ML20059E406
| ML20059E406 | |
| Person / Time | |
|---|---|
| Issue date: | 08/31/1990 |
| From: | Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Carr, Curtiss, Rogers NRC COMMISSION (OCM) |
| Shared Package | |
| ML20059E410 | List: |
| References | |
| REF-10CFR9.7 NUDOCS 9009100174 | |
| Download: ML20059E406 (5) | |
Text
,.c
. - ~
2.7 '
j
- ((-
.%,j UNITED STATES g:
NUCLEAR REGULATORY COMMISSION I
j; WASHINGTON, D. C,20555 3
I j
AllG $ ! 1990 MEMORANDUM FOR: ' Chairman Carr Comissioner Rogers
.Comissioner Curtiss Comissioner Remick FROM:-
-James M. Taylor Executive Director for Operations
SUBJECT:
.MAY 22, 1990, STAFF REQUIREMENTS MEMORANDUM ON BRIEFING OF EVOLUTIONARY LIGHT WATER REACTOR CERTIFICATION ISSUES AND RELATED REGULATORY REQUIREMENTS tin'the May 22, 1990, staff requirements memorandum (SRM), the Comission requested the staff to report to the Comission how the views of the staff's
~
consultant (s) on hydrogen detonation compare with those of the staff.
Sincethe'accidentatThreeMileIsland, Unit 2(TMI-2),-theNRChasregularly used a team of hydrogen experts from the Los Alamos National-Laboratory (LANL) l and the Sandia National Laboratory (SNL) to assist the staff with its review U
- of. hydrogen detonation. To sup11ement those efforts, the staff has used input from a consultant, Dr. Joseph Siepherd of Rensselaer Polytechnic Institute (RPI) and a comittee of the National Academy of Science (NAS).. Members of the l
NAS comittee are listed in the enclosure. -The contractors f rom the national laboratories and the RPI consultant are both recognized internationally as
~ authorities in the field of hydrogen combustion and have published extensively
'in journals and other scientific literature. This paper includes' a sumary of.
the current conclusions drawn by these experts from detailed reviews of the-detonation experimental data base and modeling efforts.
-In 1987, the NAS~ comittee published the report, " Technical Aspects of Hydrogen Control and; Combustion in Severe Light Water Reactor Accidents," which provf ded
'l a detailed review of the NRC's hydrogen. programs. With regard to detonations,
- the NAS comittee used a method to calculate the width of a detonation cell' that extrapolated from the existing data base to provide predictions for full-scale hydrogen detonation.in a light-water reactor' containment. To avoid the potential for hydrogen detonations, the NAS comittee recomended that hydrogen concentrations should not exceed 9 to 11 percent by volume.
i Dr. Joseph-E. Shepherd of RPI developed the Zeldovich-von Neumann-Doering chemical-kinetics model to predict detonation cell width. This model has been used extensively by. Dr. Shepherd and others including the NAS comittee and the SNL' experts. The methodology Dr. Shepherd used to determine the detonation-CONTACT:
-T.
Kenyon, NRR gfp_
2-1120
~
dL 388"8RP M $
NRC FE.E CENTER COPY oho o m
~'
c.-
The Comission x limit assumed that the deflagration-to-detonation transition (DDT) will not occur if the size of the detonation cell is greater than two channel widths.
DDT has been observed experimentally when the detonation cell size is smaller than one channel width. To avoid the potential for detonations, Dr. Shepherd recomended that the maximum concentration of hydrogen should not exceed 10 )ercent by volume. The method used by Dr. Shepherd was similar to the NAS met 1od.
ThehydrogenauthoritiesfromSNLhaveconductedsmall,intermediatelames, and large-scale hydrogen combustion experiments to investigate diffusion f deflagration, accelerated flames, DDT, and detonation phenomena. The detonable
. range of hydrogen in a hydrogen-air mixture for their experimental facility (Heated Detonation Tube, HDT) is 11.6 percent to 74.9 percent at 20'C and 9.4 percent to 76.9 percent at 100*C. The detonation limit is between 38.8 percent and 40.5 percent for steam at stoichiometric hydrogen-air-steam mixtures at 100*C and 1 atmosphere. SNL recomends that the hydrogen in the containment should be maintained at lower concentrations than those for which a detonation has been experimentally observed because of the uncertainties associated with scale and temperature on detonation limits and the potential-for accelerated flames to generate impulsive loads.
The data base used by SNL for detonation limits includes data from all U.S.
programs and from international programs (i.e., Italy, Federal ~ Re)ublic of Germany,andCanada).
In addition, Professor John Lee of McGill Jniversity, recognized. internationally as a leading authority in the area of combustion, was under subcontract to the SNL praject.
j In its review of hydrogen detonation, the staff has used LANL only in-the development of a finite-difference code to perform detailed hydrogen transport and mixing calculations.
H The conclusions of these authorities were considered in the staff's develop-E ment of its position on hydrogen detonation as discussed in SECY-90-016,
" Evolutionary Light Water Reactor Certification Issues and Their Relation-ship to Current Regulatory Requirements," and in the draft safety evaluation j
report on Chapter 5 of the Electric Power Research Institute (EPRI) Advanced LightWaterReactor-(ALWR)RequirementsDocument.
