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Page 1 of 16 DSAR Appendix N Reclassification of Systems Rev 3 Safety Classification: Usage Level:
Safety Information Change No.: EC 70100 Reason for Change: Delete VA-66 and clarify Auxiliary Building HVAC classification.
Preparer: J. Carlson Fort Calhoun Station
DSAR Appendix N Information Use Page 2 of 16 Reclassification of Systems Rev. 3 Table of Contents 1.0 PURPOSE ..................................................................................................................... 4 2.0 SAFETY CLASSIFICATION CRITERIA ......................................................................... 5 2.1 Safety Classes ...................................................................................................... 5 3.0 SAFETY CLASS INTERFACES .................................................................................... 9 3.1 Safety Class Interfaces for Pressure Integrity of Fluid Systems ........................... 9 3.2 Deleted ................................................................................................................. 9 3.3 Deleted ................................................................................................................. 9 3.4 Deleted ................................................................................................................. 9 3.5 Safety Class Interface for Other Equipment........................................................ 10 4.0 CORRELATION BETWEEN SAFETY CLASS AND EQUIPMENT DESIGN CODE .... 10 5.0 QUALITY ASSURANCE .............................................................................................. 11
DSAR Appendix N Information Use Page 3 of 16 Reclassification of Systems Rev. 3 List of Tables Table N System Safety Classification .............................................................................. 12 Table N Correlation Between Safety Class, Equipment Design and Quality Assurance .. 16
DSAR Appendix N Information Use Page 4 of 16 Reclassification of Systems Rev. 3 1.0 PURPOSE The purpose of this appendix is to classify the FCS mechanical systems based upon regulatory and industry guidance (RG 1.261 and ANSI/ANS-51.12) and to establish the corresponding piping and component codes of construction. The original licensing basis for the Fort Calhoun Station (FCS) did not categorize systems based on safety functions which current industry standards and NRC guidance documents have promulgated. The FCS safety-related systems are designated as Critical Quality Elements (CQE) and the Non-Nuclear Safety Related Systems are designated as either Limited-Critical Quality Elements (Limited CQE) or Non-CQE depending on the system's importance on plant safety.
Industry standards (RG 1.26 and ANSI/ANS-51.1), correlate system safety classes to ASME Section III code classes. Because of the similarity between the ASME Section III and B31.7 code classes Appendix N will correlate the Safety Classes with B31.7 code classes.
The following sections provide the safety classification criteria, safety class barrier interface criteria, correlation between safety class and equipment design, and quality assurance requirements.
1 Regulatory Guide 1.26, revision 3, 1976, Quality Group Classifications and Standards for Water, Steam, and Radioactive Waste Containing Components of Nuclear Power Plants.
2 ANSI/ANS-51.1, 1983, Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactors.
DSAR Appendix N Information Use Page 5 of 16 Reclassification of Systems Rev. 3 2.0 SAFETY CLASSIFICATION CRITERIA American National Standard ANSI/ANS-51.1, Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactors, is the guidance document utilized in the establishment of the system safety classification criteria. Based upon this standard, original and replacement mechanical equipment shall be assigned to one of three Safety Classes (SC) identified as, SC-3, Non-Nuclear Safety (NNS) CL-1 or -2 in accordance with definitions provided herein. Assignments shall be made for all mechanical equipment of the nuclear power plant. Classification shall be done on the basis of definitions contained in section N.2.1 and the interface requirements of section N.3.0.
When the interface requirements described herein are not met, the equipment shall be assigned to the more stringent Safety Class corresponding to functions of the connected equipment or justification for other defined bases shall be provided. Table N-1 provides the primary safety class designations and safety class interfaces for the FCS mechanical systems required for decommissioning.
2.1 Safety Classes Equipment shall be assigned to one of the three classes in accordance with N.2.1.3 through N.2.1.5. The equipment assigned to SC-3 is that relied upon in the plant design to accomplish nuclear safety functions. Safety classes SC-1 and SC-2 as defined in the ANSI/ANS-51.1 standard, are no longer applicable to the station in the permanently defueled condition. Therefore these requirements, as previously described in sections N.2.1.1 and N.2.1.2 are deleted.
When more than one system is capable of accomplishing a nuclear safety function and one system, on its own, satisfies all nuclear safety-related systems requirements (e.g., redundancy, diversity, capacity), the latter shall be classified to the corresponding Safety Class and the additional system as NNS.
Equipment assigned to one of the three safety classes shall meet the minimum requirements as prescribed in N.4.0. Equipment or components with more stringent design requirements than those corresponding to the applicable safety class may be utilized, however, the design code/safety class designation as set forth in Table N-2 shall be retained.
