IR 05000413/1990023
| ML20059L422 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 09/10/1990 |
| From: | Hughey C, Potter J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20059L417 | List: |
| References | |
| 50-413-90-23, 50-414-90-23, NUDOCS 9009260308 | |
| Download: ML20059L422 (9) | |
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'o NUCLEAR REGULATORY COMMISslON '
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0-101 MARIETTA STRE ET, N.W.-
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p; Report Nos.:-50-413/90-23 andL50-_414/90-23'
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L icensee: Duke Power Company.
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422 South Church Street-
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-Charlotte, NC 28242
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- Docket Nos.i-50-413 and 50-t "
License Nos.:-NPF-35 and NPF-52
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Facility Name:
Catawba: 1'and 2
- Inspection Conducted:f uly 30
' August 3, 1990 J
Inspector: - - Mb/I' d WM/o f/o/fe E
Hug ey v{
Dgte Jigned
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f/d/90-
- Approved by
'. Facilities Radiation' Protection Section fterSigned
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- Emergency-Preparedness and Radiological-
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' Protection Branch
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Division, of, Radiation. Safety and' Safeguards
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'This routine, unannounced inspection of the;- radiation protection program was =
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" conducted in the areas of internal and externa,1 exposure control, contamination '
control,'and-ALARA~.
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- Results:'
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In-.the areas inspected, violations'or deviations were not identified.
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- licensee's whole body' counting program WaLadequate in ensuring accurate counting results. Reconnended improvements oto'the quality control program were.
discussed (Paragraph 2).
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-The origina1 J combined units 1990 person-rem goal fha'd been ' revised upward'
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because of higherethan anticipated collective dor.s during.the Unit 1 %tage..
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years _ appeared to be reversing after the implementation of additional controls..
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'There: had 'been a isignificant Lreduction in contaminated area since 1989
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(Paragraph 3).'
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9009260308 900914 i
PDR ADOCK 05000413
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~ An induced crud burst was performed prior to the Unit 2 outage to reduce source
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- term. - A flush of the reactor coolant system letdown system piping was
. performed to reduce higher than expected does rates. The inspector attended a
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demonstration -of - a robotic arm for the installation and removal; of steam
- generator r.ozzle dams (Paragraph 4).
L A grating-to restrict access to the Unit 2 regenerative hee t exchanger area (extra high radiation area) was approved as a permanent fixture subsequent to
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theendoftheinspection(Paragraph 5).
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O s REPORY DETAILS
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persons Contac *
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Licensee Employees
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D. Clum, Staff Scientist
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- W. Deal, Radi; tion Protection Manager l
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- J. Forbes, Manager, Technical Services
- C. Hartzell, Compliance Manager
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B. Kimray, Supervisor, ALARA i
- V. King, Compliance
- J.. Knuti, Operations Support Manager i
G. Mode, General Supervisor
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T. Owen, Catawba; Station Manager
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- L. Schlise, General Supervisor
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Other licensee employees contacted during this inspection included technicians, security, and office personnel.
Nuclear Regulatory Commission
- W. Orders, Senior Resident Inspector
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- J.-Zeiler, Resident Inspector 2.
Internal Exposure Contal (837S0)
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10 CFR 20.103(a)(3) requires, in part, that the licensee, as appropriate,
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use measurenents of radioactivity. in the body, measurements of radioactivity excreted from the body, or any combination of.such
measurements as may be necessary for timely detection and assessment of i
individual intakes of radioactivity by exposed individuals.
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Whole Body Counting
-The licensee's onsite whole body counting equipment consisted of one L
Canberra Fastscan standup type counter containing two Sodium Iodide detectors. This equipnent was normally used for one minute screening
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counts. ' Any dagnosti:: evaluations / counts for potential internal L
contaminations were perforned in a whole body counting chair located at-an offsite corporate support center.
- Efficiency calibrations were perforned annually.
