ML20129E431
| ML20129E431 | |
| Person / Time | |
|---|---|
| Site: | 05000447 |
| Issue date: | 12/03/1982 |
| From: | Sherwood G GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20127A304 | List: |
| References | |
| FOIA-84-175, FOIA-84-A-66 NUDOCS 8506060489 | |
| Download: ML20129E431 (19) | |
Text
.
V UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION o
i In the matter of
)
General Electric Company )
Docket No. STN 50-447 Standard Plant
)
SU3MITTAL OF PROPRIETARY INFORMATION FOR REVIEW 0F 238 NUCLEAR ISLAND GENERAL ELECTRIC STANDARD SAFETY ANALYSIS REPORT (GESSAR II) i General Electric Company, applicant in the above captioned proceeding, hereby submits proprietary information to be included in the review of
.the 238 Nuclear Island General Electric Standard Safety Analysis Report (GESSAR II).
This proprietary material consists of Amendment No.11 of GESSAR II which amends Appendix 150 to Chapter 15. Appendix 150 provides a Probabilistic Risk Assessment (PRA) which quantifies the risk associated with operating a BWR/6 standard plant with a reference Mark III containment for the purpose of electrical power generation.
The PRA is providad for the Nuclear Regulatory Cornission's review of the 238 Nuclear Island GESSAR II i
for severe accident issues.
1 Respectfully submitted, General Electric by:
s/Glenn G. Sherwood i
Glenn G. Sherwood, Manager Nuclear Safety & Licensing Operation i
STATE OF CALIFORNIA )
- COUN1Y OF SANTA CLARA)
On this 3 dayof December in the year 1982, before me, Karen S.
Vogelhuber, Notary Public, personally appeared Glenn G. Sherwood, personally proved to me on the basis of satisfactory evidence to be the person whose name is subscribed to this instrument, and acknowledged that he executed l
it.
A by:
s/ Karen S. Vogelhuber Notary Public - California j
Santa Clara County 8506060499 841203 -
em ssion @ es PDR FOIA December 21, 1984 CURRAN 64-A-66 PDR 175 Curtner Avenue San Jose, CA 95125 RDH:csc: rm/I110813-1 4
6g
,-,,m,-
-,,,.-,--..-n,..,n.-n
,n.,,
,,-..,.,,,nn-,
o,.._
.,,,.v,-----,_,..__n..,---,...-~n-n
GESSAR II 22A7007 238 NUCLEAR ISLAND Rsv. 11 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class III Table 1 ESTIMATED CORE DAMAGE AND RISK COMPARISON Assessed requency of Event Risk (per year)
Per Reactor Early Latent b
Event Year Fatalities Fatalities I.
CORE DAMAGE RSS BWR/4 Mark I
~
a a
9 composite site 44x10_5
%1x10,5
-2 c
%5x10 c
N4x10 2.4x10 2.5x10 RSS BWR/4 Mark I
-5
-6
-2 6 site #6 44x10 7.8x10 2.1x10 BWR/6MargIII
-6
-5 6 site #6 5x10 NO 1.7x10 II.
U.S. NATURAL BACKGROUND Continuous 0
814 RADIATION "With WASH-1400 Methods (calculated from the reported curves).
bThe total accident-caused fatalities over the lifetime of the exposed population or the calculated excess cancers in the same population from one year of background radiation.
cComputed with the GE CRAC Code.
--,,.,,.n-----
.=
-GE5SAR l'1
~ ~~~
238 NUCLEAR ISLAND 22A7007
' GENERAL ELECTRIC COMPANY Rev.11 4
PROPRIETARY INFORMATION Class til 10%...
g L-h
- i to.-
X A.
E<
5 4
'~
10 8
~
~
k' E
E WASH ' 400 BWR ATSITE 6 E.
1
-4 w
10 E!
w 8
wEs o
h 10 w
10% -
.BWR/6 ATSITE 6-10'8, f
I I
i 0
1 2
3 10 10 10 yg 3g 3o 4
s LATENT FATALITIES PER YEAR (X) 22343 M Figure 1. Compvimon of Risk for te WASH 1400 BWR and BWRM 4
4 XVI
GESSAR II 22A7007 238 NUCLEAR ISLAND R3v. 2 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class III 2.2 SITE DESCRIPTION For this PRA, it was appropriate to select an actual site with
. average site conditions.
