Competencias de liderazgo en la comunidad

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PC BASED SIMULATOR OF NPP

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2. VERIFICATION FOR NORMAL OPERATION

Verification of simulator scenarios for normal operation and some accident scenarios has been performed and main parameters are reported in Table 1. It is expected to ensure that specified learning objectives can be achieved and the simulator performs in accordance with design.

TABLE 1. DESIGN PARAMETERS IN OPERATION IN NOMINAL POWER

Parameter Simulator

[2]

Ninh Thuan Project [3]

AES 2006 Generic Design [4]

Reactor thermal power, MW 3212 3212 3212

Nominal electric power, MW 1178–1183 1186 1198

Reactor Outlet pressure, MPa 15.91–16.11 16.2 ± 0.3 16.2 ± 0.3 Reactor coolant flow rate, m³/h 86333 88000(+2100 –3100) 88000 Reactor coolant inlet temperature, ⁰C 297.6 298.2 +2 / -4 298.2 Reactor coolant outlet temperature, ⁰C 328.8 328.6 ± 4 328.9 ± 5

Reactor heat-up, ⁰C 30.5 30.7 30.7

Pressurizer level, m 8.13 ± 0.01 8.17 ± 0.15 8.17 ± 0.15

SG water level, m 2.7 ± 0.01 2.7 ± 0.05 2.7 ± 0.05

SG steam pressure, MPa 7.0 ± 0.02 7.0 ± 0.1 7.0

Steam temperature at SG outlet, ⁰C 284.8 285.8 ± 1.0 287 ± 1.0

Feedwater temperature, ⁰C 226.8 ± 0.15 225 ± 5 225 ± 5

Feedwater flow in SG1/2/3/4, t/h 1614–1668 1602 + 112 1602 + 112 Operation at load of (%Nnom):

- 4 RCPs;

- 3 RCPs;

- 2 RCPs (opposite);

- 2 RCPs (adjacient)

100 % 64 % 49.5 % 40 %

100 % 67 % 50 % 40 %

100 % 67 % 50 % 40 % TABLE 2. FAILURES SIMULATED IN THE SIMULATOR

Failure Code Number of failures Description

CCxx 2 Damage in CC H/X elements or pumps

CHxx 2 Air leak into the containment or into the annular space between outer and inner containment shells

CPxx 7 Damages in condensate system (pump, LPH tube leak…)

CVxx 9 Failures in CVCS system

CWxx 2 CWS header leak or Clogging of treatment filters CWP

EDxx 17 Failures in electrical system

EGxx 13 Failures in generator system

FWxx 9 Failures in Feedwater system

MSxx 13 Failures in main steam lines

NIxx 3 Failure in measuring channel FMS, RIMS

RDxx 14 Malfunctions or failures in control rod groups

SIxx 4 Failures in Emergemncy Core Cooling System (ECCS) and spent

fuel pool

SWxx 3 Failures in-service water system

TCxx 10 Failures in turbine systems (steam supply, control valve …)

THxx 17 Leak, break or ruptures in RCS

TUxx 4 Failures in turbine unit (oil cooler leak, rotor vibration…)

Total 129

101 Malfunctions simulated by the Simulator are summarized in Table 2. On the view points of safety analysis, the accident scenarios frequently analyzed are in groups of THxx, FWxx, MSxx and RDxx for examples: Loss of coolant accident (LOCA), feedwater line break (FWLB), main steam line break (MSLB) or reactivity insertion accident etc.

The training courses and practices using the Simulator can be specified by three levels as follows:

1. Understanding of Technical features and main parameters of NPP, in which the trainees or students should check for:

 Main technical specification data and generic layout of AES2006 plant;

 Main normal operation systems/equipment of a WWER1200 unit;

 List and explain design basics of safety systems/equipment of a WWER1200 unit;

 List and explain design basics of auxiliary systems/equipment of a AES2006 plant.

2. Practice to startup and shutdown operations:

 List and explain WWER1200 standard operation states;

 Explain main operations sequence in transition between standard operation states.

3. Accident simulations:

 Explain main operational limits and conditions;

 List and explain malfunctions and simulate the accidents with or without operator’s actions.

Tentative plan for utilization of the simulator is to train staff of related organizations like technical support engineers, operations management and research engineers. To maintain the human resources, students, lecturers, teachers from universities are expected to be trained on the simulator. For the R&D works, it is also useful for strengthening of capacity through carrying out research/study supporting activities such as safety assessment and analysis and performing of training courses on the thermal hydraulics and technology of advanced generation of WWER reactors.

3. EXAMPLE ON REDUCED POWER OPERATION WITH ONE MCP SWITHCHED OFF

In the operation of WWER1200 which permits one or two MCPs to be switched off. The signals from the system initiates control protection system with control rods and drives will reduce power or prohibit power rise, so that it can avoid the reactor trip and prevent violation of safety limits and conditions. Figure 2 shows the flow rate of RCP–1391 used in WWER1200 NPP and its rotation speed when one out of four operating RCPs trips compared with the results from the simulator. The further studies on the simulator of WWER1200 should be performed to gain better understanding of operation processes and safety systems in modernized WWER nuclear reactors.

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(a)

(b)

FIG. 1. (a) Simulator layout; (b) Control rod groups in-reactor core of the simulator.

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(b)

FIG. 2. (a) Mass flow rate of MCP–1391 and rotation speed when one out of four operating MCPs trips (FSAR[3]), (b) Simulator.

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FIG. 3. Variation of reactivity during transient (MCP#3 OFF).

4. CONCLUSIONS

The PC based Generic WWER1200 Simulator has been installed in the Nuclear Training Center of VINATOM and defined as training tool to maintain human resource not only for VINATOM employees, but also for training and education in universities.

For the education, the use of the simulator in the link with universities it is expected to improve effectiveness and better interconnection between study subjects delivered in universities, training courses and simulator training.

Upon completion of the training courses on the simulator, participants are expected to understand basic systems, components and operating principles for WWER; learn more in design characteristics and safety concepts for WWERs; and get better understanding of various kinds of plant behaviors during normal operation, transients and accidents.

REFERENCES

[1] INTERNATIONAL ATOMIC ENERGY AGENCY, Use of Control Room Simulators for Training of Nuclear Power Plant Personnel, Vienna IAEA –TECDOC-1411, IAEA, Vienna (2004).

[2] WESTERN SERVICE CORPORATION, Generic WWER type simulator, (2015).

[3] NINH THUAN 1 NUCLEAR POWER PROJECT, Feasibility Study. Vol.3, Chapter 6. Description and conformance to the design of plant systems. NT1.0–3.101–FS–01.03.01.06.02–rev.02. unpublished data.

[4] ROSATOM, The WWER Today: Evolution, Design, Safety,

http://www.rosatom.ru/upload/iblock/0be/0be1220af25741375138ecd1afb18743.pdf

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UNIVERSITY OF UTAH RECENT LESSONS