A calibration
verification could be substituted for a full calibration if an efficiency curve check at.several preselected points was within plus
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or minus 10 percent of the previous efficiency curve. The inspector reviewed the annual etilbration package completed June 17, 1990, and found it to complete and in accordance with procedure HP/0/B/1001/21, Operation and Calibration: Canberra Fastscan-Body Burden Analysis, dated May 30, 1990. The calibration / verification was perforned using c
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a mixed gama source which was traceable to the National Institute of.
' Standards and Iechnology.
Daily performance checks were performed by counting a Cobalt-60 (1173 kev) and Cobalt-57(122 kev) check source and plotting the results on
a control' chart. Acceptance criteria that was within plus or minus 3 standard deviations of an established mean. Daily background checks were also performed.
Control charts were reestablished quarterly with new acceptance criteria that was also determined quarterly. The inspector noted that the new acceptance criteria was not based on nor tied to the previous calibration and, therefore, the newly established control charts would only indicate deviations trom the newly established mean and not from the latest calibration.
The licenses agreed to r/oluate the possibility of establishing control charts at the tine of the annual calibration and using these same limits (correctt.d for radioactive decay) for the entire calibration period.
Also discussed was the benefits of establishing control limits based on 20 or more counts instead of 10 counts as indicated by procedure.
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Internal Contaminations During 1990 so far, there had been no apparent uptakes greater than 0.5 percent maximum permissible organ burden IMP 0B), and therefore, no resultant dose assignnents from internal contamination.
No violations or deviations were identified.
3.
Person-Rem Status, Personnel Contamination Events, and Contaminated Square Footage (83750)
10 CFR 20.1(c) states that persons engaged in activities under licensas issued by the NRC should make every. reasonable effort to maintain radiation exoosures ALARA.
a.
Pr<rtr..ne. (tatur.
The inspector revieved site collective doses since 1988, and discussed thn trends and the (current 1990 goals with cognizant pl: int personne1. The following chorts t.umarizes these doses:
PERSON-R! Tit FOR UNITS 1 AND 2 YEAR GOAL ACTUAL 1988 552 556 1989 474 334
1990 062 615*
- As of June 30, 1990
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Th original combined units 1990 goal of 594 person-rem had been 11<1 sed upward to 862 person-rein because of higher than anticipated collective doses during the Unit 1 outage (January - April 1990)
resulting mainly from higher than anticipated dose rates during the changtout' of the Resistance Teniperature Detectors (RTDs),
unanticipated steam generator work (tube pull) and the resultant outage extension from 65 to 88 days.
Actual collective dose during the Unit 1 outage had been 499 person-rem.
The original goal for the Unit 1 outage was 310 person-rem.
At the time of the inspection, Unit 2 was about 50 days through a planned 70 day refueling outage. The collective exposure estimate for-the outage was 327 person-rem.
As of July 27, 1990, actual
' collective exposure was 185 person-rem. Actual exposures were trending well below estimated exposures, b.
PersonnelContaminationEvents(PCEs)
The inspector reviewed PCE suninaries since 1987.
The criteria for tracking a contamination event was greater than 150 disintegrations per minute above background on skin or clothing and did not include noble. gas or natural product contaminations. The PCEs since 1987 are summarized below:
Year No. of PCEs 1987 210 1988 281 1989 361
- 1990 517(goal)
- As of June 30, 1990 there were 303 PCEs The significant increasing trend in PCEs since 1987 was of concern to the. inspector; however, since the end of the Unit 1 outage, the licensee had implemented certain additional controls that appeared to De initially ef fective in reversing this trend.- The controls were the result of an extensive investigation by the radiation protection staff. Some of these controls were:
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Useofastaticeliminator(" Bounce")whiledryingcontamination
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protective clothing (PCs) to facilitate the removal of charged radioactive particles.
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More frequent routine and followup trasslin surveys.
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More and larger sticky pads for the removal of loose.
. contamination on shoes, 4)
Improved bagging methods for equipn.ent/ tool removal out of
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contaminated areas (use of smaller bags).
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Redesign of the entry point to lower containment to improve
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radiation protection's ability to observe undressing techniques
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and to minimize interfaces between workers inside and outside this contaminated area.
