IR 05000219/1985040
| ML20153C520 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 02/07/1986 |
| From: | Cioffi J, Pasciak W, Sherbini S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20153C514 | List: |
| References | |
| 50-219-85-40, NUDOCS 8602210060 | |
| Download: ML20153C520 (4) | |
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i-U.S. NUCLEAR REGULATORY = COMMISSION
REGION I
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Report No.
50-219/85-40-Docket No.
50-219 l-License-No.
DPR-16-Priority Category'
Licensee:
GPU Nuclear Corporation i
P.-0.-Box 388 Forked River, New' Jersey 08731 Facility Name:
Oyster Creek Nuclear Generating Station l
l Inspection At:
Forked River, New Jersey Inspection Conducted:
December 21, 1985 t//[88
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Inspectors:
a,
S. SherbiniT Radiation Specialist-date
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[or J. Cioffi, Radiation Specialist date
.. :a[7!g6 Approved by:
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W. Pasciak, Chief idad.e BWR Radiological Protection Section Inspection Summary:
Inspection on December 21, 1985 (Report No.'50-219/85-40)
Areas Inspected: Special safety inspection of the Radiation Control Program concerning the events leading to iodine uptakes in the thyroids of a number of personnel while working in the drywell. The inspection-involved 8 inspector-hours onsite by two region-based inspectors.
-Results: No violations were identified.
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DETAILS
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- 1.0' Persons Contacted 1.1 General Public Utilities-M. Littleton, Manager, Radiological Engineering P. Scallon, Manager, Radiolo~gical Controls Field Operations J. Derby, Deputy Manager, Radiological Controls Field Operations 1.2 USNRC W. Bateman, Senior' Resident Inspector J.Wechselberger{ResidentInspector 2.0 purpose
.g i The purpose of thiv inspectio'n was to investigate the events and circum-stsnces that led to iodine uptakes by workers at' the Oyster Creek Nuclear-Generating Station.
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3.0 Description A reactor scram occurred at the Oyster Creek Nuclear Generating. Station on the morning of December 15, 1985 (Sunday at 0745). Prior to the. scram, it was known that a.small leak existed in the coolant system. The leak-rate was below the applicable administrative limits and therefore no immediate action.had been taken to effect a repair.
It was also suspected that the leak was from the feedwater part of the system, this conclusion was described by the licensee as being based on the very low activities found in water samples taken~from the drywell. The scram provided an opportunity for'the licensee's maintenance workers to'make an entry-into the drywell to repair the leak.
Purging of the inerted atmosphere in the drywell started after we reactor was shut down and continued throughout Sunday,-December J,1985'.
The oxygen level, checked during a drywell entry using SCBAs, reached safe respirable levels on Monday morning, December'16, 1985. _ Air: samples taken at that time showed a-total airborne activity of 1.5 MPC*,'mostly iodine.
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Several entries were then made by. repair crews, some using respiratory equipment and some without. The first warning of higher-than expected'
airborne activities came from a sample analysis completed at 0900 on Monday, December 16, 1985. Thesamplgndicatedatotal~airborneactiv-ity of.10.4 MPC of which 4.3 MPC was I.
SCs and 2'Cs were also-x j
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- MPC (Maximum Permissible. Concentration) as used.in this report refers to the concentrations'specified.in Part 20, Appendix B,' Table 1.-
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- 3 detected. Analysis: of breathing zone. samples-confirmed these findings.
All entries ~ were suspended; for about 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and were resumed.with
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respiratory protection equipment (including charcoal-cartridges) ion the basis of-samples taken at about 1020 that showed.a. drop in airborne activity to 2.0 - 3.6 MPC of-which.1.3 - 2.5 was iodine.
Entries with respiratory protection' equipment were continued all' day and by 1720 on Monday, December 16, 1985, airisamples showed a drop in total airborne-activity to:about 0.7 MPC. On the: basis of these readings, subs'equent; entries during that day were made without= respiratory protection.
