ML20210E317
| ML20210E317 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 01/29/1987 |
| From: | Schnell D UNION ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.1, TASK-TM ULNRC-1441, NUDOCS 8702100277 | |
| Download: ML20210E317 (4) | |
Text
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1901 Gratiot Street, St. Louis Donald F. Schnell January 29, 1987 Voce President U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555 Gentlemen:
ULNRC-1441 CALLAWAY PLANT DOCKET NUMBER 50-483 LICENSE NUMBER NPF-30 CONTAINMENT HIGH RANGE RADIATION MONITOR DETECTOR CALIBRATION CERTIFICATION During our NUREG-0737 post-implementation compliance review, we have identified an issue which requires clarification by Union Electric and your concurrence.
The issue involves the certified calibration of each General Atomic containment high range area radiation monitor (CHARM)3 for at least one point per decade of range between 1 R/hr and 10 R/hr.
This requirement is referenced in NUREG-0737,Section II.F.1, Attachment 3, Clarification 1, (Table II.F.1-3).
The Callaway Plant CHARMS use a specially designed ionization chamber.
Radiation, interacting within the ionization chamber, produces ion paira in proportion to the energy deposited within the chamber.
In the process of recombination, the ion pairs produce a current within the chamber which is linearly proportional to the energy deposited, up to dose rates exceeding 8
10 R/hr.
A prototype detector was calibrated by General Atomic over 6
the range of 1 R/hr to 10 R/hr.
Following calibration, two l
transfer sources of approximately 1 R/hr and 10 R/hr, contained in a RT-ll calibrator, were used to establish detector response for each source based on the ionization chamber gamma sensitivity (Amps /R/hr).
The RT-ll calibrator allowed General Atomic to use the transfer sources for calibration of their production models based on a standard repeatable geometry traceable to the primary calibration of the prototype detector.
I The Callaway Plant CHARMS ionization chamber assemblies were manufactured to the same specifications as the prototype l
assemblies for which primary calibration and testing was performed.
The Callaway Plant CHARMS were calibrated at the l
factory using the transfer sources.
The transfer sources were 8702100277 870129 PDR ADOCK 05000493 P
/b A0 Maihng Address: P.O. Box 149. St. Louis, MO 63166 i
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_2-placed on the Callaway Plant CHARMS and the detector response, based on the ionization chamber gamma sensitivity in Amps /R/hr, General Atomic compared the Callaway Plant CHARMS was noted.
detector response with the prototype detector response to the to insure that the Callaway Plant CHARMS same transfer sources, Based on the were within the established calibration tolerance.
the detector response is linearly proportional to the fact that energy deposited and is within established calibration tolerances for the transfer sources, detector response will also be within The CHARMS calibration tolerance for all other ranges.
calibration is therefore traceable to the primary calibration of which was directly calibrated over the required the prototype, range.
Based on the above discussion, we do not believe the additional radiation exposure pepired to calibrate each detector over the range of 1 R/hr to 10 R/hr could be considered ALARA.
Therefore, Union Electric requests your concurrence in the use of the transf er sources for calibration-of the Callaway Plant CHARMS Section to meet the requirements as referenced in NUREG-0737, II.F.1, Attachment 3, Clarification 1, (Table II.F.1-3).
If you have any questions regarding this request or if additional information is required, please let me know.
Very truly yours, Donald F. Schnell BFH/ mat
A A
STATE OF MISSOURI S-S CITY OF ST. LOUIS )
Donald F.
Schnell, of lawful age, being first duly sworn.
upon oath says that he is Vice President-Nuclear and an officer of Union Electric Company; that he has read the foregoing document and knows the content thereof; that he has executed the same for and on behalf of said company with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.
By Donald F.'ScWnell
-Vice President Nuclear SUBSCRIBED and sworn to before me this d'/
day of
, 1987 JdAA'.
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V~
DARBARA J. PFAFF NOTARY PUBUC, STATE OF MISSOURI MY COMMISSION EXPIRES APRIL 22, 1989 ST. LOUIS COUNTY
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J cc:. Gerald Charnoff,.Esq.
Shaw, Pittman, Potts.& Trowbridge 1800 M.. Street, N.W.
-- Washington,. D.C.
20036' Nicholas ( A.
Petrick Executive Director
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SNUPPS 5 Choke Cherry Road Rockville,' Maryland ~20850 W. L.
Forney.
Division of Projects and Resident Programs, Chief, Section lA U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn,. Illinois 60137 i
Bruce Little-l~
Callaway Resident Office i
U.S.-Nuclear Regulatory Commission RR#1.
Steedman, Missouri. 65077 Paul O'Connor (2)
Office of Nuclear Reactor Regulation r
U.S.. Nuclear Regulatory Commission i
Mail Stop'316' 7920 Norfolk Avenue Bethesda,'MD- '20014-
~ Manager,' Electric Department Missouri Public Service Commission i
i P.O'.
Box.360
{
Jefferson. City,;MO 65102 t
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