In those papers, the staff stated its position that, because of uncertainties in the phenomenological knowledge of hyorogen generation ~ and combustion, as a minimum, evolutionary ALWRs should be designed to limit containment hydrogen concentration to no greater than 10 percent. Therefore, the staff recommended that the require-mentsof-10CFR50.34(f)(2)(1x)remainunchangedforevolutionaryALWRs.
Part (A) of this: regulation requires that:
Uniformly distributed hydrogen concentrations in the contain-ment do not exceed 10% during and following an accident that releases an equivalent amount of hydrogen as would be generated from a 100% fuel clad metal-water reaction, or that the post-acci-1 dent atmosphere will not support hydrogen combustion.
=
-.... -g N X.
4=
g
(.g t
W j
The Consission?
-.3 e,
s i
P' Unless' significant. new. information becomes available-.to warrant reconsidera.
t
, tion of this position, the-staff expects'to employ the same criteria on alli
- advanced reactor designs.
- l.,.
Original Signed Byi i
r James M.TayloF<
James M. Taylor Executive Director for Operations
Enclosure:
As stated cc w/ enclosure:
SECY.
0GC; ACRS-DISTRIBUTION Central File w/ incoming NRC PDR w/ incoming Local PDR w/ incoming; EDO 19000108-
~ED0' Reading T. Murley/F Miraglia:
J. Partlow PDSD' reading w/ incoming
-D. Crutchfield l
' W.~ Travers C.. Miller-M..Thadani 1
.GPA/CA J.-Taylor-
' E.Tana.PHAS(9000108) w/ incoming.
B. Davis-LT. Kenyon w/ incoming.
P. Shea l
i See previous concurrence
- 1-
)
l0FC - :PD5:LA*
- PDS:PM*
- TECH ED*
- PDS:D*
- DST *-
- AD*
j.....:............:............:............:............:............:............:.........-
lNAME;;PShea.
- TKenyon'
- JMain
- CMiller
- HThadani
- WTravers,
lDATEi:08/ /90 J:08/ /90
- 08/ /90
- 08/f /90
' 08/ /90-
- 08/ /90 A
lUFC. :ADSP:D*-
- ADP f
- D
- EDO,
t..... :........... :.. 4.j %
...........:N........:............:............:...........
- NAME '
- DCrutchfield:JPartl
- Jh c r
- .....
- ........... :......ki : Tllurl ey I
DATE);08/ i/90;
~ :08$/90
- 0 90
- 08/
j90 7
40FFICIAL= RECORD COPY No Document Name:
1 o
i 5
[
I
['.'
( '
n. i A
M cv ;'s,
- l aj
- o m
P
. El! CLOSURE -
-- i NAS COMMITTEE MEMBERS Nortit.n C. Rasmussen, Chairemn Herbert Kouts l
Eli K. Dabora c
- Gerard~M. faeth
. Antoni'K.*Oppenheim Daniel J..Seery n
Robert G. Zalosh James J.: Zucchetto t
1 SNL EXPERTS Marshall Berman Lloyd Nelson-i Lichung Pong.
Martin Sherman l
- Scott Slezak' Dou'glas-Stamps Sheldon.Tieszen
- " ll
. C. Channy Wong.
'LANL Ex>ert 1 Join Travis-1 RPI Expert:
Joseph Shepherd k
4 9
y I
f '
s s
a
o v
, y. c
^
c
,m e
-3 o
N
.Unless significant new information becomes available' to warrant reconsidera.
tion of this~ position, the staff erpects to employ the same criteria on all
'advancedreactordesigns.\\,
e f
\\
\\.
\\
\\
\\
James M. Taylor
\\
Executive Director
(
for. Operations
?-
Enclosure:
\\
As stated
\\
cc'w/ enclosure: '
p'S
\\
/
<ACR
\\
V l
7J v;.
N ll
-9
'DFC ::PD5:LA.
. PD5: ML,.
).....:TECHED....:......g.:.e.......'..:.#.V[ g
- PD5:D
- DgT.
AIY
....t.....:.........
k :CMiller Thedani
- WTravers lNAME-PSh
-:TK n
-:JMain:
.......:............:..........:...............\\........:............:.....
t DATEL:08 990p:08/g1/90
- 08/2 /90
~ :08/( 1 90 J:08fpk90,
-:08/)V90 m
v ia.
s
- DFC
- ;:ADSP:D)
.I GDP
- DDNRR
- EDO
.\\
......4.g.:............:...........:...........:.
i.....:...
'hfi e1
- TMurley.
- JTaylor
[':::
y NAME':DCHit
'DATE ? 208h..
g.../..d:JPartlow -
c
\\:-
0
- 08/ /90
- 08/ /90-
- 08/ /90 1
a
\\
1 0FFICIAL RECORD COPY Document Name: 5/22/90 SRM ON HYDROGEN DET.
\\
g.
s r
t t
i
..j.
.