IR 05000313/1988041
| ML20206L827 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 11/16/1988 |
| From: | Baer R, Murray B, Pederson R, Ricketson L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20206L819 | List: |
| References | |
| 50-313-88-41, 50-368-88-41, NUDOCS 8811300257 | |
| Download: ML20206L827 (8) | |
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APPENDIX V.S. NUCLEAR REGULATORY COPMISSION
REGION IV
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NRC Inspection Report:
50-313/80-41 Operating Licenses: DPR-51 50-368/88-41 NPF-6
Dockets: 50-313 50-368
Licensee: Arkansas Power & Light Company (AP&L)
P.O. Box 551 Little Rock, Arkansas 72203
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Facility Name: Arkansas Nuclear One (ANO)
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Inspection At: ANO, Russellville, Pope County, Arkansas l
i Inspection Conducted: November 3-4, 1988
Inspectors:
6hMik
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L. T. Ricketson, P.E.,U<adiation Specialist Date
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Facilities Radiological Protection Section F
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BTaine Murray, Chiefgeactor Programs Branch Ofte WahiM1 UAWb6
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hoger L. Pederson, Heal Physicist, Radiation D(te '
(4ProtectionBranch,O ice of Nuclear Reactor j
Regulation
i Approved:
M_#f6 _
// / k R.
. Baer, Chief,la ties Radiological D(te
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Protection Sectiun
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Inspection Summary
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Inspection Conducted November 3-4, 1988 (Report 50-313/88-41; 50-368/88-41)
Areas Inspected:
Special, unannounced inspection of the events surrounding the apparent overexposure of one worker performing maintenance work during the l
refueling outage, j
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Results: Within the areas inspected, three apparent violations (exceeding the
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3 rem / quarter whole body exposure limit for a radiation worker, paragraph 3; i
failure to perform acequate surveys, paragraph 3; and failure to instruct f
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w rkers of radiation hazards, paragraph 4) were identified.
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DETAILS 1.
Pe'.
Contacted AP&.
- J. M.,
4, vectti * Director, ANO Site Operations
- E.
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eenaai 5. 1ager, Plant Support ys
- E. E. t w1. Hr41th Physics (HP) Superintendent
- D.
D.
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"Dr.
-es ate Health Physicist
- R. Cr.r 1 ni to, t e Staff D. Deal, 3htft k evisor G. Vint:-
vecial sjects. HP C. A. May,.: hand.
S. L. Pettus, mechanic D. L. Helm, HP Specialist
- D L. Mic' *lk, Licensing Engineer
- D b. Lomax, Plant Licensing Supervisor M. E. Frala, Assistant Radiochemistry Supervisor Others
- D. D. Chamberlain, NRC, Section Chief, Projects Section A
- R. Haag, NRC, ANO Resident Inspector
- B. L. Bartlett, NRC, Senior Resident inspector, Wolf Creek
- W. D. Allen, Consultant, Health Physics K. R. Lemmond, HP, Power Systems Energy Services Incorporated (PSESI)
A. Murray, HP, PSESI T. Ellingson, HP, PSESI R. Perogner, Mechanic, NSS R. Pitts, Mechan'c, NSS The NRC inspectors also interviewed other licensee and contract employees.
- Denotes those present during the exit interview on November 4, 1988.
I 2.
Description of_ Event On the morning of November 3, 1988, Region IV was informed by the ANO resident inspector of a possible overexposure to a mechanic working under a steam generator on Unit 1.
The potential overexposure cccurred during the night shift (1:00 a.m. - 2:30 a.m.) on November 2, 1988. Two NRC inspectors from Region IV and one from the Office of Nuclear Reactor Regulation were dispatched to the site on the afternoon of November 3, 1988, to perform a special inspection.
The NRC inspectors observed reenactments of the events at a mockup of a steam generator by the individuals involved in the wor _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ - _ _ _
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3 One of the tasks to be performed during the outage of Unit I was the replacement of leaking gaskec; on the inspection covers located on the bottom of both "A" and "B" steam generators. ANO Unit 1 is a B&W design
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with once-through staam generators.
The inspection covers are located on the primary side *d the generators.
The inspection covers are aoout 8" diameter x 1" thick steel plates bolted to outside surface at the bottom of the steam generators. During the day shift on November 1, 1988,
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mechanics had removed the inspection covers and diaphragms from the
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inspection ports.
The work performed by the day shift was accomplished between about 5:30 p.m. and 7:30 p.m.
Similar crews on the night shift i
were to clean the gasket surfaces and install new gaskets, i
Before starting night shift work on November 2., 1988, prejob briefings
were held for the crews working on both generators.
Records show that "B"
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crew, consisting of two AP&L mechanics, two contract mechanics, a contract i
i HP technician, and an AP&L quality control technician, entered containment
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to begin work at approximately 1 a.m. on Nov(mber 2,1988. The "A" crew
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entered about an hour later.
