ML20045E085
| ML20045E085 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 06/28/1993 |
| From: | Kenyon T Office of Nuclear Reactor Regulation |
| To: | Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| References | |
| NUDOCS 9307010085 | |
| Download: ML20045E085 (5) | |
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NUCLEAR REGULATORY COMMISSION
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June 28, 1993 Docket No.52-003 Mr. Nicholas J. Liparulo Nuclear Safoty and Regulatory Activities Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, Pennsylvania 15230
Dear Mr. Liparulo:
SUBJECT:
COMMENTS ON THE CORE MAKEUP TANK TEST PROGRAM FOR THE AP600 Enclosed are comments and recommendations related to the core makeup tank (CMT) test program for the AP600. This information is based on an evaluation performed for the staff by Idaho National Engineering Laboratory. This information should be considered in finalizing the CMT test matrix, and changes should be made as appropriate.
The staff understands that changes in facility designs, instrumentation, and/or test matrices have been made for the various test programs underway to support'the design certification of the AP600.
However, the staff does not know the extent of these changes.
Because the staff has been requested by.
Westinghouse to provide an indication of the acceptability of the test programs, we request that Westinghouse identify how the CMT test program as well as the other test programs have been modified to respond to NRC comments.
Please respond to this request on a schedule to support the= testing schedules for these programs.
You have requested that portions of the information submitted in the June 1992 application for design certification be exempt from mandatory public disclosure. While the staff has not completed its review of your request in i
accordance with the requirements of 10 CFR 2.790, that portion of the j
submitted information is being withheld from public disclosure pending the
_j staff's final determination.
The staff concludes that this request for additional information does_ not contain those portions of the information for which exemption is sought. However, the staff will withhold this. letter from public disclosure for 30 calendar days from the date'of this letter to allow
/
Westinghouse the opportunity to verify the staff's conclusions.
If, after that time, you do not request that all or portions of the information in the enclosures be withheld from public disclosure in accordance with:10 CFR 2.790, this letter will be placed in the NRC's Public Document Room.
This requirement affects less than ten respondents, and therefore, is not subject to the Office of Management and Budget review under Public Law 96-511.
9307010005 930628 PDR ADOCK 05200003 j
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Mr. Nicholas J. Liparulo June 28, 1993 If you have any questions regarding this matter, you can contact me at (301) 504-1120.
Sincerely, (Original signed by)
Thomas J. Kenyon, Project Manager Standardization Project Directorate Associate Director for Advanced Reactors and License Renewal Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/ enclosure:
See next page DISTRIBUTION:
Docket File PDST R/F DCrutchfield RBorchardt PDR TKenyon FH4sselberg TEssig MSiemien Alevin MRubin PShea JMoore, 15B18 GGrant, 17G21 ACRS (11)
G h(g,),12E4 0FC LA:PDST:ADAR PM:dlf/ADAR PM:PDST:ADAR SC:PDST:AbAR NAME PShea avi TK'eNon:tz FHas@b TEssig DATE 06/%93 06/h793 06/2ff93 06/77/93 0FFICIAL RECORD COPY: CMT-TEST.TK L
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j Mr. Nicholas J. Liparulo Westinghouse Electric Corporation Docket No.52-003 AP600 cc:
fir. B. A. McIntyre Advanced Plant Safety & Licensing Westinghouse Electric Corporation i
Energy Systems Business Unit P.O. Box 355 Pittsburgh, Pennsylvania 15230 He. Juhn C. Butler Advanced Plant Safety & Licensing i
Westinghouse Electric Corporation Energy Systems Business Unit Box 355 Pittsburgh, Pennsylvania 15230 j
l Mr. M. D. Beaumont Nuclear and Advanced Technology Division Westinghouse Electric Corporation 2
One Montrose Metro 11921 Rockville Pike Suite 350 Rockville, Maryland 20852 Mr. Sterling Franks U.S. Department of Energy NE-42 Washington, D.C.
20585
)
Mr. S. M. Modro EG&G Idaho Inc.
Post Office Box 1625 Idaho Falls, Idaho 83415 Mr. Steve Goldberg Budget Examiner 725 17th Street, N.W.
Room 8002 Washington, D.C.
20503 Mr. Frank A. Ross U.S. Department of Energy, NE-42 Office of LWR Safety and Technology 19901 Germantown Road
~
Germantown, Maryland 20874 4
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i Comments on the Core Makeup Tank Test Program Supporting the AP600 Design Certification Application 1.
