IR 05000263/1977005
| ML20024G329 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 05/02/1977 |
| From: | Fisher W, Greger L, Miller D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20024G322 | List: |
| References | |
| 50-263-77-05, 50-263-77-5, NUDOCS 9102110306 | |
| Download: ML20024G329 (13) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
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REGION III
Report of Operational Radwaste Inspection IE Inspeccion Report No. 050-263/77-05 Licensee: Northern States Power Company 414 Nicollet Mall Minneapolis, MN 55401 Monticello Nuclear Operatinr, Plant License No. DPR-22 Category :
C Monticello, MN
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Type of Licensee:
BWR 1670 MWt Type of Inspection:
Routine, Unannounced Dates of Inspection:
March 29-31, 1977 L 4f Principal Inspector:
L. R. Greger,
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Accompanying Inspector:
h. E. Miller f 7/77 (Da't e)
Other Accompanying Personnel:
None Reviewed By:
W. L. Fisher, Chief
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Fuel Facility Projects and (ba t'e)
Radiation Support Section
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9102110306 770503
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SUMMARY OF FINDINGS
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Inspection Summary Inspection on March 29-31, (77-05):
Review of radioactive effluent records and procedures, process monitor calibrations, reactor coolant radiochemistry, and standby gas treatment system operation.
Two items of noncompliance concerning operability of the air ejector monitors and calibration of the reactor building vent monitor were identified.
Enforcement Items The following items of noncompliance were identified during the inspection:
Infractions
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1.
Contrary to Technical Specification B-2.4.4.d, the reactor building noble gas effluent monitor was not adequately calibrated quarterly during 1976.
(Paragraph 7.c Report Details)
2.
Contrary to Technical Specification 3.2.D.1, both steam jet air ejector off-gas radfation monitors were inoperable for approxi-mately fourteen hours during power operation on March 21, 1977.
(Paragraph 7.b Report Details)
Licensee Action on Previously Identified Enforcement Items (
None reviewed.
Other Significant Items A.
Syster.s and Components Unresolved Item - Inaccuracies in the conversion factor calculation for the off-gas stack monitor may have resulted in erroneous deter-minations of off-gas stack noble gas releases.
(Paragraph 3.b,
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Report Details)
B.
Facility Items (Plans and Procedures)
Unresolved Item - Containment purge campling and analysis require-ments will be resolved with NRR.
(Paragraph 11, Report Details)
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Managerial Items I
None identified.
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Deviatio.c Fone identified.
E.
Status of Presiously Reported Unresolved items The licensee's process monitor calibration procedures were found to be adequate f or all of the reviewed monitors, except for the reactor building noble gas effluent monitor.
(Paragraph 7. Report
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Details)
Managerent Interview
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A management interv12w was conducted with Messrs. Eliason, Fey, Jacobson, and Nolan at the conclusion of the inspection on March 31, 1977 and further by telephone with Mr. Eliason on April 13, 1977.
The following items were discussed?
A.
The inspectors reviewed the scope of the inspection and discussed the noncompliance items regarding calibration of the reactor building noble gas effluent monitor and operability of the air
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ejector off-gas monitor.
The inspectors stated that the licensee's corrective action regarding the air ejector of f-gas monitor isolation (
appeared adequate; therefore, no reply to this noncompliance would be required.
B.
The inspectors strted that the conversion factor calculations for the off-gas s.ack monitor appeared inaccurate in that the air ejector off-gas system releases were not included.
The licensee acknowledged the inspectors' comments and agreed to evaluate the conversion factor calculations and the significance of any errone-ous off-gas stack effluent data generated from the conversion factors.
(Paragraph 3.b, Report Details)
C.
The inspectors noted that although the air ejector and of f-gas stack monitors were calibrated as rcquired by the technical speci-fications, the grab samples and linearity checks performed in the calibrations were not defined in the surveillance (calibration)
procedures.
The licensee stated that the calibration procedures would be reviewed and revised as necessary.
(Paragraph 7, Report Details)
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The inspectors stated that, due to time constraints, it had not (
been determined if the required quarterly surveillance tests of the reactor building ventilation system automatic isolation func-tion had been conducted.