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Use of disposable paper coveralls over protective clothing (PCs)
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in lower containment to prevent the possible svead of
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contamination from " clean" PCs.
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More ef fort in the general decontamination of containment prior
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To help reduce noble gas contam1 nations, thc security force was switching from polyester to cotton unifoms.
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establishment of future contamination goals for the various plant work groups based on the number of previous personnel
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contamination events with a 10 percent reduction.
The. inspector also noted that about 90 percent of the licensee's '
Radiological Incident Investigation and Accountability (RIIA) reports
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were as a result'of PCEs and over 9 percent were from nobic gas and natural product (radon daughter) contaminations.
The effort to reduce PCEs will be of interest during future
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Contaminated Square footage The inspector noted a large decrease in the amount of contaminated area since 1989.
During May 1989, there was 26,762 square feet contaminated (out of a possible 160,000 square feet).
by December 1989 thu amount had been reduced to 5,798 square feet.-
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h currently through the Unit 2 outage, the amount remained consistently l
around 6,000 square feet.
This significant reduction was mainly
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No violations or deviations were identified.-
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As Low As Is Reasonably Achievable (ALARA) (83750)
I-10 CTR 20.1(c) states, in part, that licensees should make every
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reasonable effort to maintain radiation exposures as far below the limits l
.specified in Part 20 as is reasonably achievable.
Recommended elements nf i
l an ALARA program are included in Regulatory Guides 8.8 and 3.10.
a.
Crud Burst
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products, the licensee performed a crud burst at the beginning of the Unit 2 refueling outage. This crud burst occurred in two steps. The l
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first took place as the reactor coolant system (RCS) boric acid
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concentration was increased to raintain the reactor in safe shutdown i
condition resulting in a depression of' the pH.
By the end of the
boration about 1555 Curies of Cobalt-58 and 27 Curies of Cobalt-60
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had been removed through the chemical volume and control system
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(CVCS). Thesecondstep(inducedcrudburst)occurredwhen76 liters
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of hydrogen peroxide was injected into the RCS. This caused a prompt
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oxygenation of the RCS to 6 parts per million resulting in the,
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removal of an additional 503 Curies of Cobalt-58 and 6 Curies of f
Cobalt-60 through the CVCS demineralizer. A total of 2058 Curies of
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Cobah 58 and 33 Curies of Cobalt-60 was removed during the entire operation.
b.
RCS letdowa line flush After the sh:stdown for the Unit 2 refueling outage (2E003), the i
licensee discovered radiation readings (500 to 2.000 mR/hr) on the RCS letdown line inside containment to be sigrificantly higher than
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usual.
The licensee surmised that this increase occurred when the
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letdown system was normally isolated during the shutdown.
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system isolation occurred, unfortunately, during the same time period
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as the induced crud burnt (discussed above).
This trapped highly contaminated water insi, the letdown system piping before it could be cleaned up through the demineralizers. To reduce dose rates from the piping, the licensee later flushed the system for approximately 8
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l hours with CVCS demineralized water which resulted in average dose
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Remote steam generator nozzle dam removal
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L l-The inspector observed the demonstration of a robotic ' arm used for the removal and installation of steam generator nozzle dams.
The demonstration was performed on steam generator mockups located at the licensee's facility.
The arm could be installed in the steam generator bowl within 15 minutes.
The subsequent remote removal and insta11atica of the nczzle dams was performed within a similar time period.
During the beginning of the Unit 2 outage, nozzle dams were installed manually in the s;eam generators.
These dams blocked water from the hot and cold legs into the steam generator during refueling operations allowing steam generator inspection hetivities to be conducted simultaneously with refueling operations. Removal of these nozzle dams was to be accomplished with the remote mechanical arm,
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nozzle dam for practice.
An estimated dose savings of about 10
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person-rem was anticipated as a result of the use of these robotic L
arms.
The licenset had purchased two of these units for use during
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future outages.
No violations or deviations were identified.
