1. TRACY experiment for SILENE experiment simulation
Expert Group on Criticality Excursion Analysis September 22, 2005
TRACY experiment for SILENE experiment simulation
Yuichi YAMANE, Yoshinori MIYOSHI
Japan Atomic Energy Research Institute

2. Expert Group on Criticality Excursion Analysis
TRACY Core
Core specifications
Fuel : 10wt% enriched uranyl nitrate
aqueous solution
Shape : Annular (50cm/7.6cm) Transient rod at the center hole
Limitations
Maximum Power ：5000MW
Total energy : 32 MJ/experiment ( = 1018 fissions)
Maximum excess reactivity: 3.0 $
Reactivity insertion method
Rod withdrawal
Pulse withdrawal (Step insertion)
Ramp withdrawal
Fuel feed
Ramp feed
TRACYでは、調Ｔｒ棒の交換により、
新たに、添加反応度2.8２$までの超臨界実験を行なえるようになった。
今回は、過渡特性を測定した結果について報告する。
まず、測定の概要について
September 22, 2005
Expert Group on Criticality Excursion Analysis

3. Experimental Condition
September 22, 2005
Expert Group on Criticality Excursion Analysis

4. Expert Group on Criticality Excursion Analysis
Kinetic Parameters
SRAC + TWODANT with JENDL-3.2
Neutron generation time : 4.92x10-5
beff : 7.51x10-3
Reactivity Temperature Coefficient : -4.7 cent/K, -2.5 cent/K2
Reactivity Void Coefficient : -4.4x101 cent/%, -1.7x10-1 cent/%2 1 2 3 4 5 6
Delayed neutron fraction
2.51x10-4
1.63x10-3
1.47x10-3
2.96x10-3
8.77x10-4
3.19x10-4
Precursor decay constant (s)
1.27x10-2
3.17x10-2
1.15x10-1
3.12x10-1
1.40
3.87
Calculated for 370 gU/Lit. U conc. and 0.7mol/Lit. acid conc.
September 22, 2005
Expert Group on Criticality Excursion Analysis

5. Result of experiments: R317,318
The 1st peaks were greater than S2-300’s.
R318 reached the peak 1s faster than R317.
September 22, 2005
Expert Group on Criticality Excursion Analysis

6. Result of experiments : R319
The 1st peak was greater than S3-300.
R319 reached the peak 1s faster than S3-300.
September 22, 2005
Expert Group on Criticality Excursion Analysis

7. Result of experiments : R321,322
R321, R322 >> LE1-641 in the 1st peak power.
R321(0.14$/s) reached the peak at almost the same time as LE1-641 (0.097$/s) and that is 9s faster than R322(0.097$/s).
R321,R322 shutdown at about 300s by the regulation for max. fissions.
September 22, 2005
Expert Group on Criticality Excursion Analysis

8. Preliminary Result and Summary
Total release energy ratio ~ volume ratio for the case of 0.97$ insertion.
Total release energy ratio > volume ratio for the case of 2.31$ insertion.
Maximum power ratio looks independent of volume ratio.
September 22, 2005
Expert Group on Criticality Excursion Analysis