ML19221B044
| ML19221B044 | |
| Person / Time | |
|---|---|
| Issue date: | 11/24/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-09.3.1, NUREG-75-87, NUREG-75-87-9.3.1, SRP-09.03.01-01, SRP-9.03.01-1, NUDOCS 7907120302 | |
| Download: ML19221B044 (6) | |
Text
NU REG 75/087 fgR Racq%
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OpYlp/OFFICE OF NUCLEAR REACTOR REG 9
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SECTION 9.3.1 COMPRES5ED AIR SYSTEM REVIEW RESPONSIBILITIES Primary - Auxiliary and Power Conversion Systems Branch (APCSB)
Secondary - Structural Engineering Branch (SEB)
Mechanical Engineering Branch (MEB)
Electrical, Instrumentaticn and Control Systems Br anch (EICSB)
I.
AREAS OF REVIEW The compressed air system (CAS) provides air to safety-related equiprent, and also to plant equiprent used only for nomal facility operation. APCSS reviews the entire conpressed air system since there may be cases where two systems or subsystems are provided, i.e., a safety-related control air system (SRCAS), and a staticn service system for non-safety-related equipment. If the two systems are interconnected, then the area of review will extend from the safety-related oortion to the outermost isolation valve on all interconnec-tions between the two sy-tems.
If the systems are not connected, then the review will be limited to the SRCAS.
1.
APCSB reviews the systems to identify the safety-related air operated devices that are sup > lied by ?.he system, and whett'er each requires a source of supply air in order to perform the safety-related function.
2.
APCSB then reviews to detemine that:
a.
A failure of a component, or the loss of a corpressed air source does not negate the safety-related functional performance of the system.
t,.
The system components and pipes have suf ficient physical separation or barriers to protect the essential portions of the system from missiles, and from the effects of breaks and cracks in high and moderate energy fluid system piping close to the SRCAS.
3.
The APCSB reviews the system to detemine that the effects of failure of non-seismic Category I equipment or corponents will not affect the functioning of the SRCAS.
USNRC STANDARD REVILW PLAN si.nd.ed towtw,terie are p.p. red for the go.d.nr.G of t*e off ce of e ucieer Re.cio. Reguise. a otet' re. pons.bie for the rewow of.aw...one io conetruct.nd operese nuc14cr power plante These documente are fnede eve'letDe to the pubhc es part of the Commaesson 3 pokey to mform the nucleet Industry end the generel pubhc of regulatory procedures and paiecies Standard review peerie are not substrivtes for regulatory guides or the Commewen a reguistione and cor'ig>Otance efth them b5 not reTJered The standard revtew plan occt'one See heyed to Rev4ston 2 of the Standard Fo*e -t and Content of Safety Aristveie Reports for Nuclear Power Plants Not oil esctio^s of the Siendard f ormat have a correspondeng review pian Pubhshed s'saderd review p6 ens web be escoed persod.cally. es oppropnete to accommodate cornmerits and to rehe<1 new ereformeteen and esperience (gernsynente end e4eggettIone for Irnprove8'rtenI will be Cons.dered and should be ser t to the U S Nucseer Reguietory Commies.on.OHRe of Nucteer Reactor Regulation. Weebengton. D C. 2rE86
4.
APCSB reviews the design of the SRCAS with respect to the following:
Capability to isolate portions or components of the system in case of component a.
malfunction.
b.
Instrumentation and control features provided to detem.ne and verify that the system is operating in a correct moda le.g., valve position indication, pressure).
Functional capability of the system in the event of adverse environmental c.
phenomena, abnormal operational requirements, or accident conditions such as a loss-of-coolant accident (LOCA) or nain steam line break concurrent with loss of offsite power S.
The applicant's proposed technical specifications are reviewed for operating license applications as they relate to areas covered in this plan.
Secondary reviews are performed by other branches and the results used by the APCSB to corplete the overall review of the system. The secondary reviews are as follows. The SEB will determine the acceptability of the design analyses, procedures, any criteria used to establish the ability of seismi; Category I structures housing tk systen and supporting systems to withstard.he ef fects of natural phenomena such as the safe shutdown earthquake (SSE), the probable maximun flood (PMF), and tornado nissiles. The MEB will review the seismic qualification of components and confirm that the system is designed in accordance with applicabie codes and standards. The EICSB will deternine the adequacy of the design, installation, inspection, and testing of all essential electrical corponents.
II.
