ETRR-2 control rod withdrawal accident

A safety evaluation of Egypt new reactor, Egypt Test and Research Reactor number 2 (ETRR-2), has been completed successfully. Intensive efforts have been made for design basis accidents (DBA) analysis. The present work presents analysis of one of these accidents. i.e. the uncontrolled reactivity insertion accident (RIA) due to erroneous withdrawal of control rod (CR) during normal operating conditions. The reactivity insertion may be fast or slow. depending on the speed of CR withdrawal. The availability of the scam system is considered. The reactivity insertion function (RIF) is modeled by: I - an approximate ramp functions (RF), and 2 - actual S(cosine) function (CF). A computer code TRANSPI9 is developed for the analysis. It models RIA of material test and research reactors (MTR). The code was verified against results obtained from RETRAN 02 and PARET codes and showed a good agreement. The study shows that ETRR-2 core, MTR type. withstands this type of perturbation. fast or slow. in condition that the shutdown system (SHDS) is available. Otherwise the coolant, clad. and fuel temperatures may exceed their design goal values [safety limits (SL)] and the clad may ruptures. coolant may boil. and the fuel may damage. The core reciprocal period never exceeds 140 S-1 for all accident cases (minimum period is 21.98 s) which demonstrates that no explosion other than sonic blockage could occur.