ML20094C133
| ML20094C133 | |
| Person / Time | |
|---|---|
| Issue date: | 11/24/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-09.4.3, NUREG-75-87, NUREG-75-87-9.4.3, SRP-09.04.03, SRP-9.04.03, NUDOCS 9511020058 | |
| Download: ML20094C133 (7) | |
Text
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NUREG 75/087 p.too
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U.S. NUCLEAR REGULATORY COMMISSION f'g' qg/ g QW)JffSTANDARD REVIEW PLAN OFFICE OF NUCLEAR REACTOR REGULATION SECTION 9.4.3 AUXILIARY AND RADWASTE AREA VENTILATION SYSTEM REVIEW RESPONSIBILITIES Primary - Auxiliary and Power Conversion Systems Branch (APCSB)
Electrical. Instrumentation and Control Systems Branch (EICSB)
Secondary -
Mechanical Engineering Branch (MEB)
Effluent Treatment Systems Branch (ETSB)
RadiologicalAssessmentBranch(RAB) 1.
AREAS OF REVIEW The APCSB reviews the auxiliary and radwaste area ventilation system (ARAVS) from air intake to the point of discharge where the system connects to the gaseous cleanup and treatment system or station vents. The review includes components such as air intakes, ducts air conditioning units, blowers, isolation dampers and roof exhaust fans. The review of the ARAVS covers the radwaste areas and controlled access nonradioactive areas and their relation-ship to safety-related areas in the auxiliary building.
1.
The APCSB reviews the functional performance requirements and the air treatment equip-ment for the ARAVS to determine whether the ventilation system or portions of the system have been designed or need to be designed as a safety-related system. Based on this determination, the safety-related part of the system is reviewed with respect to functional performance requirements during normal operation. during adverse environ-mental occurrences, and during and subsequent to postulated accidents, including the loss of offsite power. The APCSB reviews safety-related portions of the system to assure that:
A single active failure cannot result in loss of the system functional performance a.
capability.
b.
Components and piping have sufficient physical separation or shielding to protect essential portions of the system from missiles and pipe whip, Failures of non-seismic Category I equipment or components will not result in c.
unfiltered releases of radioactive contaminants.
2.
The APCSB also reviews safety-related portions of the ARAVS with respect to the following:
USNRC STAND ARD REVIEW PLAN
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a.
The capability to detect and monitor radiction levels, b.
The capability to direct ventilation air from areas of low radioactivity to areas of progressively higher radioactivity.
The capability to detect the need for isolation and to isolate safety-related portions of the system in the event of fires, failures, or malfunctions, and the capability of
'the isolated system to function under such conditions.
3.
The applicant's proposed technical specifications are reviewed for operating license applications as they relate to areas covered in this plan.
Secondary reviews are perfonned by other branches and the results used by the APCSB to com-plete the overall evaluation of the system. The ME8 will, upon request, review the seismic qualification of components and confirm that the components, piping, and structures are designed in accordance with applicable codes and standards. The ETSB will verify that the system functional performance meets acceptable limits for rf5Toactivity releases during normal operation. The RAB reviews the system capability to monitor radiation levels. RAB also verifies the system meets the radiation protection criteria. The EICSB will determine the adequacy of the design, installation, inspection, and testing of all electrical com-ponents required for proper operation.
II. ACCEPTANCE CRITERIA I
Acceptability of the ARAVS design, as described in the applicant's stfety anilysis report (SAR), is based on specific general design criteria and regulatory guides. An additional basis for determining the acceptability of the ARAVS is the degree of similarity of the
- design with that for previously reviewed plants with satisfactory operating experience. The design of safety-related portions of the ARAVS 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 carth-quakes, tornadoes, hurricanes, and floods, as established in Chapters 2 and 3 of the SAR.
2.
General Design Criterion 4, with respect to structures housing the system and the l
System itself being capable of withstanding the effects of external missiles and inter-nally generated missiles, pipe whip, and jet impingement forces associated with pipe breaks.
3.
General Design Criterion 5, as related to shared systems and components important to safety.
4.
General Design Criterion 60, as related to the handling of radioactive materials in the ARAVS.
j 5.
General Design Criterion 64, as related to the monitoring of gaseous releases through the ARAVS, 9.4.3 2 11/24/75 k.
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i Regulatory Guide 1.26, as related to quality group classification of systems and 6.
components.