An evaluation was made of the six WASH-1400 sites relative to the overall consequence curve of WASH-1400.
This comparison indicated that site 6, the Atlantic Coastal site, is an adequate representation of an average site.
The WASH-1400 site 6 weather conditions and composite population distribution which were used in this PRA are presented in Appendix F.4.
Compared to the other sites, site 6 ranks third largest in overall population (81.4 million), third largest in total population within 50 miles and first for the largest popula-
. tion in a given sector (north sector population of 23 million).
A comparison of early and latent fatalities calculated for the WASH-1400 BWR at site 6 and the WASH-1400 composite site is shown in Figure 2.2-1 and Figure 2.2-2.
From these results it was concluded that site 6 is a representative average site, and thus, it is utilized for the consequence analysis presented in Section 6.1.
i l
[.
L l
15.D.3-31 l
l
GESSAR it' ~~"
22A7007 238 NUCLEAR ISLAND
, Rev.11 iGENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION
+ - - - -
.._ _ _. CN. III_.
1C4 10~4 x
A'
~
E s'0-5l 8
b 5
=
5 1
a.
N 4'
5 10
~
5
>u 5
8 e
t WASH 1400 BWR AT COMPOSITE SITE l
10 7 in E
E l
i 4
10 WASH 1400 8WR AT SITE 6 l
I l
10
~
0 I
2 4
5
[
10 10 10 Ig 10 10 EdRLY FATALITIES (X) 2234341 Figure 2.2-1. Site Comparison of Early Fatality Curver for WASH 1400 BWR Releanes I
15.D.3-32
-~~ 'GESSAR 11 22A7007 238 NUCLEAR ISLAND R:v.11
- GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class ill 10 10f_I WASH 1400 swr X
AT COMPOSITE SITE A
E b 104 5'
t; I
E 6
a.
M
$. ton 5
WASH 1400 8WR E
AT SITE 6 o
5 8
g w
b 10'7 l
~
N N
E F
4 10
~
10
'100 10' 10 10 10 10 2
3 4
5 LATENT FATALITIES (X) PER YEAR 22343 M Figure 22-2 Site Cbmparison of Latent Fatality Cungrs for WASH 1400 BWR Releases 1
15.D.3-33/15.D.3-34
GESSAR II 238 NUCLEAR ISLAND 22A7007 GENERAL ELECTRIC COMPANY R;v. 2 PROPRIETARY INFORMATION Class III
6.1.2 Estimated
Early and Latent Facilities (Continued) which resulted in an elevated release producing lower doses close to,the plant.
6.1.3 References 6.1-1
" Reactor Safety Study:
An Assessment of Accident Risk in US Commercial Nuclear Power Plants", WASH 1400 (NUREG 75/
104), USNRC (1975) Appendix VI, p. 13-49.
e 9
e e
9 e
15.D.3-129
GESSAR 11 22A7007 2311 NUCLEAR ISLAND Rev.11 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class ill 10 io" X
A k
10-5 t
E u<
~
E WASH 1400 8WR AT SITE 6 5
L 4
E 10 5>
i 5
U 5
8 E
10~7 s
a m<
l 4
10 8WR/6 AT SITE 6 l
l l
4 I
I I
to 0
I 2
3 4
5 10 10 10 10 10 30 l
LATENT FATALITIES PER YEAR (X)
I 2234342 Figure 6.1 1. Comparison of Risk for the Wash.1400 BWR and BWRM 15.D.3-130
GESSAR II 22A7007 238 NUCLEAR. ISLAND Rsv. 2 GENERAL ELECTRIC COMPANY PROPRIETAR*I INFORMATION Class III 7.
SUMMARY
AND CONCLUSIONS
}
This section presents the BWR/6 assessed frequency of core damage per reactor year and risk results.
These results are compared with those of the RSS BWR/4 Mark I, risk from natural background radiation and with other natural and man-made risks.
