ML20039H162
Text
(y M
UNITED STATES l.y * -
g$
j NUCLEAR REGULATORY COMMISSION y
.g WASHINGTON, D. C. 20555 g
Docket No. 50-561 fh MEMORANDUM FOR: Domenic B. Vassallo, Assistant Director for Light Water Reactors, DPM FROM:
Richard H. Vollmer, Assistant Director for Site Analysis, DSE
SUBJECT:
REVISED AAB SER INPUT FOR B-SAR-205 l
t Standard Review Plan 15.1.5 identifies three different scenarios where the radiological consequences of steam line breaks should be considered.
Our previous AAB SER input (January ll, 1977) addressed two of these but did not include the effects of a postulated steam line break with I
a stuck rod. We have analyzed the steam line break accident for this case. We have also considered the radiological consequences of a locked-rotor accident, i
We conclude that, no revision to the standard technical specifications on steam generator leakage, primary or secondary coolant activities, l'
will be required in consideration of either of these events. Our revised SER input is enclosed.
Changes are noted in the margin or by hand corrections.
Richard H. Vollmer, Assistant Director for Site Analysis Division of Site Safety and Environmental Analysis
Enclosure:
Revised AAB SER Input i
for B-SAR-205 cc: wo/ enclosure W. Mcdonald J. Panzarella P. Shuttleworth w/ enclosure See next page 8201190672 810403 l
Make the following changes:
[
l.
Table 15-1, Rod Ejsction - Case 2.
Change the 2-hour dose to the V'
thyroid from 81 to 78 rem.
2.
Table 15-3, Case 2 replace the assumptions with the following:
.,__,y..,.
~
- }
ty,.
} f f ;.,-.N, p. y K '"
- ..~.r,,
6.. -,3,..
1
.6
.,4 y
^
,t-
- T--
'u e
g
,.s
~
l f.
- ~,Re*4 I,%.
r ls f \\ ~,? *
,g t
b.
- m' ; s.. -.
m a - y
.-, w q y' =,..
e g
s
.g i
C..
4 4
n
{
7 a
v i
I
~ -.e 1
. ~, -
f ' _
s g,j
.s.
s i
V f
i
.r I
[
h'
~
t 1
+
4
-t j
!l 1
+
t I
I t_
i
..-ww b
4
{s 4
s n,.
e 4
b se 4
i I,
=n e
+
k g
s
.e+
t g g
+
t
- e.
Jfs t' 1 e c.
~.
I #
P t
+
b ". s.
t i
I e
i
- b k
di.-g e.e,-'
fq s'
. 6 4.rew*6 e
"-O*
4 r,-Epe.
'h 4 *y.
g ih-s
. g '
.g..
.,m;
- 1, -_
g"
%. ;, ' 44 -
w L;
=
f Le o
.n: :g... y,$
. > v. m -s.a r.
.y a
- >; ; R. _
E
,c(*'
. - y[ y
.',',[,
<,=,
.} ga
- y-~ ; r;
- ~
t e,
~ "
e 4
TABLE 15-1 l
' RADIOLOGICAL CONSEQUENCES OF DESIGN BASIS' ACCIDENTS
.i', j 2-hour Dose 2-hour Dos.e
' T]
to Thy'roid (rem)2 to Whole Body (rem)2
' team Generator Tube failure 26
<1 l
l Steam Generator Tube Failure with Coincident Iodine Spike 129
<1 Steam Line Failure m&,1.iv JJy 6.3
< 0.1 s
Steam Line Failure with Coincident Iodine Spike 11 (so w ars4[ p dd 0.1 3
Rod Ejection - Case 1
- 16,-
'<1 4
Case 2 81
< 0.1 Loss of Coolant 150 6.6 9
For an assumed relative concentration of 4 x 10- seconds per cubic meter.....
