Widespread Platumin Coating Flaking On Seating serfaces in BWR Safety Releif Valves.

Update Aug 19

Experiments: stellite, stellite B and now platium. 

Update Aug17

I spent about 2 hours talking to the Brunswick inspector and the public affairs people yesterday. I called the chairman's office and they got a Washington public affairs officer to talk to me. My aim with the chairman's office was gain me more influence than I deserve. If NRC officials know this emendated from chairman's office they will pay more attention to me. Basically went over the territory with BWR SRV testing failures. It is surprising the inspectors only look at this from their plant perspective...don't understand the big picture. My total objective with calling the chairman's was I want to take to their expert on Safety Relief Valves. He would have broad experience with all the troubles with the SRV. The PA guy said he would do the best that he could do. 

I got wind their is a secret white paper on SRV problems. This isn't disclosed to outsiders. I guess it is a NRC internal position paper, more about the internal agency deliberations. I asked the NRC to release the paper to me. I wonder how many secret white papers, over a host of other issues, there are within the NRC.

***The failure of the platinum to stick to the seating surfaces is a unreviewed safety problem. The problem is only looked at on a single plant bases. It is going on all over the place. Platinum is flaking off at untold BWR facilities including Browns's Ferry and Brunswick. Platinum is just the latest coating scam. This is leading to some eye popping magnitude pressure testing failures never seen before. Worst, the flaking is leading to steam cutting of the seats. This direly threatens the operability of the valves. Steam cutting the pilot valves does lead to a high probability of the valves to fling open at power and inability to shut the valve. It is also implicated in the valve not being about to open on demand and in remote. Pilgrim Plant had similar problems with SRVs. The plant grade by the NRC was severe downgraded and is directly implicated with their permanent closure. 

1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER
YEAR
Browns Ferry Nuclear Plant, Unit 2 05000260
SEQUENTIAL NUMBER
REV NO.
2019 - 002
NARRATIVE  

I. Plant Operating Conditions Before the Event
At the time of discovery, Browns Ferry Nuclear Plant (BFN) Unit 2 was in Mode 1 at approximately 91 percent power.
II. Description of Event  

A. Event Summary 

On May 29, 2019, NWS Technologies notified the Tennessee Valley Authority (TVA) with the as-found testing results of the thirteen Main Steam Relief Valves (MSRVs) [EIIS:RV], which were removed during the Spring 2019 Unit 2 Refueling Outage 20 (U2R20). Three MSRVs (BFN-2-PCV-001-0004, BFN-2-PCV-001-0018, and BFN-2-PCV-001-0019) had as-found lift settings which were outside of the +/- 3 percent band of their setpoints required for operability. 

Technical Specification (TS) 3.4.3, Safety/Relief Valves (S/RVs), requires twelve of the thirteen S/RVs to be operable for S/RV system operability. The three MSRVs were found to have been inoperable for an indeterminate period of time during the entire operating cycle between March 29, 2017, and March 2, 2019, and longer than permitted by TS 3.4.3. 

Previously, on April 27, 2018, MSRV BFN-2-PCV-001-0041 had been declared inoperable due to excessive leakage. It was removed and replaced during a midcycle outage in May 2018. Subsequent testing by NWS Technologies identified the as-found lift setting was outside the required +/- 3 percent band. At the time, BFN-2-PCV-001-0041 was the only known inoperable MSRV and the requirement of TS 3.4.3 (twelve of the thirteen S/RVs operable) was considered to be met.
Throughout this event, the two-stage MSRV pilot valves remained capable of maintaining the reactor pressure below 1375 pounds per square inch gauge (psig), which is the American Society of Mechanical Engineers (ASME) code limit of 110 percent of the vessel design pressure. The valves remained capable of performing their required safety function. 

The TVA is submitting this report in accordance with Title 10 of the Code of Federal Regulations 50.73(a)(2)(i)(B), as any operation or condition which was prohibited by the plant's TS.

