The Edison Company has decided to close San Onofre’s troubled nuclear reactors. The LA Times as well as this blog has covered their difficulties since replacing the four steam generators with ones of a new and untested design built by Mitsubishi, at a cost of $762 million.
Maybe there will be hearings or an NRC report on what went wrong. Knowing a little about engineering projects and large physics experiments and accelerators, I can imagine that errors of oversight and internal checks occurred over a long series of time. First of all, the decision to replace the previous design of the four steam generators, two in each unit, with a new one, possibly to increase energy output slightly or to reduce cost, is always a risky plan. The decision to pass this off as an already licensed replacement rather than planning for new approval from the NRC blocked independent oversight of the design and testing procedures. Calculations of the physics workings of the heat exchangers were off by a factor of four, and left no water vapor on the sides of the tubes, which led to their high vibration rate and caused unusually fast wear on them. In physics experiments, calculations are done by two independent groups, and must eventually be reconciled to agreement before the calculations are okayed. In engineering projects and experiments, smaller scale projects are usually constructed and tested before scaling up to the final size. Finally, parts or sections of the final product or at least one of the totally produced steam generators should have been tested in a simulation. Even though each of these steps increases the total cost by a small amount, they are necessary in most projects and experiments to guarantee a successful outcome. We have not heard yet which have been done.
As to the cost of decommissioning, which might cost $3 billion, remarkably, 90% or $2.7 billion has already been accumulated for that. Like most new type of projects, we can expect it to be more expensive. Still, reactor cores will be stored there for a long time, and we hope that they will be dry cask stored as soon as feasible.
As far as congressional hearings leading to unbiased scientific and engineering assessments, we only have current examples where politics and political backing by industries turns these into political games. This might be especially tricky since the local districts’ ultra-conservative Representatives are Darrell Issa (CA-49th, 63%), Dana Rohrabacher (CA-48, 61%), with previous Representative of my district Chris Cox, who was promoted to guide the SEC to the current recession, and my current Representative John Campbell (CA-45th, ).
On the replacement energy issue, I have been waiting more than a year to find out what energy sources have been used for replacement energy, but have seen nothing. There is a category of unknown mixed energy on the yearly reports of utilities, which makes it impossible to find the carbon emissions of each utility, and much may be hidden there. The yearly reports do not come out until September of the following year, since they involve the addition of ten numbers, and that must be very complicated.
The anti-nuclear groups are very happy to say that the energy will be replaced by wind and solar. However, as a California and US taxpayer, we paid high prices to develop wind and solar, planning on it to replace say the use of coal by Los Angeles, which gets 44% of its power from coal. We did not make that investment to replace an already clean power source, nuclear power. The NY Times suggests that California may try to reactivate 11 coastal natural gas plants, which were partly shut for noise, vapors, and sea water heating. Being a very large 2.2 GigaWatt plant, San Onofre had hot water dispersal down to less than a degree Fahrenheit heating, had fish guards, and had paid over a hundred million dollars in mitigation to regrow kelp forests in a neighboring coastal region.
With the elimination of two of the maybe six US nuclear reactors that are considered at high earthquake risk, and maybe the shut down of the other four if they cannot get lifetime extensions, the US nuclear industry can regain a high safety rating.