Where a single item of equipment, or a portion thereof, provides two or more functions or classes, it shall be classified to the more stringent class. Different portions of the same equipment (e.g., the tube side versus the shell side of a heat exchanger) may perform different functions and be assigned to different classes provided the equipment contains a suitable interface boundary meeting the requirements of N.3.0.
DSAR Appendix N Information Use Page 6 of 16 Reclassification of Systems Rev. 3 A support shall be classified to the more stringent class corresponding to the function provided either (a) by the supported equipment, unless failure of the support could not jeopardize the function of the supported equipment; or (b) directly by the support itself (e.g., a Seismic Category II/I condition). Exceptions may be made for intermediate elements (e.g., load-bearing housings of electric motors, valve operators, heat exchangers, or diesel engines) and access structures, whether of concrete or structural steel that carry the weight of, or provide structural stability to SC-3 equipment, either directly or through piping supports. Such intermediate elements shall be classified as SC-3 or NNS in accordance with either N.2.1.3g or N.2.1.4e, as applicable.
2.1.1 Deleted 2.1.2 Deleted
DSAR Appendix N Information Use Page 7 of 16 Reclassification of Systems Rev. 3 2.1.3 Safety Class 3 Safety Class 3 (SC-3) shall apply to equipment that is designed and relied upon to accomplish the following nuclear safety functions:
- a. Deleted
- b. Deleted
- c. Remove radioactive material from the atmosphere of confined spaces outside primary containment containing SC-3 equipment.
- d. Deleted
- e. Deleted
- f. Deleted
- g. Structurally load-bear or protect SC-3 equipment.3
- h. Provide radiation shielding for the control room or offsite personnel.
- i. Ensure required cooling for liquid-cooled stored fuel (e.g., spent fuel storage pool and cooling system).
- j. Ensure nuclear safety functions provided by SC-3 equipment (e.g.,
provide heat removal of SC-3 heat exchangers or provide lubrication of SC-3 pumps).
- k. Provide an acceptable environment for SC-3 equipment and operating personnel.
3 This applies to concrete or steel structures that are not within the scope of the piping code or component supporting structure.
DSAR Appendix N Information Use Page 8 of 16 Reclassification of Systems Rev. 3 2.1.4 Non-Nuclear Safety Class 1 Non-Nuclear Safety Class 1 (NNS CL-1) shall apply to equipment that is not included in SC-3 that is designed and relied upon to accomplish one or more selected, but limited, requirements specified to ensure acceptable performance of specific NNS functions. The selected requirements are established on a case-by-case basis commensurate with the specific NNS function performed. The functions performed by the NNS Class 1 equipment are:
- a. Process, extract, encase, or store radioactive waste.
- b. Provide cleanup of radioactive material from the fuel storage cooling system for normal operations.
- c. Extract radioactive waste from, store, or transport for reuse irradiated neutron absorbing materials (e.g., boron compounds).
- d. Resist failure that could prevent any SC-3 equipment from performing its nuclear safety function.
- e. Structurally load-bear or protect NNS equipment providing any of the functions listed in N.2.1.4.
- f. Provide permanent shielding for protection of SC-3 equipment or of onsite personnel.
- g. Provide operational or maintenance recovery functions involving radioactive materials without undue risk to the health and safety of the public.
- h. Deleted
- i. Handle spent fuel, the failure of which could result in fuel damage such that significant quantities of radioactive material could be released from the fuel.
- j. Ensure reactivity control of stored fuel.
- k. Deleted
- l. Deleted 2.1.5 Non-Nuclear Safety Class 2 Non-Nuclear Safety Class 2 (NNS CL-2) shall apply to equipment that is not included in SC-3 or NNS CL-1. This equipment is not relied upon to perform a nuclear safety function.
DSAR Appendix N Information Use Page 9 of 16 Reclassification of Systems Rev. 3 3.0 SAFETY CLASS INTERFACES If failure of Safety Class or NNS equipment connected to other Safety Class equipment could prevent the latter equipment from accomplishing its nuclear safety function, an interface barrier or isolation device shall be provided to protect the latter equipment.
3.1 Safety Class Interfaces for Pressure Integrity of Fluid Systems A membrane (e.g., heat exchanger tube, bellows, piston, O-ring, blind flange) that provides pressure boundary separation of equipment classes serves as the required barrier between any two classes, and shall be categorized to the more stringent class.
Where equipment of differing classes is interconnected, the more stringent class extends to and includes the cited barriers. Otherwise, the interface shall be in accordance with the following criteria.