B. Status of structures, components, or systems that were inoperable at the start of the event and that contributed to the event
There were no structures, systems, or components (SSCs) whose inoperability contributed to this event.

NARRATIVE 

C. Dates and approximate times of occurrences
Dates March 29, 2017
April 27, 2018
May 7, 2018
May 10, 2019
March 2, 2019
May 29, 2019  

Occurrence Unit 2 entered Mode 2 at beginning of cycle 20 (U2C20) 

BFN-2-PCV-001 -0041 declared inoperable due to excessive leakage  

Unit 2 entered Mode 4 for the replacement of BFN-2-PCV-001 -0041 

Unit 2 entered Mode 2 following the replacement of BFN-2-PCV-001 -0041 

Unit 2 entered Mode 4 for U2R20 

NWS Technologies notified the TVA with as-found testing results of the thirteen Unit 2 MSRV pilot valves removed during U2R20 

D. Manufacturer and model number of each component that failed during the event
The failed components were all Target Rock Corporation two-stage pressure control valves, model number 7567F. 

E. Other systems or secondary functions affected
No other systems or secondary functions were affected by this event. 

F. Method of discovery of each component or system failure or procedural error 

Failure of MSRVs BFN-2-PCV-001-0004, BFN-2-PCV-001 -0018, and BFN-2-PCV-001-0019 was discovered at NWS Technologies during their as-found testing of the thirteen MSRV two-stage pilot valves which were removed during U2R20. Failure of MSRV BFN-2-PCV-001-0041 was discovered based upon leakage estimates during plant operation and subsequent testing by NWS Technologies. 

G. The failure mode, mechanism, and effect of each failed component  

MSRVs BFN-2-PCV-001 -0004, BFN-2-PCV-001-0018, and BFN-2-PCV-001-0019 failed due to corrosion bonding to the valve seats as a result of the platinum anti-corrosion coatings flaking off. Two additional test lifts on each valve were within the acceptance criteria of +/- 3 percent of the required setpoint, indicating corrosion bonding caused each pilot valve to initially lift high.

NARRATIVE 

2019 - 002
Failure of MSRV BFN-2-PCV-001-0041 was caused by a delamination of a portion of the platinum anti-corrosion coating which lead to the leak. 

These guys crossed their quality and QA regulations. This platinum coating should have been proofed in a test stand with the same environment and duration as the SRVs in the reactor with a generous margin of safety.  The guys are doing unapproved experiments in a reactor.  

H. Operator actioans  

There were no operator actions associated with this event.
I. Automatically and manually initiated safety system responses 

There were no automatic or manual safety system responses associated with this event. 

Ill. Cause of the event 

A. Cause of each component or system failure or personnel error  

MSRVs BFN-2-PCV-001-0004, BFN-2-PCV-001 -0018, and BFN-2-PCV-001 -0019 failed above their setpoint band due to valve disc corrosion bonding to the valve seat as a result of the platinum anti-corrosion coating flaking off. In the case of MSRV BFN-2-PCV-001-0041, the loss of the platinum anti-corrosion coating led to leakage which affected its lift setpoint. 

B. Cause(s) and circumstances for each human performance related root cause 

No human performance related root causes were identified. 

IV. Analysis of the event 

BFN Unit 2 TS Limiting Condition for Operation (LCO) 3.4.3 requires twelve Operable S/RVs during Modes 1, 2, and 3. If one or more required S/RVs become inoperable, Required Action A. 1 requires entering Mode 3 within 12 hours and Required Action A.2 requires entering Mode 4 within 36 hours. S/RV Operability requires that S/RVs be within a +/- 3 percent band of their setpoint values in accordance with Surveillance Requirement (SR) 3.4.3.1. BFN Unit 2 has thirteen MSRVs to satisfy this requirement with margin.
When tested, the following four S/RVs were outside the allowable+/- 3 percent band. 

