ML19221B122
| ML19221B122 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-06.2.1., NUREG-75-87, NUREG-75-87-6.2.1., SRP-06.02.01.01, SRP-6.02.01.01, NUDOCS 7907120457 | |
| Download: ML19221B122 (9) | |
Text
NUREG 75/087 feRic'%
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STANDARD REVIEW PLAN b%.... #
OFFICE OF NUCLEAR REACTOR REGULATION SECTION 6.2.1.1.8 ICE CONDENSER CONTAINMENTS REVIEW RESPONSIBILITIES Primary - Containment Systems Branch (CSB)
Secondary - Instrumentatio, and Control Systems Branch (ICSB) l Accident Analysis Branch (AAB)
Structural Engineering Branch (SEB)
Mechanical Engineering Branch (MEB) 1.
AREAS OF REVIEW The CSB review of ice condenser containments includes the following areas:
1.
The pressure and temperature conditions in the containment due to a spectrum (includ-ing break size and lo ation) of loss of coolant accidents (i.e., re nt.r coolant system pipe breaks) and steam and feedwater line breaks.
2.
The maximum expected external pressure to which the containment may be bjected[
3.
The design and qualification testing of ice condenser components.
4.
The pressure conditions within containment internal structures and acting on system components and supports due to high energy line breaks.
5.
The maximum allowable operating deck steam bypass area for a full spectrum of reactor coolant system pipe breaks.
6.
The design provisions and proposed surveillance program to assure that the ice condenser will remain operable for all plant operating conditions.
7.
The design and qualification testing of the return air fan systems and system components.
8.
The effectiveness of static and active heat removal mechanisms.
9.
The minimum containment pressure use.d in the analyses of emergency core cooling system capability.
10.
The instrumentation provided to monitor and record containment atmosphere pressure and temperature and sump vater temperature under post-accident conditions.
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11.
The proposed technical specifications, at the operating license stage of review, pertaining to the surveillance requirements for steam bypass area, return air fan system operability, ice condenser operability, and vacuum relief devices.
The structural and mechanical design adequacy of the containment, its internal structures and mechanical components are the review responsibility of the SEB and the MEB.
The adequacy of the containment response to assumed piping system ruptures is the responsi-bility of the CSB.
The ICSB has review responsibility f or the ice condenser containment design. The fission product removal capability of the ice condenser is evaluated by AAB under SRP Section 6.5.4.
II.
ACCEPTANCE CRITERIA The following acceptance criteria apply to the design and functional capability of ice condenser containments:
1.
The ice condenser components should be designed, fabricated, erected, and tested in accordance with Group B quality standards, as recommended by Regulatory Guide 1.26.
The ice condenser components should be designated Category 1 (seismic);
i.e.,
designed to withstand the effects of the safe shutdown earthquake without loss of function, as recommended by Regulatory Guide 1.29.
Analyses or requalification tests should be perforned for all ice condenser compo-nents that are changed in design from that reported in Appendices M and N to the O.C. Cook FSAR (Ref. 27) to assure that the ice condenser will remain operable in the accident environment for as long as accident conditions require.
If a component was originally qualified by analytical methods, confirmation of the new design by reanalyses or a test program will be acceptable. For components that were originally qualified by a test program, the redesigned component should be requalified by a test program.
2.
The containment pressure and temperature response to postulated loss of coolant accidents should be calculated using the LOTIC-1 (or an equivalent) computer code (Ref. 34).
For plants under review for construction permits, ae co: tainment design pressure should provide 3t least a 20% margin above the highest calculated accident pressure.
Forpl'anisunderreviewforoperatinglicenses,thehighestcalculatedaccident
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pressure should not exceed the design pressure of the c orita i nthe n t.
3.
The containment pressure and temperature response to postulated secondary dystem pipe ruptures snould be based on the most severe single active f ailure of ti,e isola-tion p-ovisions in the sacondary system (e.g., main steam isolation valve failure or feedwater line isolation valve failure). The analysis should also be based on a spectr um of pipe break sizes and reactor power levels. The accident conditions Rev. 1 6.2.1.1.B-2 t
selected should result in the highest calculated centainment pressure or tempera-ture, depending on the purpose of the analysis 4.
Ice condenser subcompartment or control volume dif f erential (interna') pressures should be calculated using the Transient Mass Distribution (IMD) computer code (Ref. 28), without the augmented critical flow correlation. IMD should incnrporate the heat transfer correlation deve'oped from the 1974 full scale ice conderser tests and should include the compressibility f acter "Y" in the incompressible flow equation.
For plants l'eing reviewed f or construction permits, the design.. ferential pres-sures for all ice condenser control volumes or subcompartments, ano system cnmpo-nents (e.g., reactor vessel, pressurizer, steam generators) and supports, should provide at least a 40% margin above the highest calculated differential pressures.
