NUCLEAR ENGINEERING DIVISION

Nuclear Engineering Division (NED) is one of the most prestigious Division of Pakistan Institute of Nuclear Science and Technology (PINSTECH). The Division was established with the objective to develop technical expertise mainly in the area of Nuclear Reactor Technology. NED has been constantly providing highly trained manpower for several projects of strategic importance. The main contributions of the division in the indigenous program of PAEC are:

• Renovation and Modernization of Instrumentation and Control of Pakistan Research Reactor-1 (PAAR-1).
• Conversion and Up-gradation of PARR-1.
• Installation and Commissioning of Pakistan Research Reactor-2 (PARR-2).
• Design and Development of Nuclear Reactor Safety Systems.

Presently, besides safe and smooth operation/maintenance of PARR-1 and PARR-2, NED is involved in the research and development of nuclear science and engineering.

The facilities and techniques available in NED are:

1. Pakistan Research Reactor-1

2. Pakistan Research Reactor-2

3. Reactor Experiments

Certain kind of information regarding reactor parameters is necessary for the safe and smooth operation of a nuclear reactor. The reactor experiment group routinely measures the value of such parameters experimentally for the reactor operators. The reactor parameters measured are control rod worth, shutdown margin and  excess reactivity in the core. The experiments are also performed to measure

1. Control rod drop time.

2. Dynamic behavior of the reactor core.

3. Burnup of the spent fuel elements.

4. In-core neutron flux .

5. Void coefficient of reactivity.

6. Neutron energy spectrum

4. Vibration Analysis Laboratory

Vibration Analysis Laboratory (VAL) in the Nuclear Engineering Division at PINSTECH, is actively involved in faults detection and diagnosis by measuring the vibration of mechanical systems. The vibration detection and measuring technology is an advance approach to solve a number of vibration problems. The techniques are being used and applied in nuclear power plants for early fault detection and diagnosis, thus reducing outage of the system and increasing the availability.

The VAL is equipped with most modern and advanced equipment for field measurements, on-line continuous monitoring and off-line laboratory analysis.

5. Reactor Noise Analysis Technique

Detection and analysis of noise signals can be used to improve the performance of a nuclear reactor. The noise signals yield information on both static and dynamic behaviour of the reactor system. Noise analysis techniques have proved to be very useful in minimizing the consequences arising from unforeseen problems encountered during commissioning and normal operation of a plant. Signal analysis and processing expertise available in the Division has vast experience of applying the noise analysis techniques for kinetic parametric determination and malfunction diagnosis of research and power reactors. Noise signals from a wide variety of sensors (neutron, temperature, gamma and acoustic) are used to extract information of the operating conditions of the reactor.

Experience in the application of noise analysis techniques is in the following three main areas:

• Surveillance

Surveillance characteristics of the mnoise pattern were determined to indicate if significant changes have occurred with changes in the operating conditions or with time. Consequences of these changes on continued operation.

• Diagnostics

The forced outages or time required for problem rectification are reduced by detailing the problem.

• Parametric determination

Provides useful information to both operators and users for safe and smooth operation and utilization of nuclear reactors. Noise measurements are used to determine system's kinetic and dynamic characteristics such as transfer function, reactivity, xenon behavior, instruments response, coolant transit time etc.

Typical experimental set-up for reactor noise analysis

6. Reactor Safety Analysis

NED has been actively engaged in carrying out various safety analyses of PARR-1. The Reactor Safety Analysis Group is responsible for the determination of safe power level of the reactor, which does not compromise on safety. Steady-state thermal hydraulic and accident analyses of  PARR-1 cores are performed using standard computer codes. It is ensured that every core assembled has sufficient safety margins against ONB (onset of nucleate boiling) and DNB (departure from nucleate boiling). Calculations are performed in order to assess various accident scenarios such as: reactivity insertion accidents; loss of flow accident; loss of coolant accident. The group also analyzes the radiological consequences of any radioactivity release in case of  a severe accident.  Moreover, the group activities include the regulatory requirements related to the Pakistan Nuclear Regulatory Board (PNRB) as well as International Atomic Energy Agency (IAEA).