The licensee stated that a review of
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current technical specification surveillance requirements had been initiated and would be completed and available for review in the near future.
(Paragraph 7.c, Report Details)
E.
The inspectors noted that the Stack / Vent Noble Gas Effluent surveillance procedure (STP 0230) required revision to correct minor errors and inclusion of the off-gas stack conversion factor calculation. The licensee stated that the procedure would be reviewed c.nd revised as necessary.
(Paragraph 8, Report Details)
F.
The inspectors noted that certain standby gas treatment system
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surveillance frequencies were changed in a recent technical specification revision and, although no surveillance testing was
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overdue at the time of the inspection, that some surveillance requirements were due in the immediate future.
The licensee ackncwledged the inspectors' comments.
(Paragraph 9, Report Details)
G.
The inspectors requested that the licensee clarify, with NRR, the technical specification sampling requirements for containment purges.
(Paragraph 11, Report Details)
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REPORT DETAILS 1.
Persons Contacted L. E11ason, Plant Manager F. Fey, Radiation Protection Engineer R. Coranson, Engineer 0. Iverson, Engineer
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R. Jacobson, Engineer t
L. Nolan, Engineer
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J. Peterson, Radiation Protection Specialist 2.
General
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This inspection was conducted to examine the licensee's radwaste (gaseous, liquid, and solid) operations for compliance with NRC
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regulations.
The licensee's derivations and records of radio-active effluents were reviewed and compared with the radioactive releases reported in the licensee's semiannual reports.
Liquid and gaseous process monitor calibrations, reactor coolant chemistry measurements, and standby gas treatment system surveillance were also reviewed.
3.
Caseous Release a.
Augmented Off-Gas System The licensee's augmented of f-gas system, consisting of two recombiners and five pressurized holdup tanks added to the existing 30-minute holdup system, operated throughout calendar year 1976 with no significant problems.
Occasional leakage occurred at the hydrogen analyzers; the leakage problems have been reduced by installation of moisture traps upstream of the pumps.
The redesigned catalyst support bed continues to function properly.
Flow control problems, caused by pressure oscillations, were resolved by replacement of the flow detectors.
According to licensee personnel and review of ifcensee records, the hydrogen monitors downstream of each operating recombiner have been operabic during power operation and the hydrogen concentrations at the monitors did not reach the 4% trip point.
Storage times in the gas decay tanks have averaged about fourteen days.
No instances of less than twelve hours (
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holdup were noted. Condenser air inicakage, determined
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weekly, has averaged two to three efm.
Gas decay tank gross radioactivity is determined in conjunction with the weekly air inicakage surveillance.
Review of the licensee's surveillance
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secords of gas decay tank gross radioactivity did not reveal j
any discrepancies in surveillance frequencies or tank activities.
i According to the licensee's surveillance records, functional I
test and calibration frequencies for the off-gas hydrogen
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analyzers complied with the technical specification requirements during 1976.
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b.
Noble Cas Releases k
Continuous monitors on the off-gas stack and reactor building vents perform alarm, isolation, and quantification functions.
A technical specification change effective July 1, 1976 changed the calculational formulae for determining acceptable releases;
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the maximum release rates allowed by the technical specif1-cations did not change significantly.
According to the licensee's monitoring records, the maximum release rate experienced during 1976 was less than 10% of the technical specification limit and the average (quarterly and twelve consecutive months)
release rates were less than 5% and 10%, respectively, of the technical specification limits.
The noble gas releases are quantified from the average release rates recorded by the off-gas stack and reactor building vent
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monitors.
The conversion factors for these monitors are calculated routinely.
The off-gas stack monitor conversion factor is calculated from the air ejector isotopic results decayed to the stack release point.
Both the air ejector of f-gas system and the gland seal exhaust system discharge radio-active effluents via the off-gas stack.
Since the augmented off-gas system became fully operational in 1975, the majority of the off-gas stack radioactive effluents have origin;ted from the gland seal packing exhaust system. According to licensee personnel and the licensee's records, the air ejector off-gas system ef fluents have not been included in the of f-gas
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stack conversion factor calculations.
