Our committee continues to receive weekly updates from the radiologic health chief. We will be scheduling a trip to Vernon in order to see the activities and speak with those on site in 2 weeks.
Dr. Irwin reported that a significant leakage source has been found in a flawed concrete joint in the AOG pipe tunnel. VY and NRC concur that this is one clear source of groundwater contamination which probably occurred in the last 18-24 months. While this is one leak, it may not be the only leak. It could be that about 300,000 gallons of ground water are contaminated and could have been happening at a rate of about 100 gallons per day.
Dr. Irwin’s review of the documents indicated that the AOG system was modified in 1972, creating a very long pipe tunnel that was otherwise inaccessible to inspection. Later modifications in 1978 were described as “a set of construction practices that are, frankly, totally alien to nuclear facility construction practices.” He described one piece of form wood originally used to create a form around the impaired concrete duct that had been left there “by neglect.” Over the course of years, when the wood rotted, this created an open space or pathway for this water to leak out (especially when wet) of this otherwise sealed pipe tunnel.
When asked if he thought this could happen again, he state that these exact circumstances might not happen, however the evidence that the workmanship here was “so shoddy it would not likely pass the local town building inspector, let alone the nuclear facility inspector…This defies all basic engineering principles, in my opinion, to have so much important piping where it is physically uninspectable, let alone where you have to literally break thru 24 inch concrete flooring to get to it to affect any repairs.” It is possible that this kind of work may have occurred elsewhere.
In his discussion with the VY engineer, they acknowledged that “when this kind of work was done in 60-70′s for these nuclear power plants, people really thought that it was unlikely that these plants would have to run so long that corrosion problems such as this would occur…It was in an era when it was too cheap to meter and where multiple hundreds of nuclear power plants would exist and this one would simply be shut down after a certain period of time and a new one put up next to it to replace it.”
Dr. Irwin was also asked about the missing awareness of underground pipes, he said to his knowledge the documentation of these pipes has always been there. He saw dates from the drawings from 60′s and 70′s. He saw documents that list dates like 2007, so he didn’t know the basis for those opinions. “It seems pretty clear that people have known about all of these.”
When tritium first made itself known, they suspected this AOG pipe tunnel and drain line and had pulled drawings out to review at that time. There are system engineers that were aware of and very well described all of these systems. “Why you would think there weren’t any of these is hard to imagine.”