ASME N509:2002 pdf download NUCLEAR POWER PLANT UNITS AID CDMPONENTS
1 SCOPE
This Standard covers requirements for the designconstruction, and qualification and acceptance testingof the air-cleaning units and components which makeup Engineered Safety Feature (ESF) and other high effi.ciency air and gas treatment systems used in nuclearpower plants.
1.1 Limitations
The Standard does not cover sizing of a completenuclear air treatment system, redundancy, or single-failure requirements. It applies only to systems whichemploy particulate filtration,ambient-temperatureadsorption, or both, as the principal functional mechanism. It does not apply to condenser off-gas systems.Also, it does not apply to other applications that employprimarily gas storage or holdup, cryogenic adsorptionor fractionation, or solvent absorption as the principalmethod of gas treatment. Nor does the Standard coverrequirements for containment isolation valves, recombiners, comfort heating, air-conditioning, or ventilationto achieve ordinary cooling or industrial hygiene objectives. Field acceptance testing of nuclear air-treatmentsystems is covered in ASME AG-1, Section TA (the pri-mary reference was to ASME N510-1989).
1.2 Purpose
The Standard identifies and establishes requirementsfor filters, adsorbers, moisture separators, air heatersfilter housings, dampers, valves, fans, ducts, and othercomponents of nuclear air-treatment systems for a specific application in a nuclear power plant. The Standarcalso establishes requirements for operability, maintainability, and testability of systems necessary for the maintenance of system reliability for the design conditionsQualification and acceptance testing provisions are specified to verify the adequacy of the air-cleaning unit andcomponent design, to verify that components have beenproperly fabricated and installed, and that the systemwill perform in accordance with specification requirements.
2 APPLICABLE DOCUMENTS
The following documents supplement this Standardand are a part of it to the extent indicated in the textThe issue of the referenced document noted below shallbe in effect. If no date is listed, then the issue of thereferenced document in effect at the time of the PurchaseOrder shall apply.
ASME AG-1, Code on Nuclear Air and Gas TreatmentPublisher: The American Society of Mechanical Engineers(ASME International), Three Park Avenue, NewYork,NY 10016; Order Department: 22 Law DriveBox 2300,Fairfeld,N 07007-2300
3 TERMS AND DEFINITIONS
Terms and Definitions are located in ASME AG-1Article AA-1000 and various specific ASME AG-1 Codesections.
4FUNCTIONAL DESIGN
4.1 General
Depending on the function of the system and theconditions under which it willoperate air-cleaning unitsinclude some or all of the following internal components.(a) Prefilters are required in air-cleaning units wherdesign inlet particulate concentrations and particle sizeare such that the HEPA flter may be rendered ineffectiveprematurely. On other air-cleaning units prefilters arerecommended only when it is desired to increase HEPAfilter life.
(b) HEPA flters are required in all air-cleaning unitswhen filtration ofinlet particulate matter requires a min.imum efficiency of 99.97% for particles equal to 0.3micrometer in size.
(c) Adsorbers are required when air-cleaning unitsare designed for removal of adsorbable compounds.
(d) Moisture separators (demisters) are requiredwhen entrained water droplet concentration may begreater than 1 Ib (0.45 kg) of water per 1,000 cfm (1,700m’/hr) of airflow.
(e) Heaters should be utilized for air-cleaning unitswith adsorbers when the relative humidity of air to theadsorber exceeds 70% based upon the 1% percentilemeteorological conditions (where applicable). Fornuclear air-tmeatment systems which are unaffected byoutside air meteorological conditions, heaters should beutilized when an accident would result in an airstreamexceeding 70% relative humidity for more than 1 hr.(/ Postfilters. When adsorbers are used in ESF aircleaning units, provision shall be made for a postfilter
ASME N509:2002 pdf download
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