ML19291B704
| ML19291B704 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/08/1976 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19291B701 | List: |
| References | |
| NUDOCS 7911110176 | |
| Download: ML19291B704 (3) | |
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UNITED STATES
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J.
4 NUCLEAR REGULATORY COMMISSION i I t 9 WASHINGTON, D. C. 20555 W %'#r}
ENVIRONMENTAL IMPACT APPRAISAL BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 22 TO FACILITY LICENSE NO.DPR-50 METROPOLITAN EDISON COMPANY JERSEY CENTRAL POWER & LIGHT COMPANY AND PENNSYLVANIA ELECTRIC COMPANY THREE MILE ISLAND NUCLEAR STATION, UNIT NO.1 DOCKET NO. 50-289 Introduction By letter dated June 3,1976, Metropolitan Edison Company (Met Ed) re-quested a change to the Technical Specifications appended to License No.
DPR-50 for the Three Mile Island Nuclear Station, Unit No.1. The amend-ment would redefine the reporting requirement limits for certain higher than background radiation levels.
Discussion By letter dated June 3,1976, Met Ed requested that the entire Section 5.6.2 (Non-Routine Reports) of Appendix B to License DPR-50 be replaced to re-flect updating this section in line with Regulatory Guide 4.8.
Except for Section 5.6.2.2 (Radiological Environmental Monitoring) these changes were editorial rr.ther than substantive. After several discussions with Met Ed, we have accepted the revised Section 5.6.2.2 except for subsection 5.6.2.2(b) related to milk pathway measurements. Upon agreement by Met Ed, the language and requirements in this subsection have not been changed.
The only substantive change relates to the use of precoerational and coerational background radioactivity rather than that collected during the operational _
period only as the basis for determini1g an anomalous radioactivity measure-ment.
Aporaisal The proposal to change the basis for defining anomalous measurements as 10 times t'ie mean of the preoperational and operational data collected ISQ 049
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at a control station rather than 10 times the mean of the operational data only, does not reduce the effectiveness of tais reporting require-ment.
The precoerational/ooerational data is representative of the background level of radioactivity and provides a better mean value for determining levels of radioactivity in environmental media from plant releases. For cases when preocerational/ operational control station data is not avail-able, the applicable control station data will be used to determine anomalous measurements. The proposed deletion of a reporting require-ment associated with a measured level of radioactivity in an environmental medium greater than 4 times the control station value is acceptable because it reflects a greater accuracy for defining anomalous measure-ments on a factor of 10.
In many instances the variation in background levels could result in measurements that exceed 4 ti.'?s the control value.
Met Ed has proposed a specification for confirming levels of radioactivity when an investication level is exceeded. An investigation level is exceeded when there is a 99.9% probability of the measurement not be-longing to the background or control station level data distribution (i.e, greater than the mean value plus 3.1 times the standard deviation).
The mean value is deternined from data collected at the apolicable control station and preoperational data. An investigation level set at the mean olus 3.1 standard deviations assures that measurements that are likely to be attributable to plant effluents are investigated but that measurements which are within the normal fluctuation of the natural background are not unnecessarily investigated. This confirmatory specif-ication provides for better analysis of plant related level of radio-activity in environmental media without causing unnecessary reports to be submitted. All measurements will continue to be summarized in annual environmental reports.
Met Ed propoLad to delete the reporting requirement when individual milk samples show I-131 concentrations of 10 picocuries per liter or greater.
Individual milk samples that show high concentrations of I-131 would not have to be reported if the average concentration over a quarter time period was below 4.8 picocuries per liter. We conclude that this deletion is unacceptable because of the importance of the milk pathway for gaseous releases of I-131.
15Tl050
~3 Conclusion and Basis for Necative Delaration On the basis of the foregoing analysis, it is concluded that there will be no environmental impact attributable to the proposed action. Having made this conclusion the Comm hsion has further concluded that no environmental impact statement for the croposed action need be prepared and that a negative declaration to this effect is appropriate.
Dated:
November 8, 1976
/$73 051