IR 05000010/1978004
| ML19340A831 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/22/1978 |
| From: | Fisher W, Greger L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19340A826 | List: |
| References | |
| 50-010-78-04, 50-10-78-4, 50-237-78-03, 50-237-78-3, 50-249-78-03, NUDOCS 8009040656 | |
| Download: ML19340A831 (8) | |
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U.S. NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
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REGION III
Report No. 50-10/78-04; 50-237/78-03; 50-249/78-03 Docket No. 50-10; 50-237; 50-249 License No. DPR-2, DPR-19, DPR-25 Licensee: Commonwealth Edison Company P. O. Box 767 Chicago, IL 60690 Facility Name: Dresden Nuclear Power Station, Units 1, 2, and 3 Inspection At: Dresden Site, Morris, IL Inspection Conducted: January 24-27 and February 2 and 23-24, 1978 f
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Inspector:
L. R. Greger b
i Approved By:
W. L. Fisher, Chief 3!:2c2/77
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Fuel Facility Projects and Radiation Support Section Inspection Summary Inspection Conducted on January 24-27 and February 2 and 23-24, 1978 (Report No. 90-10/78-04, 50-237/78-03, 50-249/78-03)
Areas Inspecaed: Routine, unannounced inspection of airborne radio-active vaste systems, including: effluent releases; records and reports of effluents; effluent control instrumentation; procedures for controlling releases; containment air-cleaning systems; licensee event reports; and licensee action on previously identified enforcemeat items and commitments. The inspection involved 62 inspector-hours onsite by one NRC inspector.
Results: Of the seven areas inspected, no apparent items of noncompliance or deviations were identified in six areas; two apparent items of noncompliance were found in the remaining area (infraction - inadequate calibration of D-1 chimney gaseous monitor - Paragraph 8; infraction -
inadequate calibration of D-2/3 reactor building vent stack gasecas monitor - Paragraph 8)
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DETAILS
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1.
Persons Contacted l
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- D. Adam, Radiation Chemistry Supervisor j
- G. Bergan, Chemist J. Chan, Engineer
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P. Duggan, Engineer
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D. Eggett, Chemist l
- D. Farrar, Supervising Engineer W. Hildy, Instrument Engineer G. Myrick, Health Physicist R. Nimmer, Engineering Assistant
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J. Parry, Health Physicist G. Reimers, Engineer
- L. Scott, Chemist j
The inspectors also contacted several other licensee employees, including members of the technical and engineering staffs.
- denotes those attending the exit interview.
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2.
General
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l This inspection, which began at 8:15 a.m. on January 24, 1978, was conducted to examine the licensee's gaseous radwaste opera-tions for compliance with NRC regulations. The licensee's derivations and records of radioactive airborne effluents were reviewed. Radioactive releases reported in the licensee's semiannual effluent reports were checked against the licensee's records. Gaseous effluent process monitor calibrations and containment air-cleaning system testing were also reviewed.
3.
Licensee Action on Previous Inspection Findings
(Closed) Noncompliance (50-237/77-19, 50-249/77-19):
Inadequate quantifica*'cr. and reporting of gaseous radionuclides r0 leased from the Dr.it 2/3 chimney and the Unit 2/3 reactor buf*. ding ventilation stack. A grab sampling program was implemented to quantify routine gaseous releases. Gaseous effluents from these release paths are discussed in Paragraph 4.
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(Closed) Noncomplianco '30-010/77-10): Failure to report a halogen and particulate release rate in excess of the tech-
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nical specification limit within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Procedure DCP 1400-6 was revised in July 1977 to require that Unit I charcoal
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filters be counted 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> af ter removal. A selective review of the licensee's Unit i radiciodine surveillance records
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indicated that the 20-hour counts were being performed.
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4.
Radioactive Gaseous Relea ses The licensee's calculations and records of gaseous releases for 1977 were selectively reviewed. According to the licensee's records, gaseous releases from the Dresden site averaged less than 5% of the technical specification _ release rate limit (instantaneous) for 1977. No releases in excess of technical specification limits were identified.
As a result of a previous inspection,1/ the licensee altered the sampling method for quantification of Unit 2/3 chimney gaseous
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releases and commenced a sampling program for Unit 2/3 reactor vent stack gaseous releases. These changes were initiated in July and August 1977, respectively.
Selective review of the sa=pling results since inception of the revised sampling programs indicated that Unit 2/3 chimney noble gas releases averaged between 1000 and 2000,pci/see instead of approximately 100,pci/see as quantified from offgas samples. The differences between the release data were due to gland seal exhaust releases which had not been included in the previous quantification method. The gland seal exhaust releases increased in importance with the use of the
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augmented offgas (A0G) system, which reduced offgas releases by several orders of magnitude. The normal noble gas releases via the reactor building vent stack are at least one order of magnitude less than the present chimney releases and were also negligible before implementation of the augmented offgas treatment.