For plants being reviewed for operating licenses, the highest calculated differential pressures for all ice condenser control volumes or subcompartments should not exceed the corresponding design differential pressures.
The,-rating deck, c. team generator and pressurizer enclosures, and ice condenser lower inlet doors should be designed to withstand the maximum calculated reverse differential pressures between the upper and lowee compartments using the LOllC-2 computer code (Ref. %).
To account for uncertainties in the analysis of reverse differentia' pressures, an adequate margin should be provided above the maximum calculated reverse differential pressure.
5.
The manimum allowable area for steam bypass of the ice condenser should be greater than the identifiable bypass area for the plant (e.g., the drainage provisions to allow containment spray water to return f rom the upper compartment to the sumps in the lower compartment). The bypass area capability of the plant should be based on analyses of the spectrum of postulated reactor coolant system pipe breaks, and should be about 35 square feet or greater.
6.
The design of the ice condenser system should incorporate provisions fur periodic inservice inspection and testing of essential system components; e.g.,
the ice baskets and doors, the ice condenser temperature monitoring system, and the avail-able riass of ice.
fhe inspection and test program should assure the integrity and operability of the ice condenser system and should satisfy the requirements of General Design Criteria 39 and 40.
7.
The return air fan system components should be designed, fabricated, erected, and tested in accordance with Group B quality standards, as recommended by Regulatory Guide 1.26.
The system should be designated Category I (seismic) as recommended by Regulatory Guide 1.29.
3rj 209 6.2.1.1.B-3 Rev. 1
The inservice inspection and testing program for the return air fan system should satisfy the requirements of General Design Criteria 39 and 40.
Analyses or tests should be performed for the return air f an system components to demonstrate that the system will remain operable in the accident environment for as long as accident conditions require.
8.
Inadvertent operation of engineered safety features (e.g., the return air fan system or the containment spray system) should not cause the ext 7rnal design pres-sure of the primary containment to be exceeded. This may be accomplished through conservative containment design, use of vacuum relief devices, or electrical inter-locks that preclude inadvertent operation of the spray and fan systems. Vacuum relief devices should be provided in accordance with the requirements of the ASME Boiler and Pressure Vessel Code,Section III, Division 1, Subsection NE (Ref. 3) and should meet applicable requirements of General Design Criteria 54 and 56.
9.
Instrumentation capable of operating in the post-accident environment should be provided to monitor the containment atmcsphere pressure and temperature, and the sump water temperatu.e following an accident. The instrumentation should have adequate ranoe, accueacy, and response to assure that the above parameters can be tracked and recorded throughout the course of an accident. Regulatory Guide 1.97,
" Instrumentation for Light Water Cooled Nuclear Pcwer Plants to Assess Plant Condi-tions During and Following an Accident," thould be followed.
10.
The minimum calculated containment pressure as determined by the LOTIC-2 Code (Ref. 35) should not be less than that used in the analysis of the emergency core cooling system capability (See SRP Section 6.2.1.5, " Minimum Containment Pressure Analysis for Emergency Core Cooling System Performance Capability Studies").
11.
For those areas of review identified in subsection I of this SRP sectian as being the responsibility of other branches, the acceptance criteria and their methods of application are contained in the (RP sections corresponding to those branches.
III. REVIEW PROCEDURES The procedures described below are followed for the review of ice condenser containments.
The reviewer selects and emphasizes material from these procedures as may be appropriate for a particular case.
Portions of the review may be carried out on a generic basis for aspects of functional design common to a class of ice condenser containments or by adopting the results of previous reviews of plants with essentially the same containment functional design.
Upon request from the primary reviewer, the secondary review branches will provide input for the areas of review stated in subsection I of this plan.
The primary reviewer obtains and uses such input as required to assure that this review procedure is complete.
147 210 Rev. 1 6.2.1.1.B-4
1.
The CSB evaluates the design of the ice condenser type containment by comparing it to the design information presented in Appendices M and N to the D.C. Cook FSAR, and discussed in the staff's safety evaluation report on the plant (Ref. 27).
The CSB has reviewed the design of the Cook ice condenser as reported in these documents and has found that it satifies the acceptance criteria stated in subsection II.
Any differences from the design reported in the Cook documents are evaluated. The CSB determines that all design charges have been justified, and the components have been regialified for use in the ice condenser by the same methods originally used to qualify them, i.e.,
for simple structures which were qualified by analytical methods, a reanalysis will be accepted; and for components qualified by test programs, the tests shouid be operated on the revised design.
The CSB compares the quality standards applied to the ice condenser to Regulatory Guide 1.26.
The CSB compares the seismic design classification of the ice condenser to Regula-tory Guide 1.29.
2.