Major findings; are summarized and conclusions are drawn.
7.1
SUMMARY
OF RESULTS f
The PRA results are presented in three different ways:
- First, the assessed average frequency of core damage per year is calculated.
Second, similar to the RSS treatment of nuclear reactor risk, the BWR/6 risk results are presented by a comple-mentary cumulative frequency functions (CCFF).
Third, the estimated risk is also presented.
7.1.1 Frequency of Core Damage The assessed frequency of core damage per reactor year is calcu-
-6 lated to be N5x10
/ reactor year and is displayed in Table 7.1-1.
This frequency is calculated as the product of expected value of initiating event per reactor year and the estimated mean proba-l bility of-core damage per event summed over all of the initiating events.
The data are then broken down by major initiating events (Figure 7.1-1) and further discussed in Section 7.2.
These results demonstrate the effectiveness of BWR/6 safety features, independent of the selection of reactor site parameters and con-sequence assessment methodology.
O'7.1.2 The Risk Curves l
The CCFF curve relates the consequences of rare severe accidents to their assessed frequency of occurrence.
Primarily because of l
i 15.D.3-135 l
GESSAR II 22A7007 238 NUCLEAR ISLAND Rnv. 11 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class III 7.1.2 The Risk Curves (Continued) suppression pool scrubbing and in-vessel fission-product retention, there were no early fatalities among the CRAC runs and no BWR/6 CCFF early fatality risk curve can be constructed.
'The' risk curve for latent fatalities is presented in Figure 7 1-2 and is discussed in Section 7.2 and 7.3.*
7.1.3 Risk Risk is calculated as the product of the assessed frequency of release categories per reactor year and the estimated average number of consequences per release category, summed over all l
release categories.
The risk for BWR/6 is calculated to be
~$
- 1.7 x10 lifetime latent fatalities per reactor year and is further discussed in Sections 7.2 and 7.3.
~
O F
- The number of latent fatalities per year was calculated by dividing the total lifetime latent fatalities per accident by 30 to allow' comparison with WASH-1400 results (Section 6.1.2).
15.D.3-136 i
GESSAR II 22A7007 238 NUCLEAR ISLAND Rev.11-GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION
~
CLASS III L
10-3 104
~
x A
U I
> io-s 8
C 5
i E
WASH 1400 BWR AT SITE 6 E
E 12 2
l 5
10-6 5
E w
t 8
e L
8 E
10~7 l -
w r
BWR/6 AT SITE 6 l
10-I l
10-8 0
1 10 10 102 1E if 105 LATENT F ATALITIES PER YE AR (X)
Figure 7.1-2.
Comparison of Risk for the WASH-1400 BWR and BWR/6 15.D.3-139 l
unssax 11 22A7007 238 NUCLEAR ISLAND Riv. 2 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class III 7.2 COMPARISON WITH WASH-1400 The Reactor Safety Study (WASH-1400) and the BWR/6 PRA are similar stu' dies in that they both analyze the risk to the public from nuclear power operation.
The methodology used is basically the same (probabilistic event / fault tree analysis) and the results are presented in the same manner (complimentary cumula-tive frequency functions of offsite consequences).
Table 7.2-1 compares the frequency of core damage of both studies.
While both employed similar quantification techniques, the details of the two analyses are substantially different.
The BWR/6 and the RSS BWR/4 have significant design differences.
Also, the BWR/6 assessment is more comprehensive than the RSS.
In many cases, the BWR/6 fault trees analyze more components and more potential failure modes.
Most BWR/6 event trees contain more details allowing for more interactions.
A larger number of accident classes and release categories are modeled for BWR/6.
Furthermore, the BWR/6 analyses contain a major ATWS sequence which was not included in the RSS.
In addition, the BWR/6 PRA includes an updated assessment of initiating event frequency based on operating experience, revised component failure proba-j bilities justified by design differences and additional data, and more realistic success criteria than were available for the RSS.
i i
i The net effect of these differences is that the estimated BWR/6 j
standard plant frequency of core damage per reactor year is lower by a factor of eight, compared to the estimated RSS mean value.
