Time Delay of Thermal Neutron Detection during Power Burst in TRACY.

Yanagisawa, Hiroshi; Ohno, Akio; Ogawa, Kazuhiko; Aizawa, Eijyu; YOKOYAMA, Mitsutaka

doi:10.3327/jnst.38.591

Cited by 6 publications

(11 citation statements)

References 4 publications

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The core tank and the concrete structure are taken into account to comprehend the effect of the neutron thermalization mainly at the concrete. Fixed source calculations were performed using the MCNP4B code with an energy-dependent volumetric source of neutrons determined by the neutron energy spectrum 2) in the solution core. Timedependent ring detectors 3) were used as fluence tallies for the calculation of time response of the detectors.…”

Section: Calculation Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of Time Response of Thermal Neutron Detectors in TRACY

Yanagisawa

Ohno

2001

Journal of Nuclear Science and Technology

Self Cite

View full text Add to dashboard Cite

Section: Calculation Methodsmentioning

confidence: 99%

“…The relative transient power measured by a fast response γ -ray chamber 2) during an initial power burst was used as actual relative power because time delay of the γ -ray measurement is negligible as reported.…”

Section: Simulated Relative Powermentioning

confidence: 99%

Evaluation of Time Response of Thermal Neutron Detectors in TRACY

Yanagisawa

Ohno

2001

Journal of Nuclear Science and Technology

Self Cite

View full text Add to dashboard Cite

“…8,9) Figure 1 illustrates a schematic view of the Examination for Neutron Dose Assessment Method from Induced Sodium-24 in Human Body in Criticality Accidents TRACY reactor room and core tank. The concentration of uranium can be changed up to 500 g of uranium per liter in the solution.…”

Section: Tracy (Experimental Facility)mentioning

confidence: 99%

Examination for Neutron Dose Assessment Method from Induced Sodium-24 in Human Body in Criticality Accidents

Takahashi

Endo

Yamaguchi

2005

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

Experiments were made to verify a dose assessment method from activated sodium in human body in criticality accidents. A slab phantom containing sodium chloride solution was irradiated in the Transient Experiment Critical Facility to simulate activation of sodium in body. Monte Carlo calculations were performed to obtain quantitative relation between the specific activity of induced 24 Na and neutron dose, which was imparted by charged particles liberated by neutrons, at the phantom position. In the previous work, conversion coefficients from specific activity of 24 Na in soft tissue to whole body dose had been analyzed with the MCNP-4B code concerning neutron spectra at some hypothesized configurations with fuel and surrounding materials. One of the prepared conversion coefficients was applied to evaluate neutron dose from the measured radioactivity of 24 Na. The estimated dose agreed with the dose analyzed by the Monte Carlo calculations in the present study within an acceptable uncertainty for initial dose determination in an accident, which is indicated by the International Atomic Energy Agency. In addition, the dose assessed with the prepared coefficient from the quantity of induced 24 Na was close to a value, which had been previously measured with dosimeters for criticality accidents.

show abstract

“…The details of TRACY were described in earlier reports. 7,8) Fast response parallel plate γ -ray ionization chambers 7) were utilized for determination of γ -ray exposure rates in TRACY. The γ -ray chambers are placed at the position of 2 m away from the core tank surface as illustrated in Fig.…”

Section: Experimental Apparatusmentioning

confidence: 99%

“…7) From the experimental data, the contribution of γ rays from short-lived FPs was evaluated and compared with results from computational analyses.…”

Section: Introductionmentioning

confidence: 99%

Determination of Gamma-Ray Exposure Rate from Short-Lived Fission Products under Criticality Accident Conditions.

Yanagisawa

Ohno

Aizawa

2002

J. Nucl. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

For the assessment of γ -ray doses from short-lived fission products (FPs) under criticality accident conditions, γ -ray exposure rates varying with time were experimentally determined in the Transient Experiment Critical Facility (TRACY). The data were obtained by reactivity insertion in the range of 1.50 to 2.93$. It was clarified from the experiments that the contribution of γ -ray from short-lived FPs to total exposure during the experiments was evaluated to be 15 to 17%. Hence, the contribution cannot be neglected for the assessment of γ -ray doses under criticality accident conditions. Computational analyses also indicated that γ -ray exposure rates from short-lived FPs calculated with the Monte Carlo code, MCNP4B, and photon sources based on the latest FP decay data, the JENDL FP Decay Data File 2000, well agreed with the experimental results. The exposure rates were, however, extremely underestimated when the photon sources were obtained by the ORIGEN2 code. The underestimation is due to lack of energy-dependent photon emission data for major short-lived FP nuclides in the photon database attached to the ORIGEN2 code. It was also confirmed that the underestimation arose in 1,000 s or less of time lapse after an initial power burst.

show abstract

Time Delay of Thermal Neutron Detection during Power Burst in TRACY.

Cited by 6 publications

References 4 publications

Evaluation of Time Response of Thermal Neutron Detectors in TRACY

Evaluation of Time Response of Thermal Neutron Detectors in TRACY

Examination for Neutron Dose Assessment Method from Induced Sodium-24 in Human Body in Criticality Accidents

Determination of Gamma-Ray Exposure Rate from Short-Lived Fission Products under Criticality Accident Conditions.

Contact Info

Product

Resources

About