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Full Version: NPS_Watch Apr 12, 2018
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There are 8 EN(s) today, 3 associated with power stations.

NRC Event Notices for April 12, 2018

-------------- Power Reactor Event Notices

----------- [ Current event for NC_Harris_1 @ 0 % RX Mode; Refueling ]

"On April 11, 2018, while the Harris Nuclear Plant was shut down for a scheduled refueling outage, the reactor vessel head penetrations were being examined in accordance with the lnservice Inspection Program.

Ultrasonic examinations identified a flaw in the head penetration nozzle number 33.

The unit is in a safe and stable condition.

The flaw will be repaired prior to startup from the refueling outage.

"The flaw and repair have no impact on the health and safety of the public or station employees.

The NRC Resident Inspector has been notified."

[ This event occurred on RFO day number 5, note the RX mode. The significance of this piece of info will be explained in a future post. ]

----------- [ 2018 event history for NC_Harris_1


20180407 | Begin RFO

----------- [ Current event for LA_RiverBend_1 @ 100 % RX Mode: Power Operation ]


"At time 0150 CDT on April 11, 2018, a condition was identified that could impair the ability of the Control Building Air Conditioning System to perform its design function.

"Engineering determined that the time delay relays HVKA11-80YB or HVKA11-80YD (Division II chilled water LOW FLOW relays) could fail in a manner that challenges the design safety function of the Control Building Chilled Water System during a Loss of Offsite Power (LOP) Event.

A failure of the time delay relay HVKA11-80YB or HVKA11-80YD (Division II chilled water LOW FLOW relays) to provide the time delay function would cause both the Division I and Division II HVK chilled water pumps to start after a LOP, which in turn could hinder the auto start of either Division I or Division II chillers.

"Currently the Chilled Water System is otherwise operating as designed.

All operator actions are in place to ensure the plant meets all required designed safety system functions.

Work is currently underway to correct this design vulnerability.

"The NRC Resident Inspector has been notified of this condition."

----------- [ 2018 event history for LA_RiverBend_1 ]

20180323 | Retract MANUAL REACTOR SCRAM |


----------- [ Current event for PA_ThreeMileIsland_1 @ 100 % RX Mode: Power Operation ]

"On April 11, 2018, a hydrazine spill resulted in measurable hydrazine levels released at the station outfall to the Susquehanna River over an approximately 16 minute time period.

The hydrazine levels exceeded the station NPDES [National Pollutant Discharge Elimination System] permit effluent limitations.

The Industrial Waste Treatment system release to the river was secured and no further hydrazine was released to the river.

"The concentrations released did not threaten the downstream users or the environment.

[ Notice the lack of detail eg how many gallons per minute or any concentration value. ]

Pennsylvania Department of Environmental Protection was notified of the NPDES non-compliance on April 11, 2018 at 0542 EDT.

"Pursuant to 10 CFR 50.72(b)(2)(xi), this notification satisfies the requirement to notify the NRC of the occurrence of any event or situation related to the health and safety of the public or onsite personnel, or protection of the environment, for which notification to other government agencies has been made.

"The NRC Resident Inspector has been notified."
Hydrazine |

A simple pnictogen hydride, it is a colorless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic and dangerously unstable unless handled in solution.

Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion.

----------- [ 2018 event history for PA_ThreeMileIsland_1 ]

[ There are no other ENs for this unit ]


----------- [ Current event for
----------- [ 2018 event history for  ]
[ There are no other ENs for this unit ]
----------------- Other reactor info from daily power tracking

Region 1

MA_Pilgrim_1 is still shutdown, 37th day. [ 407 days to permanent SD ]

PA_Peach_Bottom_3 @ 86 % up from 60 %, No EN. unk reason for drop.

Region 2

AL_Browns_Ferry_3 @ holding 83 % recovering from shutdown while Restarting, No EN. used 45 of typ 43 days for RFO.

NC_Brunswick_1 @ 100 % up from 82 % recovered from shutdown while Restarting. used 32 of typ 28 days for RFO.

FL_SaintLucie_1 @ 30 % restarting from RFO used 31 of typical 29

Region 3

IL_Byron_2 @ 100 % up from 90 % - unk reason for pwr drop

IL_QuadCities_1 @ 100 % up from 87 % - unk reason for pwr drop

IL_QuadCities_2 @ 100 % up from 97 % - unk reason for pwr drop

Region 4

CA_DiabloCanyon_1 @ 50 % down from 94 %, No EN, unk reason for power drop.

AZ_PaloVerde_1 @ 99 % up from 38 % - unk reason for pwr drop.  

[ There are currently 10 units with the RPV open - ref the Current ReFueling Outage Schedule and Status ]

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