05000315/LER-2002-008
| Donald C. Cook Nuclear Plant Unit 1 | |
| Event date: | 04-25-2002 |
|---|---|
| Report date: | 8-1-2003 |
| 3152002008R00 - NRC Website | |
17. TEXT (If more space is required, use additional copies of NRC Form (366A) Conditions Prior to Event :
Unit 1, MODE 1
Description of Event:
On June 4, 2003, with Unit 1 in MODE 1, during an extent of condition review for LER 50-316/2003-004-00, "Weight of Ice Basket Below Minimum Allowed in Technical Specification (TS) 3.6.5.1," Donald C. Cook Nuclear Plant (CNP) discovered that on April 27, 2002, Unit 1 was not placed into shutdown action as required by TS 3.6.5.1.
On April 25, 2002, Unit 1 was operating in MODE 1, with ice basket weighing in progress. Ice Basket 24-1-7 was weighed and discovered to be weighing 1099 pounds (lbs.), which is below the minimum acceptable weight of 1144 lbs. as specified in TS 3.6.5.1.d. The condition was discovered during routine surveillance testing in accordance with TS 4.6.5.1.b to ensure the proper amount of ice remains within the ice condenser. Upon discovery of the low weight basket, CNP weighed the adjacent 20 ice baskets in accordance with TS 4.6.5.1.b and the weights were acceptable for the surveillance.
CNP failed to recognize that this condition constituted a failure to meet the Limiting Condition for Operation (LCO) for TS 3.6.5.1 and did not enter the associated 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> LCO action for an inoperable ice bed. Accordingly on April 27, 2002, Unit 1 was not shut down in accordance with TS 3.6.5.1.
This condition is being reported in accordance with the reporting criteria specified in 10 CFR 50.73(a)(2)(1)(B) as a failure to meet the requirements of TS 3.6.5.1.
Cause of Event:
The apparent cause of CNP's failure to comply with the action requirements of TS 3.6.5.1 was human error. The responsible individuals appeared to have focused on the surveillance and the discrepant basket impact on system structural operability and did not consider its impact on compliance with the wording in TS 3.6.5.1.d.
Analysis of Event:
The safety functions associated with this condition are:
1. The ability to absorb thermal energy resulting from a loss of coolant accident or a main steam line break to limit containment pressure rise to less than design pressure immediately following an accident, and to support longer term heat removal (until the ice bed has completely melted).
2. Provide an inventory source for the containment recirculation sump to support sump recirculation level requirements, sump pH, and sump boron requirements.
17. TEXT (If more space is required, use additional copies of NRC Rolm (366A) There is no safety significance of the condition. The representative sample of 20 additional ice baskets in the same bay revealed the 95% level of confidence weight was 1388 lbs. of ice, which is greater than the minimum of 1144 lbs. The ice condenser would have performed all of its safety functions. The overall mass of ice met the needs of each of the safety functions.
Corrective Actions:
Ice basket 24-1-7 was emptied, inspected, and refilled with the proper amount of ice in accordance with procedure 12-EHP-4030-010-262, "Ice Condenser Surveillance and Operability Evaluation.
In response to LER 50-316/2003-004-00, procedure 12-EHP-4030-010-262, "Ice Condenser Surveillance and Operability Evaluation," will be revised. This revision will incorporate an engineering verification to ensure as-found weights are consistent with previous as-left weights prior to actions being implemented to correct discrepant conditions. Further, this revision will incorporate instructions that a low ice basket weight results in an entry into the action statement of TS 3.6.5.1.
CNP will develop a lessons learned for the operations group that discusses the identified concern and reinforce the requirement to ensure literal compliance with the TS and the associated action statements. This will also be incorporated into the licensed operator requalification training.
CNP will develop a lessons learned for the system engineering group that discusses the identified concern and reiterate the need to ensure literal compliance with the TS and the associated action statements. The lessons learned will reinforce that the operability evaluation and/or condition evaluation must address not only system operability but compliance with all aspects of the TS.
CNP will develop a lessons learned for the Regulatory Affairs group that discusses the identified concern and reiterate the need to ensure literal compliance with the TS and the associated action statements and the importance of maintaining a questioning attitude.
Previous Similar Events:
The following LERs were captured because they address ice weight related concerns, but are sufficiently different from the concern being reported in LER 50-315/2002-008-00.
Therefore, the corrective actions for these events could not have prevented the occurrence of this event.
- LER 50-315/98-007-01, Ice Condenser Weights Used to Determine Technical Specification Compliance Not Representative
- LER 50-315/98-015-01, Ice Weight Requirements Potentially Not Met Due To Nonconservative Assumptions In Software Program
- 2002 — I 008 00 17. TEXT (If more space is required, use additional copies of NRC Fom► (366A)
- LER 50-315/98-026-00, T/S Surveillance Requirement 4.6.5.1.b.2 Not Met Due To Failure To Accurately Transfer Requirements Into Plant Procedures The following LER was captured because its extent of condition led to the discovery of the event that is being reported in this LER. Therefore, the corrective actions for this event could not have prevented its occurrence.
- LER 50-316/2003-004-00, Weight of Ice Basket Below Minimum Allowed in Technical Specification 3.6.5.1