ML20002D139
| ML20002D139 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 10/28/1966 |
| From: | Boyd R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML20002D137 | List: |
| References | |
| NUDOCS 8101190516 | |
| Download: ML20002D139 (2) | |
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SAFETY EVALUATION BY THE RESFARCH AND POWER REACTOR SAFETY ERANCH DIVISION OF REACTOR LICENSING 1
IN THE MATTER OF CONSUMERS POWER COMPANY BIC ROCK POINT NUCLEAR PIANT DOCKET NO 50-155 PROPOSED CHANGE NO. 11 Introduction Pursuant to the provisions of Section 50.59,10 CFR 50, the Consumers Power Company requested authorization of a change to the Technical Specifications of License No. DPR-6 for the Big Rock Point Nuclear Plant. The application for the Proposed Change No.11 was received on September 8,1966, and reques ted that ion chambers as well as the presently authorized scintillation detectors, be authorized for use in the air ejector off-gas monitoring system. This change was requested because the sensitivity of the present system is too high to permit a range of operation which will include the specified higher release rates.
Discussion The proposed change to allow use of ion chamber type detectors in the air ejector off-gas monitoring system is essentially a dif ferent method of accomplishing the monitoring of noble gas fission products. Since the noble gases within the reactor exist in nearly constant proportions to one another for extended periods of time, and since, at the instant of measurement, the short-lived fission products would have substantially decayed, the output current of sn ion chamber would be essentially proportional to the disintegration rates of tha noble gases.
Thun, such a system can be calibrated as a function of curies per second under conditions of a known gas flow rate.
The calibration of the off-gas monitoring system will continue to be based on the analysis of periodic (at least monthly) grab samples using the multichannel gamma scintillation spectrometer in the counting roo2.
The off-gas monitoring system using the ion chamber detection principle has'been in service for several months on a trial basis and has demonstrated satisfactory reliability and sensitivity characteristics through release rates from 10 uc/see to 70,000 uc/sec. The operating range of this system is six decades.
Similar systems have operated satisfactorily at the Vallecitos Boiling Water Reactor and Humboldt Bay Power Plant for considerable periods of time.
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-We have concluded that the proposed change does not present significant hazards considerations not describe:d or implicit in the h4:ards sununary report, and there is reasonable assurance that the health and safety of the public will not be endangered.
Or:h: Ar.d bj; Ro;er S. Boyd Roger S. Boyd, Chief Research & Power Reactor Safety Branch Division of Reactor Licensing Date:
OCT 2 81966 4
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