Happy New Year Fernanda!
Our idea was to keep the tungsten block-only option with the following modifications:
1- Replace nitrogen volume with concrete to solve the leak problem, which could get worse in the future
Such that nitrogen back pressuring will not work. This will also eliminate the potential of activate
Air borne nitrogen byproducts. The FESS engineer I consulted with said that filling this gap with
The appropriate low sodium concrete is not a problem.
2- Fill the area around the (original) beam pipe and the wall with solid borated poly, and continue this
upstream as much as there is space.
3- On the outside of the wall (gallery side), add 4 inches of steel plate(6ft,X6ft) followed by 2 inches
(6ft,X6ft) of borated poly Sheet. These will be stacked against the wall, around the beam pipe, steel first and
4- The contamination of the ground water for the Tungsten block calculations that Diane did, was insignificant;
11 years of operation will results in a groundwater contamination that is 1% of the regulatory limit.
Addition of concrete in place of the nitrogen will further reduce the activation outside the momentum absorber.
A MARS simulation of this model can be done once it is accepted by you.