Although the A0G addition to Unit 1 is not yet operational, a 5000 to 10,000,pci/sec increase in release rate was found when a grab sampling technique similar to that utilized on the Unit 2/3 chimney and the reactor vent stack was instituted during late 1977.
The reason for the difference has not been identified. Noble gas releases from Unit 1 generally ranged from 10,000 to 50,000 uCi/sec during 1977.
This item will be reviewed further during a future inspection.
No items of noncompliance or deviations were identified.
5.
Radioactive Iodine and Particulate Releases The licensee's calculations and records of iodine and particulate (with half-lives longer than eight days) releases for 1977 were selectively reviewed. According to the licensee's records, 1/
IE Inspection Report No. 50-237/77-19.
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T iodine and particulate releases from the Dresden site averaged
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less than 30% of the technical specification release race limit for 1977. One release in excess of the technical specification
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limit occurgyd on April 16. This release was previously reported to the NRC.-
Several reports, required by the technical specifi-cations,weresubmittgpbythelicenseeduring1977regarding releases from Unit 1.-
One purpose of the reporting requirement is to prompt the licensee to take such actions as are necessary to maintain the annual average release rate less than 10% of the technical specification limits. The annual average release rate for Unit 1 (only) iodines-and particulates was, according to the licensee's records, less than 7% of the technical specification 1Lnit.
The chimney flow rates used in the release calculations may not be consistent with the flow rates which exist at present. Errors in the flow rates effect proportionate errors in the calculated release rates. This item will be reviewed further during a future inspection.
No items of noncomp11ance or deviations were identified.
6.
Airborne H-3 Releases
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The inspector selectively reviewed the licensee's calculations
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and records of airborne tritium releases. Airborne H-3 releases are calculated based upon reactor coolant H-3 concentrations and
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moisture content and exhaust air flow rates. Calculated release rates for the site generally ranged from 5 to 25 uCi/sec. A tritium composite sampler was installed on the Unit 1 chimney during 1977. No release data were available at the time of this inspection. This item will be reviewed further during a future inspection.
No items of noncompliance or deviations were identified.
7.
Reports ef Effluents The inspecto.i reviewed the licensee's semiannual radioactive effluentrepcrtsfor1977fpirbornereleasesonly)andcorrec-tions to the '.976 reports.-
There are no further questions regerding the 1976 effluent reports. No discrepancies were identified during review of the 1977 reports.
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LER 50-10/77-10.
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LER 50-10/77-07, LER 50-10/77-08, LER 50-10/77-18.
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Ltrs, Stephenson to Keppler, dtd 3/11/77 & 6/28/77.
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N Noting that the effluent reports do not include krypton-85
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releases, the inspector discussed the desirability of reporting
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effluent data for the nuclides specified in Regulatory Guide 1.21.
If nuclides are not detected by the licensee's counting techniques, the release value may be reported as less than the
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maximum sensitivity of measurement or calculated using measured ratios to nuclides which are routinely identified and measured.
This item will be reviewed further during a future inspection.
No items of noncompliance or deviatirans were identified.
8.
Effluent Control Instrumentation Gaseous effluent / process monitor sarveillance records for calendar year 1977 were reviewed for compliance with technical specification requirements for operability, trip setpoints, and calibrations and related testing. The following monitors were -
examined:
D-1 Chimney gaseous monitor D-2/3 Chimney gaseous monitor D-2/3 Reactor building vant gaseous monitor D-1 Offgas monitor
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D-2/3 Offgas monitor
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The adequacy of the licensee's gaseous monitor calibratigys have been the subject of previous IE Inspection Reports.-
The licensee's calibration techniques are not applied censistently and in certain instances are not sdequate to assure that e.h e monitors respond, within acceptable accuracy, over the usable range of the instruments. Three consecutive quarterly "cali-brations" of the D-1 chimney gaseous monitor (June 10, 1977, September 28, 1977, and' December 12, 1977) resulted in three significantly different predictions of the monitor's response.
The " calibration" curves were each based on three grab samples of similar concentration of gaseous effluents. Extrapolation from these samples to other gaseous concentrations resulted in response curves which varied by as much as a factor of ten at some points. The licensee has, therefore, not adequately complied with the calibration requirements of Technical Specification 4.8.A.I.
The D-2/3 chimney gaseous monitor was last calibrated December 14, 1977. The calibration consisted of a response check using seven 5,/
IE Inspection Reports No. 50-237/77-19, No. 50-237/77-11, and No. 50-237/76-15.
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w cesium-137 check sources with an approximate factor of 300 range
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in activity to establish the activity response of the monitor,
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and a correlation with two grab sauples representative of potential release conditions. One shortcoming of the technique was that the activity response check did not include the equivalent activities of the grab samples, This was corrected during the inspection.
Previous calibrations of the D-2/3 chimney monitor had been performed by injecting gaseous samples collected from the off-gas system. This technique suffered from a limited range of available activities or failure to supply consistent isotopic mixtures over the activity range.