Preliminary calculations indicate that off-gas stack noble gas releases may be increased by 50% to 100% when the air ejector ofi-gas system ef fluents are included in the conversion factor calculation.
However, even a 100% increase in
.."-946 stack noble gas releases would not result in any technical.pecification release rate limits having been exceeded during 1976.
This matter will be examined further during a subsequent inspection.
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Particulate and Indine Releases lodine and particulate samplers on the off-gas stack and reactor building vents provide continuous sampling and peri-
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odic quantification of airborne effluents.
A technical specification change effective July 1, 1976 changed the calcu-lational formulae for determining acceptabic iodine and partic-ulat.) releases; the maximum release rates allowed by the technical specifiestions did not change significantly.
According to the licensee's monitoring records, the maximum and average (quarterly and twelve consecutive months) release rates experienced during 1976 were less than 10% of the technical specification limits.
No discrepancies from the technical specification surveillance requirements for radipiodine or particulate sampling werc noted. Daily sampling was not required during 1976.
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d.
Tritium Releases According to the licensee's surveillance records for 1976, off-gas stack and reactor building vents were sampled for tritium monthly and each containment purge was sampled.
Silica gel sampling was utilized to collect the vaporous tritium.
4.
I,iguid Redwaste (
No liquid radwaste releases were made during calendar year 1976 nor was any liquid radwaste shipped offsite for disposal. Waste liquids continue to be recycled for reuse in the reactor coolant system or used in processing of solid wastes.
The licensee has not experienced significant ground water or condenser inleakage.
Approximately fifteen to twenty thousand gallons of makeup water per month are required to compensate for losses via evaporation and solid radwaste consumption. The licensee's surveillance records for liquid radwaste storage activity were selectively reviewed.
No discrepancies from the surveillance requirements were identified.
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Solid Radwaste The licensee's radwaste solidification system remains out of operation awaiting completion of modifications to the mixer-feeder and drum feed pipe to improve flushing and scaling capabilities.
Additionally, video monitors will be installed on the hopper and drum feed pipe-7-(
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to improve control over mixture consistency.
According to licensee
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personnel, the solid radwaste system modifications are expected to be completed by the fall (1977) outage.
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In the interim, mobile solidification services continue to be contracted from Chem Nucicar Systems, Inc.
Mobile solidification
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operations apparently were conducted on four occasions during 1976,
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totaling approximately three months onsite time.
According to the licensee's records, approximately 3800 curies of waste were trans-ferred to CNSI for solidification and disposal during 1976.
Radwaste activity and radionuclide composition are determined from measurements made on sampics of the waste. Review of the licensee's waste disposal records did not reveal any discrepancies from the waste disposal data reported in the Effluent and Waste Disposal Semiannual Reports for calendar year 1976.
The licensee's procedures for operation of the solidification
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operations (transfer to CNSI) have been revised to include precautions to prevent inadvertent discharges.
Additionally, the temporary hose connecting "B" hopper and the CNSI mobile solidification equipment has been replaced with permanent piping.
6.
Radioactive Effluent Reports the licensee's semiannual c. fluent reports covering the periods July 1, 1975 threugh December 31, 1976 were reviewed.
The reporting format complies with the technical specification requirements.
No anomalous results were noted. The effect of the off-gas stack
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monitor conversion factor evaluation (see paragraph 3.b) on the reported releases will be reviewed during a subsequent inspection.
7.
Process Monitors a.
Off-Gas Stack Monitor Continuous off-gas stack monitoring is provided by two scintil-lation detector monitors located on an isokinetic sample line.
The monitors' outputs are averaged and printed out hourly by the process computer.
According to the licensee's records, a conversion factor for the monitor was determined weekly during the first six months of 1976 and at Icast monthly during the second six months.
The conversion factor is based on an isotopic analysis of six nuclides at the air ejector discharge and a computer prediction of fifteen nuclides.
(See paragraph 7.b, for details.)
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The inspectors reviewed surveillance test No. 0163 " Stack Monitor
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Quarterly Calibration," a portion of which describes the use of three solid Co-60 sources which are placed on the detector face to establish the linearity of response of the off gas stack monitor.
