It really does not matter. In 2018, Congress passed a law called NEIMA instructing the NRC to drastically simplify its licensing procedures for new designs. Four years later the NRC came up with a 1200 page draft which is so bad that all the applicants of which I am aware have elected to use the old system. Congress has lost control of the NRC.
I had the same original thought as you did. But after digging more deeply into the issue, I learned my initial judgement was incorrect.
The vibration was caused by a construction defect. Here is a quote from the letter from Southern Nuclear to the NRC:
"While the elevated vibrations subsided when the reactor coolant pumps were downshifted to 50%, an investigative walkdown on January 4, 2023, identified an installation non-conformance whereby an interface plate between the U-bolts and pipe on the clamp was not installed on two pipe supports, RCS-PH- 11R0107 and RCS-PH-11R0393. Since vibration was already found to be higher than anticipated in Mode 3, and based on data review, piping analysis, and walkdown, it was concluded that the risk of vibration increases beyond design limits is likely at higher power levels. Accordingly, it was determined that the missing interface plates on RCS-PH-11R0107 and RCS-PH-11R0393 be installed to bring the as-built plant in conformance with the design. This condition was identified as a nonconformance in accordance with plant procedures.
Rework to install the pipe support interface plates..."
Thus it's not the repair that required a license amendment. The amendment requested was a temporary change to the plant's technical specifications to allow it to remain in Mode 3 and to not have to return to Mode 4 or 5 while the repairs were being completed. The NRC reviewed and approved the amendment within 72 hours of submission.
The complexity of the repair is more than I thought because of the way that the large diameter pipe has to be moved and supported.
I also suspect there is a root cause investigation being done to find out why the as-built condition did not meet the design condition. Either the original workers or the QA verifiers should have been able to avoid the problem by adhering to the design drawings.
Thanks valuable info. So it was not a design screw up; it was an installation screw up. That should make the fix even easier. Just put in the missing interface plates. No way that should take anything like 30 days. Worry about whose fault it was later.
For us Sunday night quarterbacks, the situation is a little confusing. That's especially true for people like you who have a lot of professional experience with large facilities full of pipes carrying explosive or poisonous fluids and gases.
But nuclear system primary piping is unique. I'd love to be able to see photos of the location of interest that help me understand the interference that might hamper access and the sizes and thicknesses of the pipes involved.
I'm sending you a copy of Southern Nuclear's letter to the NRC, which provides a detailed description of the rework and explanation of the expected duration of the activity. It's ten days, not 30, but it's a lot easier to provide the public and the PUC with a longer and more costly estimate than to provide a more precise estimate that has to be revised if there are any unexpected delays.
Thanks Southern letter. 28 pages of legalese to say a LOCA is not a problem , since the fuel is unirradiated. There is no decay heat. There are no fission products. Stage 4 of the depressurization system is not needed in this condition. Duh! On a normal job, that would have been obvious to everybody immediately. Now let's figure out how to lift the damn pipe so we can install the interface plates. But for nuclear, this is a license amendment.
Like you, I would need to see the drawings to see how difficult the actual job is. But for my tanker crews, unfastening a couple of U-bolts, lifting the pipe a bit with some chainfalls, and sliding in the plates, maybe an hour.
to the fossil fuel industry. They do PR, assume 5% of revenue like any industry.
So with a $1.4E12 turnover, the fossil fuel industry will spend $7E10 per year on marketing, bizdev, influence peddling, to defend their turf.
How many US Senators can you buy with a fraction of $70 billion per year?
They are not always transparent about expressing themselves. Sometimes they create social groups such as "Friends of the Earth" that do some essential and good work--- but happen to be implacably anti-nuclear because they were founded by Fossil Fuel magnates.
I have a different take. See the Big Oil and Nuclear piece on this substack. I think nuclear and Big Oil could team up again. Of course, my guys think I'm crazy.
Who are nuclear’s biggest allies and enemies in the U.S. Congress?
