ML20127E690
| ML20127E690 | |
| Person / Time | |
|---|---|
| Issue date: | 03/02/1985 |
| From: | Catton I Advisory Committee on Reactor Safeguards |
| To: | Boehnert P Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1802, NUDOCS 8505200163 | |
| Download: ML20127E690 (3) | |
Text
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LT. /202-
- TO':~
Paul Doohnert q)b R 6 6138 6 I
FROM:
Ivan Catton SUE' JECT: IST Coordination Meeting
~
20 February 1985
-Bethesda.
-March 2, 1985.
!The; purpose of th'e meeting was to decide what to do with the data from-MIST and several other facilities.
I am not sure that the purpose was'sastisfied.
The atypicalities of MIST and their relationships to.the key issues to be resolved were the major focus of the meeting.
During the course of the meeting it became clear.that; There is an urgent need for plant calculations to
=
ectablish where weaknesses in calculational ability lie and what data is needed.
More emphasis needs to be placed on the basic objective of the program - being able to predict the behavior of a
full size. plant.
Issuen
.of~ scaling need early attention so that codes do not get tuned to small scale systems and later used for plant calculations.
.A plant calculation for a transient. causing strong loop
. t o, loop interactions should be run as a
basi s for l
l simulation by all available facilities (MIST, SRI, U of M).
Early comparison of the results will. yield a much cior e ' meaningful. test matrix and help define needed separjate ef f ects tests.
' More - detailed di scussion of the meeting follows.
The. major issues were re-stated as a _ starting point for discussions of MIST atypicalities and how they might be dealt.
with.
The major issues cited are as follows:-
- 1.
' Interrupted natural cir cul ati on 2.
Establishing the boiler condenser mode 3.
Re-etatabl i shi ng natural ci rcul ati on
-4.
Long term cooling 5.
Int er -l oop interactions and oscillations 6.*. Combined' primary-secondary blowdown s:
The atypicalities and their relationship to the above list of issues are shown in.the table.
.Most of the atypicalities appear to be addressed somewher e by either experiment or analysis and
~
cometimes by both.
In many casec analysis alone is thought to be DESIGNATED ORIGINAL.
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Added-by-Catton per'SECY 02.-296-TABLE.y MIST ATYPICALITIES and WHERE' THEY WILL BE ADDRESSED
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..-g--
ISSUE
.ATYPICALITY-1 2'
3 4
5 6
g Hot? Leg lSepar$ tion 1X
~,
(1,2,3,4)*
l
' = -
SG Metal Mass-X X-X
-(7)
(7)
(1,2,7)
AFW Multi-Dim.
X X
(1,2,5)
RCP12-P Char. and a NPSH X
~
(7)
^Downcomer11ocal finw-X X
X (1,2,7)
(.1, 2, 7 )
(1,2,7)'
.Downtomerjtangentia'1' Reci stcnce X
(1,2,7)
_/RVVVISimulation.
X X
X-(1,2,7)
(1,2,7)
(1,2,7)
[ Piping Metal. Mass X
X j
(7)
(7)
Low [ Pressure; Injection-X (7)
'1-P, f 2-l amp f Gtrat ; Fl ow X
~X (2,7)
(2,7)
' Hot. Leg--Flow Regime X
X (3,4)
(3,4)
X Secondary' side (7)-
-WHERE OR'.HOW' ATYPIC 4LITV WILL DE ADDRESSED
~'1. - SR1 -" 2::4 ~ Loop Ex peri ment i2.'-U of.M'2x4 Loop Experiment
!3. ANL. Hot Leg-Study Experiment 4.
SAI Hot. Leg Study Experiment c.5. ; SAI SG Study.Experiement'
- 6.cTetra' Tech Pump Study. Experiment
- 7. ' Anal ysi s
~o-X
'Anatypicality exists wherever there is an X.
~
(Ni N refers-to~where the atypicality will be addressed.
G The key component in MIST?is the downcomer.
Originally it was-to. receive extensive separate effects testing.
The Cxperiements are going to be replaced with more instrumentation
?cruf ' calculations.
Unfortunately, all we have at this time is olimination of the testing.
Very little calculations have been
w doneLand none thct really cddress the issun cro svailablo.
Thic y
'makes MIST unn:cesscrily. risky.
'The interaction between 64NL and the B & W Alliance group
,d eeems to be -very effective.
The emphasis on MIST facility cal cul ati ons - i s,. however, too great.
The MIST facility cannot cddress. transients where multi-dimensional downcomer phenomena cre'important.
There have not been enough plant calculations to determine whether or.when multi-dimensional'downcomer behavior is
.important.
The facilities cited as being able to address the
- atypicali. ties will probably yield data too into to impact on the MIST test' schedule.
This seems to be a rather foolish. state of
-cffairs.
Codes -can bridge the gap presented by.the atypicalities but one must be careful not to tune the codes.
This brings out.the needf for.
using all.three facilities (MIST, SRI, and U of M) as well as the separate effects experiments (ANL, SAI) for code verification.
Plant calculations are desperately needed to help
'in deci' ding how important the atypicalities are.
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