ENS 52228: Difference between revisions

v t e ENS Event
12:50 Jul 12, 2016
Title	Invalid Actuation of Both Trains Essential Spray Pond System
Event Description	The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73. This telephone notification is being made pursuant to the reporting requirements of 10CFR50.73(a)(2)(iv)(A) and 50.73(a)(1) to describe an invalid actuation of both trains of the Palo Verde Nuclear Generating Station (PVNGS) Unit 2 essential spray pond (SP) system. The SP system serves as an emergency service water system that does not normally run and serves as an ultimate heat sink as described in 10CFR50.73(a)(2)(iv)(B)(9). On July 12, 2016, at approximately 0550, Mountain Standard Time, Unit 2 experienced a manual actuation of both trains of the SP system. Approximately 20 minutes earlier, the failure of a +15VDC power supply on the containment purge isolation actuation signal (CPIAS) module resulted in a trip of the B train CPIAS and a momentary cross trip of the A train CPIAS, and both trains of the control room essential filtration actuation system (CREFAS). These brief actuation signals resulted in starting of some but not all essential equipment because the actuation signals cleared before most of the equipment received a start signal. Both trains of the SP system were started manually in accordance with the alarm response procedure. The A train CPIAS and both trains of CREFAS were reset. The B train CPIAS remained in a partially tripped state because of the failed power supply. The manual actuation of both A and B trains of the SP system was complete. Both trains of the SP system started and functioned successfully. The invalid actuation was the consequence of a failed +15VDC power supply on the B train CPIAS module which resulted in momentary trips of both trains of CPIAS and CREFAS. The containment building radiation monitors that actuate CPIAS exhibited normal radiation levels which would not have required CPIAS actuation. The event was entered into the PVNGS corrective action program. There was no adverse impact to public health and safety nor to plant employees. The NRC Resident Inspectors have been informed.

ENS 52228 +/-
Where
Palo Verde Arizona (NRC Region 4)
Reporting

10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation
Time - Person (Reporting Time:+1395.37 h58.14 days <br />8.306 weeks <br />1.911 months <br />)
Opened:	Jorge Rodriquez 16:12 Sep 8, 2016
NRC Officer:	Steve Sandin
Last Updated:	Sep 8, 2016
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v • d • e

v t e Emergency Notification System
Palo Verde with 10 CFR 50.73(a)(1), Submit an LER
WEEKMONTHYEAR2022-04-12T03:45:00 [Table view]
[ENS list for Palo Verde]

@@ Line 16: / Line 16: @@
 | event date = 07/12/2016 05:50 MST
 | last update date = 09/08/2016
-| title = Invalid Actuation Of Both Trains Essential Spray Pond System
+| title = Invalid Actuation of Both Trains Essential Spray Pond System
 | event text = The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
 This telephone notification is being made pursuant to the reporting requirements of 10CFR50.73(a)(2)(iv)(A) and 50.73(a)(1) to describe an invalid actuation of both trains of the Palo Verde Nuclear Generating Station (PVNGS) Unit 2 essential spray pond (SP) system. The SP system serves as an emergency service water system that does not normally run and serves as an ultimate heat sink as described in 10CFR50.73(a)(2)(iv)(B)(9).

v t e Unit 2
CE
Reactor critical	Critical
Scram	No
Before	Power Operation (100 %)
After	Power Operation (100 %)

ENS 52228: Difference between revisions

Latest revision as of 21:44, 1 March 2018

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ENS 52228: Difference between revisions

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