Interface barriers or isolation devices connecting Safety Class or NNS Fluid system equipment to other Safety Class equipment shall be capable of limiting the loss of fluid from the latter equipment if the former were to fail. The fluid loss shall be limited such that (1) if the fluid contains radioactivity, the applicable dose criteria4 are met and (2) if the fluid performs a nuclear safety function (e.g., heat transfer) sufficient inventory and pressure are maintained to perform that function. The closure time of open valves and the limitation of losses due to flow restrictions shall be evaluated when determining the loss of fluid. The loss of fluid shall be assessed for the full duration of the event. The loss of fluid limitation shall be met applying the single failure criterion to the actuation of the interface barriers or isolation devices.
3.2 Deleted 3.3 Deleted 3.4 Deleted 4
The applicable dose criteria is provided in DSAR, Section 14.
DSAR Appendix N Information Use Page 10 of 16 Reclassification of Systems Rev. 3 3.5 Safety Class Interface for Other Equipment The classification requirements for supports and mechanical movers or links shall be as required in N.2.1. No interface barrier is required when interconnected mechanical equipment consists of differing Safety Classes, mechanical equipment connected to structures or electrical equipment, or electrical equipment connected to structures.
Safety class interfaces between NNS CL-1 and NNS CL-2 shall be a single closed manual valve, check valve or flow restricting device. An open single remote manual valve is also an acceptable interface between these safety classes. An exception to this criteria is a single open manual valve, which can be used as a class boundary interface if operator action has been shown to be adequate to allow the NNS CL-1 system to perform its design function. An example of this exception is the Fire Protection System.
4.0 CORRELATION BETWEEN SAFETY CLASS AND EQUIPMENT DESIGN CODE The USAS B31.7 "Nuclear Power Piping" 1968 Draft, defined Class I, II, and III prior to the development of ASME Section III Class 1, 2, and 3 for piping in the early 1970's.
As the ASME piping code was an outgrowth of USAS B31.7, the Class I, II, and III designations of B31.7 correlate directly with Class 1, 2, and 3 of ASME Section III.
ANSI/ANS-51.1 makes a direct correlation between Safety Classes and ASME Section III classes, hence the following correlation is made:
Safety Class B31.7 Class ASME Section III Class 1(1) I 1 2(1) II 2 3 III 3 The USAS B31.7 code constitutes the FCS design code for piping, pipe fittings, and supports but does not include piping system components (valves, heat exchangers, tanks, pumps, etc). The design codes for the piping system components, as defined above, will remain as specified in the original contract specifications, purchase orders, and USAR.
The original piping code of construction shall be retained for all future plant modifications. For several systems the original piping as-built is B31.7 Class I for Safety Class 3 systems as defined in Table N-1, or B31.7 Class II now defined as NNS CL-1 or NNS CL-2. The original piping code of construction for these systems is reclassified to the piping code corresponding to safety class shown in Table N-1.
1 Safety Class 1 and 2 are no longer applicable as specified in section N.2.1. This documents the construction and safety class comparison basis.
DSAR Appendix N Information Use Page 11 of 16 Reclassification of Systems Rev. 3 Component replacements shall meet the requirements of either the original code of construction or later editions of the construction code, e.g., ASME Section III for piping and fittings. Replacement components may meet all or portions of the requirements of later editions of the construction code.
Table N-2 contains a correlation between safety class, equipment design (code of construction), and quality assurance.
The Seismic Category I requirements specified for specific plant systems is shown in DSAR Appendix F. Safety Class 3 equipment is considered to be Seismic Category I.
5.0 QUALITY ASSURANCE All mechanical equipment designated as SC-3 or NNS CL-1, 2 that provide functions listed in N.2.1.3 through N.2.1.5 have quality levels assigned to ensure the probability that the included structures, systems, and components will perform their functions.
DSAR Appendix A describes the OPPD Quality Assurance (QA) program for Fort Calhoun Station (FCS). The QA program is applied to CQE systems, (components designated Safety Class 3) and some of the Non-Nuclear Safety Class 1 systems such as Fire Protection, Radioactive Waste, and Limited CQE. The remaining Non-Nuclear Safety Class 1 and Non-Nuclear Safety Class 2 are termed Non-CQE with Special Requirements and Non-CQE respectively and have no formalized quality assurance program. Table N-2 correlates the level of quality assurance with respect to safety class.
