ML20211E325
| ML20211E325 | |
| Person / Time | |
|---|---|
| Issue date: | 09/25/1997 |
| From: | Mace M NRC OFFICE OF ADMINISTRATION (ADM) |
| To: | Smithson C PURDUE UNIV., WEST LAFAYETTE, IN |
| References | |
| CON-FIN-W-6749, CON-NRC-04-97-046, CON-NRC-4-97-46 NUDOCS 9709300095 | |
| Download: ML20211E325 (7) | |
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NUCLEAR REGULATORY COMMISSION g
WASHINGTON. D.C. 2055Hooi
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SEF 191997 Purdue Research Foundation ATTN: Chris Smithson 1021 Hovde Hall. Purdue University West Lafayette. IN 47907-1021
Dear Mr Smithson:
SUBJECT:
TASK ORDER NO. 4 ENTITLED PHASE SEPARATION IN TEES" UNDER CONTRACT NO. NRC-04-97-646 In accordance with Section G.4. Task Order Procedures of the subject contract, this letter definitizes Task Order No. 4.
This effort shall be performed in accordance with the enclosed Statement of Work.
The period of performance for Task Order No. 4 is September 30, 1997 through-December 31, 1998.
The total estimated cost for full performance of this task order is $332,941.00.
Funds in the amount of $230,591.68 are hereby obligated for performance of this task order. The Contractor shall not incur costs for this task order which exceed this obligated amount.
Accounting data for Task Order No. 4 is as follows:
B&R No.: 760-15-11-500-5 Job Code: W-6749 BOC Code: 252A RES ID: RES-C97-089 Appropriation No.: 31X0200-Obligated Amount: $230.591.68 The following individuals are considered by the Government to be essential to the successful performance of the work hereunder:
Jose Reyes The contractor agrees that such personnel shall not be removed from the effort under this task order without compliance with Contract Clause H.2-Key i
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l Purdue' Contract No. NRC-04-97-046 l
Task Order No. 4 Page 2 of 2 The issuance of this task order does not amend any terms or conditions of the subject contract, Your contacts during the course of this task order are:
Technical Matters:
Jennifer Uhle. Project Officer (301) 415-6023-Contractual Matters:
Stephen Pool, Contract Specialist (301) 415-8168
'Please indicate your acceptance of this task order by having an official, authorized to bind your-organization execute three copies of this document in E
the space provided and return two copies to the Contract Specialist.
You should retain _the third copy for your records.
Sincerely, v
Mar: H.
ce, Contractin Officer Contract anagement Branch No. 1 Division of Contracts and Property-Management Office of Administration
Enclosure:
As stated-ACCEPTED: TASK ORDER NO. 4 atL s -m,,
/NAME DATE ww OMe,w TITLE 1
STATEMENT OF WORK ~
TASK ORDER #4,
- Phase Separation in Tees"
Background
~
When a small break LOCA (SBLOCA) occurs in a conventional or advanced light water reactor, the corresponding slow depressurization rate and relatively low phasic velocities can
- lead to the presence of a two-phase stratified flow in the horizontal piping of the system if-the break is in the vicinity of the horizontal piping, and is located above the liquid interface level, then the vapor can entrain liquid if the vapor velocity is sufficient in contrast, if the break is below the liquid level interface, vapor can be pulled through, increasing the quality
' of the flow.
Phase separation determines the two-phase flow quality out of the break. In tum, the break flow quality directly affects the critical flow rate out of the break which then affects the depressurization rate and the total water inventory of the reactor system. The ability to.
accurately model phase separation and subsequent break flow quality is vital to predicting the system response and to ensuring the overall safety of the plant.
Phase separation phenomena is also impodant when automatic depressurization systems (ADS) are utilized in accident management, such as ADS 1-3 and ADS 4 in the AP600. _ -
These systems essenhally initiate a breach in the reactor system to depressurize the reactor to a state where gravity-driven or low pressure iniechon can provide inventory to the reactor.
However, the flow regimes in these conditions are considered to be generally bubbly or chum flow, so that a phase separation model for horizontal stratified flow in which inception height and entrainment/ pull-through phenomena are modeled is not appropnate.
