Part 21: Crappy Safety Relief Parts At Pilgrim

Bottom line, all the valves could have been degraded at once, and who knows how far that has gone on... 

Remember the Hatch NRC inspector felt the cause of it was Pilgrim cycled their SRV valves much more than Hatch...

You think this statement is true: Appendix B stipulates extensive quality assurance requirements to ensure all key design, engineering, and production processes are sufficiently controlled in order to guarantee the performance of safety-related equipment?

It means you got a strict QA program nationwide in paper only...

INTERIM PART 21 REPORT - POTENTIAL TEST INDUCED DEFECT IN A 0867F MAIN STEAM SAFETY RELIEF VALVES

Sounds like they took out  the SRV SN 9,4 and 3 of the Juno Blizzard plant trip.  The talking about having three SRVs open at one time and not being able to shut them. You can't throttle these valves open...it either open or shut. 

We are continuing the search for relevant Operating Experience (OE) and are currently aware of the following: 

Pilgrim 0867F: Three (3) Pilgrim 0867F main assemblies, identified as S/N 9, 4 and 3, had main guide grooving and fretting wear, as well as damage to main disc threads, piston and piston rings. All of these valves opened under limited flow as-found testing at the set pressure. Additionally, S/N 9 and 4 were manually tested and successfully opened when low pressure (approximately 100 psig) was provided at the valve inlet.
None of these valves re-closed during the limited flow test.

During testing just before they installed the valve in the plant they were damaged? 

At this time, TR believes the most likely root cause is excessive impact loads during limited flow
testing that relieves the torque applied to the piston/stem interface (de-torqueing) that may
subsequently lead to creation of a significant clearance between the piston and the main disc
(de-shouldering). If the excessive impact load also damages the locking tab, plant vibratory
loads can allow the piston to rotate creating/increasing the clearance between it and the stem. If
the clearance becomes significant, the piston tilts in its guide bore which can inhibit valve reclosing under certain conditions.

As far as the limited flow testing damaging the parts of the valve...it looks like cheap parts.