ML20244D552
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[ k NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 5, j
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MEMORW"# FOR: Carl J. Paperiello, Chief j Emergency Preparedness and Radiological Protection Branch DRSS, RIII FROM: Robert L. Baer, Chief i' Engineering and Generic Communications Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
SUBJECT:
EFFLUENT RADIATION MONITOR CALIBRATIONS l
This memorandum responds to your June 3,1985 memorandum requesting our review and evaluatinn of the adequacy of one-point calibrations for scintillation and GM detector effluent radiation monitors. ,We have discussed this issue with j
METB, NRR and they concur with our reading of the technical specification requirements.
After a review of the existing Regulatory Guides (1.21 and 4.15) and ANSI l industry standards (ANSI N13.10) which establish relevant guidance, we do not believe these documents suggest multi-point calibrations are necessary beyond i the initial preoperational acceptance testing for these effluent monitoring i
systems (sometimes referred to as " primary calbration", as used in ANSI l N13.10-1974, section 5.4.10). Section 5.4.10 further states that tie primary l ... calibration shall be related to a secondary source or method which will be used for periodic in-plant recalibrationsu" We read this as suggesting that roetine re-calibrations can be less rigorous than the one-time, initial primary l
c a l i bra tio~n. These periodic re-calibrations then should be viewed as ensuring the detection system has remained stable over time. Therefore, " single point" l calibrations using secondary sources (e.g., solid ) should be considered i adequate to meet the requirements of standard technical specifications where detectors are inherently linear.
i Assuming a licensee calibrates at a single point, we believe the licensee si.ould consider selecting that point at or near an alarm or action level.
Routinely calibrating near an al6rm point, coupled with the ongoing comparison of real-time monitor readings against laboratory analysis of periodic grab
! samples containing " normal" levels of radioactive effluents, seems to provide l an adequate assurance of proper monitoring operability. However, calibration i near an alarm point or action level is neither a requirement nor a position in the relevent guides or standard.
Contact:
Jim Wigginton '
(301)492-4967 i
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Carl J. Paperiello Region V provided in saturation problems (put pertinent to this discussion which focused on detector copies sent to all Regions, Junememorandum 12,1985). from Wenslawski to Baer and Paperiello with mance problemstesting with theby a Region plants' effluentVmonitors, licensee to determine a the potenti l fThe memoran or saturation M. tubes were most seriously affected Nal/PH tubes lessIn general, the licensee scintillator /PM tubes least affected. affected and plastic e
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Given the overall upgrade in effluent monitor ng as a res lt requirements, we believe each licensee shouldu already be abl of the NUREG-0737 adequate effluent monitoring capability at high e toranges needed duri demonstrate to provide release meaningful stream. information relative to a monit ng accidents f need not be verified by each licensee as primaryranges calibratiThe evide guidance provided by NRR for calibration of NUREG-0737 ons since previousmonitors acceptable 16, 1982). alternatives (memorandum from Eisenhut suggests other to Regional Di }
rectors, August lation moniters, given the monitors primary ca libration, n inherer,t adequate for scintil-stabilitIn summ tubes is acceptable, given that the radiation' monitThe use of single point'
} pathway) below the radiation level where o another monitored the initialtrip jfunct to show appreciable saturation losses. I To ensure control room opere ntsprimary calibration i be procedures should clearly define, emergenc these sunderstand GM effluent m event of a steam generator tube failure,ystem limitations. y implementingFor ;example caution notes) probable response as theleakage).
detector invalid readings from a SJAE GM monitthe procedure saturates, in response to a primary-secondary or (down scale worsening 4 If you have any further questions, please contact me or Jim Wigginton.
Robert L. Baer, Chief Engineering and Generic '
Communications Branch Division of Emergency Preparedness and Engineering Response DISTRIBUTION Office of Inspection and Enforcement kHVollmer, TE JGPartlow, IE ELJordan, IE BKGrimes, IE SAschwartz, IE I DAllison, IE GGZech, IE RLBaer IE DMCollins, Pl! JWigginton, IE JAxelrad, IE RGreger, Rlli EWBrach, E00 WGamill, NRR REHall, RIV RRBellamy, R1 HLThompson, NRR FAWenslawski, RV LJCunningham IE LCobb, IE TDunning, NRR DEPfR R/F JBuchanan, IE FCongel, NRR EGCB R/F 005 JWigginton R/F neb JWigginton bb:lE DE 11/ /85 0Allison RLBaer 11/ /85 11/p/85 I
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Carl J. Paperiello i Region V provided input pertinent to this discussion which focused on detector E l saturation problems (memorandum from Wenslawski to Baer and Paperiello with l 9
copies sent to all Regions, June 12,1985). The memorandum documents perfor- i mance testing by a Region V licensee to determine the potential for saturation i problems with the plants' effluent monitors. In general, the licensee found G. l M. tubes were most seriously affected, Nal/PM tubes less affected and plastic 1 I
scintillator /PM tubes least affected, i
Given the overall upgrade in effluent monitoring as a result of the NUREG-0737 requirements, we believe each licensee should already be able to demonstrate ,
adequate effluent monitoring capability at high ranges needed during accidents to provide meaningful information relative to a monitored " accident-type" release stream. The evidence demonstrating monitor operability at high ranges need rot be verified by each licensee as primary calibrations since previous I guidance provided by NRR for calibration of NUREG-0737 monitors suggests other ]
acceptable alternatives (memorandum from Eisenhut to Regional Directors, August i 16, 1982), j l
in sumary, we find " single-po9nt", routine calibrations adequate for scintil- j lation moniters, given the monitors inherent stability and a thorough initial primary calibration. The use of single point', routine calibrations for GM -
tubes is acceptable, given that the radiation monitor initiates a fail-safe I
g l trip function (isolates, or re-directs the effluent to another monitored a pathway) below the radiation level where the initial primary calibration began :
to show appreciable saturation losses. To ensure control room operators i !