Accurate modeling of phase separation is vital to reactor safety analysis. For'either a postulated break, a relief valve or an automatic depressurizabon system, the fluid quality of the effluent is a critical parameter-the higher the quality the more rapid the
' depressurization, and the lower the quality, the greater the inventory loss. For example, in the beyond design Dase accident testmg program at Oregon State University, core heat up
- was experienced during the NRC-25 senes of tests. However, the phase separation model in the RELAP5 code over-predicted the phase separation at the ADS 4 offtake when simulating this test, thereby enhancmg the plant depressurizabon rate while maximizing liquid inventory in the core. In the test, the core uncovered and heated up. Conversely, the RELAP5 code predicted that the two-phase level was always above the top of the active fuel.
Themfore, this example demonstrates that an inaccurate phase separation model can result in non-conservative predichons of core liquid inventory, the key figure of merit used in analyzing reactor safety. As a consequence of this model uncertainty it is necessary to run sensitivity calculations to bound the system behavior. This additional effort negatively
-impacts program schedule and cost.
Therefore,' for use in NRC best estimate codes, it is necessary to develop a set of suitable correlations for modeling phase separation at the break in SBLOCA conditions in the AP600 and conventional plants and for the hot leg off-take geometry for all ADS stages in the AP600. The correlations must cover the range of conditions and geometries that are prototypic of these scenarios.
2 Objectives '
The objectives of this contract are:
To identify specific parameter ranges (pressure, flow regime, phasic velocities) over
- which the phenomenon is important;-
To organize previous work into a database that can be used in future model development; To document this database so data can be easily identified when utilizing the database; To identify deficiencies in the database and then perform separate effects tests to extend and improve the database;
_ To assess existing models/ correlations against the database and note def' iencies; c
To identify or develop a senes of models that can be used in a two fluid systems-code.
Work Requirements it is estimated that 1 professor month of effort is equivalent to 3 ctudent months. The contractor shall perform the tasks delineated below:
Task 1: Determination of Range of Conditions The contractor shall determine the appropriate geometries and range of conditions ov:sr which the phase separation models must be apphcable for use in analyses of:
+
- SBLOCA in conventional pie;* and the AP600
+
SBLOCA induced by a stuck opea PORV in conventional plant
+
ADS 1-3 in the AP600
-+
ADS 4 in the AP600 This task must utilize plant design information, test data (appropriately scaled) and code calculation results to determine the required parametric ranges With this information,'
current _ scaling methodology will be used to modify these ranges so that data can be selected and/or developed for use in the model select on/ development of Task 5.- The results of this task will be submitted to NRC in the form of a letter report in both text and electronic format. Once reviewed by NRC, this information will be used to narrow the range of data that is collected in Task 2.
Estimated Duration: 0.75 months
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Task 2i-Literature Search NRC will provide the contractor with the results of a literature search performed by the staff.
This information shall then be supplemented with work published in the year of this contract, that is applicable for development and assessment of the phase separation models delineated in Task 1. The identified work shall be compiled into a list organized by the.
- categones of analytical studies, experimental work, and a combination of both analytical and l
experimental work. This revised list shall be submitted to NRC in the form of a letter report in both text and electronic format.
. Estimated Duration:.1 month Task 3: Database Subtask 3.1: Compilation of Data Upon completion of Task 2, all data taken in the identified experiments shall be compiled into a database for use in further modelmg efforts and developmental code assessment. All :
measured parameters in the expenment (pressure, flow rate, etc.) shall be listed as a -
funcbon of measurement locahon and labeled accordingly. The data shall be put in a form consistent with the NRC Databank format. The fomist and delivery procedure will be
. provided by the NRC at a later date.
Estimated Duration: 2 months
.i Subtask 3.2: Documentation of Data The form of the data from each experiment and the run number of the experiment shall be documented so that someone unfamiliar with this contract can utiiize the database for model developmer,t and code developmental assessment.' Therefore, for each experiment, a brief '
. summary shall be provided includmg the geometrical set-up of the experiment depicted with diagrams clearly denoting the locations of the instrumentation. The labels of the L instrumentation shall be consistent with the labeling method used in the database. The condebons of the experiment shall be summarized so that the user will not have to refer to the database to determine the ranges of conditions studied.: All facility description given in the publication shall be documented. The documentation shall include any data relevant to model dr;@Tient.- If the expenment is comprised of several runs, the aforementioned documentation _shall te provided for each run. The resuks of Subtask 3.2 shall be submitted.
