"I'll gladly pay you Tuesday for a hamburger today"
How incompetent can you be...in two plant facility, back to back fuel failure outages of both plants and three months apart. Worst, Unit two had to shutdown prematurely for three weeks in order to repair fuel assemblies...meaning more than one assemblies is damaged containing many fuel pins.
I find it astonishing and very worrying in a domestic nuclear power plant, they expect more and future fuel failures. The cladding and the pellet are a principal safety barrier and I can't believe how careless Exelon is!
I am worried about the magnitude of the problem nationwide based on North Anna and both LaSalle plants having serious fuel integrity problems within such a short period of time, plus one was shut down mid cycle.
Dominion Nuclear Is In Trouble: North Anna's Uranium Memory BlackoutsThe North Anna and LaSalle damaged fuel pins and spilled fuel pellets speaks to me as this is a widespread event and relatively unprecedented. North Anna is a PWR and LaSalle is a BWR. Unit 2 with the mid cycle shutdown has issues with radiation and contamination problems. The NRC indicates they may have had issues with being overwhelmed with radiation problem with the damaged fuel. Generally incompetent with repeatedly over spilling the vessel and the water then being much more radioactive than normal.
I find it astonishing and very worrying in a domestic nuclear power plant, they expect more and future fuel failures. The cladding and the pellet are a principal safety barrier and I can't believe how careless Exelon is!
I am worried about the magnitude of the problem nationwide based on North Anna and both LaSalle plants having serious fuel integrity problems within such a short period of time, plus one was shut down mid cycle.
April 25, 2014SUBJECT: LASALLE INSPECTION REPORT 05000373/2014002; 05000374/2014002
Unit 1
On January 21, Unit 1 began coasting down to refueling outage (RFO) L1R15, which began on February 10, when the unit was disconnected from the grid. Following completion of the outage, the unit was restarted and synchronized to the grid on March 1.a. Inspection Scope
During a review of items entered in the licensee’s CAP, the inspectors selected for additional review a CAP item documenting a root cause evaluation entitled “Fuel Degradation Caused by Debris Fretting in L2C14,” AR 01601318. The inspectors reviewed associated documentation and interviewed licensee Radiation Protection staff to understand the current state of the issue and to ascertain the specific course of action that the licensee has planned to address current or future fuel leaks. This review constituted one in-depth PI&R sample as defined in IP 71152-05.
This guy was so bad they couldn't wait for the refueling outage...it was mid cycle shutdown for leaking bundles (more than one) and a safety relief. You got junk circulating in the main coolant system and they are installing junk safety relief valves.
August 1, 2014SUBJECT: LASALLE INSPECTION REPORT 05000373/2014003; 05000374/2014003Unit 2The unit began the inspection period operating at full power. On April 26, 2014, Unit 2 began shutting down for a mid-cycle maintenance outage, L2M17, to locate and replace leaking fuel assemblies, and replace a leaking safety relief valve. The outage began on April 27 when the unit was disconnected from the grid. Following completion of the maintenance activities, the unit was restarted and synchronized to the grid on May 6. Full power was achieved on May 9.
Wonder how long the safety relief valve was leaking.
The purpose of the maintenance outage was primarily to remove and replace any leaking fuel bundles inside the reactor vessel, and to also replace a leaking main steam safety relief valve.
What a tremendous waste of money this is. Half way through the operating cycle they had to shutdown for a quickie two week mid cycle outage because of fuel failure and a bum SRV. Then another three months later they scam on poorly designed MSIV and in another shutdown for two weeks.
Licensee Event Report 2014-001-00
Wasn't once there was a scam on the MSIV leaving the open seat. Bet you they took that margin of safety out to save pennies. Least Hi pressure will take you out
On August 5, 2014, at approximately 1734 hours CDT, Unit 2 automatically scrammed from 100% power on high neutron
flux, followed by a Group I containment isolation. Following the Group I isolation, the control room operators noted that the position indication for valve 2B21-F022C, the inboard 2C Main Steam Isolation Valve (MSIV), showed dual indication rather than full closed.
Troubleshooting of the 2C MSIV determined that the valve stem disk had separated from the stem, which allowed the main disk to drop into the main steam flow path. The resulting reactor pressure transient added positive reactivity, which caused the high neutron flux scram. Increased steam flow in the other three main steam lines resulted in a nearly simultaneous high main steam line flow Group I containment isolation.
How many times you think it was scheduled for an outage and then cancelled because they just ran out of outage time. This is epidemic scheduling work in a outage and then cancelling it.