DSAR Appendix N Information Use Page 12 of 16 Reclassification of Systems Rev. 3 Table N System Safety Classification P&ID No. System Safety Class 11405-M-2 Auxiliary Bldg. HVAC HVAC equipment and ductwork NNS CL-1&2 11405-M-5 Demineralized Water Connections to LPSI for Alt SFP Cooling SC-3 Balance of System NNS CL-2 11405-M-6 Waste Disposal System Interface with SIRWT (SIRWT Cleanup) NNS CL-1 El 995' - 6" Refueling Canal Low NNS CL-1 Point Drain in Containment El 976' - 6", 4" F.D. to Containment NNS CL-1 Sump and Sump Pumps Balance of System NNS CL-1&2 11405-M-7, Waste Disposal System NNS CL-1&2 8, 9 11405-M-10 Component Cooling System SI Pump Seal coolers and piping SC-3 Control Room A/C piping NNS CL-2 Charging pump oil coolers NNS CL-2 Letdown heat exchanger NNS CL-2 Balance of System SC-3
DSAR Appendix N Information Use Page 13 of 16 Reclassification of Systems Rev. 3 Table N-1 (Continued)
P&ID No. System Safety Class 11405-M-11 Spent Fuel Pool Cooling Pool Cooling Water System SC-3 Fuel Transfer Drain Pump Piping SC-3 Spent Fuel Pool Cooling Emergency NNS CL-1 Cross-Tie Piping 11405-M-40 Component Cooling Water System Balance of System SC-3 11405-M-42 Nitrogen, Hydrogen, Methane, Propane, and Oxygen Gas Nitrogen Piping connected to Component SC-3 Cooling Surge Tank Piping Connected To Waste Disposal NNS CL-1 System Balance of System NNS CL-2
DSAR Appendix N Information Use Page 14 of 16 Reclassification of Systems Rev. 3 Table N-1 (Continued)
P&ID No. System Safety Class 11405-M-97 Misc. HVAC System Control Room Air Inlet SC-3 Control Room HVAC NNS CL-2 Emergency. Diesel Gen. Air Inlet, NNS CL-1 Radiator Exhaust Dampers, and Duct Balance of System NNS CL-2 11405-M-98 Waste Disposal System NNS CL-1&2 11405-M-99 Waste Disposal System Aux. Bldg. Floor NNS CL-2 Drains 11405-M-100 Raw Water Raw Water Supply Piping SC-3 Discharge Piping in the Aux. Bldg. SC-3 Discharge piping in the Turbine Bldg. NNS CL-1 Balance of System NNS CL-2 11405-M-262 Fuel Oil System/Lube Oil System NNS CL-1&2 11405-M-264 Instrument Air System Air piping to SC-3 valves SC-3 Balance of system NNS CL-2 11405-M-266 Fire Protection NNS CL-1&2
DSAR Appendix N Information Use Page 15 of 16 Reclassification of Systems Rev. 3 Table N-1 (Continued)
P&ID No. System Safety Class 627-D-8053 Waste Evaporator Package (abandoned in place) NNS CL-1 C-4175 Typical Valve Air Source Valve Configurations Air Source for Safety Related Valves SC-3 Required to Hold or Change Position All Other Air Sources for Valve NNS CL-2 Actuation E-23866-210-130 Safety Injection and Containment Spray System LPSI pumps and Shutdown Cooling SC-3 Heat Exch. (8)
SIWRT SC-3 Piping for Alternate Spent Fuel Pool NNS CL-1 Cooling Balance of System NNS CL-2 B-120-F03001 Emergency Diesel Generator Lube Oil NNS CL-1 System B-120-F04002 Emergency Diesel Generator Jacket NNS CL-1 Water System B-120-F07001 Emergency Diesel Generator Starting Air Pressure Boundary from Air Receivers to NNS CL-1 Air Start Motors Air Compressors and Associated Piping NNS CL-2
DSAR Appendix N Information Use Page 16 of 16 Reclassification of Systems Rev. 3 Table N Correlation Between Safety Class, Equipment Design and Quality Assurance SAFETY CLASS EQUIPMENT CODE OF CONSTRUCTION (1) QUALITY ASSURANCE (2)
SC-3 Piping (5) B31.7, Class III - 1968 draft CQE Piping System Components(4) Original Contract Specifications CQE NNS CL-1 Piping B31.1(7) (6)
Piping System Components(4) B31.1 and Note 3 & 7 (6)
NNS CL-2 Piping (5) B31.1 Non-CQE Piping System Components(4) B31.1 and Note 3 Non-CQE NOTES:
- 1. "Code of Construction" connotes design, fabrication, installation, and testing.
- 2. 10CFR50 Appendix B applies to all CQE equipment.
- 3. NNS piping system components shall be commercial grade (e.g.,. pressure vessels to ASME section VIII, pumps to manufacturers standards, etc.).
- 4. Piping system components are valves, heat exchangers, pumps, etc.
- 5. Piping includes pipe fittings and pipe supports.
- 6. Limited CQE, Radioactive Waste Disposal, Fire Protection, or Non-CQE with special requirements.
- 7. Not applicable to Fire Protection.
- 8. Shutdown heat exchangers (AC-4A/B) were originally designed and constructed to the standards of ASME,Section III, Class C, and TEMA Class R requirements.