the manufacturer were calibrated to a tolerance level of +/-10%of a known Cs-137 source traceable to a United Kingdom National Standard. Subsequent calibrations were performed by the licensees Environmental Laboratory to respond to a tolerance level of +/- 15% of a known Cs-137 source traceable to NIST.EPDs that required repair were sent to a calibration vendor located in West Columbia, South Carolina for repair and subsequently calibrated at that facility to a tolerance level of +/-10% using an Am-241 source traceable to NIST. Licensee procedure 60AC-HPX-017-0, Radiation Protection Instrumentation Program, required radiation survey instruments used to assign or control worker exposure be initially and subsequently calibrated to read within +/-10% of the actual calibration source dose rates using radiation sources traceable to NIST. Additionally, 10 CFR20.1501 (b) requires licensees to ensure that instruments and equipment used for quantitative radiation measurements (e.g., dose rate and effluent monitors) are calibrated periodically for the radiation measured. Although the EPD is not generally used as a substitute for typical dose rate survey meters, it is used to initiate worker actions in lieu of a survey meter in accordance with TS 5.7.1.b which requires incorporation of the EPD into the routine instrument calibration program. From a review of licensee records and discussions with cognizant licensee representatives, the inspectors determined that the licensee had not established a site specific standard for calibrating EPDs or compared the response of the EPDs using the different sources. The use of an Am-241 source, a low level gamma emitter was not representative of the energy ranges in the licensees isotopic mix. In addition, the inspectors determined that the calibrations performed by the licensees environmental laboratory were not consistent with the licensees calibration methods for other instruments used to control worker exposure. This item is unresolved pending NRC review of the licensees evaluation of the EPDs response using NIST traceable sources representative of the energy spectrum of radiation fields at the licensees facility and a review of the licensees specific calibration method for EPDs. URI 05000321, 366/2010002-01, Review Licensees EPD Calibration Methodology. |
| Site: | Hatch  |
|---|---|
| Report | IR 05000321/2010002 Section 2RS5 |
| Date counted | Mar 31, 2010 (2010Q1) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71124.05 |
| Inspectors (proximate) | S Shaeffer B Caballero E Morris J Beavers C Dykes D Hardages Shaefferw Loo H Gepford S Rose E Morris P Niebaum B Collins L Pressley A Nielson L Mahlahlal Mahlahlas Shaeffer W Loo H Gepford S Rose E Morris P Niebaum B Collins L Pressley A Nielson |
| INPO aspect | |
| ' | |
Finding - Hatch - IR 05000321/2010002 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Hatch) @ 2010Q1
Self-Identified List (Hatch)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||