Regulatory Guide 1.29, as related to seismic design classification of system components.
7.
8.
Regulatory Guide 1.52, as related to system functional performance requirements, j
Regulatory Guide 8.8, "Information Relavent To Maintaining Occupational Radiation 9.
Exposure As Low As Practicable (Nuclear Reactors)."
10.
Branch Technical Positions APCSB 3-1 and MEB 3-1, as related to breaks in high and moderate energy piping systems outside containment.
111. REVIEW PROCEDURES The procedures below are used during the construction permit (CP) review to determine that the design criteria and bases and the preliminary design as set forth in the preliminary For safety analysis report meet the acceptance criteria given in Section 11 of this plan.
the review of operating license (OL) applications, the procedures are utilized 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 i
by the applicant are in agreement with the requirements for system testing, minimum perform-ance, and surveillance developed as a result of the staff's review.
I As a result of various ARAVS designs proposed by applicants, there will be variations in system requirements. For the purpose of this review plan, a typical system is assumed which f
has fully redundant subsystems, each having an identical essential (safety features) portion.
For cases Where there are variations from this typical arrangement, the reviewer would adjust the review procedures given below. However, the system design would be required to meet the acceptance criteria given in Section II. The reviewer will select and emphasize material from this plan as may be appropriate for e particular case.
1.
The SAR is reviewed to verify that the system descriptian section and piping and instru-earntation diagrams (P&TDs) -show the ARAVS equipment used for, nomal operation', the ambient temperature limits for the areas serviced, anti the filtration capacity of the system filters. The system! performance rwquirements section is reviewed to detemine
'that it describes allowable component operational degradation (e.g.., loss of function, damper leakage) and 11escribes the procedures that willi be followed to detect and correct these conditions. The teviewer, using results from1 allure modes and effects analyses as appropriate, detennines that the safety-related; portion of the system is capable of functioning in spite of the failure of any active component.
2.
The system P&lDs, layout drawings, and component descriptions and characteristics are then reviewed to determine that:
Essential portions of the ARAVS sre correctly identified and are isolable from a.
non-essential portions of the system. The P& ids are reviewed to verify that they clearly indicate the physical divisions between such portions and indicate design l
classification changes. System drawings are also reviewed to verify that they i
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show the means for accomplishing isolation and the description is reviowed to identify minimum performance rQquirements for the isolation dampers. For the l
typical system, the drawings and description are reviewed to verify that two automatically operated isolation dampers in series separate non-essential-portions and components from the essential portions.
b.
Essential portions of the ARAVS, including the isolation dampers separating essen-tial from non-essential portions, are classified seismic Category I and Quality j
Group C or higher Component and system descriptions in the SAR that identify j
mechanical and performance characteristics are reviewed to verify that the above i
seismic classification has been included, and that the Pa!Ds indicate any points of change in design classification, j
3.
The reviewer verifies that the essential portion of the system has been designed so that system function will be maintained as required in tr,e event of adverse environmental phenomena or in the event of certain pipe breaks or loss of offsite power. The reviewer l
evaluates the system, usiag engineering. judgment and the results of failure modes and effects analyses to determine that:
The failure of non-essential portions of the system or of other systems not designed a.
to seismic Category I standards and located close to essential portions of the system, or of non-seismic Category I structures that house, support, or are close to essential portions of the ARAVS, will not preclude operation of the essential portions of the ARAVS. Reference to SAR sections describing site features and the general arrangement and layout drawings will be necessary, as well as the SAR tabulation of seismic design classifications for structures and systems. State-ments in the SAR that verify that the above conditions are met are acceptable. (CP) b.
The essential portions of the ARAVS are protected from the effects of floods, hurricanes, tornadoes, and internally and externally generated missiles. Flood protection and missile protection criteria are discussed and evaluated in detail under the standard review plans for Chapter 3 of the SAR. The location and the design of the system, structures, and fan rooms (cubicles) are reviewed to deter-mine that the degree of protection provided is adequate. 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 components of the system will be located in individual cubicles or rooms that will withstand the effects of both flooding and missiles is acceptable,
' The total system has the capability to detect and control leakage of radioactive c.
contamination from the system. It is acceptable if the system P&lD indicates monitors and alarms located in the system intakes that are capable of detecting radioactive leakage and provisions for automatically isolating the ARAVS before the first contaminated airborne particles and gases reach the normal ventilation exhaust ducts. Two automatically actuated dampers in series should be provided for isolation of non-essential portions of the system.
