This paper reports the outcomes of the first of three planned questionnaire surveys in the first phase of a broader Hong Kong based study on ‘Joint Risk Management’ (JRM). The survey compared perceptions on both present and preferred risk allocation, including JRM, in construction contracts. Data was mainly collected in Hong Kong and mainland China (with most respondents having working experience from Hong Kong) from various professionals and practitioners representing broad groups of academics, consultants, contractors and owners (clients). Survey results reinforce previous observations (in Canada) of the divergences in perceptions on both present and preferred risk allocation, both within and between different contracting parties. The present study reveals quite wide (marked) divergencies with many individual cases of diametrically opposing views on allocating particular risks within specific groups. Despite such divergencies, respondents professed a general enthusiasm towards JRM, irrespective of their contractual or professional affiliation. Moreover, they generally preferred to assign reduced risks from either one or both contracting parties to JRM, rather than shifting more risks to the other party. This is indicative of a perceived trend towards more collaborative and teamwork based working environments.

The present work gives a methodology for assessing radiological concentration of ¹³¹I, ¹³²I, ¹³³I, ¹³⁴I, and ¹³⁵I due to a hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh. The concentrations were estimated through different pathways like ingestion of vegetation, milk, and meat from air and ground deposition. The maximum air concentrations for all 16 directions were found at 110 m distance from the core of the reactor and it was found to be highest in the southern (S) direction. The maximum ground concentration occurred immediately just after the accident in different directions. In all pathways, the most concentration was found to be in S-direction. The concentrations in vegetation of ¹³¹I, ¹³³I, ¹³⁵I were significant, while no concentrations of 132I and 134I were observed. The concentration in vegetation for ¹³¹I was found to be highest than all other isotopes of iodine. The concentrations of ¹³³I were found to be higher and concentrations of ¹³⁴I were observed to be lower in both milk and meat compared to other radio isotopes of iodine. In the case of a radiological accident, the results of the present study will be a valuable guide for adopting radiological safety measures for radiation protection against the ingestion of vegetables, milk and meat from around the research reactor at AERE, Savar, Bangladesh

No abstract

No abstract

In reactor physics tests, it is important to monitor sub-criticality continuously during criticality approach. Reactivity measurements by the inverse kinetics method are widely used during the operation of a nuclear reactor. This technique is successfully applied at sufficiently high power level or to a core without an external neutron source where the neutron source term in point reactor kinetics equations may be neglected. For operation at low power levels or in the sub-critical domain, the increase in the fluctuation of the neutron signal may cause difficulties in the evaluation of reactivity and the effect of direct emission from the external neutron source may not be neglected. Therefore, contribution of the neutron source must be taken into account and this implies knowledge of a quantity proportional to the source strength, which calls the source term and then it should be determined. The research work has been conducted to measure reactivity with source term using a dedicated reactivity measurement system by the Least Square Inverse Kinetics Method (LSIKM). Application to a simulator of HANARO research reactor, Korea Atomic Energy Research Institute (KAERI), with known source strength and reactivity worth has showed consistent and satisfactory agreement.