IR 05000259/1981005
| ML18025B495 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/06/1981 |
| From: | Hosey C, Troup G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18025B489 | List: |
| References | |
| 50-259-81-05, 50-259-81-5, 50-260-81-05, 50-260-81-5, 50-296-81-05, 50-296-81-5, NUDOCS 8105120226 | |
| Download: ML18025B495 (12) | |
Text
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UNITEDSTATES NUCLEAR REGULATORY COMMISSION
. REGION II
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101 MARIETTAST.; N:W., SUITE 3100
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ATLANTA,GEORGIA 30303 Report Nos.
50-259/81-15, 50-260/81-5 and 50-296/81-5 Licensee:
Tennessee Ijtalley Authority 500A Chestnut Street Chattanooga, TN 37401 Facility Name:
Browns Ferry Docket Nos.
50-259, 50-260 and 50-296 License Nos.
DPR-33, DPR-52 and DPR-68 Inspection at. Browns Ferry Nuclear Plant near Athens, Alabama Inspector:
G. L. Troup Approved by: '~ yV C.
M. Hos y, cting Chi f, Facilities Radiation
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Cr If)
Date Signed Date Sig ed
Protection Section, Te hnical Inspection Branch Division of Engineering and Technical Inspection
.SUMMARY, Inspection on February 9-13, 1981 Areas Inspected
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This special; unannou'need insp'ection involved 33 inspector-hours on s'ite in'the
,,".:,.;.,areas, of-..radiant jon. protecti on"..encl ud/IIg.eval uati on'
f, personnel, doses,, author.-...,,....,
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ized dos'es, dosimetry'nd" reportselating" to an 'appar'e'nt" overex'posu'r'e'f 'a'
worker.
Results Of the four areas inspected, no violations of NRC 'requirements or deviations were identified in three areas; one violation was found in one area (.failure to retain exposure data in accordance with 10 CFR 20. 102.).
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DETAILS Pesons Contacted Licensee Employees Browns Ferry Nuclear Plant
"J. L. Harness, Assistant Plant Superintendent
"D. C. Cummins, Assistant Health Physics Supervisor
- R. T. Smith, equality Assurance Supervisor
~T. L. Chinn, Compliance Supervisor
~E. M. Cargill, Assistant Radiation Control Supervisor (Outage)
- W. Simpkins, Health Physics Engineer Radiological Hygiene Branch, Division of Occupational Health and Safety S.
G. Bugg,'upervisor, Radiation Exposure Management Group Nuclear Power Division, Office of Power J.
W. Hufham, Assistant to the Director Other licensee employees contacted included 2 construction craftsmen,
technicians, 2 security force members and 3 office personnel.
NRC Resident Inspector
- R. F. Sullivan
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J.
W. Chase
"Attended exit interview
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Exit Interview The igspection scope and findings were summarized on February 13, 1981 with those persons indicated in paragraph 1 above.
The inspector reviewed the results of his investigation of the apparent overexposure and stated that his investigation indicated that the individual had not received a dose to his body of the magnitude indicated by the TLD.
This was the same conclu-sion which the licensee had reached.
Regarding the violation concerning retention of exposure forms (paragraph 6),
the inspector stated that the principal concern dealt with the large numbers of records which are pro-cessed during outages and the need to implement controls to assure that they are handled.and,.filed peoperly.,
nqt just the specifics of one.particular record.
These comments were acknowledged by Mr. Harness.
Licensee Action on Previous Inspection Not inspected.
Findings e
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Unresolved Items Unresolved items were not identified during this inspection.
5.
Description of Event a.
On January 6,
1981, the TVA Radiation Exposure Management Group reported that the thermoluminescent dosimeter badge (TLD) issued to an outage worker (individual A) for the month of December, 1980 indicated a
dose of 2.818 rems.
When this dose was added to the dose previously received by the individual during the fourth calendar quarter, the total dose for the quarter was 3.429 Rems;
CFR 20. 101 (b) specifies a maximum dose during a calendar quarter of 3 Rems.
b.
