ML20235N079
| ML20235N079 | |
| Person / Time | |
|---|---|
| Issue date: | 05/18/1987 |
| From: | Catton I Advisory Committee on Reactor Safeguards |
| To: | Boehnert P Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1889, NUDOCS 8707170424 | |
| Download: ML20235N079 (2) | |
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o UNITE D ST/.1 ES NUCLEAR REGULATORY COMMISSION i
n i ADVISORY COMMITTEE ON REACTOR SAFEGUARDS g? g 7
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WASHINGTON, D. C. 20555 RETYPED
'%,,[ 8 May 18, 1987 MEMORANDUM FOR:
Paul Boehnert, Senior Staff Engineer r*r FROM:
Ivan Catton, ACRS Consultant C'
SUBJECT:
COMMENTS ON THE B&W OTSG AUXILIARY FEED HEAT TRANSFER STUDIES I fcrgot to include my comments on the B&W OTSG Auxiliary Feed heat l
transfer studies.
It is clear that if calculation of natural circu-l lation and boiler-condenser mode processes are to be performed with confidence, one must understand the heat transfer. The question is whether or not we understand the physics well enough to model it and/or is it impcrtant enough to require a major experimental effort.
To my knowledge, no one has attempted to properly model the processes governing AFW heat transfer. The modeling, if not done already, should be of film evaporation on the tubes with the number of tubes determined l
by CCFL on the tube support plates. There are EPRI SETS (separate effects tests) as well as MIST tests and some plant full scale data that need study. With the available data, model development should be possible. A major question is how one might use such a model and confirm its adequacy.
Unfortunately, system codes like TRAC and RELAP 5 use a " heat transfer package." Further, the codes do not have the flexibility to treat specific components like the OTSG in a different way (different than one treats the core). A first or high priority task should be to modify the existing codes to allow for component specific characteristics. This should not be understood to mean a new code. Without this capability, it is not clear what the data will be used for, and unused data is not worth very much. Further, if not careful, the codes will just be tuned in some non-physical way which is a high risk approach that must be discouraged.
I recommend that RES be asked for a plan describing what will be done to accommodate component modeling before a test program is initiated, i
An experimental program should be built around existing EPRI, MIST and plant data in a meaningful way if it is to be useful.
I recomend that RES be asked to prepare such a plan clearly delineating how the parts will be brought together before testing is initiated.
DEM NAID caIGIgAL 717 4 070510 certifjed By
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CT-1BB9 PDR
.y Paul Boehnert, ACP.S May 18, 1987
- Quick Look reports of UPTF tests have been completed. 'A request to RES-must be made if we are to receive them..I think.they will be very helpful in our assessment of uncertainties. Could you initiate such a.
request't We should also request TRAC 2D/3D calculation reports. Here
.you should ask for draft copies as. final reports may be' months away.
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