The combination of the use of the solid source linearity check and the isotopic analysis performed in conjunc-tion with the conversion factor determination comprises an acceptable calibration of the monitor.
The off-gas stack monitor isolation trip setpoints are determined in conjunction with the monitor calibrations. The trip setpoints were found to be consistent with the technical specification limit for the maximum nobic gas release rate.
According to the licensee's records, functional test and calibration frequencies during 1976 complied with the technical specification requirements.
Selective review of the licensee's records did not reveal any instances of monitor inor arability during 1976.
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b.
Air Ejecter Monitor Continuous air ejector of f-gas monitoring is provided by two off-line ionization chamber monitors.
The licensee's records indicate that the air ejector monitor conversion factor (mR/hr to NCi/sec) was determined weekly during the first six months of 1976 and at least monthly during the second six months.
The conversion factor is based on an isotopic analysis of six nuclides at the air ejector discharge and a computer prediction of fifteen nuclides.
t An cicctronic calibration of the air ejector monitor is performed quarterly.
Solid source linearity checks are performed during refueling outages. The combination of the solid source linearity check and an isotopic analysis of air ejector discharge comprises an acceptable calibration of the monitor.
The air ejector monitor isolation trip setpoints are determined in conjunction with the monitor calibrations.
The trip setpoints were found to be consistent with the technical specification limit for the maximum off-gas stuc' nobic gas release rate (120 minutes decay).
Operation with tne of f-gas holdup system recombiners
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bypassed was not necessary during 1976.
According to the licensee's records, functional test and calibration frequencies during 1976 complied with the technical specification require-ments.
Selective review of the licensee's records did not reveal any instances of monitor inoperability during 1976.
Itowever, both-9-
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monitors were inoperabic for approximatelyj urteen hours fo (
during power operation on March 21, 1977.-
The monitors had been isolated for maintenance during plant shutdown on March 20, 1977 and the isolation valves were erroneously Icft isolated at the completion of the maintenance work.
Technical Specification 3.2.D.1 requires that the air ejector of f-gas radiation monitors be operable during reactor power operation.
The licensee's corrective action was reviewed.
The results of the licensee's review of the work request procedures and the radiation monitor flow alarm operation will be reviewed during
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subsequent inspections.
c.
Reactor Building Vent Monitors Continuous noble gas monitoring of the reactor building venti-lation exhaust is provided by an off-line continuous air monitor (CAM).
The monitor output is averaged and printed out
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hourly by the process computer.
According to the licensee's surveillance records, functional test and calibration frequencies during 1976 complied with the technical specification require-
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ments.
However, the calibrations routinely performed on the monitor utilize solid sources which apparently have not been cross calibrated to gaseous standards.
Therefore, the solid source checks provide only a linearity determination of the monitor. The licensee continues to use the calibration curves supplied by the manufacturer of the vent monitor for quanti-fication of reactor building vent releases.
It was noted that (
the manufacturer had performed a Kr-85 calibration of the monitor and calculated the expected monitor response to addition-al isotopes based on the beta energies and the detector wall thickness.
Attempts by the licensee to verify the manufacturer's curves have been conducted (although not quarterly); the resultant data have not been entirely consistent with the manufacturer's curves.
The licensee has not fully complied with the requirements of Technical Specification B-2.4.4.d, which requires that the reactor building vent zonitor be calibrated quarterly. According to licensee personnel, a scintillation detector is being evaluated as a possibic replace-
ment for the present detector.
Results of the licensee's evaluation will be reviewed during a subsequent inspection.
Two CM monitors in the reactor building ventilation plenum perform isolation functions.
The monitor trip setpoints were consistent with technical specification requirements.
However, surveillance records were not readily availabic to demonstrate 1/
RO 050-263/77-06, NSP to RIII, dated 4/4/77.
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thel quarterly isolation surveillance tests required by the
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technical specifications.
This item will be reviewed further during a subsequent inspection.
d.
Liquid Effluert Monitor and Discharge Canal Monitor Liquid radwaste effluent and discharge canal monitoring is provided by separate, in-line, scintillation detector monitors.
A review of the licensee's surveillance records indicated that i
functional test and calibration frequencies during 1976 complied
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with the technical specification requirements.
