Right, if Palisades nuclear plant was a person. He could cold bloodily shoot somebody dead. If he could remain at large in the community in excess of three years...the rules say nobody could charge him for any crime or NRC violation. All he’s got to do is get away with for three years without being caught.
The agency habitually has the inability
to connect the dots. This is a NRC cover up. The NRC only presents the happy
ever after story. From the event date of Oct 2011 to the inspection report of
Aug 2012, the potential of a severe accident was right around the corner. We
could had three seals fails out of four with severe pump impeller or worst
damage in 1984...a much worst accident was right around the corner any
time operating outside the FSAR and improper quality reactor component parts
The accident could begine any time a huge impeller blade sloughs off.
2012 inspection report: Additionally, pieces suspected to be from impellers were discovered in the bottom of the reactor vessel in 1984 and 2007.
Why didn’t the agency and the big dog NRR connect the dots between
the 1984 and 2011...to disclose to the public that operating these components
outside the FSAR could lead to a severe event like 1984? Does the agency get to
pick and choose what information it release to make Palisades looks good? Just
put the best face on any terrible event Palisades creates for themselves, the
Industry and the nation?
So this is the pattern of the agency and Palisades picking the happy land information to release to the public. Putting a grossly inaccurate spin on actual and potential events at these plants. You are intention miscommunicating risk to the public and not demanding a change in behavior according to real risk the community faces with Palisades.
So in 1984 the plant was ascending up
in power to 57% when a broken impeller almost seized up the motor. God know how
long the pump was "knowingly" operating contrary to the FSAR and
equipment designs in 1984 when stresses threw off a big hunk of impeller blade.
The severely unbalanced impeller tore off the cap screws and the two guide
pins. The impeller wobbled around inside the pumps casing for many hours with
only the remaining guide pins attaching the impeller to the safety.
Additionally, pieces suspected to be from impellers were discovered in the bottom of the reactor vessel in 1984 and 2007.
Man,
I 'd like to be at that plant in 1984. To see that cloud of metal shards,
missing cap screws and pieces of casing circulating around in the coolant like
sandblasting the fuel pins and steam generators for months. Anyone find the cap
screws yet? Didn't a RCP go crazy in the China Syndrome?
****Now I get it...these were on the secondary side...do they report what they find in the primary inlet side?
****Now I get it...these were on the secondary side...do they report what they find in the primary inlet side?
I'd certainly like to see the coolant activty record and the record of fuel pin failure over these years.
STEAM GENERATOR TUBE INSPECTION REPORT for the 2012 REFUELING OUTAGE, 1R22, EC39067
There are three tubes in SG E-50A that were removed from service preventively in contact with a loose part at the top of the hot leg tubesheet (TSH) in Row 130 Column 61, Row 132 Column 61, and Row 133 Column 62.
These
guys are funny...they don't remove the loose part. They aren't interest in what
broke?
These tubes had no wear indications from the loose part but were stabilized and removed from service by tube plugging to prevent issues due to wear from the loose part in the future.
So the worst accident I see is a LOCA
through the failure of the pump mechanical seals and the destruction of the
pump casing. The largest size hole of the Reactor Coolant Pump Loop pipe.
These guys are operating way out of
their stated risk analysis and this is a cover-up of it. The secrecy and lying
creates this opportunity.
Hell,
it is probably not illegal to tell the public the probability of an accident is
this to their face, then to conspire to operate these plants at a much higher
accident risk level behind the scenes. It is just probably illegal just to tell
the truth.
I am saying, if Palisades is the model for honesty and integrity throughout the NRC and the Nuclear industry, then a accident of infinite consequences could be right around the corner.
I am saying, if Palisades is the model for honesty and integrity throughout the NRC and the Nuclear industry, then a accident of infinite consequences could be right around the corner.
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF
INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555
January 15, 1985
Information Notice No. 85-03: SEPARATION OF PRIMARY REACTOR COOLANT PUMP
SHAFT AND IMPELLER
Addressees:
All pressurized water power reactor facilities holding an
operating license (OL) or construction permit (CP).
Purpose:
This information notice is provided to alert recipients of
an event involving primary reactor
coolant pump impeller separation from the pump
shaft. It is expected that recipients will review the information for applicability
to their facilities and consider actions, if appropriate, to preclude similar problems occurring at their
facilities. However, suggestions contained in this information notice do not
constitute NRC requirements and, therefore, no specific action or written
response is required.
