Dead Ender Junk Plant Clinton: Special Rules And Regulation For Dead Ender Plants

Update 7/28

Had a discussion with the resident and senior resident for about 45 minutes on this today. The NRC said they generally agree with my philosophy concerning this event. He said a recent inspection report had 14 violations. It must be the upcoming once because I went over the last 4 or 5 inspection reports not seeing it. NRC said this event is under investigation, we can't disclose much. I told them the theme with this discussion was having reduced oversight for a dead-ender plants. The NRC said they and Clinton are Midwesterners, they take pride in the work.  
The NRC says the containment sumps showed no sign of leaking until the shutdown began. I explained I couldn't understanding the magnitude of the current leakage while shutdown and it not showing up as containment leakage during normal operations considering more energy a much higher temperature and pressure. They assured me it wasn't leaking during the cycle. So the leaks began sometime during the shutdown process. I began/opened up the conversation saying I believe the two flex hose leaks were caused by new main steam line vibrations. 

***I believe the NRC inspectors on them saying no leakage during the last cycle. But it doesn't seem plausible with two flex hoses mysterious beginning to leak at the same time during the shutdown on a long term corrosion cracking leak as Clinton stated in the LER. It is like the chances

 "The cause of this event was IGSCC."

of winning the billion dollar lottery. To get there with the leaks beginning in the shutdown process, with simultaneous flex hose instrumentation leaks in completely different giant main steam lines, indicates there was some simultaneous large abnormal shaking of all main steam lines during the shutdown. A slug of water, a big valve slamming shut or something going down in all the steam lines.***

I thought I had them with not doing any inspections on the two flex hoses not replaced. The NRC SAID Clinton did UT and dye penetrant testing on the not replaced flex hoses. I still thought it not conservative with replacing all four (or more) flex hoses as a precautionary measure.       

To my Russian friends: This is how the USA does nuclear power in a democracy. Its not perfect. 

 
05000461

The issues I got it

1) Special interpretation of regulatory oversight for dead ender plants

2) This leak could obscure more safety related leaks.

3) There could be incipient cracks in the A and D instrument line?

4) They could be treating all the safety like this.

5) I suspect this is cause be a recent increase in Main Steam Line vibrations.  

***This guys got one year of life left in them.***

• Exelon Announces Early Retirement of Clinton and Quad Cities Nuclear Plants

Company begins taking steps to shut down plants

• Scheduled for shutdown June 2017.

This looks a lot like the same leak just prior to the 2007 shutdown event. What didn't they make a drywell inspection in the lead up to the outage? This is insanity posing this as a shutdown event. It is a falsification and misleading to the public. The is a at power event and much more energy behind the leak. The pressures and temperature driving the leak(s) would be much larger.    

MSL 'B' had water leaking slowly in a thin, steady stream. 

MSL 'C' had water dripping out slowly, less than 5 dpm.

Main Steam Line Flexible Hose lntergranular Stress Corrosion Cracking Identified During Refueling Outage

Licensee Event Report 2016-007-00

On May 17, 2016 with the plant in Mode 4 during Refueling Outage C1R16 personnel entered the drywell to perform a system walkdown. At 0945 CDT water was identified leaking from flexible hoses located at the inner elbows of main steam line (MSL) B and MSL C. It was determined that the leakage was from the flexible hoses associated with the MSL flow instrumentation. The degraded flexible hose on MSL B was previously replaced in 2008 and on MSL C in 2007. An analysis determined the failure mechanism of the degraded flexible hoses as lntergranular Stress Corrosion Cracking (IGSCC). Main Steam Line C flexible hose had previously failed in 2007 due to IGSCC. Corrective actions taken for that event did not prevent a recurrence of the condition identified during C1R16. The leaking flexible main steam line hoses and the remaining flexible hoses on the MS Ls B and C were replaced during C1R16. The remaining inner elbow flexible hoses on MS Ls A and D have been scheduled for replacement during the next refueling outage C1R17. This condition is reportable under 1 O CFR 50.73(a)(2)(ii)(A), as a condition that resulted in the condition of the

nuclear power plant, including its principal safety barriers being seriously degraded.

