ML19256D686
| ML19256D686 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/23/1976 |
| From: | Bland J Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19256D683 | List: |
| References | |
| NUDOCS 7910220605 | |
| Download: ML19256D686 (2) | |
Text
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r ENVIRONMENTAL IMPACT APPRAISAL THREE MILE ISLAND PROPOSED TECHNICAL SPECIFICATION CHANGE NOS.
33.2 and 33.3 Evaluation The proposed change for the determination of anomalous measurements from 10 times the operational control station level of radioactivity in environ-mental medium to 10 times che mean of the preop / operational control station data does not reduce the effectiveness of the reporting requirement.
The preop / operational data is representative of the background it /el of radio-activity and provides a better mean value for determining levels of radio-activity in environmental media from plant releases.
For cases when preop /
operational control station data is not available, the applicable control station data will be used to determine anomalous measurements.
The proposed deletion of a reporting requirement associated with a measured level of radioactivity in an environmental medium greater than 4 times the control station value is in keeping with current NRC guidelines, proposed Regulatory Guide 4.8.
In many instances the variation in background levels could result in measurements that exceed 4 times the control value. The licensee has proposed a specification for confirming levels of radioactivity when an investigation level is exceeded. An investigation level is exceeded when thater is a 99.9% probability of the measurement not belonging 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 determined from data collected at the applicable control station and preoperational data.
An investigation level set at -he mean plus 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 1453 046 79102206N
the natural background are not unnecessarily investigated. This confir=a-tory specification provides for better analysis of plant related level of radioactivity in environmental media without causing unnecessary reports to be submitted.
All measurements will continue to be su=marized i annual environmental reports.
The licensee proposed to delete the reporting requirement when individual milk samples show I-131 concentrations of 10 picoeuries per liter or greater.
Individual milk samples that show high concentrations of I-131 would not nave to be reported if the average concentrations over a quarter time period was below 4.8 picoeuries per liter. We conclude that this deletion is unacceptable because of the importance of the milk pathway for gaseous releases of I-131.
The licensee has agreed to revise the proposed change to retain the present.
Technical Specification requirement that individual milk samples showing I-131 concentrations of 10 picoeuries per liter or greater be reported.
The proposed change in non-radiological reporting requirement for a written report when a Limiting Condition for Operation is exceeded from within one week to within two weeks does not alter the effectivenass of the program and is in accordance with current NRC practice. The licensee is still required to make a report within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by telephone and telegraph to the Office of Inspection and Enforcement - Region I when an LCO is exceeded.
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