05000318/LER-2021-003, Auxiliary Feedwater Pump Inoperable Due to Improper Reset of Trip Throttle Valve
| ML21266A021 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  (DPR-069) |
| Issue date: | 09/23/2021 |
| From: | Dullinger J Exelon Generation Co |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML21266A019 | List: |
| References | |
| LER 2021-003-00 | |
| Download: ML21266A021 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3182021003R00 - NRC Website | |
text
Abstract
On August 10, 2021 it was determined that the 22 Auxiliary Feedwater (AFW) Pump trip throttle valve was not reset properly in March 2021. As a result, the 22 AFW Pump was determined to be inoperable for a period longer than allowed by the technical specification condition completion time. The 22 AFW Pump was subsequently reset properly. The cause of the improper reset of 22 AFW Pump trip throttle valve was due to inadequate procedural guidance. Actions were taken to update the procedure providing additional detail to ensure the trip throttle valve is reset properly.
(See Page 3 for required number of digits/characters for each block)
(See NUREG1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)
E. SAFETY ANALYSIS
The subject condition satisfies the criteria in NUREG-1022, Revision 3, for a condition prohibited by the plants technical specifications. Therefore, this event is reportable pursuant to 10CFR 50.73(a)(2)(i)(B).
Calvert Cliffs Nuclear Power Plant Technical Specification Limiting Condition for Operation (LCO) 3.7.3, Auxiliary Feedwater (AFW) System, requires two AFW trains operable in Modes 1, 2 and 3. Condition A is entered if one steam-driven AFW pump is inoperable. The required action for Condition A is to align the remaining operable steam-driven AFW pump to automatic initiating status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, and to restore the inoperable steam-driven AFW pump to operable status within 7 days. Condition E is entered if the required action and the associated completion time of Condition A, B, C, or D is not met. The required action for Condition E is to be in Mode 3 within six hours and to be in Mode 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Contrary to the above, on March 20, 2021, with Unit 2 in the mode of applicability, one steam-driven AFW pump was inoperable (22 AFWP) and the remaining operable steam-driven AFW PP (21 AFWP) was not aligned to automatic status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Therefore, the required action for Condition A was not met. This was unbeknownst to the operators at the time. Therefore, Condition E was not entered, and required actions for Condition E were not met.
The station failed to recognize and meet the requirements of Technical Specification Conditions 3.7.3.A and 3.7.3.E. Therefore, this condition is reportable pursuant to 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by the plant's Technical Specifications.
This event did not result in any actual nuclear safety consequences.
F. CORRECTIVE ACTIONS
Required corrective actions have been completed. The 22 AFWP was reset properly on March 26, 2021.
Actions were taken to update the procedure to provide additional detail to ensure proper alignment and full engagement is achieved when the pump is reset.
G. PREVIOUS OCCURRENCES
No previous similar events have occurred at the site within the last five years.
H. COMPONENT FAILURE DATA
Component IEEE 803 IEEE805 FUNCTION ID SYSTEM ID 22AFWP P
BA The steam-driven auxiliary feedwater pump manufacturer is Terry Turbine Company.