Digital Reactivity Computer System

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ADRCS

• DRCS(Digital Reactivity Computer System) is a mandatory equipment used for LPPT(Low Power Physics Test)-ANS/ANSI 19.6.1_ in Korean PWR(Pressurized Water Reactor).
• DRCS receives a rapidly changing signal from the Ex-Core(Uncompensated Ion Chamber or Fission Chamber), measured and processes digitally.
  (Significant improvement in the reliability of measurements over traditional analog installations)
• The core operating variable of Reactivity, Neutron Flux and RCS(Reactor Coolant System) Temperature should be monitored in real time.
• Reactor core characteristics are automatically analyzed using the analysis software, as well as safe monitoring of the reactor conditions.
  (Analysis Item : POAH(Point Of Adding Heat), BEP(Boron End Point), ITC(Isothermal Temperature Coefficient), Rod Worth Measurement(SWAP, DCRM))
• Compatible for all PWR and PHWR(Heavy Water Reactor) use.

On-line Neutron Inverse Count Rate Using Excore Detector

• ONICE is capable of monitoring the sub-critical conditions of the core and raising an alarm when approaching to initial critical of core.
• ONICE is used for the fuel loading and the initial critical access test of the reactor, and is used for real-time monitoring of the sub-critical conditions of the core.
• ONICE is capable of continuously monitoring the core changes through real-time monitoring.
• ONICE has improved user convenience by software(automating) the loading of fuel and the initial critical approach procedure.

Temporary Neutron Monitoring System

• TNMS is used to monitor the sub-critical multiplication during the initial core fuel loading of PWR.
• The leakage rate of neutrons is very small during the fuel loading in the initial core, and we can not monitor it only with the ENFMS(Excore Neutron Flux Measurement System)
• TNMS, a dunker built-in the neutron detector, monitors the subcritical conditions of the core in real time during fuel loading.

TNMs Dunker

Signal Processor

Monitoring Software

Auxiliary Ex-core Neutron Flux Monitoring System

• AENFMS is for monitoring the sub-critical of core and ensuring the stability of the reactor during fuel loading and initial critical approach.(FSAR : K=0.98, 0.5cps)
• AENFMS plays the role of a start-up channel of ENFMS during initial fuel loading and initial critical approach.
• AENFMS has improved measurement sensitivity by at least 10 times more than traditional equipment.
• AENFMS is fixed using a support for the radius of reactor insulation located at 9 degrees clockwise from fission chamber A, D channel of ENFMS.

CoSi

• CoSi is and educational simulator for LPPT
• CoSi enables realistic training by identical description of the actual MCR(Main Contorl Room) panel and characteristics of the low power section of the reactor.
• CoSi accurately describes the core characteristics using a proven RAST-K
• LPPT tranning is possible by linking CoSi and DRCS

Measurement Technic

• Existing boronometer have low measurement accuracy at high boron concentration.
• High boron concentration reduces the neutron counts measured by absorption of neutrons.
• To overcome the disadvantages in high boron concentration, high sensitivity detectors were add. And the conversion function was optimized using MCNP code.

Existing System Detector : 0~5000 ppm → BF3 4ea
Improvement System Detector:
0 ~ 1500 ppm → BF3 4ea
1500 ~ 5000 ppm → BF3 4ea + He3 2ea