ENS 40684: Difference between revisions

v t e ENS Event
22:30 Apr 18, 2004
Title	Residual Heat Removal System Isolation Due to a Rise in Reactor Pressure
Event Description	At 1830 hours0.0212 days <br />0.508 hours <br />0.00303 weeks <br />6.96315e-4 months <br /> on 18 April 2004, Nine Mile Point Unit 2 was restoring from reactor pressure vessel leakage test. Reactor pressure was ~82 psi, temperature ~178 degrees, reactor level was solid with both reactor recirculation pumps running in slow speed per the leak test procedure. 'B' residual heat removal system was being warmed up in preparation for going in to service. Reactor water cleanup reject from the vessel was secured to maintain RPV [Reactor Pressure Vessel] pressure stable in order to provide driving head for flow through the residual heat removal discharge line to radwaste. The line is warmed up from the reactor, back through the Shutdown cooling isolation valve, to radwaste prior to placing shutdown cooling in service. When warm-up criteria are met, the operating procedure directs securing flow. When flow was secured, this effectively isolated the solid reactor vessel, resulting in a rise in reactor pressure. Pressure peaked at ~146 psi before operators established reactor water cleanup reject flow. When RPV pressure reached 128 psi, the residual heat removal system isolation was automatically initiated as designed. The shutdown cooling injection valve, which was open to support piping warm-up, closed as designed. All other shutdown cooling valves were closed prior to the event per the warm-up lineup. RPV is currently depressurized with shutdown cooling in service. All systems are functioning as expected. The licensee notified the NRC Resident Inspector. * * Retraction on 06/01/04 at 1512 EDT from Chris Skinner to John MacKinnon * * * The following is a retraction of ENS Notification #40684: On April 18, 2004, Nine Mile Point Unit 2 reported Residual Heat Removal Shutdown Cooling System isolated due to a pressure spike while warming up the piping. The shutdown cooling injection valve, which was open to support piping warm-up, closed as designed. All other shutdown cooling valves were closed prior to the event per the warm-up lineup. Accordingly, Control Room personnel conservatively initiated ENS reporting under 10CFR50.72(b)(3)(iv)(A) in response to the valid containment isolation signal. Subsequent analysis has concluded that, although the isolation signal was valid, it was not a general containment isolation signal (i.e., the isolation signal only involved the shutdown cooling system) and the shutdown cooling function of the Residual Heat Removal System is not listed under 10CFR50.72(b)(3)(iv)(B) as a system that is required to be reportable. This system isolation does not meet the reporting requirements of 10CFR50.72(b)(3)(iv)(A). Therefore, this notification made on April 18, 2004, is being retracted. The NRC Resident Inspector was notified. NRC R1DO (Ron Bellamy) notified.

ENS 40684 +/-
Where
Nine Mile Point New York (NRC Region 1)
Reporting

10 CFR 50.72(b)(3)(iv)(A), System Actuation
Time - Person (Reporting Time:+1.25 h0.0521 days <br />0.00744 weeks <br />0.00171 months <br />)
Opened:	David Richardson 23:45 Apr 18, 2004
NRC Officer:	Arlon Costa
Last Updated:	Jun 1, 2004
40684 - NRC Website Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 40684\u003C/a\u003E - \u003Ca href=\"/Nine_Mile_Point\" title=\"Nine Mile Point\"\u003ENine Mile Point\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EResidual Heat Removal System Isolation Due to a Rise in Reactor Pressure\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 40684 - Nine Mile Point\n","link":"","lat":43.52021388888889,"lon":-76.40656388888888,"icon":"/w/images/b/be/Constellation_icon.png"}],"imageoverlays":null}
v • d • e

v t e Emergency Notification System
Nine Mile Point with 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2024-09-23T11:20:00 [Table view]
[ENS list for Nine Mile Point]

@@ Line 16: / Line 16: @@
 | event date = 04/18/2004 18:30 EDT
 | last update date = 06/01/2004
-| title = Residual Heat Removal System Isolation Due To A Rise In Reactor Pressure
+| title = Residual Heat Removal System Isolation Due to a Rise in Reactor Pressure
 | event text = At 1830 hours on 18 April 2004, Nine Mile Point Unit 2 was restoring from reactor pressure vessel leakage test.
 Reactor pressure was ~82 psi, temperature ~178 degrees, reactor level was solid with both reactor recirculation pumps running in slow speed per the leak test procedure.

v t e Unit 2
GE-5
Reactor critical	Not Critical
Scram	No
Before	Cold Shutdown (0 %)
After	Cold Shutdown (0 %)

ENS 40684: Difference between revisions

Latest revision as of 21:23, 1 March 2018

Navigation menu

ENS 40684: Difference between revisions

Latest revision as of 21:23, 1 March 2018

Navigation menu

Search