ML20234B565
Text
t l
O/D l
G E N E R A L fre; E LE CT R I C
.lomC enoDuCTs l
C0MPANY DIVISION l
l i7s cungwee Ave., sAs ;ose, c4tir. 9sica... Ame4 coor 4es, tat 297 g,
l s'
April 15, 1966 Dr. R. L. Doan, Director 0;
APR2219 s [4-Division of Reactor Licensing 8.14 h!b United States Atomic Energy Commission C0 dffg Washington, D.C.
20545 6
8 (b
CP N
Dear Dr. Doan:
k At the time of the seminar on the Reactor Core Isolation i
Cooling (RCIC) system last October, it was our plan to submit N
this system for formal review and approval, independently of any specific license application. Our plans later changed, as U,
it appeared to us that the system could best be evaluated as I
an integral feature of an over-all plant design.
It is for this reason that we have not folicwed up on the original plan, I
nor provided a response previously to the questions raised in your letter of mid-November.
The RCIC_ system _is being_ incorporated in the design for the Quad. Cities,plitnt, and we want to supply you with the information which will be needed to resolve the questions which have been raised with regard to safety. A memorandum is attached 7
which provides some information on points brought up in your.
l letter. We further plan to send you by May 16 an advance copy j
of the isolation cooling section of the Quad Cities P1nne nec43n and Analysis Report. This will contain additional material on l
safety aspects of tihe new system, and serve as a basis for further discussions as may be required.
,,,-- ; 3 'd0(T[1 k'.
I Sincerely yours, 4
y gWOJ ^'
q g.g 9 na E
' L U./e 4
O. H. Creager /
33 Consultant - Nq lear Engineering 8707060105 070610 (ognt ION OG Q" -t_e,, 'I,-
U
/
,./, n, t,,,,,-, o
, u.,
PDR FOIA THOMASB7-40 PDR Ag gy,go sugy fB668[Sf/4//)
A b@s*gPui 5 :,lAN A
_ _ ~ __ _ _
i 11 14, 1900-
/
c)
(4
. i,.
r i.9 r.m ci. u..
g
- Mject:
Reply to letter by R. L. Doan, Director DRL, US AEC, to r
Dr. O.11. Creager, APED, dated November 17, 1965.
4.'
4 '
~
tr O
t.h;,
I
Reference:
Report, the RCIC System (Reactor Core - Isolation Cooling) a
-l 1
by J. E. Kjemtrup dated October 15, 1965.
N'Rik. I I
The following is in response to the questions on the RCIC System s.I raised in the subjiet letter.
\\
guestion #1 Using the RCIC system, what would be the minimum amount of primary water
)
blowdown that would be released to the containment before the reactor is de-1 I
pressurized to 150 psig and the reactor primary system could again be rescaled l
with decay heat removal being accomplished by the shutuuun cooling system? What j
would be the magnitude of radioactivity transported to the suppression pool with n
I major cladding f ailure?
(For example, 1% clad f ailure in a 1,600 Hwt reactor).
Iit l
Answer Reactor blowdown f rom 1,000 psig and 545*F to 350 psig and 365*F to the I
suppression pool via the RCIC system takes two hours, limited by the maximum allowable cooling rdte of the reactor:
100*F per hour. The blowdown consists of 3'.0,000 lbs. The RCIC feedwater pumps can keep the core coolant inventory constant.
If only one RCIC feedwater pump is available, the feedwater rate vill
,i equal the blowdown rate after 15 minutes of decay from full power operation scram.
After 15 minutes decay, one RCIC feedwater pump capacity will exceed the blowdown rate. At no time will the core be in danger of being uncovered.
At the end of the two hour blowdown period, in a 1,600 Mwt reactor with 1%
0 clad failure, there will have been 2.4 x 10 curies of noble gases and 17 curies of halogens transported to the suppression pcol. All of the noble gases will pass through the suppression pool to the containment air space and about 0.57 curies of halogens will partition to the containment air space.
