Resolution of Generic Safety Issues: Item B-32: Ice Effects on Safety-Related Water Supplies (Rev. 1) ( NUREG-0933, Main Report with Supplements 1–34 )
This issue was identified in NUREG-04713 and addressed the concern that additional information was needed on the potential effects of extreme cold weather and ice buildup on the reliability of various plant water supplies. Experience gained during past severe winters indicated that a more thorough understanding of the potential effects of severe ice conditions was necessary to confirm that the design and operation of safety-related water supplies would ensure adequate operation of safety systems. Guidance for the review of licensee submittals regarding ice effects is contained in SRP11 Section 2.4.7.
The loss of plant water sources (particularly the ultimate heat sink) by ice formation, blockage by ice dams, etc., could impair a plant's core cooling capability during shutdown. This issue affects all plants located in geographical areas in which there has been a history of ice formation, ice jams, ice floes, etc.
The loss of essential service water in LWRs from various causes, including ice effects, was addressed in the evaluation of Issue 153.1280