Clarification of Surveillance Requirements for HEPA Filters and Charcoal Adsorber Units in Standard Technical Specifications on ESF Cleanup Systems (Generic Letter No. 83-13)
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 March 2, 1983 TO ALL APPLICANTS FOR OPERATING LICENSES AND HOLDERS OF CONSTRUCTION PERMITS FOR POWER REACTORS Gentlemen: SUBJECT: CLARIFICATION OF SURVEILLANCE REQUIREMENTS FOR HEPA FILTERS AND CHARCOAL ADSORBER UNITS IN STANDARD TECHNICAL SPECIFICATIONS ON ESF CLEANUP SYSTEMS (Generic Letter No. 83-13) It has come to our attention that the Surveillance Requirements for HEPA filters and charcoal adsorber units in ESF atmospheric cleanup systems as stated in the Standard Technical Specifications (STS) in use by applicants for operating licenses require clarification. The current revisions of the STS for all power reactors do not clearly reflect the required relationship between the guidance provided in Regulatory Guide 1.52, Revision 2, and ANSI N510-1975; the testing requirements of the HEPA filters and charcoal adsorbers units; and the NRC staff assumptions used in its safety evaluations for the ESF atmospheric cleanup systems. In order to clarify this relationship, the wording in the Surveillance Requirements for testing the HEPA filters and charcoal adsorber units has been modified. We have enclosed the revised testing requirements for HEPA filters and charcoal adsorber units in ESF atmospheric cleanup systems that are to be used in your submittal of proposed Technical Specifications, or, if your proposed Technical Specifications have already been submitted, the staff will make the necessary revisions. These changes will also be incorporated in the next revision of the STS. The generic changes are indicated by a line in the margin of the Surveillance Requirement. Specific ESF atmospheric cleanup systems have not been indicated since the changes apply only to the testing of HEPA filters and charcoal adsorber units in every ESF atmospheric cleanup system. This request has been approved by OMB Clearance Number 3150-0011, which expires April 30, 1985. Sincerely, Darrell G. Eisenhut, Director Division of Licensing Enclosure: "Revised Surveillance Requirements for Testing of HEPA Filters and Charcoal Adsorber Units" 8303020321 . ENCLOSURE Revised Surveillance Requirements for Testing of HEPA Filters and Charcoal Adsorbers Units 1. At least once per 18 months, or (1) after any structural maintenance on the HEPA filter or charcoal adsorber housings, or (2) following painting, fire, or chemical release in any ventilation zone communicating with the system, by: 1) Verifying that the cleanup system satisfies the in-place penetration and bypass leakage testing acceptance criteria of less than (*)% and uses the test procedure guidance in Regulatory Positions C.5.a, C.5.c, and C.5.d of Regulatory Guide 1.52, Revision 2, March 1978, and the system flow rate is cfm +- 10%. 2) Verifying, within 31 days after removal, that a laboratory analysis of a representative carbon sample obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of Regulatory Position C.6.a of Regulatory Guide 1.52, Revision 2, March 1978, for a methyl iodide penetration of less than (**)%; and 3) No change 2. After every 720 hours of charcoal adsorber operation, by verifying, within 31 days after removal, that a laboratory analysis of a representative carbon sample obtained in accordance, with Regulatory Position C.6 b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of Regulatory Position C.6.a of Regulatory Guide 1.52, Revision 2, March 1978, for a methyl iodide penetration of less than (**)%. 3. After each complete or partial replacement of a HEPA filter bank, by verifying that the HEPA filter bank satisfies the in-place penetration and bypass leakage testing acceptance criteria of less than (*)% in accordance with ANSI N510-1975 for a DOP test aerosol while operating the system at a flow rate of cfm +- 10%. 4. After each complete or partial replacement of a charcoal adsorber bank, by verifying that the charcoal adsorber bank satisfies the in-place penetration and bypass leakage testing acceptance criteria of less than (*)% in accordance with ANSI N510-1975 for a halogenated hydrocarbon refrigerant test gas while operating the system at a flow rate of cfm +- 10%. * 0.05% value applicable when a HEPA filter or charcoal adsorber efficiency of 99% is assumed, or 1% when a HEPA filter or charcoal adsorber efficiency of 95% or less is assumed in the NRC staff's safety evaluation. (Use the value assumed for the charcoal adsorber efficiency if the value for the HEPA filter is different from the charcoal adsorber efficiency in the NRC staff's safety evaluation). ** 0.175% value applicable when a charcoal adsorber efficiency of 99% is assumed, or 1% value applicable when a charcoal adsorber efficiency of 95% is assumed, or 10% value applicable when a charcoal adsorber efficiency of 90% is assumed in the NRC staff's safety evaluation.
Page Last Reviewed/Updated Tuesday, March 09, 2021
Page Last Reviewed/Updated Tuesday, March 09, 2021