understand GM effluent monitor system limitations, emergency implementing ; {
procedures should clearly define these system limitations. For example, in the l event of a steam generator tube failure, the procedures should highlight (e.g.,
caution notes) probable invalid readings from a SJAE GM monitor (down scale 4 i response as the detector saturates, in response to a worsening primary-secondary leakage). 1 If you have any further questions, please contact me or Jim Wigginton. l Robert L. Baer, Chief :
Engineering and Generic :
Communications Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
- i DISTRIBUTION RHvollmer, IE ELJordan. IE SASchwartz, IE RLSaer, IE JGPartlow, IE BKGrimes, IE GGZech, IE JAxelrad, IE l DAllison, IE JWigginton, IE EWBrach, E00 RRBellamy, R1 ; l DMCoiiins, P!! RGreger, Rll! REHall, RIV FAWenslawski, RV WGammill, NRR HLThompson, NRR T0unning, NRR FCongel, NRR l LJCunningham, IE LCobb, IE JBuchanan, IE DCS DEPER R/F EGCB R/F JWigginton R/F 1
- 5ee previous concurrences ,
JWigginton DAllison RLBaer 11/ /85 11/ /85 11/p/85 :
l
\ -
Carl J. Paperiello Region V provided input pertinent to this discussion which focused on detector saturation problems (copies sent to all Regions, Wenslawski - Baer/Paperiello, June 12, 1985). Given the overall upgrade in effluent monitoring as a result of the NUREG-0737 requirements, we believe each licensee should already be able to demonstrate adequate effluent monitoring capability at high ranges needed during accident to provide meaningful information relative to a monitored
" accident-type" release stream. The evidence demonstrating monitor operability at high ranges need not be verified by each licensee, as primary calibrations since previous guidance provided by NRR for calibration of NUREG-0737 monitors suggest other acceptable alternatives (Eisenhut - Regional Directors, August 16, 1932 memorandum).
In sumary, we find " single-point", routine calibrations adquate for scintil-lation monitors, given the monitors inherent stability and a thorough initial primary calibration. The use of single point, routine calibrations for GM tubes is acceptable, given that the radiation monitor initiates a fail-safe trip function (isolates, or re-directs the effluent to another monitored pathway) below the radiation level where the initial primary calibration began to show appreci.ble saturation losses. .To ensure control room operators t
understand GM effluent monitor system limitations emergency implementing procedures should clearly define these system limitations. For example, on the steam generator tube failure, the procedures should highlight (e.g., caution notes) probable invalid readings from a!SJAE GM monitor (down scale response as the detector saturates, in response to 5 Worsening primary-secondary leakage).
Ifyouhaveanyfurtherquestions,pleakecontactmeorJimWigginton. 1 i'
Robert L. Baer, Chief Engineering and Generic l Communications Branch Division of Emergency Preparedness and Engineering Response Offi'ce of Inspection and Enforcement t
l DISTRIBUTION I
RHVollmer, IE ELJordan, IE 1 SASchwartz, IE RLBaer, IE <
JGPartlow, IE BKGrimes, IE t GGZech, IE JAxelrad, IE DAllison, IE JWigginton, IE EWBrach, EDO RRBellamy, RIl DMCollins, Ri! REHall, RI /f. dIyj A'.22E' FAWenslawski, RV WGamill, NR HLThompson, NRR TDunning, NRR.
FCongel, NRR LJCunningham,41E LCobb, IE JBuchanan, IE.
1 DCS DEPER R/F .
EGCB R/F JWigginton R/F DEp r DE )ER:IE - DEPER:lE JWi inton DAllison RLBaer 11/ /85 11/p/85 1
11/ /85 L - - - - - _ - - - - - - _ - _ - - _ - - - - - - - - - - - - - - - - - - -__