ML20117C653
| ML20117C653 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 08/20/1996 |
| From: | Brons J COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20117C657 | List: |
| References | |
| NUDOCS 9608270465 | |
| Download: ML20117C653 (2) | |
Text
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I Commonwealth lilison Company IW Opus Place thm ners Grtne, 11.60515 i
August 20,1996 l
Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Errata to the Braidwood Station Annual Radiological Environmental Operating Reports for 1994 and 1995, NRC Docket Numbers STN 50-456 and STN 50-457.
Enclosed are errata data to the Braidwood Station Annual Radiological Environmental Operating Reports for 1994 and 1995. The errata provide corrections to the previously reported maximum doses resulting from aquatic effluents (adult receptor). The corrections were made due to the discovery of an inaccurate river flow factor in the Offsite Dose Calculation Manual (ODCM) l and associated computer program. In addition, several ODCM data entry errors occurred in 1995 which resulted in an incorrect curie total being used for the dose calculation. (Note: the curie totals reported in Table 1.2-1 are l
correct.) Although the re-calculated total body doses (Tables 3.2-1 and 3.3-1) have increased, all doses are less than 2% of 10 CFR 50 Appendix I limits and less than 0.07% of the 10CFR20 limit. Additional details are provided on the attached pages.
In response to the errors reported from Braidwood Station, Comed is in the process of reviewing the ODCM data tables and calculations to ensure no errors exist in other ODCM parameters and methodologies.
Two copies of these errata are provided for your use. Two copies will be forwarded to Region lll and one copy to the Resident inspector.
Sincerely yours, i
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C. Brons
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1 Juclear Support Vice President
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Enclosure giygg cc:
B. Beach, Regional Administrator, Region Ill C. Phillips, Senior Resident inspector, Braidwood R. A. Assa, Project Manager, NRR k%ealthWm\\ensta. doc A IInicum CompJny I
Attachment Errata to the Braidwood Station Annual Radiological Environmental Operatina Reports for 1994 and 1995 During a review of the 1995 Braidwood Station Annual Radiological Environmental Operating Report, it appeared that the maximum doses, calculated by the Offsite Dose Calculation Manual (ODCM) computer program to a member of the public from aquatic effluents, were lower than expected. An investigation of the apparent discrepancy identified several errors. First, inaccurate river flow factors were found in the ODCM and the associated computer program for 1994 and 1995. In addition, errors were found in the data entry for 1995 for the ODCM calculations.
In January,1994, the ODCM and associated computer program was revised to incorporate updated river flow values for the Kankakee River. River flow factors associated with the drinking water pathway and fish pathway calculations were to be revised from 5630 cfs to 3950 cfs. However, errors occurred wherein the drinking water pathway river flow factor was revised to 18,500 cfs and the fish pathway river flow factor remained at 5630 cfs. As of this report, the flow factor associated with the drinking water pathway has been corrected to 3950 cfs and the correction of the flow factor associated with the fish pathway is in progress.
These errors resulted in an under reporting of the 1994 and 1995 calculated doses in Table 3.2-1 (Maximum Doses [ mrem] resulting from Aquatic Effluents -
Adult Receptor) and Table 3.3-1 (10CFR20 Compliance Assessment).
Data entry errors occurred in 1995 in which the total curies released in liquid effluents were not correctly entered into the ODCM computer program. These errors resulted in an additional under reporting of the 1995 calculated doses in Table 3.2-1 and Table 3.3-1. The curie totals reported in the 1995 Annual Radiological Environmental Operating report are correct and do not need to be revised.
In summary, the revised 1994 reported doses in Table 3.2-1 increased by a factor of approximately 2.63 for Total Body and 2.36 for Internal Organ based on the correction of the river flow factor. Revised 1994 reported doses in Table 3.3-1 increased by a factor of 2.51 for Unit 1 and 2.86 for Unit 2. The revised 1995 reported doses in Table 3.2-1 increased by a factor of approximately 5.81 for Total Body and 3.54 for Internal Organ based on the correction of the river flow factor and the data entry errors.
l Revised 1995 doses reported in Table 3.3-1 increased by a factor of 4.02 for Unit 1 and 2.29 for Unit 2. A revised Table 3.2-1 is provided for 1994 and 1995 which i
l contains the updated maximum annual doses (mrem) resulting from aquatic effluents l
(adult receptor) and the updated compliance status (%of Appendix I) to 10CFR50, Appendix 1. A revised Table 3.3-1 is also provided for 1994 and 1995 which contains the updated total effective dose equivalent (mrem /yr) and updated compliance status
(% of 10CFR20) to 10CFR20. In addition, a revised Section 3.2, Liauid Effluent Pathways, is provided for 1994 and 1995, updating the maximum whole body and organ doses stated in the last sentence.
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