ENS 55734
ENS Event | |
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20:14 Feb 5, 2022 | |
Title | Technical Specification Required Shutdown |
Event Description | The following information was provided by the licensee via email:
At approximately 1402 EST on 2/5/2022, with the Unit in Mode 1 at approximately 98 percent power, Operations was performing a valve lineup and inadvertently isolated a portion of the Reactor Coolant System (RCS) Letdown System, resulting in the system relief valve lifting and entry into the Makeup and Purification System Malfunction Abnormal Procedure due to loss of letdown. Pressurizer level increased and Technical Specification (TS) Limiting Condition for Operation (LCO) 3.4.9 CONDITION A was entered at 1414 EST due to Pressurizer level not below the limit of 228 inches, which has a REQUIRED ACTION to restore Pressurizer level within one hour. A rapid plant down power was initiated at approximately 1430 EST to reduce Pressurizer level. At 1514 EST on 2/5/2022, TS LCO 3.4.9 CONDITION B was entered, which has a REQUIRED ACTION to place the Unit in MODE 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in MODE 4 in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. As the Unit was continuing to down power, this represents initiation of a Technical Specification required shutdown, and this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(i). At approximately 1542 EST the down power was stopped at 15 percent power. Pressurizer level was restored to less than 228 inches at approximately 1603 EST, and TS LCO 3.4.9 was exited. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
Where | |
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Davis Besse Ohio (NRC Region 3) | |
Reporting | |
10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | |
Time - Person (Reporting Time:+-1.33 h-0.0554 days <br />-0.00792 weeks <br />-0.00182 months <br />) | |
Opened: | Nicholas Buehler 18:54 Feb 5, 2022 |
NRC Officer: | Brian Lin |
Last Updated: | Feb 5, 2022 |
55734 - NRC Website
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Unit 1 | |
---|---|
Reactor critical | Critical |
Scram | No |
Before | Power Operation (98 %) |
After | Power Operation (15 %) |
WEEKMONTHYEARENS 562842022-12-23T20:13:00023 December 2022 20:13:00
[Table view]10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown ENS 557342022-02-05T20:14:0005 February 2022 20:14:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown ENS 520792016-07-01T09:42:0001 July 2016 09:42:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Failure to Perform Technical Specification Required Shutdown ENS 413302005-01-13T14:49:00013 January 2005 14:49:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Entry Into Technical Specification Required Shut Down Due to Loss of Essential Bus 2022-02-05T20:14:00 | |