The mechanics were outfitted with bubbl6 i
suits and wore 12 dosimetr/ packets, consisting of thermeluminescent
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dosimeters (TLD) and 0 - 1500 mrem self-reading dosimeters (SRD), located
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on the hecd, trunk (front and back), gonads, arms, legs, hands, and feet.
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The contract HP technician providing coverage for "B" crew entered the area under the steam generator and performed a prework survey.
He stated that the radiation levels under the opening of the inspection port were approximately double the 2 to 2.5 R/h levels he was expecting, so he cut the stay time in half (to 20 minutes) for the mechanics. The first mechanic entered and began work by removing the old gasket with a scraping
tool.
The mechanic stated that the gasket came loose much easier than anticipated and fell to the fluor (or perhaps hit and rolled).
The HP technician did not see the gasket fall and remained unaware of the presence of the old gasket on the floor.
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The mechanics performed the work on a rotational basis with up to two j
workers being under the steam generator at times.
The HP technician
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performad two radiation surveys during the operations.
During both surveys, two mechanics were performing work.
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At various times during the job, the HP technician checked the SRD worn on
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the chests (trunk-front) of the mechanics. These were the only 5P.0s worn by the "B" group on the outside of their plastic clothing.
The crew accomplished its intended work and left the area at approximately f
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Members of the crew stated that the total time spent under the steam j
j generator for the entire job was probably 40 to 50 minutes.
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After the job was complete, the mechanics exited containment and the HP
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technician read SRDs other than those wurn on the chest.
On finding
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higher readings than anticipated, he notified the HP shift supervisor,
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just before 3 a.m.,
that one individual could have received an overexposure.
The HP shift supervisor read all SRDs and found two dosimeters for one mechanic to be off scale.
The SRD worn on the chest of individual "A" showed 800 mrem.
It was later determined that for worker
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"A" three SRDs, those on both thighs and the lef t foot, were off scale and
two SRDs for worker "B,"
those on the feet, were also off scale.
The attachment shows the TLD results for workers "A" and "B".
The HP shift supervisor took statements and evaluated the situation. He later explained that, in order to get better results, he ordered the TLD badges to be held at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for fading compensation before processing. At approximately 5 a.m., November 2, 1988, he notified the HP superintendent of the possible overexposure.
l Meanwhile, the "A" crew continued to work. Higher radiation levels than
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expected were also found under "A" steam generator.
The crew attempted to I
I lower the levels by adding lead shielding, but the work was eventually terminated at approximately 5 a.m. on November 2, 1988, when the HP technician saw indications of possible administrative overexposures.
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Work was officially halted on both generators by the HP shift supervisor at 5:45 a.3, and he directed that comprehensive surveys of both steam
generators ce performed.
Followup survey results of the area under "B" i
steam cenerator indicated 40 R/h on the old gasket, which was found lying inside the skirt in the general work area and spots on the floor reading i
50 R/h and 10 R/h. General area radiation levels were 1 to 2 R/h.
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i After receiving a briefing on a pcssible overexposure durirg the morning l
of November 2, 1988, the General Manager, Plant Support directed that all maintenance work on the inspection covers be terminated until a joint
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meetiig of the ALARA Committee and the ALARA-Program Management Comnittee i
coulc be held to evaluate the situation. ALARA committee member s were briefed on the possible overexposure, presumably resulting from hot partie.les, and additional procedures were discussed and implemented by way of a rqvision of the Radiation Work Permits.
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The area below both steam generators was decontaminated by vacuuming the area to remove loose hot particles.
The General Manager, Plant Support
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allowed completion of the inspection cover maintenance work to resume on
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"A" steam generator the afternoon of November 2, 1988. The "A" steam l
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generator inspection cover job was completed on November 2 1988, with no
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significant v9rker exposure.
3.
Radiation Exposure Controls Tne radiation exposure controls were reviewed to determine compliance with the requirement of 10 CFR Parts 20.101(a), 21.101(b), and 20,201(b).
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Attachment 1 shows the TLD results for both individuals that had f
j off. scale SRDs. The TLD's readings indicate that one of the i
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a mechanics involved in work under "B" steam generator received a dose ot'
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3.216 rems to the right thigh, resulting in a accumulative whole body dose for the calendar quarter of 4.546 rems. None of the other workers involved in the operation exceeded NRC limits.
10 CFR 20.101(b) requires that a licensee not permit individuals in a restricted area to receive an occupational dose to the whole body of greater than J rems in any calendar quarter.
The 4.5 ram exposure is an apparent violation of 10 CFR 20.101(b).
(313/8841-01; 368/Ceal-01)
Surveys A survey performed by the licensee after work was stopped on the morning of November 2, 1988, under "B" steam generator, showed radiation levels on the gasket, which was removed and fell to the floor, of 40 R/h and two hot spots on the floor measured 50 R/h and 10 R/h (60 rad, beta). Although the licensee has not previously identified hot particles, the removal of the hot spots by vacuuming on the afternoon of November 2 would indicate that the sources of radiation may have been particles.
