Cook Plant: Interesting Plant Trip???

Think of how widespread this kind of engineering incompetence is at this two unit site. This would be my example of mind boggling engineering stupidity ultimately driven by financial pressures. This is only going to get worst. I just don't think the NRC has the capability to fix this management.      

SUBJECT: D. C. COOK NUCLEAR POWER PLANT, UNITS 1 AND 2 NRCINTEGRATED INSPECTION REPORT 05000315/2015003; 05000316/2015003; AND07200072/2015001

November 12, 2015

Introduction: A finding of very low safety significance (Green) was self-revealed on April 23, 2015 when the Unit 2 reactor was manually tripped shortly after startup from a refueling outage due to two condenser steam dump valves failing open. Contrary to the requirements of Modification Procedure PMP–5040–MOD–007, the design of the new valves that were installed was not compatible with the steam dump system.

In 2013, the licensee decided to replace the existing steam dump valves with a new design due to an increasing number of valve failures and other issues. However, design work and planning to perform the modifications failed to meet timeliness milestones prior to the outage. Contrary to the modification procedure for these circumstances, the change was not considered ‘fast-track,’ therefore, additional risk assessments and management oversight were not provided. Additionally, prior to the start of the modification package, components were procured ‘at-risk’ given the shortened timeline available to get the modification ready. Guidance in the modification procedure required personnel to confirm that a design had progressed sufficiently before allowing ‘at-risk’ procurement. In this case, procurement occurred prior to the start of the modification package. Further, stakeholder meetings to assess the modification only occurred after parts had been procured (i.e., the design had already been selected). Attendance at the meetings was also noted to be poor. As a result of the issues in adhering to the modification process, key attributes regarding the operation of the steam dump system were not incorporated into the design of the new valves; namely, the fact that the steam dump lines can be subject to significant amounts of condensate under normal operations. The design of the new valves allowed some of this condensate to be trapped in the valve body, unlike the original design. The potential for this condition was not considered when selecting the design nor conveyed as a possibility to the valve manufacturer. When steam was admitted to the valves, a two-phase flow dynamic was established due to the trapped water. This, combined with a different plug design in the new valves, created a significant backpressure within the valves, causing them to fail open. This conclusion was determined by an outside engineering firm the licensee consulted as part of the root cause process, and was accepted by the licensee.

Just think how expensive this screw-up was. Issues

1)      You catch the enormous magnitude of the normalization of devience going on here. They are severely addicted to NOD.

2)      The DG maintenance crew was negligently incompetent.

Annual Followup of Selected Issues: Failure of 1AB Emergency Diesel Generator

Inspection Scope  

On May 21, 2015, the 1AB EDG suffered a failure of the #4 main bearing during a post-maintenance test run. As a result of the failure, the EDG automatically shutdown on high bearing temperature. At the time of the failure, Unit 1 was in day three of a 14 day TS action statement allowed for major EDG maintenance outages. Because repairs would exceed the allowed outage time, on June 1 the licensee shutdown Unit 1 in accordance with TSs. During the forced outage, the license repaired the EDG, which included replacement of the crankshaft and several bearings. Following repairs, the licensee tested the 1AB EDG.

These issues had an impact on the volume of air remaining in the system upon this particular EDG start. Regarding the other factors necessary for arcing to occur, during repairs it was identified that the #6 rear connecting rod bearing had been damaged during a maintenance period in 2008. The degradation helped complete a current path for the arcing to occur

Updated and Reposted from 4/28
April 28:

Yea, 25% this morning... 

April 27:

(Tiny nuke company)

(AEP CEO) This strategy of investing in the regulated companies, particularly Wires and Transmission, focus on continuous improvement initiatives, such as lean practices, the crescendo in savings over time. And a culture of continued disciplined execution of our employees around operational excellence continues to produce positive results.

The Cook Plant is still at 0% power today? Nothing in the news? Man, they got a great cloaking device on site.  

 "manually tripped due to an uncontrolled cooldown"  

Honestly, you have a cooldown of a reactor still fully up a power by two failed steam dump valves slamming open. How many times have we seen this?

Outage began March  25? Must have just started up? Must have scammed on 20 to 30%. NRC says % last night and scammed at 5 am.  So it was relatively low power...transitioning onto the turb. Maybe not even at the point of adding heat. We are talking about a big cooldown.

Not even in the media?

They had a severe cooldown while at power, then they had to manually scam? I wonder what the max d/p was across the steam generator.

This guy is going to a special inspection...

MANUAL REACTOR TRIP DUE TO A SECONDARY PLANT TRANSIENT
"On April 23, 2015 DC Cook Unit 2 Reactor was manually tripped due to an uncontrolled cooldown due to two (2) failed open steam dump valves. The cause of the failure is still under investigation. 

"This event is reportable under 10 CFR 50.72(b)(2)(i) Tech Spec Required Shutdown, as a four (4) hour report; 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation, as a four (4) hour report; and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Reactor Protection System (RPS), as an eight (8) hour report. 