2rem - roentgen equivalent man i
3 Case 1 assumes al'1 releases through the containment.
4 f
Case 2 assumes all releases through the secondary system. -
l TABLE 15-2 i
ASSUMPTIONS USED IN THE ESTIMATE OF LOSS-OF-COOLANT ACCIDENT DOSES 1.
Thermal power Icvel 4100 megawatts 2.
Operating Time 3.0 years 3.
Reactor Building Leak Rate (0-24 hours) 0.10 percent
(>24 hours).-
0.05 percent.
4.
Iodine Composition i :. >
Elemental i.. 'n u,...
- r.......
.1 L u-:91appreent ' h :.i.I c.
...Elem
. Particulate.
...,_.4 u...
-...A. percent....,....... '
..u.
Organic f.
. 'i. par, ent.
i.)... -
't re..
.. Orp.4.percetit,' : li.p t ent
- s. forp 5.
Two-llour Thyroid Dose Reduction Factor for Spray 5.5 7_..._,_,
.,.a e'^
,n.-,m
's
a TABLE 15-4 (Cont 'd.)
19.
All releases through the secondary system (except Rod Ejection Accident, Case 1).
O 20.
For accidents assumed to occur in coincidence with an' iodine spike, the primary coolant concentration is as limited by the standard
. T,echnical Specifications for 48-hour periods (60 microcuries per gram 1-131 equivalent at 100 perc*ent power).
- 21. - 10 percent of iodine and noble ' gases fue1 activity in gaps.
TABLE 15-5
' ASSUMPTIONS USED IN ANALYSIS OF
~ ' ' ' ~ ~ ' *~ ' " ~ ~ ' ' ' '
STEAM GENERAT0k TUBE FAILURE ACCIDENT 1.-
Isolation of failed steam generators within 30 minutes of accident.
'2.
Steam generators controlled at safety valve settings.
i 3.
No mor.e than 130,000 pounds of primary coolant are transferred to the
]
secondary side of the faulty steam generator following the accident.
4.
Pressure equalization between defective steam generator and primary - -
system reached within 30 minutes.
I i
t TABLE 15-6 6
ASSUMPTIONS USED IN ANALYSIS OF STEAM LINE FAILURE ACCIDENT J
.l.
Steam.line isolation valves fully close within 10 seconds of break.
2.
Only one steam generator blows down even if one of the isolation valves fail to close.
3.
Contents of one steam generator (44,000 pounds of water and 6,000 pounds
,h of steam) released to epvironment as steam within 30 seconds.
t.
f 4
+
g
'.. S M y-y
--.e.3, w,
i 4
t i
i Domenic B. Vassallo 2
E I
i t
cc: w/ enclosure l
S. Hanauer j.
H. Denton j
D. Muller t
F. Miraglia r
s J. Miller R. Boyd i
L. Crocker 1
- 0. Parr j
T. Cox
~
R. Vollmer l
D. Bunch j
G. Chipman J. Wing l
1 1
l-t
,l
$[
s I
i p
t e
i i
I l
C
.. +
, L..
~
~
I cubic meter (30 meter elevated release) or less at the nearest exclusion area boundary will be required in order to meet the 150 rem thyroid dose guideline value for Case 2.
For sites with poorer dispersion conditions, lower primary to secondary steam generator tube leak rate technical specifications may be required.
~
15.I.4 Steam Generator Tube Failure and Steam Line Failure
. The assumptions used in the analysis of the steam generator tube-
~
failure and steam line failure accidents are'11sted in Tables 15-4, 15-5, and 15-6.
The resulting doses for these accidents are listed in Table 15-1 for a relative' concentration of 4 x 10~
second' per cubic meter.
s These doses were calculated based on the maximum activity con-~
centrations in the primary and secondary coolants specified in i
j the technical specifications for recent Babcock and Wilcox plants.
For plants of the B-SAR-205 size the coolant activity limits may- --
have to be lowered in order to assure that the doses for these accidents do not exceed appropriately low fractions of 10 CFR 100 y
for sites with atmospheric dispersion values higher than 4 x 10 seconds per cubic meter.
