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NPS_Watch Jun 18, 2018
#1
The Daily Dose - Exposing the nuclear power industry while the nuclear power industry exposes you.


There are 5 EN(s) today, 1 associated with power stations.

[  ]

NRC Event Notices for June 18, 2018  
https://www.nrc.gov/reading-rm/doc-colle...618en.html
[ page nav working, event dates are entered but event time missing. ]
----------------------------------------------------------------------------------------------------------------------------------------------------
----------------- Power Reactor Event Notices
----------------------------------------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------------------------------------
----------- [ Current event for AR_Arkansas_1 ]

20180616 | AR_Arkansas_1 | MANUAL REACTOR TRIP DURING STARTUP |
https://www.nrc.gov/reading-rm/doc-colle...ml#en53459

"At 1121 CDT on June 16, 2018, Arkansas Nuclear One, Unit 1 (ANO-1)

performed a manual reactor trip due to a Turbine Bypass valve failing open on reactor startup.

At the time, ANO-1 was in Mode 2 at approximately 2 percent power.

"The failed Turbine Bypass valve resulted in an over cooling event
and the Over cooling Emergency Operating Procedure (EOP) was entered.

Main Steam Line Isolation (MSLI) automatic actuation occurred on 2 of the 4 channels of Emergency Feedwater Initiation and Control during the over cooling event in the 'B' Steam Generator.

The remaining channels of MSLI were manually actuated by the control room staff from the control room.

[ Surprise ! Only 2 of 4 automatic sequences worked, the other 2 had to be manually initiated, no one knew that two weren't working until they were needed. ]

Over cooling was terminated after the closure of the Main Steam Isolation Valve (MSIV)
and reactor coolant parameters were stabilized as directed by the Over cooling EOP.

Additionally, Gland Sealing Steam was lost to the main turbine due to the closure of the 'B' Steam Generator MSIV
and Loss of Condenser Vacuum Abnormal Operating Procedure was entered.

"This is a 4-hour non-emergency 10 CFR 50.72 (b)(2)(iv)(B) notification due to a Reactor Protection System actuation (scram)
and an 8-hour non-emergency 10 CFR 50.72 (b)(3)(iv)(A) notification for safety system actuation."

All control rods fully inserted into the core during the trip.

Heat removal is via the Atmospheric Dump Control valves to atmosphere.
[ Unclear if this is from the primary loop ( rad contaminated ) or secondary loop. ]

The NRC Resident Inspector has been notified.

The licensee also notified the State of Arkansas.
[ Note they notified the State gov., not usual procedure. ]

[ This is the second time this unit has experienced an emergency shutdown while trying to restart after the recent RFO. ]

[ Cascade of failures shows how one failure leads to others. There's no telling how many other unknown failures are lurking
in the background, and the NRC will help to ensure you don't find out.
]

-------------------

TURBINE GLAND SEAL SYSTEMS – ENGINEERING DATA
http://uniquesystems.com/wp-content/uplo...ystems.pdf

Most steam turbines have a shaft-sealing system which uses carbon rings
to isolate the rotor assemblies on both ends with steam injected to prevent air in-leakage into the turbine.

This leakage would reduce turbine efficiency and flow into the condenser down stream of the turbine further
reducing system efficiency.

This “gland steam” must be removed by an ejector or other vacuum-
producing device to prevent it from flowing back into the turbine.

----------- [ 2018 event history for AR_Arkansas ]

20180612 | AR_Arkansas_1 | PRESSURE BOUNDARY LEAKAGE IDENTIFIED WHILE SHUTDOWN |
https://www.nrc.gov/reading-rm/doc-colle...ml#en53456

20180516 | AR_Arkansas_1 | AUTOMATIC REACTOR TRIP DUE TO LOSS OF MAIN FEEDWATER PUMP |
https://www.nrc.gov/reading-rm/doc-colle...ml#en53404

20180508 | AR_Arkansas_1 | 0 % reason for SD unk

20180507 | AR_Arkansas_1 | Exit RFO @ 100 %

20180325 | AR_Arkansas_1 | Begin RFO

20180315 | AR_Arkansas_1;2 | DEFECT REGARDING CERTAIN PRESSURE TRANSMITTERS AND AMPLIFIER CIRCUIT CARD ASSEMBLIES |
https://www.nrc.gov/reading-rm/doc-colle...ml#en53263


--------------------------------------------------------------------------------------------------
----------- [ Current event for

----------- [ 2018 event history for

--------------------------------------------------------------------------------------------------
----------- [ Part 21 Notice ]
----------------------------------------------------------------------------------------------------------------------------------------------------
----------------- Other reactor info from daily power tracking
-----------------------------------------------------------------------------------------------------------------

[ ]


Region 1

NY_Nine_Mile_Point_2 | @ 100 % was lowered ot 64 % Saturday, no EN, reason for power drop unk.

MA_Pilgrim_1 @ 100 % : 98 % ; 98 % : 98 % ; 98 % ; 98 % ; 99 % ; 99 % : 98 % , no EN, reason for power drop unk.


Region 2


AL_Browns_Ferry_3 @ 79 % : 52 % ; 52 % saturday, no EN, reason for power drop unk.  
[ Unit unable to achieve full power since exiting RFO Apr 03 ] ( used 45 of typ 43 days )

SC_Robinson_2 @ 0 % , no EN, reason for power drop unk.

SC_Summer_1 @ 100 % ; dropped to 99 % Saturday, no EN, reason for power drop unk.


Region 3

MI_DC_Cook_1 100 %, dropped to 97 % Saturday, no EN, reason for power drop unk.

OH_Perry_1 @ 90 %, no EN, reason for power drop unk.

IL_Quad_Cities_2 @ 100 % Saturday ; 87 % Friday, no EN, reason for power drop unk.



Region 4

AR_Arkansas_1 @ 0 % [ suffered a new SD Jun 16 - ref EN above ]

WA_Columbia_2 @ 100 % : 100 % ; 100 % Saturday ; 82 % down from 98 % ; 98 % ; 100 % ; 85 %



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[ There are currently 0 units with the RPV open - ref the Current ReFueling Outage Schedule and Status ]

posted by Staup Knewkinus a Dane Gerous production. All human rights reserved.
 
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