"The electrical grid is stable and Unit 2 continues to be supplied by offsite power. All control rods fully inserted. Decay heat is being removed via steam generator Power Operated Relief Valves due to steam dump valves being manually isolated. Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 2 remains stable in Mode 3 while conducting the post Trip Review. No radioactive release is in progress as a result of this event.

"The DC Cook Resident NRC Inspector has been notified." 

There is no indication of primary to secondary leakage and there is no impact on Unit 1.

SAN ONOFRE 

REGION: 4 |NOTIFICATION DATE: 07/01/2002|
| UNIT: [] [2] [] STATE: CA |NOTIFICATION TIME: 00:33[EDT]|
| RXTYPE: [1] W-3-LP,[2] CE,[3] CE |EVENT DATE: 06/30/2002|
+------------------------------------------------+EVENT TIME: 18:58[PDT]|
| NRC NOTIFIED BY: CONOSCENTI |LAST UPDATE DATE: 07/01/2002|
| HQ OPS OFFICER: JOHN MacKINNON +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: NON EMERGENCY |WILLIAM JOHNSON R4 |
|10 CFR SECTION: | |
|ARPS 50.72(b)(2)(iv)(B) RPS ACTUATION - CRITICA| |
| | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE
|
+-----+----------+-------+--------+-----------------+--------+-----------------+
| | |
|2 A/R Y 18 Power Operation |0 Hot Standby |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| AUTOMATIC REACTOR TRIP ON LOW STEAM GENERATOR PRESSURE DUE TO TWO
ADDITIONAL |
| STEAM DUMP VALVES FULLY OPENING DURING STARTUP. |
| |
| System Affected |
| "Primary: Rx Trip, CEA, RCP's stayed on, PLCS" |
| "Secondary: SBCS Open, MSIV's, ADV, MFW, AFW" |
| |
| Actuations and Their Initiating Signals |
| "MSIS A & B @ 741 PSIA. Lowest Seen = MSIS setpoint" |
| |
| Causes |
| "Prelim: 4 SBCS All Fast Open . . . " |
| |
| Effect Of Event Plant |
| "Low S/G Pressure Rx Trip, Turbine Trip, MSIS isolated secondary. CVCS |
| remained in service. MSIS verified and rest, then AFW initiated. (Did not |
| want cooldown from steam-driven AFW Pp. Adequate S/G water level maintained |
| throughout. Approx. 50% NR)." |
| |
| Actions Taken or Planned |
| "EOI's: S023-12-1 (SPTA's), S023-12-2 (RTR), OI: S023-S-1.3.1 S0123-0-14 4 |
| Hour" |
| "E-PLAN Review P S/G" [decreased]) |
| |
| The licensee was going to bring the main turbine on line which was rolling |
| at 1800 rpm. Two steam dump bypass valves were open dumping steam to the | | main condenser to help maintain reactor power at 18%. Unexpectedly two| main condenser to help maintain reactor power at 18%. Unexpectedly two |
| additional steam dump bypass valves opened. When these two additional steam |
| dump bypass valves opened the first two open valves initial started to close |
| then they went full open. Steam generator pressure decreased to the low |
| steam generator pressure setpoint of 741 psia at which point an automatic |
| reactor trip plus a main steam isolation signal (MSIS) was generated, main |

These guys got a automatic scram and no mention of a out of control cool down?  

| steam isolation valves (MSIV's) closed. All rods fully inserted into the |
| core. Atmospheric steam dump valves were used to maintained proper reactor |
| coolant system temperature. The licensee said that they did not have any |
| leaking steam generator tubes. Proper steam generator water inventory was |
| verified at which time the MSIS signal was reset, then one Motor Driven |
| Auxiliary Feedwater Pump was manually initiated to maintain proper steam |
| generator water level. Main feedwater system isolated due to the MSIS |
| signal and the reactor trip. All emergency core cooling systems, emergency |
| diesel generators are fully operable if needed. The electrical grid is |
| stable. The licensee is investigating why the two additional steam dump |
| bypass valves opened. |
|

Hmm?  Cook must be in a media dead spot?

POINT BEACH: REACTOR POWER EXCEEDED FSAR ANALYZED 

On 10/12/12 at 0420 CDT the Unit 2 Steam Generator B Atmospheric Steam Dump Valve (ADV) spuriously opened while in automatic control. This resulted in indicated reactor power exceeding the FSAR analyzed value of 1810.8 MWt. Prompt operator action was taken and reactor power was restored to within limits in approximately four minutes. The operators placed the Atmospheric Steam Dump Controller to manual and closed the ADV successfully. This event is being reported under the criteria in 10 CFR 50.72 (b)(3)(ii)(B).

NRC Notified By: RUSS PARKER
10 CFR Section: 50.72(b)(3)(ii)(B) - UNANALYZED