[
A more realistic treatment of fission product transport modeling relative to the RSS is included in the BWR/6 PRA.
Credit was taken for in-vessel retention and for fission product scrubbing l
15.D.3-140
GESSAR II 22A7007 238 NUCLEAR ISLAND Rsv. 11 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class III 7.2 COMPARISON'WITH WASH-1400 (Continued) in a saturated suppression pool.
In the RSS, BWR risk was evaluated for a composite of sites, which was meant to represent a composite of all BWR sites in the United States.
In the BWR/6 analysis, the risk was evaluated at a specific site (RSS Site 96).
The difference in risk due to the site difference is small as can be seen by comparing the curve for the WASH 1400 BWR at the composite site with the curve for the WASH-1400 BWR at Site #6 (Section 2.6).
Another difference in the evaluation of risk was the use of an updated version of the CRAC code in the BWR/6 analysis.
The difference in risk due to the use of a different CRAC code was small and is shown in Appendix F.4.
Figure 7.1-2 compares the RSS and BWR/6 CCFF risk curves for latent fatalities.
The risk of latent fatalities for the BWR/6 is less than the risk for the WASH-1400 BWR at Site 6 by a factor
~
of about 280 (Table 7. 2-1).
This reduction is primarily due to
~'
the additional prevention and mitigation features of the BWR/6 -
Mark III design.
Another measure of risk is the assessed average number of conse-quences (early and latent fatalities) per reactor year.
The RSS provided no evaluation of average number of consequences specif-ically for the BWR.
Only risks for the combined average for the BWR and PWR plants were provided (Reference 7.2-1).
To provide a basis for comparison with the WASH-1400 BWR, the average number of consequences was estimated from the RSS BWR CCFF curves.
The l
BWR/6 risk is lower by several orders of magnitude as shown in Table 7.2-1.
\\
15.D.3-141
t GESSAR II 22A7007 238 NUCLEAR ISLAND Ray, 2 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION CLASS III 7.2.1 References 7.2-1
" Reactor Safety Study:
An Assessment of Accident Risk in U.S. Commercial Nuclear Power Plants," WASH-1400 (NUREG 75/014, U.S. Nuclear Regulatory Commission (1975).
4 9
4 l
i 1
15.D.3-142
.GESSAR II 22A7007 238 NUCLEAR ISLAND R%v. 11 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION Class III Table 7.2-1 ESTIMATED CORE DAMAGE AND RISK COMPARISON Assessed
- " Y of Event Risk (Per Year)
Per Reactor Early Latent Event Year Fatalities Fatalitiesb I.
CORE DAMAGE RSS BWR/4 Mark I
~
a a
-5
-S
-2 9 composite site 44x10 41x10 c
45x10 c
-5 N4x10 2.4x10-5
- 2. 5x10 -2 RSS BWR/4 Mark I
-5
-6
-2 9 site 46c 44x10 7.8x10 2.1x10 BWR/6 Mark III
-6
-5 9 site #6C 5x10 40 1.7x10 II.
U.S. NATURAL BACKGROUND Continuous 0
814 RADIATION 4
"With WASH-1400 Methods (calculated from the reported curves).
bThe total accident-caused fatalities over the lifetime of the exposed population or the calculated excess cancers in the same j
population from one year of background radiation.
Computed with the GE CRAC Code.
I 15.D.3-143
GESSAR II 22A7007 238 NUCLEAR ISLAND Rnv.2 GENERAL ELECTRIC COMPAN'_'
PROPRIETARY INFORMATION Class III 7.3 COMPARISON TO OTHER RISKS The risk associated with reactor accidents can also be compared with the average natural background exposure in the United States, by estimating the mean value of lifetime cancer fatalities due to an average background dose of 100 millirem per person per year.
Man-Rem exposure from background radiation is calculated for the same 500 mile radius area and the same population demography (81.4 million people) used for the postulated accident.
The US NRC estimated excess lifetime death rate of 100 cancer fatalities / million person-rems is used for this analysis (Reference 7.3-1)
The latent fatalities risk associated with BWR/4 or BWR/6 reactors is significantly lower than the corre-sponding background radiation risk by four and seven orders of magnitude, respectively (Table 7.2-1).