15.X.5 Reactor Coolant Pump Rotor Seizure
~
The event postulated is an instantaneous seizure of the rotor of a reactor coolant pump. Flow through the affected loop is rapidly reduced, leading to a reactor and turbine trip. The sudden decrease in core coolant flow while the reactor is at power results in a degra-dation of core heat transfer which for B-SAR-205, is calculated to I
result in fuel damage to 4.8% of the core.
l On the basis of our experience with the evaluation of similar accidants for plants of similar design, we have concluded that the consequences
[
of this accident can be controlled by limiting the permissible primary to secondary coolant leak rate so that potential offsite doses are small.
We will include appropriate limits on the primary to secondary leakage in the technical specifications for plants referencing B-SAR-205.
I i
TABLE 15-1 RADIOLOGICAL ' CONSEQUENCES OF DESIGN BASIS AGCIDENTS 2-hour Dose 2-hour Dose l
to Thyroid (rem) to Whrile Body (rem) i Steam Generator Tube failure 26
<1 Steam Generator Tube Failure with Coincident Iodine Spike 129
<1 Steam Line Failure 6.3
< 0.1 Steam Line Failure with Coincident' Iodine Spike 11
< 0.1 h Steam Line Failure with Stuck' Rod' 44
< 0.1
~
Rod Ejection - Case 1 16
<1 l
Case 2 78
< 0.1 Loss of Coolant 150 6.6
-4 1For an assumed relative concentration of 4 x 10 seconda per cubic meter.
2rem - roentgen equivalent man Case 1 assu=es all releases through the containment. -
4Case 2 assumes all releases through the secondary system.
TABLE 15-2 ASSUMPTIONS USED IN THE ESTIMATE OF LOSS-OF-COOLANT ACCIDENT DOSES l
1.
Thermal power level 4100 megawatts 2.
Operating Time 3.0 years 3.
Reactor Building Leak Rate (0-24 hours) 0.10 percent
(>24 hours) 0.05 percent.
4.
Iodine Compospion l
l Elemental 91 percent f
. Particulate 5 peseent Organic 4 percent 5.
Two-Hour Thyroid Dose Reduction Factor for 5.5 Spray l
c
.. - ~, m mcva 19.
All releazas through th2 escondary cystec (sxcspt Rod Ejection Accidtnt, Cass 1).
20.
For accidents assumed to occur in coincidence with an iodine spike, the primary coolant concentration is as limited by the standard Technical Specifications for 48-hour periods (60 microcuries per gram 1-131 equivalent at 100 percent power).
21.
10 percent of iodine and noble gases fue1 activity in gaps.
TABLE 15-5 ASSUMPTIONS USED IN ANALYSIS OF STEAM GENERATOR TUBE FAILURE ACCIDENT i
1.
Isolation of failed steam generators within 30 minutes of accident.
2.
Steam generators controlled at safety valve settings.
3.
,No mor.e than 130,000 pounds of primary coolant are transferred to the secondary side of the faulty steam generator following the accident.
4.
Pressure equalization between defective steam generator and primary system reached within 30 minutes.
i t
TABLE 15-6 ASSUMPTIONS USED IN ANALYSIS OF STEAM LINE FAILURE ACCIDENT
/
.1.. Steam line isolation valves fully close' within 10 seconds of break.
.2.
. ~
Only one steam generator blows dcwn even if one of the isolatica valves fail to close.
3.
Contents of one steam generator (44,000 pounds of water and 6,000 pounds of steam) released to environment as steam within 30 seconds.
4 One' percent of the fuel rods experience cladding failures (DMBR<l.30) for' case of one stuck rod.
}
5 All iodine in the failed SG initially and resulting from tube leakage, is released to the environment.
G
(
i I
i I
r-4 w-=
e