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d, The eesential portions of the system are protQcted from the effects of high and moderatQ enQrgy line break 3, Layout drawings are reviGwed to assure that no high or moderate energy piping systems are close to essential portions of the ARAVS, 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 this information are given in the corresponding review plans, t
Components and subsystems necessary for preventing the release of radioactive e.
The contaminants can function as required in the event of loss of offsite power, system design will be acceptable if the ARAVS meets minimum system requirements as stated in the SAR assuming a failure of a single active component within the system or in the auxiliary electric power source which supplies the system. The SAR is reviewed to see that for each ARAVS component or subsystem affected by the loN of offsite power, the resulting system flow capacity will not cause the loss of preferred direction of air flow from areas of low potential radioactivity to areas of higher potential radioactivity. Statements in the SAR and the results of failure modes and effects analyses are considered in verifying that the system meets these requirements. This will be an acceptable verification of system functional reliability.
4.
The descriptive information, P& IDS, ARAVS drawings, and failure modes and effects analyses in the SAR are reviewed to assure that essential portions of the system can function following design basis accidents assuming a concurrent single active failure.
The reviewer evaluates the 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 system isolation or filtration require-ments are met for each accident situation for the required time spans, For each case, the design will be acceptable if minimum system requirements are met.
IV. EVALUATION FINDINGS The reviewer detennines that sufficient information has been provided and his review supports conclusions of the following type, to be included in the staff's safety evaluation report:
"The auxiliary and radwaste area ventilation system (ARAVS) includes all components and ductwork from air intake to the point of discharge where the system connects to the gaseous cleanup and treatment system or station vents. The scope of the review of the ARAVS for the plant included layout drawings, piping and instrumen-tation diagrams, and descriptive information for the system and the auxiliary supporting systems that are essential to its safe operation, [The review has determined the adequacy of the applicant's proposed design criteria and bases for the auxiliary and radwaste area ventilation system and the requirements for system performance to preclude an unacceptable release of contaminants to the environment during nonnal, abnormal, and accident conditions. (CP)] [The review has determined that the design of the auxiliary and radwaste area ventilation system and auxiliary supporting systems is in confonnance with the design critaria and bases. (0L)]
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"The basis for acceptancQ in the staff review has been conformance of the appli.
cant's designs and design criteria for the ARAVS and necessary auxiliary supporting systems to the Commission's regulations as set forth in the general design criteria, and to applicable regulatory guides, staff technical positions, and industry standards.
"The staff concludes that the design of the ARAVS conforms to all applicable regulations, guides, staff positions, and industry star.dards, and is acceptable."
V.
REFERENCES
').
10 CFR Part 50. Appendix A, General Design Criterion 2. " Design Bases for Protection Against Natural Phenomena."
2.
10 CFR Part 50. Appendix A.' General Design Criterion 4 " Environmental and Missile Design Bases."'
3.
10 CFR Part 50, Appendix A, General Design Criterion 5. " Sharing of Structures, Systems, and Components."
4 10 CFR Part 50, Appendix A, General Design Criterion 60, " Control of Releases of Radioactive Materials to the Environment."
5.
10 CFR Part 50, Appendix A. General Design Criterion 64, " Monitoring Radioactivity Releases."
\\
6.
Regulatory Guide l.26, " Quality Group Classifications and Standards for Water, Steam,
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and Radioactive-Waste-Containing Components of Nuclear Power Plants."
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7.
Regulatory Guide 1.29 " Seismic Design Classification."
8.
Regulatory Guide 1.52, " Design. Testing, and Maintenance Criteria for Atmosphere Cleanup System Air Filtration and Adsorption Units of Light-Water-Cooled Nuclear Power Plants."
9.
Regulatory Guide 8.8, "Information Relevant To Maintaining Occupational Radiation ExposureAslowAsPracticable(NuclearReactors)."
i i
10.
Branch Technical Positions APCSB 3-1, " Protection Against Postulated Piping Failures in Fluid Systems Outside Containment," attached to Standard Review Plan 3.6.1,
.and MEB 3-1, " Postulated Break and Leakage Locations in Fluid System Piping Outside Containment," attached to Standard Review Plan 3.6.2.
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