ML20003B248
| ML20003B248 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck, Millstone File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 02/02/1981 |
| From: | Stein W LAWRENCE LIVERMORE NATIONAL LABORATORY |
| To: | Tinkler C Office of Nuclear Reactor Regulation |
| References | |
| TF81-021, TF81-21, NUDOCS 8102100550 | |
| Download: ML20003B248 (8) | |
Text
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s NUCLEAR SYSTEMS SAFETY PROGRAM 1
TF81-021 February 2, 1981 Mr. Charles Tinkler Containment Systems Branch Division of Systems Safety, Office of NRR U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Required Plant Specific Information for SEP Containment Analysis
Dear Mr. Tinkler:
Per our recent telephone conversation, in order to complete containment analyses for the Millstone I and Haddam Neck nuclear plants, certain plant specific information is necessary.
In particular we desire listings of the input decks for RELAP computer code blowdown and reflood calculations and also an input deck for a CONTEMPT computer code containment calculation. specifies in detail the desired information.
Thru informal contact with R. Harris of Northeast Utilities, most of the desired information is available. Per telephone conversation with Ralph Caruso (the NRC project manager for these plants), a docketed formal request for the desired information from Ralph Caruso to Northeast Utilities is probably necessary. Your timely help in coordinating this request will.be greatly appreciated and is also very necessary to allow a timely completion of our SEP analyses.
Sincerely, bM
-Werner Stein Thermo Fluid Mechanics Group.
Nuclear Systems Safety Group WS:km 8102.02/1861u.
g3 cc: D. Vreeland.
5 G.-Cummings B. Bowman L. Cleland
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The NRC Systematic Evaluation Program analyses include performing analyses of reactor containments based on current NRC criteria. These analyses include calculations of the containment pressure and temperature response due to water / steam discharges from a reactor blowdown.
The analyses of the reactor blowdown will be performed using the computer code RELAP4-Mod 7 and the containment calculations will be performed using the computer code CONTEMPT-LT/028.
To perform the above calculations, it is desired to obtain a listing of an.
input deck for a RELAP4 reactor blowdown and reflood calculation. Since such decks probably do not exist the latest RELAP or RETRAN deck used as, for example, a peak cladding temperature calculation will suffice.
It is not envisioned that the decks will properly represent _the reactor and the coolant system for our purposes but will properly represent the geometry of the system.
A listing of the input deck for a CONTEMPT containment calculation is also desired.
The attachment further describes the type of information desired with each input listing.
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REQUIRED PLANT-SPECIFIC INFORMATION FOR SYSTEMATIC EVALUATION PROGRAM CONTAINMENT ANALYSIS The following list of questions /conments are intended to define the plant specific infonnation required with the blowdown and reflood RELAP input decks, and containment analysis CONTEMPT deck.
The specific analysis to be perfonned will include a double-ended guillotine pump suction break, and a steam line break. Unless otherwise stated, all infonnation provided in the input data deck will La assumed to be that which accurately represents the plant.
Blowdown (1)
Please provide a nodalization diagram for the input deck which identifies the fluid volumes and flowpaths.
If available, a diagram defining the heat conductors, fills, valves, etc., would also be helpful.
(2)
Please define the purpose '(kind of analysis) for which the deck is set up, the basic assumptions for the initial and boundary conditions, and the code version the deck runs on. A copy of a recent document which describes the dec'k (the model) would also be help'ul.
(3)
Where special modeling techniques are used, and hence the input parameters are not representative of the physical description of the plant, please define the best estimate values and describe the reason for these special modeling techniques. For instance, if a large flow area was used to eliminate momentum ef fects, so state and define the most representative flow area. -
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(4)
If tha input deck contains any proprietary data which cannot be supplied, please provide an alternate source of nonproprietary data adequate for these analyses.
(5)
Define the rated core power and reactor coolant pump power.
Also define the safeguards power or the percentage over rated power allowed before an overpower trip would occur.
(6)
If known, please define the primary and secondary conditions for the safeguard power operation, e.g., what is the primary system flow rate and the cold and hot leg temperatures, and the secondary pressure or temperature and the feed water and steam line mass flow rates.
(7)
Define the maximum inventories which could be available in the system. Are the volumes in the deck defined for cold or hot (considering thermal expansion) conditions? Define the normal and maximum operating levels for the pressurizer and. steam generators.
