SAFETY P R A C TIC E S - gnssn - International Atomic Energy Agency

This publication is no longer validPlease see http://www-ns.iaea.org/standards/3.2.6. Protection against fire and explosionFire protection programme assessment is outside the scope of this publication;however, the following questions should be included in the review of fire protectionand preventive measures.Basis for acceptanceCode, paras 357-359.Safety Guide 50-SG-D2.Safety Guide 50-SG-D7, paras 309, 310, 567, 583.Assessment questions(1) Are the physical separation, barriers, enclosures and fire zones of each redundantdivision of the EPS designed to contain the effects of fires and explosionswithin that division without affecting the other redundant divisions, includingallowance for secondary effects, i.e. smoke, heat and fire propagation?(2) Is the fire suppression system (fluid and actuation) designed and zoned so thatits operation (normal or spurious) or a rupture at any given point will affectonly a single redundant division of the EPS, taking into account secondaryeffects, e.g. flooding, sprays and leaks?(3) Is the fire detection system designed so that a fire in one fire zone will not causefalse actuation of the fire suppression system in other fire zones throughinfiltration and false detection of smoke or heat?Note: further questions relating to electrical systems can be found in Section 3.3.2.3.2.7. Effects of environmental conditions and equipment failuresStructures, systems and components of the EPS are protected or otherwisecapable of withstanding the effects of the environmental conditions associated withanticipated operational states and accident conditions. Dynamic effects resultingfrom equipment failures included in the design basis, e.g. missiles, pipe whipping,fluid discharges and flooding, should be taken into account.Basis for acceptanceCode, paras 360, 361, 1206, A204.Safety Guide 50-SG-D4.Safety Guide 50-SG-D7, paras 703-707.14