ACCEPTANCE CRITERIA The acceptability of the design of the safety-related control air systen, as described in the applicant's safety analysis report (SAR), is based on specific general design criteria and regulatory guides. An additional basis for determining acceptability of the system will be the degree of similarity of the design with that for previously reviewed plants with satisfactory operating experience. The design of the SRCAS is acceptable if the integrated design of the system is in accordance with the following criteria:
1.
General Design Criterion 2, as related to structures housing the system and the system itself being capable of withstanding the effects of natural phenomena such as earth-quakes, tornadoes, hurricanes, and floods, as established in Chapter 2 of the SAR.
2.
General Design Criterion 4, with respect to structures housing the systems and the system itself being capable of withstanding the ef fects of external missiles and internally generated missiles, pipe whip, and jet impingement forces associated with pipe breaks.
3.
General Design Criterion 5, as related to the capability of shared systens and compo-nents important to safety to perform required safety functions.
18 269 9.3.1-2
4.
Regulatory Guide 1.26, as related to the quality group classification of systems and components.
5.
Regulatory Guide 1.29, as related to the seismic design classification of system components.
6.
Branch Technical Positions APCSB 3-1 and MEB 3-1, as related to breaks in high energy piping or cracks in moderate energy piping systems outside containnent.
III.
REVIEW PROCEDURES, The procedures below are used during the construction permit (CP) review to deternine that the design criteria and bases and the preliminary design as set forth in the preliminary safety analysis report meet the acceptance criteria given in Section II of this plan. For oper ating license (OL) reviews, the procedures are used to verify that the initial design criteria and bases have been appropriately implemented in the final design as set forth in the final safety analysis report. The procedures for OL reviews include a determination that the content and intent of the technical specifications prepared by the applicant are in ac.eement with the requirements for system testing, minimum performance, and surveil-
'ince developed as a result of the staff's review.
As a result of various CAS designs provided for different plants, there will be variations in systen requirements. For the purpose of this plan, a typical system is assumed which has two indecendent systems, the plant service air system, and a safety-related control air system (SRCAS). For cases where there are variations from this arrangement, the reviewer adjusts the review procedures giver below. However, the systen design would be required to meet the acceptance crihria in Section II.
The reviewer will select and emphasize nate-rial from this plan as appropriate for a particular case.
1.
The SAR is reviewed to identiff from information in the system description section snd the piping and instrumentation diagrams (P& ids) the SRCAS equipment used for normal operation and fur safety feature operation. The reviewer determines that the system design is acceptable, taking into account tha worst expected component operational degradation (e.g., wet or dirty air). The procedures to be followed to detect and correct these conditions when degradation becomes excessive are also reviewed.
2.
The reviewer, using the result; of failure modes and effect9 analyses, determines that the systen, when operating in the normal mode, is capable of sustaining the loss of any active component. The reviewer determines, on the basis of previously approved systems or independent calculations, that the ninimum system requirements (as stated in the SAR) are met for these failure conditions.
3.
The system P& ids, layout drawings, and component descriptions and characteristics are reviewed to determine the following:
Essential portions of the ERCAS are correctly identified and are isolable from a.
the non-essential portions of the system. The P& ids are reviewed to verify that 9.3.1-3 3
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they clearly indicate the physical division between each portion. System drawt gs are also reviewed to verify that they show the reans for accomplishing isolation and the system description is reviewed to identify minimum performance requirements of the isolation valves. For the typical system, the drawings and descriptions are reviewed to verify that twa automatically operated isolation valves in series separate non-essential portions and components from the essential portions.
b.
Essential portions of the '3RCAS, including the isolation valves separating essential fron non-essential portions, are classified Quality Group C or higher and seismic Category I.
Component and systen descriptions in the SAR that identify rechanical and performance characteristics are reviewed to verify that the above classifications have been included, and that the P& ids indicate points of change in any design classification.
4.
The reviewer verifies that the systen has been designed so that systen function will be maintained, as required, in the event of adverse environmental phencrena, certain pipe breaks, or a loss of offsite power. The reviewer evaluates the system, using engineering judgment and the results of failure rodes and effects analyses to deter-mine that:
The failure of non-essential portions of the system or of other systems not a.
designed to seisnic Category I standards and located close to essential portions of the SRCAS, or of non-seisnic Cat. gory I structures that house, support, or are close to the SRCAS, will not preclude operation of the essential portions of the SRCAS. Reference to SAR Chapter 2 (which describes site features) and the general arrangement and layout drawings, as well as to the $AR tabulation of seismic design classifications for structures and systems will be necessary. Statements in the SAR to the effect that the above conditions are ret are acceptable.
b.
