ML20215N073
| ML20215N073 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/24/1986 |
| From: | Schnell D UNION ELECTRIC CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.1, TASK-TM ULNRC-1393, NUDOCS 8611040246 | |
| Download: ML20215N073 (5) | |
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1901 Gratiot Street. St. Louis Donald F. Schnell Vice President October 24, 1986 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Denton:
ULNRC-1393 CALLAWAY PLANT DOCKET NUMBER 50-483 LICENSE NUMBER NPF-30 WIDE RANGE GAS MONITOR CONCENTRATION DISPLAY 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 inability of the General Atomic wide-range gas monitor (WRGM) to continuously display and record the measured noble gas concentration as equivalent Xe-133 concentration or microcurie per cubic centimeter of actual noble gases.
This requirement is referenced in NUREG 0737,Section II.F.1, Attachment 1, Clarification 1 (Table II.F-1).
s The Callaway Plant wide-range gas monitor assembly contains three gas detectors for. detecting radioactivity in a continuous gas sample during accident conditions.
The low-range detector uses a beta sensitive plastic scintillator and photo-multiplier tube.
The mid-range and high-range detectors are cadmium telluride (CdTe), chlorine-doped, solid state devices.
Each detector is calibrated to determine efficiency for Xe-133 and to determine the energy response curve..
The WRGM calculates noble gas concentration using the detector efficiency for Xe-133 and the gross counts per minute above the lower discriminator setting.
However, the detector gross output is dependent on the sample spectrum energy distribution which changes with time following an accident.
This changing spectrum is not accounted for in the display of the WRGM.
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4 Therefore, Union Electric requests a variance from the requirement as referenced in NUREG-0737,Section II.F.1,, Clarification 1 (Table II.F-1).
We propose to manually correct the monitor display to account for noble gas spectrum changes with time, using emergency plan procedures,
. during an emergency when there are significant changes in the sample spectrum energy distribution as compared to Xe-133.
This proposal is based on our interpretation of NUREG-0737,Section II.F.1, Attachment 1, Clarification 4b which allows for procedural-or calculational methods for correcting monitor readings for_ changes in radionuclide spectrum distribution as a function of time.
The correction factors will be based on the SNUPPS FSAR Chapter 15 accident scenarios and the monitor energy response curves.
If you have any questions regarding this response or if additional information is required, please let me know.
Very truly you s, Donald F.
Schnell BFH/plh 1
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'i STATE OF MISSOURI )
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Donald F. Schnell, of lawful age, being first duly sworn upon. cath 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.
Schnell Vice President Nuclear SUBSCRIBED and sworn to before me this A M day of d/[/ud 1986,-
[)' uAzw (1//e/p BAR!iARAd. PF AFIP #
NOTARY PUBUC, STATE OF MISSOURI 22, 1989 gy cgm AISSION EXPIRES APRIL ST. LOUIS COUNTY.
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cc:. Gerald Charnoff, Esq.
Shaw, Pittman,'Potts & Trowbridge 1800 M. Street, N.W.
Washington,'D.C.
20036 Nicholas A.-Petrick Executive Director SNUPPS' 5 Choke Cherry Road Rockville, Maryland. 20850 C. W.'Hehl-Division of Projects and-
-Resident Programs, Chief, Section lA U.S. Nuclear Regulatory Commission Region III 799 Roosevelt-Road
. Glen Ellyn, Illinois 60137
' Bruce Little Callaway -Resident Office -
U.S. Nuclear Regulatory Commission RRil Steedman, Missouri 65077 Paul O'Connor Office of Nuclear Reactor Regulation' U.S. Nuclear Regulatory Commission Mail Stop 316 7920 Norfolk Avenue Bethesda, MD 20014 i
Manager, Electric Department
' Missouri Public Service Commission P.O. Box 360 Jefferson City, MO 65102 1
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3456-0021.6 Nuclear Date DFS/ Chrono.
D.
F.
Schnell J.
E. Birk J. F. McLaughlin A.
P. Neuhalfen R. J. Schukai M. A.
Stiller S. E.
Miltenberger H. Wuertenbaecher D. W.
Capone-D.
E. Shain A.
C.
Passwater W.
R. Campbell
. endling W
R. P.
D.
E.
Shafer D.
J. Walker O. Maynard (KG&E)
H. Wuertenbaecher D. W. Capone D.
E.-Shain A. C. Passwater W.
R.
Campbell R. P. Wendling D. E.
Shafer D.
J. Walker O. Maynard (KG&E)
J.
H. Smith (Bechtel)
G56.37 (CA-4 60 )
Compliance (J.
E. Davis)
NSRB (Sandra Auston) 3456-0028(83-28)
N. G.
Slaten B.
F. Holderness 3456-0545.18.1 l
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