RIVER BEND STATION – NRC SPECIAL INSPECTION REPORT 05000458/2015009; PRELIMINARY WHITE FIND
Request a reset of River Bends simulator and simulator fidelity of all Entergy simulator?
“During power ascension following
startup, RFP B did not start. The licensee re-racked its associated circuit breaker
and successfully started RFP B.”
“The team identified an
apparent violation of 10 CFR 55.46(c)(1), “Plant-Referenced Simulators,” for
the licensee’s failure to maintain the simulator so it would demonstrate expected
plant response to operator input and to normal, transient, and accident
conditions to which the simulator has been designed to respond.”
Pilgrim simulator problems
and River Bend within a months of each other only discovered in a troublesome
plant trip?
Another work around tripping
MFP to control level because of leaking FRVs…
*“On several occasions, the
team noted that the licensee chose the expedient solution rather than complete
an evaluation to determine that corrective actions resolved the deficient condition.”
“Other examples included the
licensee’s choice to have operations personnel rack in and out breakers (MFP),
and have maintenance personnel manually operate a limit switch, on the
makeup and start logic for the RFP C minimum flow valve, when the RFP did
not start.”
NRC widely allow a plant to
spin out of control in a complex system, eventually leads to a ANO event (dropped
stator and flooding problems).
“Only four minutes elapsed
from the time of the scram until the time the Level 8 (high) reactor water
level isolation signal was reached. Consequently, operations personnel did not
have sufficient time to gain control and stabilize reactor vessel level in the required
band.”
“However, operations
personnel stated that the plant did not respond in a manner consistent with
their simulator training.”
*However, operations personnel
stated that the plant did not respond in a manner consistent with their
simulator training.”
*It looks like operations
works for everyone else instead of everyone else working for operations.”
Engineering centric instead of operations centric.”
HB Robinson breaker event: “The team identified that the licensee’s maintenance
programs for Division I, II, III, and non-safety 4160 V and 13.8 kV breakers
installed in the plant may not meet the standards recommended by the vendor,
corporate, or Electric Power Research Institute (EPRI) guidelines.”
Why so many issues with faulty
cards: SFRV in manual and RPS?
The operations staff is
amazingly adaptive with not approved work-arounds and degraded components.
If looks to me the staff
went to the SFRV because the FRVs were grossly leaking…
“In reviewing the feedwater
system data from the December 24, 2014, scram, the licensee estimated 500,000
lbm/hr leaked past the closed FRVs. This represents approximately 3 percent of
the full-power feedwater flow and significantly exceeds the design
specification for leakage of 135,000-150,000 lbm/hr.
The licensee identified
excessive leakage past the FRVs during testing in 1986. At the time of
inspection, the licensee could not produce any corrective actions taken to
identify or correct leakage past the FRVs. Further, the licensee had not
quantified the amount of leakage past the FRVs prior to the December 24, 2014,
event and NRC Special Inspection.”
So why isn’t this A
COVER-UP: “The team reviewed the history of Level 8 (high) RFP trips and noted
that similar issues of concern were raised by the NRC in 2012. Specifically, a
Supplemental Inspection, performed in 2012, for a White performance indicator
associated with reactor scrams with complications documented the failure to
recognize a Level 8 (high) trip as an adverse condition and enter it into the
corrective action program. This non-cited violation was documented in NRC
Inspection Report 05000458/2012012.”
“The team identified an
apparent violation of 10 CFR 55.46(c)(1), “Plant- Referenced Simulators,” for
the licensee’s failure to maintain the simulator so it would demonstrate
expected plant response to operator input and to normal, transient, and accident
conditions to which the simulator has been designed to respond. As of January
30, 2015, the licensee failed to maintain the simulator consistent with actual plant
response for normal and transient conditions related to feedwater flows, alarm response,
and behavior of the SFRV controller. As a result, operations personnel were challenged
in their control of the plant during a reactor scram that occurred on
December 25, 2014.”
“During an investigation
into the report at the OSRC (Onsite Safety Review Committee) for the SCRAM on
December 25, 2014, that feed regulating valve leakage (FRV) contributed to the
Level 8 received reactor vessel, it was determined by analysis that there is
sufficient evidence that leakage by the Feedwater Regulating Valves presents a
significant challenge to Operations during a scram event.”
Is a single issue, or is it
really an intentional or a inability to keep the simulator accurate?
Work arounds:
• Work Order WO-RBS-00404323: RFP B supply breaker
repetitive failures to close potentially reduces the number of feedwater pumps
available to operations personnel during a transient following reactor pressure
vessel water Level 8 (high). Operations personnel would rack out and then rack
the breaker back in until the breaker would function properly. This work order
was initiated on February 3, 2015, following discussions with the NRC
inspection team.
how long did this go on?
• Work Order WO-RBS-00396449: RFP C minimum flow
valve does not stroke fully open which prevents starting the C feed pump.
Maintenance personnel would manually operate a limit switch on the valve to
make up the start logic for the RFP. This work order was initiated on October
10, 2014.
• Work Order WO-RBS-00346642: leakage past FRVs
when closed complicated post-scram reactor water level control. Operations
personnel proceduralized the closure of the main feedwater isolation valves to
stop the effect of the leakage.
This work order was
initiated on March 27, 2013.
Wednesday, July 15, 2015 at 2:20PM
