Update to Millstone 3 elevated pH tests
- Westinghouse Electric Corp., Pittsburgh, PA (United States)
- Northeast Utilities, Hartford, CT (United States)
In view of the potential radiological benefits of elevated coolant pH operation, Northwest Utilities (NU), in support of an EPRI-Westinghouse program, agreed to operate the Millstone 3 plant at the start of its second fuel cycle as a demonstration of the effect of elevated coolant pH on out-of-core radiation fields. Operating with an elevated pH is defined as operating with an average lithium concentration of 3.35 ppm, until reaching an end of cycle pH of 7.2 or 7.4. The plant operated during its second and third cycles with an elevated coolant pH. The end of cycle pH during the second cycle was 7.4, and 7.2 during the third cycle. (During the first cycle, operation was with a coordinated pH of 7.0). Evaluation of the dose rate trends in Millstone 3 after two cycles of elevated coolant pH operation concluded that an elevated coolant pH resulted in a 15 percent lower component dose rate compared to other plants that operated with coordinated pH 6.9. However, due to a possible increase in fuel clad corrosion, operation during cycle 4 was restricted to pH 6.9 coordinated chemistry, with the exception of the last two months during which the pH increased to 7.35. At the end of cycle 4 (EOC4), there was a greater increase in component and crud trap dose rates than expected. This paper reviews the radiological trends in the plant and discusses the potential causes for the increase in the dose rates at EOC4.
- Research Organization:
- US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Div. of Regulatory Applications; Brookhaven National Lab. (BNL), Upton, NY (United States)
- OSTI ID:
- 54655
- Report Number(s):
- NUREG/CP-0143; BNL-NUREG-52440; CONF-940505-; ON: TI95008770; TRN: 95:012689
- Resource Relation:
- Conference: 3. international workshop on implementation of ALARA at nuclear power plants, Long Island, NY (United States), 8-11 May 1994; Other Information: PBD: Mar 1995; Related Information: Is Part Of Proceedings of the Third International Workshop on the implementation of ALARA at nuclear power plants; Khan, T.A. [comp.] [Brookhaven National Lab., Upton, NY (United States)]; Roecklein, A.K. [Nuclear Regulatory Commission, Washington, DC (United States). Div of Regulatory Applications]; PB: 810 p.
- Country of Publication:
- United States
- Language:
- English
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