ML20209B787
Text
- .: ?
- #p Q o,
UNITED STATES 8
c(
g NUCLEAR REGULATORY COMMISSION
\\; vW p c.
WASHINGTON, D. C. 20555
- ....f NOVEMBER ~ C 1982 MEMORANDUM FOR:
Licensing Project Managers FROM:
Thomas M.'Novak, Assistant Director
.for Licensing Division of Licensing
SUBJECT:
BOARD NOTIFICATION - SEMISCALE TEST RESULTS (Board Notification No.82-107)
The ASLB, ASLAB or Comission (as appropriate) were notif'ied of the subject report for the following plants:
Callaway Unit 1 W "n ed 3 Comanche Peak Units 1/2 diablo Canyon Units e/o Palo Verde Units 1/2/3 Summer 1 Midland Units 1/2 Floating Nuclear Plants 1-8 The subject report closes out Board Notification 82-93 recently senc September 24, 1982.
For those plants which are contested but for which the hearing has not yet started, please ensure that the substance of BN 82-107 is addressed in your SER or SSER'. Attached is a summary of the subject report for your information.
Moma& i'& 'Ml
-Q s M. Novak, Assistant Director for Licensing Division of Licensing
Enclosure:
As stated cc: Licensing BCs f
pg g
s
/
L -
f[UCL !. AH hc bdU TUh Y h0:.N.-[ t..:: -
7 ygig.4,5 k
,l
[.7,,.- t/
m.sw.c.wn, o : ; sss
(. y ~.Qy/jl-
'q.L OCT 19122
=...*
MECRA';DUM FOR:
Darrell Eisenhut, Director,. Divisich of Licensing iROM:
' Roger J. Mattson, Director, Division of Systems Integration
~
SUBJECT:
BOARD NOTIFICATION CONCER!iING RECENT SEMISCALE TEST RESULTS In my memorandum dated August 30, 1982 I reported the results, of a recent
-Semiscale " feed and bleed" test (S-SR-2).
In that memorandum, I stated that' there was insufficient information available at that time to draw any. con-clusions from the results and we would pursue resolution of this issue and inform the Boards of our conclu'sions following completion of our evaluation..
The purpose of this memorandum is to request that you inform the Boards that we have completed our evaluation and have concluded that Semiscale test S-SR-2 does not exhibit any new phenomena and can be adequately predicted by our computer codes.
.Semiscale test S-SR-2 simulated a loss of all feedwater which resulted in a-complete dryout of the secondary side of the steam generators.
This resulted in a pressurization of' the primary system.
The scaled PORV was opened to de-t -
pressurize the primary system _to below the HPI pump shutoff head.
This action, referred to as primary feed and bleed, was done in an attempt to reach an e.quilibrium thermal-hydraulic condition for core cooling.
This involves re-
.lieving the primary pressure increase due to core decay heat through the PORY and replacing the primary coolant ir.ventory lost out of the PORV with HPI coolant. The high head charging pump was assumed to be inoperable for this test.
Prior to achieving this equilibrium thermal hydraul'ic condition, the core simulator rods' began to heat up excessively.
Our evaluation and conclusions are based on RELAP-5 analyses conducted by EG&G, Idaho, for-the Office. of Nuclear Regulatory Research of both the Semi-scale S-SR-2 test and a corresponding feed and bleed mode of operation for a typical Westinghouse' 4-loop plant (RESAR plant). These analyses have shown the following:
1)- A RELAP-5 analysis of the Semiscale test SR-2 demonstrates the code's ability to accurately calculate both the overall system response and
' local responses.
The RELAP-5 results show good quantitative agree-
. ment with the test data.
l 2)
RELAP-5 feed and bleed analyses for a Westinghouse RESAR plant de-sign both with and without full ECCS (charging and HPI) agree with L
the genera 1 ' behavior seen in the Semisca.1e experiments.
(TheRESAR
- calculation with ECCS results in steady state core cooling being achieved and an eventual restoration of subcooling in the primary system.}*
'ine RESAR calculation assumed that ECCS charging flow was available and a decay heat curve was used while Semiscale used only HPI pumps and a constant power level.
CONTACT:
M. Keane, x28957
& llo ?
/[Carrt:il } Eisenhut
~2-(CT 1-5 G33-4dditior. ally, the following conclusions are reached about t'he Semiscale test results.
After voiding of the hot leg, the ability tc maintain steady state core cooling is considered within the experimental ur) certainties of the values of core decay heat, PORV characteristi:s and HP7 pumping capa-bil ity.
A small reduction in core power or PORV..r. ass flowrate or an in-crease in HPI flowrate would probably have resulted in stealdy-state core cooling before core uncov,ery.
The RELAP-5 calculation of the test results in either steady-state cooling before core uncovery or just as core un-covery begins depending on how uncertainties in steam generator heat trans-fer are treated in the code input.
The test analysis confirms our previous conclusion that the viability of feed and bleeo as well as the system response is a function of many para-meters, including core decay heat level, PORV characteristics, ECCS pump-ing capacity-and. operator action time. - In su. mary, our review of the test data and the RELAP-5 analyses performed.to predict this test data lead us to conclude that no new phenomena are exhibited by Semiscale test 5-SR-2 and that the staff's RELAP-5 analysis code,adecuately predicts the test data and associated thermal hydraulic phenomena.
We point out that regardless of the conclusions that may have been reached from this test regarding viability of feed and bleed, feed and bleed coolina is not a desian basis reouirement considered necessary to meet tne Commis-
..sion's Regulations for any LWRs currently licensed or being considered for a license.
We are providing this follow-up evaluation due to the interest in feed and bleed cooling expressed in recent licensing proceedings and be-
- cause we be.lieve it is in 'the best interest of the regulatory process to
- keep the licensing boards informed of these recent test results.
These analyses and this test are not a generic indication of the ability of PWRs to feed and bleed.
The detailed capatiility of a PWR to feed and bleed must be determined by individual analyses.
^
f l
\\
9 l
WM
'?,W Roger J. Mattson, Director Division of Systems Integration cc:
H.'Denton E. Case S. Hanauer l
D. Ross, RES l'
.H. Sullivan, RES
- 0. Bassett, RES j
M. Cutchin, OELD
-