(8)
Are the reactor coolant pump definitions in the data deck accurate and complete? State the pump rated conditions,. if not accurately defined in the input data deck.
If two-phase pump performance data are available, please provide. 0therwise, the Semiscale test data will be used. Please define the friction coefficients for a third order polynomial if known. Does the plant design contain an antireverse rotation mechanism?
(9)
A complete and accurate description of the heat conductors should be provided with the input data deck.
Please verify that the dimensions for the fuel rod heat conductors are adequately representative of the current plant fuel for the analyses to be performed.
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(10) Please define the valve characteristics including the loss coef-ficients and area versus time characteristics. Of major impor-tance is the time required to close, after receipt of signal, for feedwater and steam line isolation valves.
(11) ECCS physical descriptions. Provide a complete description of the accumulator, HPIS and LPIS performance characteristics and the assumptions which should be used with single active failure criteria.
(a) Accumulators. Verify that the model accurately describes the accumulator and line connecting to the primary system, volumes, flow areas, friction losses, and elevations.
Define the nominal and maximum liquid inventory within each accumulator volume and the noainal and maximum expected (tech. spec.) temperature'of the water in the accumulator.
In addition, the cover gas pressure and injection location in the pritaary system should be defined.
(b) The HPIS and LPIS flow versus primary system pressure per-formance curves as defined at the primary system injection
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locati,on is required. Again, define the total number of.
pumps normally available and the assumptions used with single active failure criteria. Define the source of water for each system, the nominal and maximum (tech. spec.)
temperature, e.nd total inventory available.
(12) Supplied reactor kinetics information should be defined as best estimate or conservative and is usually assumed to be beginning of life for these analyses. Valves appropriate for both the pump suction break and the steam line break should be provided. Because the nature of these two tr.instents is somewhat different, separate infonaation for each transient may be required. For instance, for_ the pump suction break, the,
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1 scram infomation is of secondary inportance because the reactor shuts down due to the density reactivity feedback.
Specific infomation to be supplied should include the density reactivity, Doppler reactivity, the nominal axial power shape distribution, and the direct moderator heating fraction.
(13) Provide a basic description of the plant safety system operation for nomal conditions versus single active failure criteria, and define the effect on these systems due to the loss of outside power. Specific definition is required to model reactor scram, pump trips, and secondary isolatiun of feedwater and steam line, the activation of HPIS, LPIS, and accumulators.
In addition, the activation times for fan coolers and spray coolers 'in the containment will be required. A description of the sianal acti-vating the trip as well as the delay tdme for initiation of the activity is required.
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_u (14) A description of the trip signal, setpoints, and delay times for initiation of each action must be defined. Pleasedefinef.he-nomal expected setpoints and delay times and also discuss the
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reasonable.conservatisms which should be assumad for each item.
Reflood Most of the additional infomation discussed above for the blowdown deck is also comon to that required for the reflood analysis. Hence, the-reflood
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deck should be reviewed relative to the questions and comments defined in the blowdown section above.
(1)
Provide a description of the model, identify the type of analysis for which the deck is now defined, and the code version for which the deck will run.
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(2)
Define the assumptions used in the model, discuss any special modeling techniques used.
(3)
Provide a copy of a nodalization diagram.
(4)
Define the containment design pressure, and nominal and expected (tech. spec.) operating pressure and humidity.
Containment Some of the specific infomation and all of the general infomation re-quested above relative to the CONTEt4PT input deck will be required.
General infomation includes identifying the version of CONTEMPT for which the deck is defined, the kind of analysis, general assumptions modeled in the input deck, and a description of the purpose for which the deck was used. Additional specific information required is as follows:
(1)
Provide a quotable reference for the heat structure data defined in the deck.
(2)
De' fine the nomal and maximum expected teaperature pemitted in the containment drywell during normal operations.
If a wet well pool exists, as in the case of BWR's with pressure suppression system, also define corresponding pool temperatures.
(3)
Verify that the initiation times, flow rates, and heat renoval rates in the deck for the sprays and coolers are currently valid.
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(4)
Define the maximum teaperatures of any and all ECC water injected into the core or sprayed into the containment.
-(5)
Define the contaiment spray and fan cooler activation time.or activation. signal and delay time due to the break and/or loss of I
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outside power. Also, define the nur.6er of spray and cooler
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systems normally available and the nunber to be assumed considering single failure criteria.
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