The effect of space radiation on deterministic electronic circuits is a well researched topic. However, the statistical quality of non-deterministic numbers generated by True Random Number Generator (TRNG) circuits, critical for secure communication in space applications, has not been extensively explored in literature. This paper presents implementation of a resource-optimized Mixed Mode Clock Manager (MMCM) based TRNG circuit on Xilinx Field Programmable Gate Arrays (FPGA), along with the results of statistical tests. The advantage of this study is the execution of Single Event Effects (SEE) tests, enabling a detailed examination of the TRNG circuit's performance under space radiation. Additionally, based on SEE test results, the TRNG circuit is redesigned using the fault tolerant design techniques. The performance of the applied fault tolerant design technique on the TRNG circuit is examined through a repetition of SEE tests.