ENS 53304

v t e ENS Event
07:06 Mar 31, 2018
Title	Secondary Containment Inoperable Due to Failed Surveillance Test
Event Description	At 0206 [CDT] on March 31, 2018, with the plant in Mode 1 at 100% rated core thermal power, Grand Gulf Nuclear Station experienced a loss of Secondary Containment. During the performance of a Standby Gas Treatment System (SGTS) drawn down test with Auxiliary Building train bay door (1A319A) as the secondary containment boundary, Grand Gulf was unable to maintain secondary containment pressure, as required by SR [surveillance requirement] 3.6.4.1.4, greater than or equal to 0.266 inches of water vacuum for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Following initial vacuum draw down, secondary containment pressure degraded to 0.225 inches of water vacuum with operators in the field reporting air leakage from door 1A319A. The test was secured and Secondary Containment was declared inoperable and Technical Specification 3.6.1.4 A.1 was entered. Following completion of the failed surveillance test, Secondary Containment was returned to an operable status at 0315 hours0.00365 days <br />0.0875 hours <br />5.208333e-4 weeks <br />1.198575e-4 months <br /> on March 31, 2018, by returning the system to a previously known operable configuration by closing doors 1A310, 1A312 and 1A319. This is being report under 10 CFR 50.72(b)(3)(v)(C). The licensee has notified the NRC Resident Inspector.

ENS 53304 +/-
Where
Grand Gulf Mississippi (NRC Region 4)
Reporting

10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material
Time - Person (Reporting Time:+2.9 h0.121 days <br />0.0173 weeks <br />0.00397 months <br />)
Opened:	Wesley Marshall 10:00 Mar 31, 2018
NRC Officer:	Howie Crouch
Last Updated:	Mar 31, 2018
53304 - NRC Website
v • d • e

v t e Emergency Notification System
Grand Gulf with 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material
WEEKMONTHYEAR2022-10-27T17:28:00 [Table view]
[ENS list for Grand Gulf]

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