The contract HP technician providing coverage for the "B" crew stated to the NRC inspecto-s during interviews that he had not identified the old gasket or the spots on the ficor as additional sources of radiation and speculated that they were perhaps shielded by the bodies of workers who were present during his second and third surveys or, in the case of the spots on the floor, by the movement of the lead blankets.
The NRC inspectors reviewed the calibration records for the survey instrument used by the HP technician and determined that the instrument was in cal;bration
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at the time of use.
10 CFR 20.201(b) requires that each licensee make such surveys as may be l
necessary to comply with all sections of Part 20. As defined in 10 CFR 20.201(a), "survey" means an evaluation of the radiation hazards incident to the production use, release, disposal, or presence of radioactive materials or other sources of radiation under a specific set i
of conditions. The failure to perform an adequate survey in order to identify the 40 R/h-50 R/h radiation levels is an apparent violation of 10 CFR 20.201(b).
(313/8841-02; 368/8841-02)
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The qualifications of the contract HP technician were reviewed and found to satisfy ANSI 18.1-1971 criteria for a senior health physics technician.
4.
Instruction to Workers The licensee's activities were reviewed to determine compliance with 10 CFR 19.12.
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Through interviews and the review of survey records, the NRC inspectors determined that after the inspection cover had been removed from "B" steam
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generator, the HP technician providing HP coverage during the day shift of November 1, identified an area below the plane of the opening of the
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inspection port measuring 20 R/h. Also through interviews, the NRC inspectors determined that the HP technician and mechanics vorking on the night shift were not informed of the existence of the 20 R/hr radiation level.
The night shift HP technician stated that he expected maximum radiation levels under the generwtor to be about 2-2.5 R/hr and that he
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was not advised of any 20 R/hr levels.
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10 CFR 19.12 requires that all individuals working in or frequenting any portion of a restricted area shall be kept informed of the hazards due to radiation in that area.
The failure to instruct workers in the radiation hazards present in the work area is an apparent violation of 10 CFR 19.12.
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(313/8841-03; 368/8841-03)
i 5.
Chemical Cleaning - Primary System The NRC inspectors reviewed licensee activities to determine the possible origin of the hot particles found during the maintenance work on "A" and
"B" steam generator inspection covers. A likely source of the hot particles could be the results of chemical cleaning of the primary system accomplished at the beginning of the refueling outage. As part of the i
Unit 1 1988 refueling outage, the licensee decided to add hydrogen peroxide into the primary coolant system in an attempt to initiate a crud burst to reduce plant radiation levels and subsequent person-rem values.
The chemical cleaning conducted during August through September 1988 was j
the first decontamination of this type perforced by the licensee.
Hydrogen peroxide was added to the system beginning August 31, 1988.
The licensee's data indicated that the hydrogen peroxide acted as a chemical cleaner and dissolved most of.he crud.
During the period September 1-14, 1988, the licensee estimated that about 85 percent (178 cartes) uf the activity in the primary system was removed by the purification
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demineralizers.
There is some speculation that the chemical cleaning procedure could have also dislodged hot particles present in the primary t
system and caused the particles to be distributed to locations such as the steam generator inspection cover areas.
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6.
NRC Inspectors' Observations An inspector observation is a matter discussed with the licensee during
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the exit interview,
^bservations are neither violations, deviations, nor
unresolved items.
They have no specific regulatory requirements, but are
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suggestions for the licensee's consideration.
The following two
observations were noted:
Ternination of Work Activities
i Work continued on steam generator "A" for approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> af ter the
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HP shift supervisor learned of potential overexposure problems on steam
generator "B".
The HP shif t supervisor did not inform
"A" crew of the i
problems encountered on "B" generator and did not determine if work should
also be stopped on "A" generator. Work was stopped when the "A" crew HP technician identified possible administrative overexposures.
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Radiation Work Permit Revisions The HP technician providing coverage for "B" crew stated that he found
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radiation levels "about twice as high as expected." However, he did not delay work and notify the HP shift supervisor to determine if the conditions and requirements specified on the Radiation Work Permit should be reviewed and revised.
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7.
Exit Meeting The NRC inspectors met with the NRC resident inspector and licensee representatives denoted in paragraph 1 on November 4,1988, and summarized the scope and findings of the inspection as presented in this report.
Licensee representatives acknowledged their understanding of the inspection findings.
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ATTACHMENT 1 TLD LOCATION INDIVIDUAL A IND:VIDUAL B mrem mry Head 309 361 Trunk-Front 674 565 Trunk-Back 202 275
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Right Arm 400 516
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Lef t Arn, 464 490 Gonards 1092 1016 Right Leg 2021 1266 Left Leg 3216 1186 Right Foot 1075 1607 Left Foot 1690 2329 Right Hand 534 572 Left Hand 671 740 I
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