On January 7,
1981 the Radiation Exposure Management Group reported that the TLD issued to another outage worker (individual B) indicated a
dose of 2.21 Rems.
The fourth quarter dose for thisindividual was 2.793 Rems, which is below the regulat'ory limit.
C.
Both individuals were outage workers working in the same work crew.
No other workers on the crew received a dose for the month of December greater than 600 millirems as measured by TLD.
The doses for the two individuals as measured by self-reading dosimeters were 804 millirems and 786 mi llirems, respectively.
6..
Evaluation of Doses a.
Following the identification of the apparent overexposure to indivi-dual A, the licensee initiated an investigation to establish the validity of the dose and to identify the cause(s)
of the overexposure.-
. Included 'in this.investigation were:..
Review...of:.dosimeter,,logs.
(rezero..logs),
r adiological.,;-incident...,
re'port's,'nd'pecial
'work perm'its (SWP's')';"'2)
Review of radiation surveys of work areas and conduct of special radiation surveys to identify any hot spots or streamers which might have previously not been identified; (3)
Calculation of doses based on radiation levels and stay times for each SWP; (4)
(5)
Interview with both individuals and the crew foreman; Comparison of. doses for. bath',ndividuals with the doses of other workmen who performed'he same work at hhe same time; and (6)
Testing of TLD's for adequate respons b.
Based on this investigation, nothing was identified which indicated that the doses received. by the two individuals were of.the magnitude measured by the TLD's.
The inspector reviewed the results of the licensee's investigation, independently calculated doses based on the SWP information and compared the doses received by other members of the work crew with the doses for the two individuals for both self reading dosimeters and TLD's.
The inspector also inspected the TLD storage area for possible sources which might have affected the measured doses, and reviewed the records of when radiography was performed in the areas where the individuals worked.
The inspector did not identify any probable cause for the high dose for the two individuals.
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The inspector also interviewed the general foreman and individual A by telephone.
Neither individual. was able to provide any information not previously prov'ided to the licensee.
Neither individual was able to provide any information which would explain the disparity in doses between the workers on the crew and individuals A and B.
7.
Authorized Doses a
permits an individual to receive a whole body dose of 3 rems provided that a
Form NRC-4 has been completed in accordance with'ection 20. 102, and the accumulated lifetime dose does not exceed
, 5 (N-, 18)
rems.
If, these, actions have not been. completed, then the permissible dose is l>4 rems per calender quarter.
b.
The inspector reviewed the records for individual A and verified that a current:Norm-NRC-4 had been completed by him in September 1980.
The
.inspector.= also.
reviewed. the
. Personnel'..
Exposure Computer Printout, (issued twice daily) and verified that the cumulative lifetime do'se and
,, al,l.owable lifetime,.hosp,hag...been.
determi.oed....,Neither:.
an, autharized,...,...,
'" " 'dose'f 3 rems'or tfie 'assigned dos'e of 3'.4'29 'rems would'iave resulted'=
in the individual exceeding his allowable lifetime dose.
The inspec-tor had no further questions on the authorized dose for individual A.
C.
The inspector also reviewed the dose records for individual B.
How-ever, the licensee could not locate the current Form NRC-4 either in the plant files or in the dosimetry files.
Discussions with indi-viduals involved with these records at the plant revealed that the individual had fill'ed out the Form NRC-4 in November 1980.
The indi-viduals involved stated that the individual and his foreman had come to the office together and discussed the need for a current form before it was signed, The. in.spector reviewed the. Personnel Exposure Computer Printouts for November 26.
The first printout at': 14 a.m; showed that the individual did not have a current form and his allowable quarterly dose was 1,250 mrems; the second printout at 7: 19 p.m.
showed that the individual had a current'form and his allowable quarterly dose was
3,000 mrems.
The individual who does the computer input told the inspector that the data are taken directly off the form so if the computer base was changed, then the completed form was available.
Based on the computer records and discussions with the personnel, the inspector concluded that a
Form NRC-4 had been completed for indivi-dual B but had been lost or misplaced.
Despite an extensive search of the files, the form could not be located.
d.