Another comparison is made to natural and. man-made hazards, based on statistics for the frequency of these' hazards in the USA as displayed in Figures 7.3-1 and 7.3-2 (Ref. 7.3-2).
These figures compare the actuarial or estimated average U.S.
frequency of fatalities per year caused by natural or manmade hazards (adjusted to site 6 population) to the assessed frequency of latent fatalities per year attributed to hypothetical nuclear accidents.
For example, on the average there is about one tornado and four aviation accidents per year which cause at least ten fatalities each.
This is compared to the assessed
-6 frequency of less than lx10 per year of reactor accidents with one or more fatalities.
Thus the risk from nuclear accidents at site six is smaller by a factor of more than a million than the risk associated with most natural and man-made hazards.
The comparison in this case is not exact since fatalities as a result of these hazards are immediate and their frequency is substantiated by experience, whereas the reactor curves result from a best estimate calculation of potential latent fatalities.
15.D.3-144
i GESSAR II 22A7007 238 NUCLEAR ISLAND RIv, 2 GENERAL ELECTRIC COMPANY PROPRIETARY INFORMATION CLASS III 7.3.1 References 7.3-1
" Instruction Concerning Risks from Occupational Radiation Exposure," Regulatory Guide 8.29, U.S. Nuclear Regulatory Commission (1981), Tables 1 and 6.
7.3-2 A. - Coppola, R. E. Hall, "A Risk Comparison," NUREG/CR-1916, U.S. Nuclear Regulatory Commission (1981).
G S
15.D.3-145
GESSAR II 238 NUCLEBR ISLAND 22A7007 GENERAL ELECIRIC COMPAN" Rev. 2 r
PROPRIETARY BFORMATION Class III 7.4 OVERVIEW OF CONDITIONS AND 3 IMITATIONS This study is generally based on state-of-the-art methodology and does not present an innovatism approach to risk analysis.
All PRA studies are subject to eartain limitations.
The major limitations applicable to this Mk study are described and dis-cussed below.
7.4.1 Plant and Data The BWR/6 PRA addresses a standard plant at a selected site with a representative grid for that site.
The analysis is based on NSSS. and BOP design drawings that characterize the BWR/6 standard plant, and on design modificaties to the standard plant.
Human, component and system failure probabilities are based primarily on commonly used generic data from operating experi-ence and other nuclear sources. Mean values or values judged to represent mean values were used throughout the analysis.
It is recognized that the analysis of a specific plant design at an actual site may produce differet results.
7.4.2 Scope This PRA study addresses the potential risk to the public from nuclear accidents during operation.
The risk associated with other activities such as normal operation or fuel handling, storage and disposal is not trasted.
The risk associated with external events, such as earthquake, fire, flood, aircraft crash or sabotage is not considered, except to the extent that they are included in the data base for the frequency of loss of off-site power.
Human error undels include errors resulting from operator failure to act, as directed by procedures, as a func-tional part of the system.
Inadvertent scram due to human error 15.D. 3-14 8 V
t 4
GESSAR 11 22A7007 238 NUCLEAR ISLAND R:v.11 GENER AL ELECTRIC COMPANY PROPRIETARY INFORMATION Class ill 10' 0
10 FLOOD TORNADO ACTUARIAL g
ASSESSMENT HURRICANE 10'I EARTHQUAKE
\\
10~2
~
\\
\\
\\
\\
\\
h 10 4
NATURAL HAZARDS 5
N b 10
~
B W
E O 10-5 E
10,4 METEORITES 10*7
~
BWR/6 LATENT
\\
FATALITIES AT SITE 6
\\
NOTE: NO EARLY FATALITIES RECORDED FOR BWR/6 4
10
~
\\
\\
\\
10~8 0
1 2
3 4
5 6
7 10 10 10 10 10 10 10 3o NUMBER OF FATALITIES (N) 22343-04 Figurr 7.3-1. Risk Comparison Betwn Natural Hazards and BWRM 15.D.3146
-.