The calibrations consist of an electronic calibration and the use of three solid Co-60 sources, which were cross calibrated to a Cs-137 liquid calibration perfermed in August 1970.
No discrepancies were identified in.the conduct of the calibrations or functional
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tests.
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8.
Procedures
The following Operations Manual changes were reviewed:
B.5.11 Process Radiation Monitoring (2/6/76)
B 7.3 Solid Radwaste (4/6/76).
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The listed procedural changes were noted~to have been reviewed by the Operations Committee.
The changet do not appear to degrade the licensee's radioactive effluent control capabilities.
Review of the licensee'sisurveillance procedures revealed that the Stack / Vent Noble Gas Effluent procedure (STp 230) contained three procedural errors.
The errors did not appear to have generated.
significant inaccuracies in the calculated data.
It was also noted that the conversion factor calculation (off-gas stack monitor)
included in STP 230 is not the conversion factor calculation actually used for quantifying off-gas stack releases.
9.
Standby Cas Treatment System
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The charcoal beds were replaced during the last refueling outage (September - October, 1975).
Since that time "A" train has been operated about 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> and "B" train about 500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />. According to licensee records and discussions with licensee personnel regarding SBGT operation during calendar year 1976 and 1977 to date:
(1) a minimum of one SBGT train was operable at all times; (2) whenever one train was inoperable, the operability of the other train was demonstrated; (3) in-place and laboratory testing results met the (
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technical specification requirements; (4) filter pressure drop, (
heater power output, and automatic initiation testing results met the technical specification requirements; and (5) no maintenance affecting HEPA or charcoal filter leak-tight integrity was conducted.
l The licensee's surveillance records for calendar year 1976 and 1977
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to date were selectively reviewed.
Except as noted below, no
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discrepancies from the technical specification requirements were
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noted.
A technical specification change effective September 27, 1976, changed the frequency and acceptability criteria for certain surveillance testing and added a requirement for monthly operability
testing of both SBGT trains.
As reported by the licensee, the operability surveillance conducted from September 27, 1976 to January 25, 1977 did not include the monitoring and recording of,j
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system flow rate as required by Technical Specification 4.7.B.l.i The licensee was noted to have implemented the required surveillance
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testing effective January 25, 1977.
The current technical specifications require that certain surveil-lance testing be conducted at intervals not to exceed 18 months instead of the previous frequency of once per operating cycle.
Within this category, charcoal laboratory tests ("B" train), filter pressure drop, and heater power output surveillance were last conducted during early October 1975.
The completion of these surveillance tests within the specified frequencies will be examined during a subsequent inspection.
I 10.
Reactor Coolant Chemistry The licensee's reactor coolant radiochemistry results for calendar year 1976 were reviewed.
No discrepancies from the technical specification surveillance requirements for radiciodine sampling or monthly gamma isotopic analyses were noted.
Radiciodine surveil-lance during 1976 was not dependent upon air ejector monitor increases.
According to the licensee's records, the reactor coolant radioiodine concentrations (I-131 dose equivalent) averaged about 1 1/2% of the technical specification limit; the maximum radiciodine concentration was less than 2 1/2% of the technical sp<cification limit.
Radio-iodine concentrations during the year were approximately an order of magnitude lower than during the previous year.
This reduction was due, principally, to the replacement of leaking fuci elements late in 1975.
Reactor coolant radiolodine concentrations are expected to continue to decrease as tramp fuel is eliminated from internal core surfaces.
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R0 050-263/77-02, NSP to RIII, dated 2/24/77.
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Containment Purne
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k According to licensee personnel and records, all drywell purges are conducted through the standby gas treatment system.
Drywell purges were conducted approximately biweekly during 1976.
The radioactive effluents are quantified by the off-gas stack monitor.
The technical speciffeations require that each purge be sampled and analyzed for tritium and principal gamma emitters.
The licensee's records substantiate these analyses, except that noble gas samples and analyses are not routinely conducted.
The licensee will request clarification, from NRR, of the technical specification requirements regarding noble gas sampling.
This matter will be reviewed further during a cubsequent inspection.
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