The offgas monitors for all three units were noted to have undergone activity response checks during the most recent refueling outages. Additionally, grab sample " calibrations" were performed quarterly during 1977. The trip setpoints are conservatively determined from the quarterly " calibrations."
These " calibrations" suffer from the same problems as the D-1 chimney monitor " calibration" described earlier in this section. The activity response curves appeared to be conducted properly. Had it not been for conservatisms introduced by the chemists, the trip setpoints on the offgas monitors may not
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have complied with the technical specification requirements.
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The licensee is required, by technical specifications, to continuously monitor airborne radioactive releases from the D-2/3 reactor building vent stack. As the result of a recent inspection, the licensee commenced sampli stackfornoblegasreleases.gytheD-2/3reactorbuildingvent The grab sampling, performed weekly, appears adequate to quantify relatively constant releases but is not a viable method of accounting for anomalous releases.
The only gaseous monitors presently installed in the reactor building ventilation effluent path are the G-M detectors designed to redirect ventilation effluents through the standby gas treatment system when predetermined radiation levels are attained. According to the licensee's records, these G-M detectors were calibrated quarterly and functionally tested monthly during 1977. The " calibrations" did not, however, include a correlation between the detector response and gaseous activity. Thus, the quarterly " calibrations' did not fulfill the calibration requirements of Technical Specif. cations 4.8.A.1 and 1.0.E.
A licensee surveillance coordinator schedules and maintains records of instrument calibrations to ensure compliance with 6/
IE Inspection Report No. 50-237/77-19.
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the technical specification requirements. Review of the surveil-lance records revealed that certain procedures referenced for calibration of gaseous effluent and process monitors were not sufficient by themselves to ensure compliance with the technical specification rquirements for calibration of those monitors.
The completion of additional procedures not referenced in the surveillance schedule, was required to meet the technical specifi-cation requirements. The licensee was advised to revise the surveillance system to include these additional procedures. This item will be reviewed further during a future inspection.
9.
Unit 1, Offgas Explosion Followup The inspector reviewed environmental sampling results for the
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September 25, 1977 offgas explosion on Unit 1.
M: increase in environmental radioactivity attributable to the incident was observed.
The door to the Unit I chimney will be reinforced by the addition of stiffeners and holddown bolts. An engit.eering analysis of the modified door's ability to withstand over-pressurizations associated with offgas explosions has been
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initiated. The results of this analysis will be reviewed
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during a future inspection.
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No items of noncompliance or deviations were identified.
10.
Unit 1, Augmented Offgas Treatment The augmented offgas (A0G) treatment addition to the Unit 1 offgas system remains inoperable due to problems with the two hydrogen analyzers. Moisture accumulation in the analyzers simulates a high hydrogen concentration condition causing shutdown of the A0G system. According to licensee personnel, water traps will be installed upstream of the analyzers in an attempt to sileviate the erroneous analyzer outputs. Current schedules cr11 for installation of the water traps and further testing of tre A0G equipment within the next one to two months.
This item wi]l be reviewed further during a future insoection.
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No items of noncompliance or deviations were identifie'.
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Radwaste Procedures The inspector reviewed the following procedures which had been initiated or revised since the preceding radwaste inspection:
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d DCP 1400-6, Counting and Release Rate Determination of
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Chimney and Vent Stack Charcoal and Particulate
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DCP 2700-5, D-2/3 Chimney Monitor Calibration
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DCP 2700-6, Noble Gas Release Rate Determination Using Marinelli Beaker
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DRP 1710-4, Counting Room Reporting Criteria The rerisions did not appear to decrease the effectiveness of the radwaste program.
It was noted that certain gaseous effluent sampling and process l
monitor calibration procedures require revision to accomodate recent changes in the conduct of these activities. This item
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will be reviewed further during a future inspection.
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No itens of noncompliance or deviations were identified.
12.
Standby Cas Treatment System (SBGTS)
The SBGTS surveillance records (Unit 2/3) for calendar year
1977 were reviewed. Modifications required to perform certain
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surveillance testing were completed during November 1977 on trainAandduringFebruary1978onprainB. Except as reported
in a previous IE Inspection Report,- no discrepancies from the technical specification surveillance requirements were identified. Surveillance procedure DOS 7500-2, issued during January 1977, is utilized to conduct the monthly surveillance d
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testing.
It was noted that DOS 7500-2 does not require that the flow rate or heater status associated with the surveillance
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i test be recorded. The licensee initiated a revision to DOS
7500-2 to correct these omissions prior to the conclusion of the inspection.
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13.
Review of Nonroutine Events
The inspector reviewed the licensee's actions regarding the l
radiological aspects of the following licensee event reports.
No items of noncompliance or deviations were identified.
LER 50-10/77-35: Offgas Monitor Failure (9/23/77)
LER 50-237/78-7: Standby Gas Treatment System Surveillance Omission (2/1/78)
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IE Inspection Report No. 50-237/77-11.
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