The realization of the new installations constitutes an important plant modification, the influences on the safety of the processes must be evaluated. Preliminarily to the Preliminary Safety Report extended according to the contents of Annex C-Part 2 of Legislative Decree 105/15, in accordance with the control model and continuous improvement of P.D.C.A. processes (Plan, Do, Check, Act), and in line with what is indicated in UNI 10616 and UNI 10617, the “Plan” phase of the Safety Management System for the Prevention of Major Accidents, provides for the identification of hazards and assessment of the relevant risks and, in particular, the identification of protection systems suitable for coping with those residual risks identified in the design phase and which do not allow the creation of an intrinsically safe process (“inherently safe”).
Given the design phase (“Feasibility”) the most suitable method for identifying any protection systems, the LOPA (“Layer Of Protection Analysis”) methodology appears, by virtue of the possibility it offers to make estimates of “orders of magnitude “Of the risk parameters” frequency “and” consequence “.
This methodology is also indicated by the IEC-61508 and IEC-61511 standards for identifying any level of safety integrity to be requested from the protection systems. The Preliminary Safety Report and the LOPA analysis were also inputs for the Fire Project Evaluation referred to in Ministerial Decree 18/10/2019