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< 0ocket:F11e 40-2 gy og g3 METB Docket Ftie MElB Readtng File Docket No. 50-244 ADRP Reading Flie HEHORANDUM FOR: Frank J. Miraglia, Assistant Director for Safety Assessment. DL FROM:
Daniel R. Muller, Assistant Director for Radiation Protection StBJECT:
R. E. GlHNA NUCLEAR POWER PLANT EFFLUENT RADIOACTIVITY MONITORING SYSTEM ALARM SETPOINTS AND SURVEILLANCE REQUIREMENTS ('fAC NO. 49342)
In accordance with the subject TAC dated February 15, 1983, the Meteorology and Effluent Treatnent Branch (MElB) has completed the revim and evaluation of the alarm setpoints and operational surveillance requirenents for effluent radioactivity nonitoring systems contained in the report (Item Ho. 3) titled " Responses to Long Tem Connitments in Ginna Stean Generator Tube Rupture Incident Restart Safety i
Evaluation Report" submitted by Rochester Gas and Electric Corporation and dated November 22, 1982.
During our review, we visited Ginna Station and observed the ef fluent radioactivity nonitoring systems in operation, and discussed with the licensee the basis for the monitor alam setpoints, the monitor operational surveillance requirenents and the plant procedures for operating and calibrating the monitoring systems. Based on our review of the report and discussion with the licensee, we find that the corrective actions taken by the licensee, subsequent to the incident, are n; cept-able-and that monitoring systens in operation meet the requirenents specithd iri NUREG-0737 (Item II.F.1, Attachment 1) and Standard Review Plan Section 11.5.
Our safety evaluation of effluent radioactivity monitoring systems is enclosed for inclusion in the supplemental issue to Ginna Restart SER (NUREG-0916) on irple-mentation of long tem cemitment items.
This review was perfomed by Jay Lee (x27637), and any questions may be directed to him.
Original signed by Daniel R. Muller Daniel R. Iblier, Assistant Director for Radiation Protection Division of Systems Integration
Enclosure:
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4 SAFETY EVALUATION EFFLUENT RADI0 ACTIVITY MONITORING SYSTEM ALARM SETPOINTS AND OPERABILITY SURVEILLANCE RE0VIRDiENTS GINHA STEAM GENERATOR TUBE RUPTURE INCINDENT RESTART SER LONG TEW COMMITHENTS
1.0 INTRODUCTION
The unmonitored release pathway for airborne radioactive materials from the R. E. Ginna Nuclear Power Plant to the environment during the steam generator tube rupture incident involved two ef fluent radioactivity monitoring systems:
(1) Tra main steam radiation monitoring system, which is designe< to detect, indicate, record, alam, and quantify radioactive materisis released from the steam generator PORVs and safety valves; and (2) Tr.e air ejector radiation nonitoring system, which is designed to detect, indicate, record, alam, and quantify releases of radioactive materials in noncondensible gases l' rom the secondary system steam via the air
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ejector and turbine gland seal exhaust.
During the incident, a high radiation alam setting for main steam radiation monitoring system was not reached and this prevented the system from activating the recorders. Later attempts to retrieve the data from the monitoring data processing system also failed due to a malfunction of the monitor during the incident. The licensee stated in his incident evaluation report that the monitor malfunction is believed to have been due to a small smudge of dirt or residue which caused electrical leakage on a printed circuit board. In addi-tion, the steam generator PORY and safety valve positira monitoring function failed during the incident. The licensee states that inadequate adjustnent DESIGP:ATED 03ICI RI, Cett12ses sg ht' G/g' l c
e 4 1.0 of the new actuator rods installed on the s&fety valves, and open sliding links on terminal blocks in the relay room for the PORV, caused the inoper-ability of the valve position monitor.
i For the air ejector radiation monitoring system, the SPING R-15A low range monitor actuated a high radiation alarm during the incident, ar.d was suspected of having been of f scale af ter attivating the SP!NG R-15A middle range nonitor.
However, while the low range monitor was of f scale, no 10-minute average radiation readouts or recordings were obtained from the SPING R-15A middle range monitor because its high alarm setpoint was not reached and this pre-vented the system fron activating the recorder.
Subsequent to the incident, the licensee made corrections on alann setpoints f.gr bnth main steam and air ejector effluent radiatior, monitors.
Therefore, the staff had no safety concerns prior to Ginna restart; however, the staff stated in the Ginna Restart SER (NUREG-0916) that we will review und evaluate the licensee's corrective actions for both main steam and air ejector radia-tion monitoring systems within three months subsequent to the plant restart.
2.0 EVALUATION 2.1 Main Steam Radiation Monitoring System In our evaluation, we have reviewed (1) the adequacy and basis of the monitor high alarm setpoints, (2) the monitor operability surveillance program,-(3) the monitor ranges and sensitivity with respect to their capability to cover acci-dent conditions, and (4) procedures or calculative methods to be used for converting monitor readings -to release rate per unit time.
, 2.1 Subsequent to the incident, the alarm setpoint has been icwered to 0.1 mR/hr f rca 1.0 mR/hr. The alam setpoint of 0.1 mR/hr is just above ambient back-ground radiation levels to provide maximum sensitivity while preventing spurious alams.
The monitoring system consists of a collimated energy-compensated Geiger.