to NRC in the form of a letter report in both text and electronic format.-
Estimated Dur:.uon:- 1 month -
Task 4: Development of Separate Effects Test Plan Any ranges in which experimental data are sparse, or missing entirely from the ranges identified in Task 1, shall be documented and any models/ correlations identified in the literature search as appropriate to this work shall be reviewed as a means of defining what l
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4 types of information is required in phase separation model development and assessment.
l Using this information, a separate effects test matrix shall be prepared with the aim of..
extending and improving the existing database to sid model selection / development in Task 5.
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1The rationale for the test matrix (why a particular test is needed), the deficient ranges of data in the database, and the test matrix shall be documenwi and submitted to NRC as a letter report in both text and electronic format.- Additionally, th, letter report shall include how the proposed experiments will be used to develop a model suitable for incorporation into a two-
)
fluid systems thermal-hydraulic code. Upon review of this documentation, NRC will i
authorize the experimentation. No experimentation is to be performed until NRC authorization is received.
Estimated Duration: 2.25 months f
Task 5: Experimentation This task is comprised of 4 subtasks. All experiments shall be performed in support of -
. rectifying deficiencies in the expeii,Tiental database as authorized by NRC in Task 4.
Expenmentation shall be performed in support of model sevelopment for one scenario identified in Task 1.
Subtask 5.1: Schedule A schedule of the test program shall be developed. This schedule shall include what steps will be required before each test is run. For example, if a set-up must be built in support of a test, then the required time must be allotted on the schedule. The schedule shall be submitted to NRC as a letter report in both text and electronic format. Once reviewed and accepted, the experimentation may begin.
Subtask 5.2: Design For each run that requires an experimental set-up, the design, instrur?sntation location and uncertainty and scaling rationale shall be submitted to NRC for review in the form of a letter report in both text and electronic format. Once authonzed, constructi* of the facility may begin' The design description must include all details required v cofe issessment and must conform to the documentation procedures outlined in Subtask 3 2.
Subtask 5.2: Construction Once authorized upon completion of Subtask 5.2, the construction of the facility may ensue.
Subtask 5.3: Measurements The authorized experiments shall then be run and the data recorded. The test procedure and results shall be documented for each run and shall be submitted to NRC as a letter
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5 report in both text and electronic format.- Any modifications made to the facility design described in the letter report of Subtask 5.2 shall be included and shall be consistent with the documentation requirements outlined in Subtask 3.2, Additionally, the data obtained shall be submitted to NRC in a format consistent with the NRC Databank.
Estimated Duration: 5 months Task 6: Model Selection / Development The models/ correlations identified in the literature search as appropriate to this work shall be reviewed by comparing the results to the database over the range of model applicability.
Plots of the results shall be made denoting the experimental values, the model predictions, and the data uncertainty. A statistical evaluation of the comparisons and the theoretical
- development ot 'he models shall also be performed. The documentation shall also include a p
summary of each 'nodel, the range of applicability of each model, and any model
- deficiencies. A de' ailed model derivation shall be provided to the NRC through copies of the works listed in the mults of the literature search. No propriety information shall be used in the model development.
A correlation will be identified or modified to provide NRC with the capability of modeling phase separation phenomena for the scenario studied in Task 5. This selection will be made in conjunction with NRC staff. If the NRC and the contractor determine that no model is suitable to a particular application, one will be modified or developed with guidance and review from the NRC. This model shall also be compared to data as outlined in the guidelines above.
The results of this task shall be summarized and submitted to NRC in the form of a letter report in both text and electronic format.
Estimated Duration: 3 months Meetings and Travel For successful completion of the work required in this contract, it is anticipated that the contractor shall travel to the NRC office in Rockville, MD at the times specified below. The contractor may. propose additional travel deemed necessary for the successful completion of this effort. All travel shall be approved in advance by the Project Manager, be specifically performed in support of this project, and be in compliance with Federal Transportation Regulations.
Task 1,2,3,4 Upon completion of Tasks 1,2,3 and 4, one two-day meeting for two people.
Task 5 -
In support of Task 4, one three-day meeting for two people.
Task 6 -
In support of Task 5, two three-day meetings for two people.
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