Repair work was completed and the reactor was. restarted'on. Monday,
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December. 16, 1985
.Drywell' entries--were made at 0648'on Tuesday, December 17, 1985,.using positive pressure air. purifying. respirators,-
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to perform a 1000 pound inspection. No' airborne samples had been-collected prior to the entries. Analysis of samples collected during<
this entry showed total airborne activities ranging from.11 - 28 total
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MPC with 9 -~21 MPC iodine.. As a result of this finding,. all persons'-
who made entries during the period December 15 - December 17, 1985 were assayed on the whole body counter. A total of 17 persons wereiny'olved and 15.of them were found to have thyroid uptakes of iodine.
Results from the whole body counter assays were obtained from the licensee by the NRC inspectors and a preliminary NRC analysis was performed to determine the extent of the exposures. The analysis was based on.the ICRP report #2 internal dosimetry model and metabolic data.
The retention func-tion for a single intake was obtained from ICRP 10A. ' The results of this -
analysis for the highest exposed individual arecshown.below.
Inhaled activity: 34 MPC-Hr equivalent activity Percent maximum permissible organ burden:
9%
Committed dose:
75 mrem 3.1 Findings The licensee's internal exposure' controls during the drywell entries by personnel on December 16 and'll, 1985 were reviewed against criteria contained in:
10 CFR 20.103, " Exposure of individuals'to concentrations of
radioactive materials in air :in restricted areas,"
10 CFR 201, " Surveys,"
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Technical. Specifications 6.11 and 6.13, " Radiation Pro'tection
Program" and "High Radiation Area," respectively, and ANSI Z88.2-1980, " Practices for Respiratory Protection."
- The licensee's performance relative to these'~ criteria vos determined-t froth interviews with the Radiological Engineering Manager and -Radio-logical Controls Field Operations Manager; review of airborne j
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samplingandwholebodycounting. data:relatedtbitheabove' described; events;:and review of ' selected procedures' incitding No' 915.12,-
Revision 11,. " Radiation Work l Permit," and No.j 9300-ADM-4020.02,
. Revision 2, " Description and Selection of Respiratory Prbtection'
Equipment."
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Within the scope of:this review, no. violations were identified;and.
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the intakes did not require an assessment by:the licensee. L However,-
the inspectors noted that the-potential for permitting a significant:
uptake;should be minimized by. verifying fanticipated ' levels (1 e.,
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unmeasured prior to entry)'in a.more timely basis, especially when c recent airborne results' indicate the ' existence of'an unidentified source of airborne radioactivity.
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Procedure No. :9300-ADM-4020.02 discussed the~ situation when-it'is-impractical or. impossible to obtain' current airborne: radicactivity.
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measurements prior'to an entry.
It stated that past airborne concentration histories for the area shall be used in' estimating.
expected. airborne radioactivity levels and that'an air samplefshall be taken during such an entry to verify actual levels However, the licensee does not provide guidance concerning the timeliness of-this s
assessment.
The licensee evaluated the Breathing Zone AirfSamples (BZAs) taken'
during the entry to verify anticipated? levels in:the drywelliafter the work act'vity had been completed. The evaluation:of the BZA results indicated the exposures to-personnel resulting fromjthe events described in this report were well-below t,he regulatory.
limits, principally because the total time in the drywell was minimal.
Based on-the above, the' inspectors discussed with the licensee the need to review and revise, as necessary,.the-procedures for, control =
of internal exposures when surveys ' prior to entry'are not available and to address evaluating samples taken'during-entries into unknown
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areas on a more timely basis. This licensee stated that this problem would be studied and appropriate corrective actions would be taken.
This item will be reviewed during a subsequent ~ inspection (50-219/85-40-01).
- 4.0 Exit Interview The inspector met with the Radiological Engineering Manager at th9 con-clusion of the inspection on December 21,' 1985. The inspector summarized
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the purpose, scope and findings of the inspection. At no. time during this
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inspection.was written material'provided to the licensee by theLinspectors.
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