ML20155E230
| ML20155E230 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/05/1988 |
| From: | Schnell D UNION ELECTRIC CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737 ULNRC-1840, NUDOCS 8810120192 | |
| Download: ML20155E230 (6) | |
Text
1901 Gr&d Stru t pxt O'!c Eu !43 St lwi t.kvu'r E3166 314 554 2652 Union Euienuc o#m!!?'~"..
October 5, 1988 U.S. Nuclear Regulatory Commission Attn Document Control Desk Mail Station P1-137 Washington, D.C.
20555 ULNRC-18 4 0 Gentlemen:
DOCKET NUMBER 50-483 CALLAWAY PLANT WIDE RANGE GAS MONITOR CONCENTRATION DISPLAY Ref.:
1)
ULNRC-1393, dated October 24, 1986 2)
T. W. Alexion letter to D.
F.
- Schnell, dated August 15, 1988 Reference 1 requested a variance from the requirement as described in NUREG 0737,Section II.F.1, Attachment 1, Clarification 1.
Reference 2 requested additional information concerning this variance request.
Attached please find the information requested by Reference 2.
If you have any questions concerning this information, please contact me.
Very truly yours, n
/
i Donald F.
Schnell i
WEK/keb Attachment l
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cc:
Gerald Charnoff, Esq.
Shaw, Pittman, Potts & Trowbridge 2300 N.
Street, N.W.
Washington, D.C.
20037 Dr. J. O. Cermak CFA, Inc.
4 Professional Drive (Suite 110)
Gaithersburg, MD 20879 R. C.
Knop Chief, Reactor Project Branch 1 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 Steedraan, Missouri 65077 Tom Alexion (2)
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 316 7920 Norfolk Avenue Bethesda, MD 20014 Manager, Electric Department Missouri Public Service Commission P.O. Box 360 l
Jefferson City, MO 65102 U.S.
Nuclear Regulatory Commission ATTN:
Document Control Desk i
Washington, D.C.
20555 l
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q Attachment to ult 1RC-1840 Page 1 of 4 Item 1.
Provide a block diagram of the General Atomic Wide Range Gas Monitor (WRGM).
Response: A block diagram of the Callaway Plant General Atomic Wide Range Gas Monitor is shown in Eiqure 1.
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Item 2.
Demonstrate how the information from the WRGM RM-80 microprocessor and junction box uses the signal from the stack velocity system to maintain flow control and for calculating effluent release rate (microcuries per second).
Summarize how these curves are developed.
Please use recent data to demonstrate how the release rates are calculated from the stacks.
Response: Isokinetic Flow Control When the sample pump in on in either or both sample lines, the sample flow rate io controlled isokinetically by the Wide Range Gas Monitor (WRGM)
RM-80 microprocessor as described below, except when a purge is in progress.
A mass flow meter in each sample line sendn the WRGM RM-80 an analog signal that is proportional to the flow rate in the sample line.
Also, the unit vent flow measurement systen provides the WROM RM-80 with an analog signal that is linerally proportional to process flow rate in the unit vent.
Each signal is applied to a separate analog to digital converter (ADC) contained in the WRGM RM-80.
The ADC outputs are converted into a flow rate (SCFM) by multiplying by an ADC to SCFM flow conversion factor for that flow path contained in the WRGM RM-80.
For isokinetic flow control, the isokinetic flow control ratio setpoint in the WRGM RM-80 is multiplied by the process flow rate to obtain the desired sample flow rate.
This calculated sample flow rate is compared to the semple flow rate and the flow control value opening is varied by the WRGM RM-80, as required, to maintain the proper nample flow rate for isokinetic sampling.
Effluent _Roleas_o R_ ate A gross effluent release ratn for all isotopes in the gas sample is calculated by the WRCM RM-80.
This release rate in uCi/sec in the product of activity fl w rate (SCFM) and a concentration in uCi/cc, process 3 conversion factor 4.72E+02 cc/ft / min /sec.
The WRGM RM-80 selects the most accurate of the three detectors for the effluent release activity.
Detector selection is performed by the WPGM RM-80 ba*ed on mid and high range detector accepted range point setpoints.
The proconn flow rate in derived from the unit vent flow measurement system an doncribed above.
Page 2 of 4
The effluent release rate calculated by the WRGM is not used to calculate normal effluent releases to the environment from the Callaway Plant.
Samples are taken per Callaway Plant Technical Specifications and analyzed for individual isotope activities.
These activities are used in our effluent release program as described in the offsite Dose Calculation Manual, 1
Page 3 of 4
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Item 3:
Please verify:
that noble gaa effluent mogitors with an upper a.
range capacity of up to 10 uCi/cc.(Xe-133) are j
installed, 1
f b.
that the rangg extends from normal conditions i
(ALARA) to 10 uCi/cc (Xe-133),
i c.
that the system provides continuous capability during and following and accident, d.
that a design description of the system identifying the specifications in accordance with Table II.F.1-1 is available, t
e.
that procedures and calculational methods are I
established, f.
that instrument rarges will overlap to cover the i
entire range of effluents, from normal through i
accident conditions.
Response
At the request of NRC Region III, Union Electric has j
performed a line by line compliance review of NUREG 0737 Section II.B.3 and II.F.1 (Attachments 1,2, and f
3).
In this review we verified that each of the above 4
requirements is satisfied.
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