Description:
On September 16, 1984, the Palisades Nuclear Plant had been
operating for approximately three days in the process of initial power
ascension following a refueling outage...
IR2012003: The research concluded that the cause of the failures is fatigue-related effects from the operation of the pumps in conditions beyond the maximum flow rates and below the minimum net positive suction head recommendations as described in the UFSAR and other design documentation. These conditions are present when operating only one or two PCPs during reduced temperatures and pressures (typically during startup and shutdown activities.
...The plant was at approximately 57
percent power. At 3:45 a.m. (EDT), reactor coolant pump (RCP) seal cavity
pressures indicated that the first (lower) and second (middle) seals had failed
simultaneously, and an orderly shutdown was commenced. At 5:20 a.m., the third
(upper) seal failed. The reactor was
taken off-line and, at approximately the same time, the pump vibration level
reached the "danger" level (10 mils). The pump was then secured. In
the 3-hour period prior to securing the pump, the electric current to the pump
had increased by approximately 10 to 15 percent.
Inspection Report 2012003 references this 1984 event. Why didn't the NRC disclose in the 2012003 this severe seal and pump damage was a possibility till the replacement? Were they prettying up the engineering certainty-uncertainty? Did the Offices of Research and Nuclear Reactor Regulation in 2011 till the next outage consider the 1984 event as a possible acceptable and a safe outcome to the 2012 outage? Without question, the NRC considers the mysterious 1984 event as a sentinel issue...a cornerstone.
(2012003: "The licensee identified impeller cracking had been observed at Palisades on several occasions since 1984, when the pumps had been removed for inspection and refurbishment/replacement. Additionally, pieces suspected to be from impellers were discovered in the bottom of the reactor vessel in 1984 and 2007")
During the event, the
flow in the loop driven by the affected pump remained normal. During the
examination to determine the extent of the seal failure and to evaluate
required repair, major damage to pump components was discovered. The bolts and
guide pins that secure the impeller to the shaft had been severely damaged.
Unexpected wear on the pump impeller/shaft assembly and pump internals was
found. The impeller is normally fastened to the shaft by eight cap screws and
four guide pins. However, when the pump was examined, all eight cap screws and
two of the four guide pins were found broken. The impeller had been kept in
rotation by the two guide pins that had remained intact. Stationary pump parts
showed unexpected wear in 360 degrees of arc; rotating pump parts showed wear
in 180 degrees of arc.
It is amazing. The NRC has allowed this plant simultaneously for decades to run outside the FSAR and with poor quality impellers.
The RCP at Palisades is a Byron Jackson 850 rpm, single
stage, centrifugal pump 1 with a 42-inch diameter impeller and a 4,000-hp
Allis-Chalmers motor. The pump has four seal stages with controlled bleed off
(and no seal injection) for cooling. Because an impeller was damaged during
1983 by an apparently unrelated failure, another impeller and pump shaft
assembly was installed as a unit in February 1984.(Come on, the 1983, 1984 and 2011 event were all related and caused by the same issue. Running this system not according to the FSAR and causing damaging vibrations and fatigue.) Procedures prescribed by the
pump manufacturer were, followed for the installation of the impeller/shaft assembly;
however, no manufacturer's representative was present when the installation
took place. This assembly had been stored horizontally in the plant store room
for approximately 12 years after it had been used in the 1972 time-frame during
initial hot functional testing. It is this impeller/shaft assembly that failed
on September 16, 1984, after the pump had accumulated approximately 1,300 hours
running time before the event.
(Did you catch between the official notification and the update this shifted from a single impeller issue into a common cause issue...from the utility's fault to a manufacturer issue effecting many impellers.)
The analysis of the failure of the eight cap screws and the
two guide pins indicated that failures resulted from fatigue and impact
loading. The two out of four guide pins that did not fail were bent, which
caused the pump shaft to be forced upward and the impeller to be forced
downward. No bolt corrosion was found. Although a sheared RCP shaft occurred at
Surry 1 in November 1973 as a result of a manufacturing defect, the event
described here is the first involving the potential separation of a primary
coolant pump impeller from its shaft.
Discussion:
Events leading to the pump impeller/shaft failure cannot be
precisely determined; however, examinations of the cap screws indicate that
abnormal stress caused them to fail. It is believed that the pump
impeller/shaft assembly caused the abnormal cap screw stresses that ultimately
led to the failure. It is now believed that the improper torquing of the pump
screws was the root cause.
