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On January 28, 2001 at 2245, with the plan … On January 28, 2001 at 2245, with the plant operating in Mode 1 at 100% reactor power, both the inside (PSL-303) and outside (PSL-304) Containment isolation valves for the Pressurizer steam space sample line failed to close when attempted from the Control Room. The valves had been open since 1455 that same day to perform degassing of the Pressurizer. The valves were immediately declared inoperable.</br></br>The outside Containment isolation valve was manually closed using a gagging device and its breaker was opened to comply with Technical Specification actions. The breaker was danger tagged to ensure compliance was maintained. Inspections and tests were performed. Evidence of internal binding (galling) was found. The root cause was determined to be inadequate design clearances to allow for thermal growth of internal valve components. The vendor (Flowserve Engineering) has been contacted for review of the failures for 10CFR21 reporting considerations and agreed that the failures meet the criteria for 10CFR21 reporting. They have agreed to file the required report. The condition is herein being reported pursuant to 10CFR 50.73(aX2Xv) and 10CFR50.73(aX2XviiXC). The inability of the valves to close was determined to have low safety significance due to other available valves, operator actions credited, a closed system, and available thermal margin. The condition did not compromise the health and safety of the general public. The current licensing and design bases remained bounding. This event is considered a Safety System Functional Failure (SSFF).</br></br>WO FORM 36611-2001)ional Failure (SSFF).
WO FORM 36611-2001) +
On January 28, 2001 at 2245, with the plan … On January 28, 2001 at 2245, with the plant operating in Mode 1 at 100% reactor power, both the inside (PSL-303) and outside (PSL-304) Containment isolation valves for the Pressurizer steam space sample line failed to close when attempted from the Control Room. The valves had been open since 1455 that same day to perform degassing of the Pressurizer. The valves were immediately declared inoperable.</br></br>The outside Containment isolation valve was manually closed using a gagging device and its breaker was opened to comply with Technical Specification actions. The breaker was danger tagged to ensure compliance was maintained. Inspections and tests were performed. Evidence of internal binding (galling) was found. The root cause was determined to be inadequate design clearances to allow for thermal growth of internal valve components. The vendor (Flowserve Engineering) has been contacted for review of the failures for 10CFR21 reporting considerations and agreed that the failures meet the criteria for 10CFR21 reporting. They have agreed to file the required report. The condition is herein being reported pursuant to 10CFR 50.73(aX2Xv) and 10CFR50.73(aX2XviiXC). The inability of the valves to close was determined to have low safety significance due to other available valves, operator actions credited, a closed system, and available thermal margin. The condition did not compromise the health and safety of the general public. The current licensing and design bases remained bounding. This event is considered a Safety System Functional Failure (SSFF).</br></br>WO FORM 36611-2001)ional Failure (SSFF).
WO FORM 36611-2001) +
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