Pre-Operational Commissioning

Following construction and installation testing, pre-operational commissioning is performed to demonstrate that equipment and systems perform in accordance with design criteria so that initial fuel loading, initial criticality and subsequent power operation can be safely undertaken. Pre-operational tests at elevated pressure and temperature are referred to as hot functional tests. 

Pre-Operational Commissioning of Systems with Safety Significant Functions... 

Section 14.2.9.1, Chapter 14 ofthe EDCD (Reference 10.3 includes detailed descriptions of the pre-operational commissioning required for the safety significant systems identified below ... 

This section identifies those commissioning tests that are performed following completion of the pre-operational commissioning but prior to initial criticality testing. These tests include those performed prior to core load to verify that the plant is ready for core loading, the loading of the core and the tests performed under hot conditions after the core has been loaded but prior to initial criticality. 

The pre-operational safety report (POSR) provides confidence that the as-built and commissioned plant meets the safety requirements and can be released for operation. 

Pre-operational and / or start-up commissioning is performed on those systems that are ... 

The start-up commissioning begins with iititial fuel loading after the pre-operational testing has been successfully completed. 

Pre-operational and start-up commissioning are performed using commissioning specifications and procedures. The specifications will cover (but are not limited to) ... 

The design, testing, start-up and operating experience from previous pressurised water reactor (PWR) plants is utilised in the development of the initial pre-operational and start-up test programme for the APIOOO plant. This will include any lessons learnt from the commissioning of... 

Pre-operational testing is performed as system and equipment availability allows. The interdependence of systems is also considered. Sequencing of the start-up tests depends on specified power and flow conditions and intersystem prerequisites. The start-up test schedule establishes that, prior to core load, the test requirements are met for those plant stmctures, systems and components that are relied upon to prevent, limit or mitigate the consequences of postulated accidents. Commissioning is sequenced so that the safety of the plant is not dependent on untested systems, components or features. 

A cursory list of tests to be carried out in the different commissioning phases should be presented. In particular, a summary description of pre-operational and/or startup testing planned for each unique or first of a kind principal design feature should be included in the pre-operational SAR. The summary test descriptions should include the test method and test objectives. Test acceptance criteria, where appropriate, may be presented in the SAR or may be part of the detailed test procedures and referenced separately. A tentative time schedule for the test programme should be presented, with a clear identification of the tests considered prerequisites for other tests. Further discussion on matters to be covered in this section of the SAR is provided in Ref. [34]. 

Partly with the high stakes in mind, changes have been made in U.S. reactor equipment and operation since the TMI accident to reduce the chance of another accident. The results of these changes are reflected in the predictions of probabilistic risk assessments and by a variety of direct performance indicators. For example, in one measure for U.S. reactors, since the pre-TMI days there has been a reduction of more than a factor of 100 in the number of precursors to potential core damage accidents, as reported by the Nuclear Regulatory Commission (Muley, 1990 Belles et al., 1998). 

Process engineers (or EPC vendor) will prepare pre-commissioning and commissioning procedures, and also check lists for these activities. They will also train operators, and coordinate between the EPC contractor, operations and project departments. Pre-commissioning is performed in a systematic way to complete the following activities. 

After completion of pre-commissioning, the revamped plant will be commissioned by introducing raw materials and adjusting the plant operating parameters to the desired targets (Lawson, 1999). 

Traditionally mining headframes are constructed over the mine shaft to facilitate hoisting, provide head cover, facilitate safe access to the shaft and in some cases, to house a tower mounted friction hoist. In an effort to increase production and minimize down time, schedule, capital and construction costs, an approach was conceived to convert an existing service shaft into a production shaft. To better streamline the conversion process, a two phased approach was developed for the surface conversion. First, a penthouse would be constructed over the existing operational headframe and outfitted with a pre-commissioned hoisting plant. Second, the existing service headframe would be demoHshed and replaced with a new modular production headframe complex. 

Talvivaara s focus has remained firmly on production ramp-up throughout the years 2009 - 2012. Optimization of the already operating equipment and processes continued, and pre-requisites for full-scale production were fulfilled through the commissioning of the second production lines. 

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