PWR molar ratio control application guidelines: Volume 3, Hideout return evaluation guidelines. Final report
- GEBCO Engineering, Inc., Sebastopol, CA (United States)
Molar ratio control (MRC) represents a viable approach for controlling bulk water chemistry in plants experiencing steam generator degradation resulting from secondary side intergranular attack/stress corrosion cracking. EPRI summarized application guidelines in Volume 1 of PWR Molar Ratio Control Application Guidelines to assist utilities in implementing a site-specific MRC program of maintaining crevice pH in a near-neutral range. Three additional volumes complete the guidelines: Volume 2: Industry Experience; Volume 3: Hideout Return Evaluation Guidelines; and Volumes 4 & 5: Effectiveness Evaluation Methods. The additional three volumes contain significantly greater detail on specific topics and are designed for utility specialists responsible for various phases of MRC implementation. This volume presents hideout return guidelines for implementing MRC. Routine modification of the MRC program is based on evaluating hideout return data from the previous shutdown and adjusting the ionic species in bulk steam generator water during the subsequent cycle. The recommended approach is based on the premise that the crevice pH{sub (t)} will be near neutral if the ratio of the highly soluble cation and anion impurities in the crevice is near 1.0. A Molar Ratio Index (MRI) is defined in this approach. Two hideout return models are presented to help understand hideout return of soluble and insoluble species. Hideout return data from eleven plants are evaluated using the two models. Specific recommendations are given for sampling and analyses and data evaluation for MRC.
- Research Organization:
- Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); GEBCO Engineering, Inc., Sebastopol, CA (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 149980
- Report Number(s):
- EPRI-TR-104811-V3; TRN: 96:005119
- Resource Relation:
- Other Information: PBD: Nov 1995
- Country of Publication:
- United States
- Language:
- English
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