It really does not matter. In 2018, Congress passed a law called NEIMA instructing the NRC to drastically simplify its licensing procedures for new designs. Four years later the NRC came up with a 1200 page draft which is so bad that all the applicants of which I am aware have elected to use the old system. Congress has lost control of the NRC.
Yes, the license to design model is horrible. That model is designed to give make work to bureaucrats.
This is one big "Bruh" moment. One of many from the NRC.
Jack:
I had the same original thought as you did. But after digging more deeply into the issue, I learned my initial judgement was incorrect.
The vibration was caused by a construction defect. Here is a quote from the letter from Southern Nuclear to the NRC:
"While the elevated vibrations subsided when the reactor coolant pumps were downshifted to 50%, an investigative walkdown on January 4, 2023, identified an installation non-conformance whereby an interface plate between the U-bolts and pipe on the clamp was not installed on two pipe supports, RCS-PH- 11R0107 and RCS-PH-11R0393. Since vibration was already found to be higher than anticipated in Mode 3, and based on data review, piping analysis, and walkdown, it was concluded that the risk of vibration increases beyond design limits is likely at higher power levels. Accordingly, it was determined that the missing interface plates on RCS-PH-11R0107 and RCS-PH-11R0393 be installed to bring the as-built plant in conformance with the design. This condition was identified as a nonconformance in accordance with plant procedures.
Rework to install the pipe support interface plates..."
Thus it's not the repair that required a license amendment. The amendment requested was a temporary change to the plant's technical specifications to allow it to remain in Mode 3 and to not have to return to Mode 4 or 5 while the repairs were being completed. The NRC reviewed and approved the amendment within 72 hours of submission.
The complexity of the repair is more than I thought because of the way that the large diameter pipe has to be moved and supported.
I also suspect there is a root cause investigation being done to find out why the as-built condition did not meet the design condition. Either the original workers or the QA verifiers should have been able to avoid the problem by adhering to the design drawings.
Rod,
Thanks valuable info. So it was not a design screw up; it was an installation screw up. That should make the fix even easier. Just put in the missing interface plates. No way that should take anything like 30 days. Worry about whose fault it was later.
Jack:
For us Sunday night quarterbacks, the situation is a little confusing. That's especially true for people like you who have a lot of professional experience with large facilities full of pipes carrying explosive or poisonous fluids and gases.
But nuclear system primary piping is unique. I'd love to be able to see photos of the location of interest that help me understand the interference that might hamper access and the sizes and thicknesses of the pipes involved.
I'm sending you a copy of Southern Nuclear's letter to the NRC, which provides a detailed description of the rework and explanation of the expected duration of the activity. It's ten days, not 30, but it's a lot easier to provide the public and the PUC with a longer and more costly estimate than to provide a more precise estimate that has to be revised if there are any unexpected delays.
Rod
Rod,
Thanks Southern letter. 28 pages of legalese to say a LOCA is not a problem , since the fuel is unirradiated. There is no decay heat. There are no fission products. Stage 4 of the depressurization system is not needed in this condition. Duh! On a normal job, that would have been obvious to everybody immediately. Now let's figure out how to lift the damn pipe so we can install the interface plates. But for nuclear, this is a license amendment.
Like you, I would need to see the drawings to see how difficult the actual job is. But for my tanker crews, unfastening a couple of U-bolts, lifting the pipe a bit with some chainfalls, and sliding in the plates, maybe an hour.
Thanks for the detailed response. That is helpful and I can see it was not a design change.
Nuclear power is extremely dangerous
to the fossil fuel industry. They do PR, assume 5% of revenue like any industry.
So with a $1.4E12 turnover, the fossil fuel industry will spend $7E10 per year on marketing, bizdev, influence peddling, to defend their turf.
How many US Senators can you buy with a fraction of $70 billion per year?
They are not always transparent about expressing themselves. Sometimes they create social groups such as "Friends of the Earth" that do some essential and good work--- but happen to be implacably anti-nuclear because they were founded by Fossil Fuel magnates.
Grumpy,
I have a different take. See the Big Oil and Nuclear piece on this substack. I think nuclear and Big Oil could team up again. Of course, my guys think I'm crazy.