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External Exposure Control (83750)
Section 6.12.2 of the Technical Specifications states in part that areas accessible to personnel with radiation levels greater than 1,000 mR/ hour at 45 centineters (18 inches) from the radiation source or from any surface which the radiation penetrates shall be provided with locked doors to preven + unauthorized entry.
This section also states that for individual high radiation areas accessible to personnel with radiation levels grrster than 1000 mR/ hour that are located within large areas, such
- s PWR containnent, where no enclosure exists for purposes of locking, and where no enclosure can be reasonable constructed around the individual area, that individual area shall be barricaded, conspicuously posted, and.
a flashing light shall be activated as a warning device.
NRC Information Notice 88-79; " Misuse of Flashing Lights for High Radiation Area Controls." dated October 7, 1988, gives additional guidance on the problems involving the misuse of the flashing lights and the interpretation of the Technical Specification.
During an extensive tour of the Unit 2 containment, the inspector noted that the entrance hatch to the regenerative heat exchanger area was posted as an extra high radiation area (greater than 1,000 mR/ hour) and was further posted with a flashing light.
The heat exchanger area entrance was accessed from the 565 foot elevation of lower containment up a 6 foot ladder permanently attached to the wall.
To prevent unauthorized entri the licensee had additicnally wrapped the ladder with plastic sheeting. A lockable door was not installed at the entrance to the heat exchanger
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L A radiological survey conducted in the regenerative htat exchanger room on July 18, 1990, indicated that the highest general area radiation reading was 1,700 millirem per hour with the highest contact reading (on the heat exchanger)being3,000milliremperhour.
After the inspector questioned as to why the area was not locked, the licensee proauced Work Request Number 0837 HPS dated September 28, 1988, requesting the fabrication of grating covers to be placed over the entrance to the Unit i regenerative heat exchanger room.
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inspection, the licensee determined that the rovers had Nen completed but l
l had been stored in a warehouse for several nonths.
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protection group was unaware that the covers had ken fabricated and L
stored.
Subsequently, during the week of the inspection, the grating was temporarily secured over the entrance to the Unit 2 regenerative heat exchanger area by chaining and locking to the ladder below.
Subsequent to the inspection the Radiation Protection group requested the
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Design Engineering Group to evaluate the feasibility of leaving the l
gratings in place during power operations.
Possible seismic interactions of the grating with Quality Assurance (QA) Condition I components during an accident was of concern to the licensee.
As a result of this evaluation, the Design Engineering Group determined that it was acceptable i
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for the gratings / barriers to remain in place during plant operations after some minor modifications.
This evaluation also applied to Unit I which had a similar situation.
This evaluation was docurented by the licensee in a Memo to file No. CN-1144.06, CN-1144.13, dated August 29, 1990. As of August 30, 1990 the Unit 2 grating / barrier had been modified and was in place as a permanent control.
The grating to the Unit I heat exchanger
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entrance was to be installed during the next feasible power entry since the unit was at full power.
No violations or deviations were identified.
6.
PlantTour(83750)
The inspectcr spent several hours touring the Auxilary Building and Unit 2 containeent (upper and lower) noting general radiological conditions, potting, and housekeeping.
General area dose rates in Unit 2 containnent varied between 10 and 50 mR/ hour.
The icwer containment area was very congested, due to the design features of the ice condenser containtent, making work very difficult in many areas. Housekeeping was generally good in all areas of the plant except around the Unit 2 steam generator lower manway access platforms.
No violations or deviations were identified.
7.
InformationNotice(92717)
The inspector reviewed Information Notice 90-44; Dose-Rate Instruments Underresponding to the True Radiation Fields," dated June 29, 1990, with the licensee.
The inspector insured that the hotice had been received by the appropriate plant personnel since radiation detection instrumentation referred to in the Notice is comonly used on site by the licensee.
No violations or deviations were identified.
8.
Exit Interview 1he inspection scope and results were sumarized on August 2,1990, with those persons indicated in Paragraph 1.
The inspector. described the areas inspected and discussed the inspection findings.
Proprietary information is not contained in this report.
Dissenting coments were not received from the licensee.