The CSB reviews the analysis of the containment pressure and temperature response to postulated loss of-coolant accident The CSB has reviewed the LOTIC-1 code which is used to determine the containment pressure and temperature response, and has determined that the code is acceptaM e for containment analysis. The CSB assures that the LOTIC-1 code has been used and that the input assumptions to the l
code are conservative. Code revisions and improvements will also be considered.
The CSB reviews the analysis of the containment temperature and pressure response to postulated secondary system pipe ruptures. The CSB determines the acceptability l
of the analytical methods and plant sensitive input assumptions used in the analysis of the containment response.
CSB determines from the results of analyses of postulated loss-of-coolant accidents and secondary system pipe ruptures that the peak calculated containment pressure does not exceed the design pressure of the containment, for plants at the operating license stage of review. For plants at the construction permit stage of review, the CSB will ascertain from the results of asilyses reportcd in the safety analysis report that the design pressure provides a margin of at least 20% above the maximum calculated pressure.
The CSB determines that the maximum temperature transients calculated for postulated loss-of-coolant accidents and secondary system pipe ruptures have been considered in establishing the environmental qualification requirements for equipment and components required to mitigate the consequences of loss of-coolant accidents and secondary system pipe ruptures, respectively. If thermal analysis is used to establish the qualification of instrumentation and components for use in superheated
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6.2.1.1.B-5 Rev. I
steam environments, upon request of the PSB or ICSB, the CSB will review the analyt-ical methods and assu.nptions used in the analysis. The CSB will inform the request-ing branch (es) of the acceptability of the thermal analyses.
The CONTEMPT-4 code is being developed to provide improved capability to analyze the long term response of an ice condenser containment to a loss-of-coolant accicent.
When the CCNTEMPT-4 code is available, the CSB will perform confirmatory analyses using this code.
3.
The TMD code is used to evaluate the transient pressure responses (internal) of the ice condenser containment subccmpartments. The code is described in the proprietary report WCAP-8077 (Ref. 28).
The TMD code utilizes an ice condenser heat transfer coefficient obtained from the 1974 full scale section tests of the ice condenser.
The TMD code also u;.ilizes a compressibility f actor "Y" to account for compressible flow effects. As stated in the D.C. Cook Safety Evaluation Report, the CSB has reviewed the assumptions and (quations used in the TMD code and with the exception as th c,. i. i c o i iIow model used to predict subcompartment vent mass flow rates, his ct,ncluded that the TMD code conservatively calculates transient pressure response.
The TMD code calculates the critical flaw of a two-component, two phase fl' aid (air, steam, and water) assuming a thermal equilibrium condition. However, a correction f actor is them applied to the calculated critical flow.
The CSB has not accepted the use of this corrected critical flow, referred to as " augmented flow," and has required that the short-term transient responses of subcompartments be determined using the IMD code without applying a correction factor to the critical flow; i.e.,
without the " augmented flow" corre!ation.
Before accepting the containment tratsient responses calculated by the TMD code, l
the CSB reviews the modeling of the containment subcompartments, the size and area of assumed vents between nodes, volumes of nodes, the flow loss coefficients for each vent modeled, and the heat transfer coefficients within the ice condenser.
The CSB will determine from the safety analysis report that the TMD code, without the " augmented flow" correlation, has been utilized to determine the transient pressure response in each subcompartment that contains a high energy line, and in adjoining subcompartme its.
The CSB reviews the maximum calculated differential pressures and pressure profiles for each subcompartment. For plants at the construction permit stage of review, the CSB will ascertain that it is the applicant's intent to de3ign all internal structures with a margin of 40% between the maximum calculated differential pressure and the design differential oressure of the structure or component. At the operat-ing license stage of reviewt, the CSB will ascertain that an appropriate margin exists. Howeser, changes in technology and calculational methods may affect the margin.
The CSB will then determine that the maximum calculated differential 147 212 Rev. 1 6.2.1.1.B-6
pressures do not exceed the desico diiferential pressures for the internal struc-tures. When maximum calculated differential pressures which exceed the pressures used in the design of the internal structures are identified the CSB request the SEB D
to evaluate the adequacy of the affected internal structures. The loads on tompo-i 1
nents or their supports installed within the compartment due to possible pressure gradients will be evaluated by MEB.
lhe CSB will coordinate the review of dynamic pressure loads for components and equipment supports, and when the design basis loads have been identified the CSB will request the MEB to evaluate the design adequacy of the components and supports.
Modification to the RELAP4 code to include two phase, two-component mixtures and ice condenser modeling have been made.
This will improve the capability of the code for use in short term response analysis of ica condenser plants. The CSB will use the RELAP4 code to conduct confirmatory analyses. The COMPARE code is also being modified to permit the short term response analysis of ice condenser plants.
4.
The C5B reviews the methods, input assumptions, and results of the applicant's steam bypass analysis. The applicant's analysis should show conci-erable margin between the maximum tolerable bypass leakage area and the identifiable bypass area required to allow spray water drainage back to the containment sump.