The essential purtions of the SRCAS are protecter from the effects of floods, hurricanes, tornadoes, and internally or externally generated missiles. Seismic design, flood protection, and missile protection criteria are discussed in detail in Chapter 3 of the SAR. The location and the design of the system, structures, or cubicles are reviewed to determine that the degree of protecticn is adecuate.
A statement to the effect that the system is located in a seismic Category I structure that is tornado missile and flood protected, or that conpanents of the system will be located in individual cubicles or rooms that will sithstand the ef fects of tornado winds, flooding, and missiles is acceptable.
c.
An adequate SRCAS air supply source is available, considering the loss of offsite power. The system design will t>e acceptable if minimum performance requirements, as stated in the SAR, are met assuming a concurrent failure of a sinale active component, including ar, energency power source. The SAR information is reviewed to verify that for each SRCAS component or subsystem affected by the loss of offsite power, system capability meets or exceeds the minimum requirements.
Statements in the SAR and the results of failure modes and effects analyses are 9.3.1-4 40 171 14U (I f
considered to assure that the system neets these requirements. This will be acceptable verification of system functional reliability, d.
The essential components of the system are protected from the effects of high and moderate energy line breaks. Layout drawings are reviewed to assure that no high or moderate energy pipi.19 systems are close to essential portions of the SRCAS, or that protection from the effects of failure will be provided. The means of providing such protection will be given in Section 3.6 of the SAR, and procedures for reviewing the information are given in the corresponding review plans.
S.
The descriptive information, P& ids, SRCAS drawings, and failure modes and effects analyses in the SAR are reviewed to assure that the SRCAS will function folicwing design basis accidents assuming a concurrent single active failure. The reviewer evaluates failure modes and effects analyses presented in the SAR to assure function of required components, traces the availability of these components on system drawings, and checks that the SAR contains verification that minimum corpressed air flow require-ments are met for each degraded situaticn for the required time spans. For each case the design will be acceptable if minimu"1 systen reauirements are met.
IV.
EVALUATION FINDINGS The reviewer verifies that sufficient information has been provided and that his review supports conclusions of the following type, to be included in the staff's safety evaluation report:
"The compressed air system ir.cludes all components and piping and the points of connec-tion or interfaces with other systems. The scope of the review of the compressed air system for the plant included layout drawings, piping and instrumen-tation diagrans, and descriptive information for operation of essential portions of the system. [The review has determined tne adequacy of the applicant's proposed design criteria and design bases for the system with regard to the need to maintain a con-tinous air supply to s S'y-related components during all conditions of plant opera-tion. (CP)] [The review has determined that the applicant's design of the corpressed air system and auxiliary supporting systems is in conformance with the design criteria and bases. (OL)]
"The basis for acceptance in the staff review has been conforr:ance of the applicant's designs and design criteria for the corpressed air systen anc n?cessary auxiliary
,upporting systens to the Connission's regulations as set forth in the general design criteria, and to applicable regulatory guides, branch technical positions, and industry standards.
"The staff concludes that the design of the conpressed air systen conforms to all applicable regulations, guides, staff positions, and industry standards, and is acceptable."
} d] } I}
9.3.1-5
V.
REFERENCES 1.
10 CFR Part 50, Appendix A, General Design Criterion 2, "Cesign Bases for Protection Against Natural Phenor"ena."
2.
10 CFR Part 50, Appendix A, General Design Criterion 4, "Environrental and Missile Design Bases."
3.
'l CFR Part $0, Appendix A, General Design Criterion 5. " Sharing of Structures, Systems, J Components."
4.
Regulatcry Guide 1.26, " Quality Group Classifications and Standards For Water, Steam-and Radioactive-Waste-Containing Cor:ponents of Nuclear Power Plants," Revision 1.
5.
Regulatory Guide 1.29, " Seismic Design Classification," Revision 1.
6.
Branch Technical Positions APCSB 3-1, " Protection Against Postulated Piping Failures In Fluid Syster,s Outside Containment," attached to Standard Review Plan 3.6.1, and MEB 3-1, " Postulated Ereak and Leakage Locations in Fluid System Piping Outside Containment," attached to Standard Review Plan 3.6.2.
9 9.3.1-6 ib
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