The cause of the stem-disk separation on the 2C MSIV was fretting wear attributable to marginal design. The root cause of the event was a legacy decision made in 2008
deferring installation of a manufacturer upgrade that would have prevented the failure. Corrective actions include installing the upgrade on all MSIVs on both units, and reviewing previous deferral decisions made using the same decision-making process.
B. DESCRIPTION OF EVENT:
On August 5, 2014, at approximately 1734 hours CDT, Unit 2 automatically scrammed from 100% power on high neutron flux, followed by a Group I containment isolation. Following the Group I isolation, the control room operators noted that the position indication for valve 2B21-F022C, the inboard 2C Main Steam Isolation Valve (MSIV)[SB], showed dual indication rather than full closed.
Troubleshooting of the 2C MSIV determined that the valve stem disk had separated from the stem, which allowed the main disk to drop into the main steam flow path. The resulting reactor pressure transient added positive reactivity, which caused the high neutron flux scram. Increased steam flow in the other three main steam lines resulted in a nearly simultaneous high main steam line flow Group I containment isolation.
This occurrence is reportable under 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in the automatic actuation of any of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). An ENS report was made to the NRC (EN# 50346) at 2120 CDT on August 5, 2014, pursuant to 1 OCFR 50.72(b)(2)(iv)(B) and 50.72(b)(3)(iv)(A). This event constitutes an unplanned scram with complications in accordance with NEI 99-02, Revision 7.
C. CAUSE OF EVENT:
The cause of the stem-disk separation on the 2C MSIV was fretting wear attributable to marginal design. A formal root cause investigation was conducted, which determined that the root cause of the event was a legacy decision made in 2008.
J Exelon Skimpy (Popeye the Sailor Man)
The vulnerability of the Rockwell International MSIV to stem-disk separation was a known issue. In 1989, Rockwell
"Why fix it today when you can wait until it breaks at power."
developed an "MSIV Improvement Package" with a more robust stem-disk design configuration. The station initially planned to install this upgrade on all 16 MSIVs (two Units with four inboard and four outboard MSIVs each); however, based upon the results of inspections performed on several MSIVs, the upgraded design was installed on only seven before it was decided to defer the remaining nine installations until additional corrective maintenance work was required. This decision was made in 2008 using the Operational and Technical Decision Making (OTDM) process.
D. SAFETY ANALYSIS:
The safety significance of this event was minimal. A reactor scram with closure of the MSIVs is an analyzed event. Reactor pressure control was maintained using reactor core isolation cooling and the safety relief valves. Reactor level control was maintained with the feedwater system initially and then with use of the Low Pressure Core Spray (LPCS) system. High pressure core spray was operable throughout the event. The normal heat sink through the main condenser could have been re-established by resetting the Group I containment isolation signal and opening the MSIVs in one main steam line. The main turbine bypass valves could then be opened as necessary to transfer decay heat to the main condenser.
Unit 1 just came out of their out their outage and they will at least go through another year with questionable and marginally designed MSIV. Maybe they will have a mid cycle shutdown later this year in order to fix more bad fuel. MSIVs like this are unsafe and these kinds of hard shutdowns damages other components in the nuclear plant. The wait until it breaks philosophy in order to fix it is a very costly attitude.
E. CORRECTIVE ACTIONS:• The upgraded design was installed in the four remaining Unit 2 inboard MSIVs. This was completed in August 2014 during the forced outage following the event.
• The upgraded design will be installed in the five remaining Unit 1 MSIVs that still have the vulnerable stem disk assembly.
Oh, it is in a process, I always trust management...it must be right. This OTDM process is a abomination. A component in the nuclear side of a large main steam line is marginally designed and expected to fail leading to a disk to stem separation. These large steam lines and heated water at 500 degrees carries a tremendous amount of energy and temperature. It threatens a main steam line rupture and this is a terrible accident in a nuclear plant. It threatens killing a lot of employees and permanently shutting down a nuclear plant. Damaging the whole nuclear industry. I am certain Exelon considered a very narrow range of risk, ones who wholly supported Exelon's financial goals. A justification if seen in the full light of day would seem to be crazy and corrupt as hell to the stakeholders and employees.
• Previous decisions that used the OTDM process to defer installation of a configuration change intended to mitigate High and Medium consequence issues will be reviewed using the Nuclear Risk Management Process implemented on 7/9/14. The Nuclear Risk Management
Process is a consistent process to evaluate and manage risk across a broad range of potential risks including the Operational Decision Making process (former OTDM process). This process addresses issues identified in the root cause investigation associated with the 2008 decision to defer the upgraded design for the MSIVs. Those issues included assessment of degradation rates and the review and verification that input data for decision making is complete and accurate.
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