ML20117P401
| ML20117P401 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/30/1985 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| 1157, NUDOCS 8506060078 | |
| Download: ML20117P401 (3) | |
Text
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' Docket No. 50-346 g
' License No. NPF-3 RCHARD P. CROUSE Serial-No. 1157 vc=****"
w May 30,'1985-Director of' Nuclear Reactor Regulation Attention:
Mr.. John F. Stolz Operating Reactor Branch No. 4 Division of Licensing United States Nuclear Regulatory Commission Washington, D..C.
20555
Dear Mr. Stolz:
This' letter is being submitted in regards to an inspection conducted by Region III on November 26-30, 1984 (Log'No. 1-1093, Inspection Report 84-30).. Toledo Edison committed, per Open Item 346/84-30-02, to contact.
the office of Nuclear Reactor Regulation (NRR) regarding the station vent stack monitor sample stream. The Inspection Report'open item states:
During a previous inspection, licensee representatives stated the sample stream drawn from the stack into the monitor is ex-hausted outside.the turbine building. This matter was referred to the Meteorological and Effluents Treatment Branch of NRR for review in accordance with Standard Review Plan (SRP) 11.5.
NRR's evaluation stated this sampling pathway is not consistent with Acceptance Criteria 11.2.c of SRP 11.5, which indicates sample streams are to be directed back to the point of origin or to an acceptable radwaste system. This matter was discussed with the Station Superintendent who agreed to contact NRR regarding the sample stream return by June 1,1985.
The design of the station vent stack radiation monitor exhaust was based on'the following:
1.
Standard Review Plan (SRP) 11.5, Process and Effluent Radiological Monitoring Instrumentation and Sampling Systems, pertains to the monitoring of plant liquid and gaseous process streams and effluent release points.
8506060078 850530 1
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PDR ADOCK 05000346 O
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THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO. OHIO 43652 L
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Dock:t No.f50-346 E
-License No. NPF.
Serial No.'1157 May 30,:1985-Page 2-SRP.11.5 Sections II.1, 11.3, and II.4 are applicable to the' station vent. stack monitors <as well as other.
' gaseous' release path monitors. The station vent moni-
-tor measures,the radioactivity of the air stream in
~
the' station vent as it is released to the environment.
~
The' location of the vent monitor' exhaust to the environ-
~ ment is not significant from an activity release stand-point because all radioactivity.in the monitored effluent stream-(station vent stack) is directly.~ released to the atmosphere.-
2..
Sample flow rate is approximately 3.0 SCFM for each of
'the two vent monitors..This compares to a vent stack flow rate (release rate) of typically 120,000 SCFM. The difference in release points is.in elevation only as the station vent stack exhausts 250 feet Above Ground Level
'(AGL) and the monitor exhausts 45 feet AGL.
1 Additional filtering takes place within the radiation moni-tors as particulate and charcoal filters are part of-the sample path. Attachment I represents the vent ~ stack sample
' stream flow path and release points.
3.
Design'of.the station vent stack monitor with tubing de-livering the exhaust back.to the vent. (greater than 125 feet of tubing) would not'only.-be unnecessary, but would increase the back pressure on the sample pump, reducing the sample inlet. flow rate.
The reduction in sample. inlet flow-rate would increase sample line'plateout of particulates, providing a.less representative sample. The present monitor exhaust de-sign (short exhaust line) minimizes sample pump back pressure and the resulting sample line plateout.
Acceptance criteria-II.2.c of SRP 11.5 is not applicable to the station vent. stack monitor because the monitored sample stream.is an effluent release pathway and not.a radwaste process stream.' The present sample
. stream configuration is ac'ceptable from a radioactivity release stand-1 point and obtains a sample more representative of the vent stack activity than a design that routed the monitors' exhaust back to the station vent.
IVery truly yours,
.:=
- RPC:SGW:CMK:nif encl.
cc:.DB-l'NRC Resident Inspector
-ATTACHMENT 1 2nocxot No.30-346 Lican e.No. NPF-3 i
-S# rial No. 1157
'May 30 1985 yg c y o s
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(TYR OF TWO)
STATION EXHAUST el20,000 SCFM A
A VENT
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MONITOR EXHAUST MONITOR
= 3 SCFM g l
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N V
V w v A w.w ev a w m, s s w 3,
+ w e + * ~ ~ a - ~ - m *'L *'N' M A' P = PARTICULATE FILTER C = CHARCOAL FILTER
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