ML20008F621
| ML20008F621 | |
| Person / Time | |
|---|---|
| Site: | Allens Creek File:Houston Lighting and Power Company icon.png |
| Issue date: | 04/20/1981 |
| From: | Brooks W Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20008F600 | List: |
| References | |
| NUDOCS 8104210395 | |
| Download: ML20008F621 (4) | |
Text
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,ou 9 U'ilTED $!;TES OF A:1 ERICA IJUCLEAR REGULATOEY C0:11 55I9 ;
BEFORE T.4E AT0' IC SAFETY A:0 LICE!;51!13 B3 RD In tne ;1atter of
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riDd5TO'i LIGHTI!13 & P0..'ER C01PA'iY
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Docket 'b.
50-456
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(Allens Creek lluclear Generating
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Station, Unit 1)
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f4RC STAFF SUPPLE l1EilTAL Thil'10:;Y OF
'! ALTER L. BR00':S RELATIVE TO THE LPCI COLD SL'J3
[Doherty Contention 7]
Q.
Please state your nane and position W1th the f;RC.
A.
- 1y nane is llaltar L. 3 rooks.
I an enployed by the U.S. :Juclear Regulatory Colnission as a Senior Reactor Physicist in the Core Perfoman:e Branch.
Q.
Have you prepared a statenent of educational and professional qualifications?
A.
Yes.
It is attached to this testinony.
Q.
ilhat is the purpose of your testinony?
A.
The purpose of ay testinony is to respond to Doherty Contention 7 which alleges as follows:
The design of obtaining Low Pressure Coolant Injection (LPCI) core spray water from the suppression pool following exhaustion of the condensate storage tank during Loss of Coolant Accident (LOCA), Reactivity In',ertion Accident (RI A),
or Transient '.Jitho;t Scran (AT!!S) is an unnecessarily high risk to Petitioner's safety and environnent interests because suppression pool water is colder than reactor coolant; hence when sprayed in the core it will increase core rcactivity causing high 81042103f&
4v
y P00R ORIGINAL teoperatJre and increase possibility or actuality of fuel nelt and fnciation of a critical nass.
4 In the event that water fran the suppression pool is injected ir.to the care af ter a scrar, uill it result in positive raictivity insertion?
A.
Only if tue water in tne suppression pool is at a louer telperature than that in the reactor.
In that event, because the injection of cold water into the core increases noderator density, the reactivity will increase.
Q.
Will the positive reactivity insertion overcone the shutdoun reactivity of t1e inserteri contral roJs?
A.
No.
General Design Criterion 25 requires tnat a reactivity contr01 systel capable of holding the reactor core subtritical under cold conditions be provided.
In boiling water reactors such as ACNGS, the contral rods are designed to be caiable of naintaining the reactor subcritical by at least a one percent reactivity change at 20 degrees Celsius (63 degrees Fahrenheit) when the nost reactive control rod is held out of the core.
Q.
Hoa do you know that ACNGS neets General Design Criterion 26?
A.
The nethods used to calculate the reactivity of cold, xenon free cores have been conpared to neasurenents in nany boiling water reactors.
A sunnary of these conparisons is given in General Electric licensing i
topical report NEC0-20945, " BUR Sinulator flethods Verification" which has i
been reviewed and approved b/ the Staff.
These conparisons show that cold reactivities are calculated to within about 0.3 percent reactivity change.
In addition, the cold critical rod configuration is neasured for l
l l
L
P00R ORIGINhi.
Cnh reactur during startup testing for each cycle.
Tnis configuration is coapared to the predicted value and the two values are required by tunnical Specifications to be.Jithin ane percent reactivity change of e3ch other.
Further, the shutdown nargir is required by Technical Spec"Tications to be greater than a certain value which is cycle dependent but which is always greater than 0.38 percent reactivity.
Q.
You have quoted the shutdoun nargin for 63 degrees Fanrenheit.
What happens if tnis tenperature were to be lower?
A.
Tne shutdown nargin aculd be reduced by about one-tento of one percent reactivity change for a 30-degree reduction in tenparature. Any further reduction would begin to increase the shutdovn nargin.
Q.
Wh*t ds yo; conclude?
A.
I conclude, based on the foregoing discusion that injection of coid aater fron the suppression pool cannot lead to criticality in the AC';GS reactor af ter it has stranned.
There is, therefore, no possibility of fuel nelt.
G.
Inis contention also expresses a concern regarding tne 'njection of cold water fron the suppression pool after an ATWS. Have you adcressed tais concern?
A.
do.
The operation of reactor systems and the condition of the reactor core following an ATUS will be addressed by the IRC Staff when it responds to the ATAS issues.
i STATEMENT OF PROFESSIONAL QUALIFICAfl0NS OF Walter *.. Brooks Present Employment - I joined the Nuclear Regulatory Conaission (then the Atonic Energy Connission) in September of 1914.
I an a nenber of the Core l
Perfornance Branch of the Division of Systems Safety with the title of Senior Reactor Physicist.
In my position, I have prinary review responsibility for core physics aspects of licensing submittals and, upon request fron the Auxiliary Systens Branch, the criticality aspect of fuel storage facilities.
Education - B.A. in Mathematics, Lincoln Memorial University, 1943 M.S. in Physics, Nea York University,1950 Pn.D. in Physics, New York University, 1953 Previous Employnent - Gulf-United Nuclear Corporation and its predecessor conpanies, United Nuclear Corporation, Nuclear Development Corporation of America, and Nuclear Developnent Associates. My duties, during my employnent fron 1953 to 1974, included the following:
Performance and evaluation of critical experiments for D.,0 noderated lattices Performance and evaluat. ion of light water moderated lattice critical experinents Performance and evaluation of fast reactor critical i
experiments Developnent of calculation nethods for D,0 noderated reactors Verification and nodification of a nodal calculation I
technique for light water reactors.
Publications Nunerous reports on the results of critical experiments and methods development.
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