If it is assumed that all of the heat in the steam that blows down is transferred t$ the suppreuion
_ = _ - _ _
- y4 - (
1
(
.po91 water and, the containment air and to no other men.bers and no heat is irnasferred out:of. containment, the temperature of the pool and conthir. ment air-will reach 167*F and the pressure in the containment will. approach 7 psig.
r
[
.Under,these conditions, the leak rate based on Figure VII-1 (Post Accident Drywell ll
. Pressure and.1.eakage Rate) of Preliminary Safeguards Summary Report for Oyster-l
. Creek Nuclear. Power Plant, Unit No. I will approach 0.38% per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Relcase of.-fission products out of the containment system and to the stack under these l
con <litions assuming 95% efficiency for halogen and solid removal by the high 1
efficiency and charcoal' filters will result in a total dose for the two hour.
7-breakdown period of not gr' cater than 2 p Rad for the passing cloud case and
- II 0.06'p Rad for the thyroid ca'se.
If the suppression pool water is circulated through heat exchanges to prevent
[
'an. increase in temperature, there will be no increase in containment pressure and
-o N
- E no. transport of fission products out of the containment.
1-ii i
lJ Ouestion #2 1
6 Under normal planned usage of the RCIC system with high primary coolant radio-11
- activity Icvels (e.g., gross. fission product of 50 ac/cc), what would be the i
expected amount.of activity released to the containment system during-a shutdown caused by.a turbineytrip on loss of condenser vacuum? Also, what would be the pressure rise in the containment while using the system?
9 1-Answer Under normal planned usage of the RCIC system, the reactor would be scrammed
-and'thepressurewouldbeheldat1,000psigwhiledecayheatistrans5erreddirect1 to the suppression pool via the electromatic valves and make-up water is added to the'reacter by the turbine-pump units of the RCIC system.
In the case of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of'use, the expected amount'of activity released to the containment system with
- a. gross fission product of 50 pc/cc in the reactor water would be approximately 16 curics to the suppression pool.
Of the 16 curies gross fission product in the pool water.not more than 0.5 curie could be expected to be released to the contain-c
l
( g s
n, a t air.
There would be no increase in containment pressure and no Icakage of flasion products from containment during the above planned usage as the suppression
~
exchanger would be in operation to keep the pool temperature at near pool heat i
}
an.Lient temperature.
If it is assumed that the suppression pool heat exchangers are not used, then the pool temperature would approach 204*F, containment pressurc i
J2.5 psig; after 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of RCIC use with no heat transferred out'of containment.
Question #3 Very important that the review documentation contain comprehensive analysis of use of system and its attendant safety considerations as well as bases for utilizing this system in lieu of the Isolation Condenser System.
l 1
Answer We refer you to our report by J. E. Rjemtrup, 15 October, 1965. wherein we fj have made a comprehensive analysis of this design, reviewed safety considerations
'N I
in appraisal of safety margins, and listed our bases in Design Criteria.
is Over and above this document, we reiterate some of the points brought out in
?
our presentation of 21 October 1965.
- h As you recall, we reviewed the advantages, disadvantages and motivation behind the RCIC versus the isolation condenser.
The RCIC is compact, more casily tested, uses standard esta'glished components, represents an additiona3 make-up source of reactor water and CRD cooling, and requires smaller piping and smaller containtuent i
1 By conparison the Isolation Condenser is a historically accepted BUR system i
which consists of a minimum number of mechanical components, is easily started, and i
represents a self-contained system with minimum dependence on other systems. However j as our plants grow in size this Isolation Condenser becomes a massive component j
that is difficult to arrange in the plant and still maintain the regid gravity head that is needed for natural circulation and requites thorough design analyses i
to assure the ability to withstand the thermal stresses when placed into operation e
______---____.___-_---_-.-_-_-__-a
's
(
(
s ',
4-The Isolation Condenser has sufficient water storage to permit operation for approximately one hour without make-up and without auxiliary power.
After this, i.
make-up is required which can be obtained from condensate storage or the fire i
vater system as a back-up.
The RCIC can operate for a number of hours without the i
containment heat exchanger and auxiliary power--as shown in Figure 4 of Reference (1)
An evaluation of these considerations is naturally a matter of judgment.
As we stated in our presentation, in our judgment the RCIC is equivalent to cr exceeds the Isolation Condenser and the US AEC criteria for the Isolation Condenser.
l n
I il i
,I s
f I
I 44
- a 9
9 e
B
_