The CSB determines the adequacy of the margins provided for the full spectrum of reactor coolant pipe ruptures. Factors affecting the determination include the proposed inspections and tests to determine bypass leakage area and whether the design of the plant will permit access to seals between the upper and lower compartments for inspection. At the operating license stage, the CSB reviews the proposed technical specifications to assure that adequate surveillance will be maintained for the steam bypass area.
5.
The CSB reviews the initial prcgrams for ice loading and subsequent verification of individual ice basket and total ice load >. In addition, it reviews design provi-sions for monitoring the status of the ice ccndenser during plant operation to assure that.the ice condenser retains its full capability. The CSB also reviews the aspects of the ice condenser design which will allow inspection and functional testing of ice condenser components during various modes of plant operation.
Specific areas to be evaluated are the ice condenser temperature instrumentation system, lower inlet door position monitoring system, proposed ice basket inspection programs to determine total ice weight, proposed inspection and testing programs for intermediate and top deck doors, floor drains, lower inlet doors, ice condenser flow passages, divider barrier seals, and access hatches.
'ne CSB determines that the proposed surveillance programs and attendant design provisions fulfill the intent of General Design Criteria 39 and 40.
At the operating license stage, the CSB also evaluates the proposed technical specifications that have been established to assure ice condenser operability.
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6.2.1.1.B-7 Rev. 1
6.
The CSB reviews the environmental conditions used in the qualification testing of the return air fan system components. The CSB determines whether the test condi-tions are representative of post-accident conditions to which the equipment may be subjected. The CSB will ascertain that the equipment can operate in the accident environment for as long as accident conditions require. The CSB reviews analyses demonstrating that where required, the return air fan system and its components are designed to withstand the transient differential pressures to which the systems would be subjected following a loss of-coolant accident.
The CSB reviews the provisions made in the design of the return air fan system and the proposed program for periodic inspection and functional testing of the system and components for comp 1' ice with the intent of General Design Criteria 39 and 40.
The CSB determines the at eptability of the proposed periodic surveillance program for the return air fan s3 tem, taking into account the extent and frequency of testing proposed and the practices established for previous ice condenser plants.
At the operating license stage, the CSB also evaluates the technical specifications for the return air fan system that have been proposed to assure system operability.
7.
The CSB reviews the analysis of the maximum depressurization transient due to inadvertent operation of the containment sprays or return air fans.
The CSB reviews the assumed containment initial conditions, methods of calculation, and spray system efficiency to determine whether the containment depressurization analysis is conservative. If the external design pressore of the containment is shown to be exceeded, the CSB will ascertain that containment vacuum relief devices to mitigate the consequences of inadvertent operation of the sprays or fans have been provided, or administrative controls have been established and interlocks provided to prevent inadvertent operation of the sprays or fans.
If containment vacuum relief devices are used, the CSB reviews the analysis provided to demonstrate that the response time of the relief devices is short enougn to prevent depressurization of the containment below the external design pressure. The CSB determines that the vacuum relief devices comply with the requirements of Subscction NE of Section III of the ASME Boiler and Pressure Vessel Code.
CSB reviews the design of the vacuum relief devices and proposed inspection and testing programs to ensure that the intent of General Design Criteria 54 and 56 is fulfilled. If administrative controls are established and electrical interlocks provided to preclude inadvertent operation of the sprays or fans, the CSB in conjuction with the ICSB review the acceptability of l
these provisions from a functional standpoint. At the operating license stage of review, CSB also reviews the proposed technical specifications to assure that adequate surveillance and administrative control will be maintained over the vacuum relief devices.
8.
The CSB determ nes whether instrumentation capable of withstanding post-accident i
environments, and recording equipment, has been provided to monitor and record the course of an accident within the containment. The CSB also determines that the instrumentation and recording equipment can accomplish the objectives stated in Rev. I 6.2.1.1.B-8 14_/
214
subsection II.
This review effort is coordinated with the ICSB. The ICSB, in SRP Sectin 7.3, has review responsibility for the acceptability of, and the qualifica-tion test program for the sensing and actuation instrunentation of the plant protec-tion system, the ice condenser temperature monitoring system, and the post-accident monitoring instrumentation and recording equipment.
9.
The CSB reviews the minimum containment pressure analysis for the emergency core cooling system performance evaluation in accordance with SRP saction 6.2.1.5,
" Minimum Containment Pressure Analysis for Emergency Core Cooling System Perform-ance Capability Studies."
IV.
EVALUATION FINDINGS The conclusions reached on completion of the review of this section are presented in SRP Section 6.2.1.
V.
REFERENCES The references for this plan are listed in SRP Section 6.2.1.
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6.2.1.1.B-9 Rev. I