Mueller detector (Eberline Model SA-11) on each main steam line, and the 0.1 mR/hr alarm setpoint is calibrated to a radioactivity concentration of 0.01 uCi/cc (Xe-133) in main steam. The monitnr has a maimum range 3
4 of 10 uCi/cc (10 mR/hr) which is consistent with the requirements specified in NUREG-0737 (Item 11.F.1, Attachment 1). The monitor is capable of functioning both during and following design-bases accident.
The system indicates radioactivity readouts locally, and in the main control room and Technical Suoport Center (TSC).
An audible alarm sounds iocally and in the main control room. The monitor system c'an be programmed to automatically print radioactivity concentrations in main steam for the last 24 hourly averages once a day and the last 23 ten minute averages every four hours.
In the demand mode, the last 24 daily averages, the last 24 hourly averages, ar.d last 23 ten minute averages, and the current value for radioactivity concentra-tion (uCi/cc) and/or ielease rate (uCi/sec) can be printed.
The system is functionally tested quarterly in accordance with Ginna Test Procedure TP-17.3, Rev.10, dated September 9,1982. Activation of recorders for radiation level, as well as safety valve and atmospheric steam dump valve 4
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l 2.1 positions, are verified on receipt of a high alarm signal by the portable source.
i subsequent to the incident, the licensee has (1) lowered alann setpoint, (2) inspected and replaced affected monitor printed circuit boards which caused monitor malfunction, (3) readjusted actuator rods installed on the safety valves which caused the inoperability of the valve position monitoring, and (4) im-plemented operational surveillance test procedures. Based on our observation of the monitors in operation, our review of the licensee's calibration and test procedures, consistency with the requirements specified in NUREG-0737, L,
and corrective actions taken by the licensee subsequent to the incident, we find the main steam radiation vanitoring system to be acceptable.
2.2 Air Ejector Radiation Monitoring System In our evaluation, we have reviewed (1) the adequacy of readouts and recording capability, (2) the adequacy of all monitor alarm setpoints, (3) the monitor operabilty surveillance program, (4) the procedures or calculative methods to be used for converting the iaonitor readouts to release rate per unit time, h
and (5) the need to provide a continuous and instantaneous indicator-recorder (strip chart), in addition to the 10-minute average readouts in the computer to indicata release rate of airborne radioactive materials from the air ejector exhaust to the environment.
The system consists of two.adiation monitors: the R-15 monitor and the SPING R-15A monitor. The R-15 monitor is a sodium iodine detector (Victoreen Model No. 843-03) mounted on the outside of the 8-inch diamenter exhaust pipe and
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. 2 2.2 has a range of 10 to 10 cpm gamma radiation (equivalent to O to 0.1 uCi/cc).
The response of this monitor is recorded on a strip chart and also fed to a computer. During the incident, the strip chart recorder for the R-15 monitor went of f scale.
The SPING R-15A monitor (Eberline Model SPING-4) is a high range monitor and has three sensitivity ranges with a separate detector for each range.
Range _
Detector Range,uCi/cc Alarm Setpoi.,t, uCi/cc t.ow beta scintillation 10-6 to 0.05 2 x 10
-5 Middle compensated GM tube 2.8 x 10 to 10 2 x 10' High compensated GM tube 0.03 to 10 2
Subsequent to the incident, the high range monitor (R-15A) alert and high alarms for low, middle and high range channels nave been reset to correspond to a percentage of the plant release rate limit and have been specified in Ginna Operating Procedure P-9, Rev. 33, ' Radiation Monitoring System dated January 18, 1983.
Setpoints are preset so that an alarm is activated by a higher range monitor before tne lower range monitor goes of fscale. In addi-tion, the lowest range monitor of R-15A will alarm before R-15 reaches full sc al e.
The high range monitor (R-15A) readout. recording and alam capabilities and programmabilities are identical to those of the main steam radiation monitors.
in addition, the monitor readouts are automatically printed every 10 minutes in the control room and TCC, if any R-15A channel reaches a high alam condition 4
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6-2.2 while the alann condition exists. Both nonitor operability surveillance pro-grams require (1) daily channel check, (2) monthly source check, (3) quarterly functional test, and (4) annual channel calibration.
The moni tor operating procedures and calculative methods to be used for con-verting the monitor readouts to release rates are described in Ginna Operating Procedure PC-?3.5, Rev. 1, da ted March 2,1983.
Since nei ther instantaneous 3
meteorology parameters nor release rates are used for accident dose calcula-tions, a strip chart recorder, in addition to the 10 minute average readouts in the computer, is not needed for the high range monitor.
Based on our observation of the monitors in operation; our review of the licensee 's operational, calibration, and test procedures; consistency with the requirements specified in NUREG-0737 and Standard Review Plan Section 11.5;
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and corrective actions taken by the licensee subsequent to the incident, we find the air ejector radiation monitors (R.15 a'd R-15A) to be acceptable.
3.0 CONCLUSION
S Based on the foregoing evaluation, we conclude that the corrective actions taken by the licensee subsequent to the steam generator tube rupture incident are adequate and, therefore, we find that the main steam and air ejector radiation monitoring systems in operation are acceptable.
The basis for acceptance in our review has been (1) conformance of the systems to the
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3.0 requirements specified in NUREG-0737 (Item II.F.1, Attachment 1) and Standard Review Plan Section 11.5, (2) our observation of the monitoring systems in operation, (3) our satisf actory review of Ginna operating and calibration procedures for the monitoring systems, and (t.) adequate monitor alann setpoints anc satisfactory operational surveillance requirements.
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