***There were no safety consequences associated with this condition. This event is reportable under the provisions of 10 CFR 50.73(a)(2)(ii)(A) for the condition of the nuclear power plant including its principal safety barriers being seriously degraded. A plant shutdown was not required since the plant was in Mode 4 during refueling outage C1 R16. 

***CAUSE OF EVENT 

IGSCC resulted in the failed flexible hose discovered during the C1R16 walkdown. The root cause evaluation tor this event determined that the corrective actions to prevent recurrence of the condition identified June 18,

They are repeating the failed to eliminate and significantly reduce the factors in this new LER

*2007 (LER 2007-003) failed to eliminate or significantly reduce below threshold any of the three factors required for IGSCC to exist (susceptible material, tensile stresses, and aggressive environment).

***CORRECTIVE ACTIONS 

The leaking flexible main steam line hoses and the remaining flexible hoses on the MSLs Band C were replaced during C1R16. The remaining inner elbow flexible hoses on

Why didn't they proactivity replace the A and D flex hoses? Where is the testing like UT proving the flex instruments hoses don't have any incipient cracks.

MSLs A and D have been scheduled tor replacement during the next refueling outage C1 R17. A design modification is planned to eliminate or significantly reduce at least one of the three factors required for IGSCC (susceptible material, tensile stress, or corrosive environment) to below the threshold where IGSSC can be initiated. 

PREVIOUS SIMILAR OCCURENCES

LER 2007-003-00: IGSCC Causes Pressure Boundary Leak and Reactor Shutdown

On June 18, 2007, Operations performed a plant shutdown at 1241 hours to assess indications of a drywell steam leak and repair the leak. On June 19 at 0635, Maintenance personnel entered the drywell and found pressure boundary leakage on a one-inch diameter ASME Section Ill Class II stainless steel braided flexible hose assembly on the 'C' Main Steam Line flow elbow low-pressure instrumentation tap. Operators entered the actions of Technical Specification 3.4.5, which required a plant shutdown due to reactor coolant pressure boundary leakage. The cause of this event was IGSCC. Flexible hose assemblies installed in IGSCC susceptible locations were replaced. Susceptible flexible hose assemblies that were not currently in service were cut out and the lines were capped. Preventive maintenance was established to periodically replace susceptible flexible hose assemblies installed in IGSCC susceptible locations.

 All the drywell conditions of leaking instrumentation flex hoses seen in 2007 weren't seen in 2016? Come on.

LER 2007-003-00

"Operators checked the MSL guard pipe temperatures and Reactor Recirculation [AD] seal [SEAL] parameters and found them unchanged. The DW head temperature increased from 200 degrees Fahrenheit (F) to 211 degrees F. The DW pressure rate of change also increased. At 0520 hours, the DW floor drain inleakage was 0.3 gallons per minute (gpm) and slowly trending up. These conditions were indicative of a possible high energy leak in the drywell.

Operators entered the Abnormal Release of Airborne Radioactivity and the Reactor Coolant Leakage emergency operating procedures.

At 0800 hours, the unidentified leakage was less than the Technical Specification (TS) limits of 5 gpm (0.7 gpm) for unidentified leakage, of 30 gpm (2.7 gpm) for total leakage averaged over the previous 24 hour period, and of 2 gpm increase in identified leakage in the previous 24 hours (went from 0.09 to 0.6 gpm) in Model1.

Operators continued to monitor the steam leak indications, and at 1241 hours, Operators made a decision to perform a plant shut down starting at 2000 hours in order to access the DW to identify the source of the steam leak and make repairs. The shutdown process started at 2011 hours.

On June 19, at about 0635 hours, with the plant in Mode 2 (Startup/Hot Standby) and reactor power at about 1 percent, Maintenance personnel entered the DW and identified the source of the steam leak was a one inch diameter ASME Section III Class 11 stainless steel braided, flexible hose assembly [PSX] on the "C" Main Steam Line flow elbow low-pressure instrumentation tap. Leakage from this source is classified as pressure boundary leakage; therefore, operators entered the actions of Technical Specification 3.4.5 that require the plant be in Mode 3 in 12 hours and Mode 4 in 36 hours. Operators fully inserted all control rods by 1103 hours on June 19."