ZERO POWER CHECK POINT EXPERIMENTS. VOLUME III. ERDL-TASK 100, PHASE 3

Technical Report · Mon Jun 01 00:00:00 EDT 1959

OSTI ID:4208926

Three experiments were performed to furnish additional information on the 45-element core reported in MND-E-1847-II. The critical water height for this core was found to be 9.99 in. The reactivity worth of a small amount of water was also evaluated. The total reactivity of the core was determined in several ways using 2% Cd in a Cd-Sn alloy as the core poison. The reactivity values are: incremental rod withdrawal-7.9% DELTA K/K incremental cadmium addition-7.8% DELTA K/K, and uniform cadmium removal--7.4% DELTA K/F. Alternate schemes for cadmium removal were tried to check the reactivity values established. Flux measurements were made in selected positions of the core before and after Cd addition to determine if a neutron spectral shift occurred. The Au resonance and epicadmium neutron flux showed an increase after Cd insertion while the thermal and fast flux decreased. There is a spectral shift when cadmium is used to poison out and measure the core reactivity. Four APPR-1 stationary fuel elements were compared to determine the two having the closest reactivity. These two are to be used as preliminary standards for comparison of ANPP critical experiments on the APPR-type reactor. The proposed semi-empirical method of determining total core reactivity by analytical extrapolation of experimental values of reactivity near the critical water height is not in agreement with the experiment. The total reactivity determined by this method was 11.7% DELTA K/K. AnaLytical duplication of the critical water height core and the critical core with the bank inserted resulted in calculated reactivities approximately 0.9% DELTA K/K too low. The calculated reactivity of the nearly critical cadmium-poisoned core was approximately 2.5% DELTA K/K too high. (auth)

• Research Organization: Martin Co. Nuclear Div., Baltimore
• DOE Contract Number: DA-44-009-ENG-3318
• NSA Number: NSA-13-021725
• OSTI ID: 4208926
• Report Number(s): MND-E-1847-III
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-59
• Country of Publication: United States
• Language: English

Related Subjects

REACTORS
CADMIUM ALLOYS- CONFIGURATION- CONTROL ELEMENTS- CRITICALITY- MEASURED VALUES- POISONING- REACTIVITY- REACTOR CORE- REACTORS- RESEARCH REACTORS- RODS- TIN ALLOYS- VOLUME- WATER
CADMIUM- EPITHERMAL NEUTRONS- FAST NEUTRONS- GOLD- MEASURED VALUES- NEUTRON FLUX- REACTIVITY- REACTORS- RESEARCH REACTORS- RESONANCE- SPECTRAL SHIFT- THERMAL NEUTRONS
CRITICALITY- ERRORS- FUEL ELEMENTS- MATHEMATICS- MEASURED VALUES- REACTIVITY- - REACTORS- RESEARCH REACTORS- SM-1- STANDARDS- VARIATIONS- VOLUME- WATER