The rationale for the selection of the test pressures is not clear to the staff.
Rather than testing at 20, 100, 700, and 2250 psia, the staff suggests that testing be conducted at. 20, 500, 1100, and 2250 psia. These--
give a more even distribution of saturation pressures, which can affect the rate of wall and water surface condensation, and are thought to be more representative of the pressures at which draining of the core makeup tank (CMT) is expected to be important.
2.
The staff does not understand the basis for the parameters chosen for i
variation in the test matrix. :The staff cannot discern a consistent scaling basis for these parameters. Describe thr: scaling rationale in-
- n. ore detail so that the staff can understand why specific values of, for iratar:e, CMT drain rates' were chosen.
In the absence of such an explanGhr., the staff recommends the following:
a.
Scale the CMT drain rates to give values of approximately 5.7,11.1, 16.2, or.d 25 gpm as the preferred flows to bracket those expected in l
the plant.
b.
Linear and reduced-height scaling of the steam heights in condensation Tests I through 8 give 11.1 and 40.3 inches, respectively. Testing at these heights will provide data that more closely matches the_ scaled relative amounts of condensatior. on the walls and water surface.
c.
In Tests 36 through 41, the staff suggests.that the CMT drain rate be reduced from-the maximum achievable to_a value that represents a consistent scaling approach. Drain rates such as those' suggested in Comment 2.a above would represent such values.
In addition, the staff recommends that the suggestions transmitted previously regarding-depressurization rates and the fraction of the CMT volume that is heated in these tests be reviewed and considered.
d.
The staff suggests that tests similar to Tests 90 through 24 be conducted, but with depressurization as well as draining. This will allow observation of the effect of depressurization on condensation 1
rates without the additional complication of opening Steam Line #2.
3.
The attached comments are the results of a study by INEL on CMT facility instrumentation. These results indicate that addition of several flow, pressure, and temperature measurements would significantly improve the accuracy and reliability of the data from the facility, and would aid considerably in the use of the data for code assessment. Address these recommendations.
Enclosure
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INEL Recommendations on CMT Test Facility Information 1.
It is recommended that instrumentation be added to directly measure steam flow rates (for example, turbine flow meters) for Steam Line #1. This instrumentation is needed to perform an accurate mass balance on the CMT by measuring the steam flow entering the CMT from the Steam Reservoir.
The mass balance will increase the accuracy and reliability of the test data for many of the tests, particularly those aimed at determining wall and water surface condensation rates.
2.
It is recommended that instrumentation to directly measure steam and water l
flow rates be added to Steam Line #2. This instrumentation will also l
improve the CMT mass balance and should be located in a vertical section i
of the line.
It will measure water flows during recirculation and steam flows once the line has cleared.
l 3.
It is recommended that two fluid thermocouples be added at the 3/4 full I
elevation to aid in determining the shape of the radial fluid temperature profile across the test vessel. Although the vessel diameter is relatively small (about 20 inches), it is doubtful that the fluid i
l isotherms will be perfectly horizontal. One of these thermocouples should reach the centerline of the vessel, and the other should be about six
)
l inches from the wall. A knowledge of the degree of mixing in the radial i
direction will aid in specifying the size and location of volumes in the computer models used to evaluate performance of the full-size CMT.
4.
Additional differential pressure measurements are recommended to assist in i
better interpreting the data. Some of these added measurements are located in the vertical legs of Steam Line #2, where they will indicate l
the presence of a single-phase water, single-phase steam, or a two-phase mixture. These measurements will assist in determining whether the line has cleared of liquid, and whether slugging of a two-phase fluid is occurring. Other measurements will indicate pressure drops that can be l
used to ensure that computer simulations provide an accurate model of the apparatus.
The recommended additional differential pressure measurements are:
a.
From the top of the Steam / Water Reservoir Vessel to the isolation valve inlet in Steam Line #2.
b.
Across the isolation valve in Steam Line #2.
l c.
From the outlet of the isolation valve in Steam Line #2 to the inlet of the tee with Steam Line #1.
d.
Across the isolation valve in Steam Line #1.
e.
From the steam line tee to the top of the CMT vessel.
f.
From the CMT vessel outlet to the Steam / Water Reservoir Vessel inlet.
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