The event and the above conclusion regarding the cause of
the failure raise three issues which should be emphasized. (1) Disassembly and
reassembly of primary reactor coolant pumps is an operation which should be
done in a rigorous manner employing manufacturer's recommendations and proper procedures.
(2) The nearly simultaneous failure of the two seal stages is indicative of the
seal package under abnormal stress. This stress, concurrent with high pump
vibration is indicative of possible severe pump damage. Operator response to
these indications led to the pump being shut down before the final two guide
pins failed, thus, preventing a more severe event. This action was a prudent
response to the situation. (3) Although the event described here is apparently
isolated, it demonstrates the credibility of a pump failure event which could
lead to a rapid flow decrease transient of the type expected with a sheared
shaft event. Most PWRs have a licensing basis analysis for that event or the
similar seized rotor event. These analyses generally assume an automatic response
of the plant's reactor protection system which generates a reactor trip as a
result of low reactor coolant flow.
See, between the OE and NRC information, it is all unreliable crap information. Nothing agrees!
IE INFORMATION NOTICE
NO. 85-03, SUPPLEMENT 1: SEPARATION OF PRIMARY REACTOR COOLANT PUMP SHAFT AND
IMPELLER
IE Information Notice
85-03 described an event at the Palisades Nuclear Plant involving the
separation of the primary reactor coolant pump impeller from the pump shaft
during operation. That notice stated that electric current to the pump
increased by approximately 10 to 15 percent in the 3-hour period prior to securing
the pump. Subsequent information received from the licensee indicates this
current increase did not occur.
The postulated cause
of the Palisades' cap screw failure was fatigue about brought by preload on the
bolts insufficient to resist cyclic loading. This is believed to have been
caused by the poor surface condition of the cap screw threads. This condition
resulted in the specified torque values not being sufficient to properly
preload the cap screws that join the impeller to the shaft in 1971. This
situation suggests two points that should be stressed. First, the failure
described in IN 85-03 was not caused by improper disassembly and reassembly of
the reactor coolant pump; rather, the problem apparently occurred during
initial assembly. Second, the cause of under tightening of the cap screws was
the poor (rough) surface condition of the screw threads themselves. Thus, use
of the torque to measure axial bolt loading was, in this case, misleading.
See, between the OE and NRC information, it is all unreliable crap information. Nothing agrees!
OE13604, Palisades, Byron Jackson/Flowserve: Three cracks were found in a primary
coolant pump impeller that was removed for refurbishment during the 2001 refueling
outage. The three cracks were similar in nature; each started on a separate impeller vane at
the suction side of the vane tip near the hub and then transverses in the vane in a linear
fashion. Prior to the removal of the pump, the pump exhibited no symptoms that would
indicate the presents of the cracks.
***The root cause concluded that a combination of increased residual stresses, caused by a lack
of the proper post weld heat treatment at the manufacturing facility, and high stress risers,
due to poor fabrication practices, allowed the stresses associated with the starting and
stopping of the pump to initiate fatigue-type cracks on the impeller vanes.
Based on Flowserve's evaluation, the cracks initiate perpendicular to the vane leading edge
and completely penetrate the vane. Most of the cracks have propagated back into the vane
and appear to self-arrest in the thicker vane cross-section. In a few cases the crack
propagated in a semi-circular direction. In one case the semi-circular section was lost from
the impeller. A piece approximately 3" by 6" was found in the reactor vessel. No evidence
of ISCC attack has been observed. The problem was caused by lack of post weld heat
treatment for repairs that were made during post manufacturing.
The stuck piece of impeller in the core today: "The metal is 5 inches by 12 inches long".
A means for external monitoring and detection of this condition does not exist. Impeller
cracking can only be determined by removal of the impeller from the pump, chemical
decontamination, and inspection by visual and liquid penetrate examination techniques. The
cracks are not detectable without removal of the oxide layer from the impeller by chemical
decontamination.
Flowserve recommends that pump impellers in excess of 175,000 hours of service (-20
years of running service) be removed and inspected for cracking to preclude in-service
failure. However, they have found cracking as early as 13 years. Davis-Besse has replaced
all four reactor coolant pump rotating elements in 1986 as due to issues with the RCP shaft
cracking. Preliminary estimate of the operation time for these impellers is estimate at
-103,000 hours (-12 years).
Review of the Acceptance Data Package for the 4 rotating elements that were installed in
1986. Tle Data Packages shows that all 4 impellers had weld repairs performed without
post-heat treatment. It is preferred that the currently install impellers should be refurbish
due to less starts on these than the current spares.