S/RV Number Set~oint Test Result Difference BFN-2-PCV-001-0004 1155 1215 +5.2% BFN-2-PCV-001-0018 1145 1197 +4.5% BFN-2-PCV-001-0019 1135 1214 +7.0% BFN-2-PCV-001-0041 1155 1230 +6.5%
00

NARRATIVE 

Prior to startup from U2R20, all thirteen MSRV pilot valves were replaced with refurbished valves which were certified to lift within +/- 1 percent of their setpoint. Operating Experience has shown that Target Rock two-stage MSRV setpoint drift is not a uniform, linear process. The corrosion bonding increases at a random rate. Without an accurate and reliable model for predicting or estimating the setpoint drift development, the point in time where the setpoint exceeded the +/- 3 percent limit cannot be reliably determined. Since this drift occurred during the operating cycle when the MSRVs were installed, MSRVs BFN-2-PCV-001-0004, BFN-2-PCV-001 -0018, and BFN-2-PCV-001-0019 are conservatively considered to be inoperable for an indeterminate period of time between March 29, 2017, and March 2, 2019. MSRV BFN-2-PCV-001 -0041 was considered to be inoperable from April 27, 2018 until entering Mode 4 on May 7, 2018, for replacement. More than one MSRV was considered to be inoperable during the entire operating cycle and longer than permitted by TS 3.4.3. 

TS LCO 3.0.4 states that when an LCO is not met, entry into a Mode or other specified condition in the Applicability shall only be made when the associated ACTIONS to be entered permit continued operation in the MODE or other specified condition in the Applicability for an unlimited period of time. Because Unit 2 made Mode changes from a mid-cycle on May 10, 2018, while TS 3.4.3 was not met, Unit 2 was in violation of TS 3.0.4. 

V. Assessment of Safety Consequences 

System availability was not impacted by this event. The failure of the MSRV pilot valves to meet their TS 3.4.3 specified mechanical setpoints does not impact their remote-manual operation or activation through the MSRV Automatic Actuation Logic, since these operating modes and functions rely upon electrically signaled control air solenoids to open the MSRV pilot valves. 

The bounding maximum over-pressurization analyses are performed each fuel cycle to show that the requirements of the ASME code regarding overpressure protection are met. The analyses are performed specifically to show that the dome pressure TS limit of 1325 psig is not exceeded and that the vessel pressure does not exceed the limit of 1375 psig. In addition, the Anticipated Transient Without Scram (A TWS) pressurization analyses are also performed to demonstrate that the 1500 psig peak vessel pressure limit is not exceeded. 

For the ASME analysis, the existing analysis setpoint groupings conservatively bound the eleven lowest as-found MSRV opening setpoints; however, the highest as-found valve opening setpoint falls outside the bounds of the existing analysis valve groupings. Therefore, the limiting ASME overpressurization event, identified as the ASME with main steam isolation valve closure at 102 percent rated power/ 105 percent rated flow at coastdown, was re-analyzed based on the as-found lift settings. The re-analysis determined a maximum dome pressure of 1272 psig and maximum vessel pressure of 1305 psig, which are within the ASME limits.
For the A TWS analysis, the existing analysis valve setpoint groupings conservatively bound the eight lowest as-found MSRV opening setpoints; however, the four highest valve setpoints fall outside the existing analysis valve groupings. Therefore, the limiting A TWS overpressurization event, identified as the A TWS pressure regulator failed open at 100 percent rated power I 81 percent rated flow at beginning of cycle, was re-analyzed based on the as-found lift settings. The re-analysis determined a maximum vessel pressure of 1414 psig, which is within the ATWS limit.
TS Bases 3.4.3 states that the overpressure protection system must accommodate the most severe pressurization transient. The MSRVs remained capable of maintaining the reactor pressure below 1375 psig, which is the ASME code limit (110 percent of the vessel design pressure). The valves remained capable of performing their required safety function. Therefore, as defined in NEI 99-02, failure of the MSRV pilot valves was not a safety system functional failure. 

Based on the above, the TVA has concluded that sufficient systems were available to provide the required safety functions needed to protect the health and safety of the public...