Determination of main reactor parameters for flibe (Li2BeF4)‎ cooled peaceful nuclear explosive reactors (PACER)‎

Abstract EN

This study analyzed main reactor parameters such as vapor production possibility, explosion chamber volume, equilibrium pressure–temperature, and neutronic behavior of a PACER (peaceful nuclear explosive reactor) producing electrical energy by means of repetitive explosions during certain periods for different values of coolant zone position (DR) and coolant zone thickness (DRc), with enough tritium breeding and more fusion energy absorption.

Flibe (Li2BeF4) with different volume fractions is preferred as a coolant.

In addition, the flibe inlet temperatures were selected as Tin = 823 K and 1540 K.

According to neutronic calculations, for tritium breeding and fusion energy absorption at certain DRc values, a saturation level is reached.

In other words, tritium breeding and fusion energy absorption behave asymptotically after a certain DRc, although the flibe thickness increases.

The saturation TBR (Tritium Breeding Ratio) and M (fusion energy absorption ratio) values are 1.27 and 1.07, respectively.

The saturation points for the TBR are higher than the saturation points reached by M.

This means that the flibe mass requirement for maximum M will be lower than that for TBR.

The flibe mass (m) calculated by DR and the saturated DRc increase with increasing DR.

Thereby, the flibe mass requirement increases from ≈200 tonnes to ≈6500 tonnes with increasing DR from 50 to 700 cm.

Thus, to reduce the flibe mass required for sufficient tritium breeding (TBR > 1) and more fusion neutron energy absorption (M = 1), DR must be as low as possible.

However, low flibe mass can cause a higher flibe temperature in the reactor chamber.

To decrease mechanical and chemical damage caused by high temperature on the chamber wall, the flibe zone must be selected at a place adjacent to the wall.

Figures and equations are obtained from which the explosion chamber volume, flibe mass, vapor amount, and equilibrium pressure at saturation conditions can be calculated easily for any given explosion yield and desired flibe temperature.

For example, for flibe mass higher than 2500 tonnes (DR > 400 cm) and low explosive charge yield (≈2 kt-TNT = 8.37×1012 J), only saturated flibe vapor or heated liquid flibe can be produced at the PACER.

In this case, an exchanger model with two loops, similar to those in pressurized water reactors, for vapor production should be preferred.