ML19343A516
| ML19343A516 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 02/18/1965 |
| From: | Boyd R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML19343A515 | List: |
| References | |
| NUDOCS 8011140440 | |
| Download: ML19343A516 (2) | |
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UNITED STATES ATOMIC ENERGY COMMISSION, HAZARDS ANALYSIS BY THE RESEARCH AND POWER REACTOR SAFETY BRANCH DIVISION OF REACTOR LICENSING IN THE MATTER OF YANKEE ATOMIC ELECTRIC COMPANY PROPOSED CHANGE NO. 61 DOCKET NO. 50-29 Introduction Pursuant to the provisions of Section 50.59 of the Commission's regulations,
Yankee Atomic Electric Company in Proposed Change No. 61, dated February 2, 1965, requested authorization of a change in the Technical Specifications er attached as Appendix A to License No. DPR-3.
This proposed change would fu authorize control of the pH of the main coolant system vater with up to 20 g
ppm of ammonia during reactor operation with more than 5 ppm boron present in the coolant water.
Discussion The Yankee reactor is authorized to operate with the pH of the main coolant water in the range from 5.0 to 10.5 and with boron concentrations up to 1300 ppm; however, chemical additives to control pH are not permitted when more than 5 ppm of boron are present.
The reactor is normally operated with neutral pH (7.0), but has operated for periods of several months with high pH.
Previous operation of the reactor at high pH levels has resulted in.
gradual increases in reactivity of approximately 0.005, both with and without boron in the coolant.
These reactivity gains were subsequently lost when the reactor coolant was returned to neutral pH.
These reactivity changes have occurred over a period of several hours, they are easily controlled, and, therefore, no safety problems are presented.
. :n Yankee is conducting a program to determine the interrelation among reactivity, pH, boron and other related parameters. To permit development of a flexible test program, Yankee has requested authorization to control the pH with up j
to 20 ppm ammonia in the coolant water when more than 5 ppm of boron are also present.
Change No. 60 authorized operation for a period of 60 days with up to 10 ppm ammonia and not more than 600 ppm of boron present in the
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coolant water.
The reactor was operated in this manner for several weeks during November 1964, and no unusual effects were noted.
Operation of the reactor with up to 20 ppm ammonia present in the coolant represents only a
'small extension of the operating conditions authorized previously and, in our opinion, the reactor can be operated safely in the' manner proposed by Yankee.
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Conclusion We have concluded that the proposed change does not present significant hazards considerations not described or implicit in the hazards summary l
report, and that there is reasonable assurance that the health and safety l
of the public will not be endangered.
Original rigned by:
Roger S. Boyd Roger S. Boyd, Chief Research & Power Reactor Safety Branch Division of. Reactor Licensing E=J Date:
TEB 181965 l
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