CFR 20. 102(c)(2)
requires that the licensee shall retain and pre-serve records used in preparing Form NRC-4.
In that the form could not be located after an extensive search the inspector concluded that it had not been retained.
This is a violation.
(259/81-15-01, 260/296/
81-05-01).
The inspector emphasized to licensee management that care must be exercised to assure that personnel records such as these are properly handled and filed, expecially when during outages when copious amounts of records are being generated.
This comment was acknowledged by licensee representatives.
Dosimetry a.
During work in the radiation control areas, individuals wore both self-reading dosimeters and thermoluminescent dosimeters (TLD's).
Doses recorded on work permits were based on self-reading dosimeters.
The inspector asked if the dosimeters used by the two individuals had been checked for accuracy, malfunction, etc.
A licensee representative stated that for much of the work; high range dosimeters had. been issued.
when entering the area and returned when exiting.
The same dosimeter was not used each time so any discrepancies which might be identified with a particular dosimeter could not be related to the dose any particul.ar'individual,may or may not have received.
b.
The TLD's used by-TVA contain two chips.
To evaluate the dose, each
,,,, ch$ p,. 3;s.,read.seperately.:.,
Tge...inspector,
.reviewed, the strip chart,,..
'ri'nt'o'ut *for 'the 'energy out'put ("glow'urves" ) for 'the
'two ch'ip's'n " " """ '"
the TLD worn by individual A., glow curves for other chips and the light response curves for checking the instrument performance.
The relative size of the peaks for the two chips were comparable and were markedly larger than the peaks for other chips.
The shapes of both curves were consistent with the curves for other chips and indicated no anomalies or breaks and the light response curves appeared normal.
Based on these records the inspector did not identify any irregulari-ties which would invalidate the dose of 2.818 Rems which was reported for the TLD of individual A.
c...A licensee representative discussed the checks performed on the TLD
'" chips, which included checking for a retained dose due to"improper preparation and response to a
known dose.
The licensee representative stated that the checks did not indicate the presence of a retained dose and the chip responded properly to the known dose.
The inspector
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reviewed the data from the exposure of several chips, including the two chips from the TLD issued. to individual A, and concluded that the response to a
known dose was consistent for the chips and did not indicate any anomaly in the performance of the chips.
A licensee representative stated that. based on the checks of the chips, the dose of 2.818 Rems was measured by the chip as a true dose but nothing can be concluded concerning the dose which the individua,l might have received because there was no way of determining when or how the dose was received.
9.
Reports a.
CFR 20.405 (a) requires that each licensee shall make a report in writing within 30 days of each exposure of an individual to radiation in excess of the applicable limits in section 20. 101.
On February 4,
.1981 the li,censee submitted a written report of the exposure which
. exceeded the quarterly limit for whole body exposure of 10 CFR 20. 101-(b).
After.reviewing the report the inspector had several questions concerning the actions taken during the investigation by the licensee and the conclusions drawn.
These were discussed with a
licensee representative during the inspection.
The inspector requested that a
supplemental report be submitted to clarify these questions; this was t
acknowledged by the licensee representative.
A supplemental report was submitted on February 13, 1981.
The inspector had no further questions concerning the report.
C b.
CFR 19.13(d) requires that when a licensee is..required pursuant to
CFR 20.405 to report to the Commission any exposure of an indivi-dual in excess of regul,atory. limits, the licensee shall also furnish the'i.ndividual,.a report on his exposure data.
The inspector reviewed
- .the report"whi.ch'-was: sent".to 'individual',A,on.February. 4, 1981..in: ac.-
cordance with 10 CFR 19. 13(d); the inspector had no further questions.
10.
Conclusion a.
In the report of the event, the licensee stated
"based on work records and pocket dosimeter data, there is no indication of an exposure of the magnitude indicated by the TLD badges".
This position gas substanti-ated by the licensee's investigation and by the inspector's review.
The inspector concluded that the individual did not receive a dose to.
his person of the magnitude on the TLD and that an overexposure had not occurred.
b.
The licensee's report further stated
"since this discrepancy cannot be accounted.,for, the TLD data will. be entered;into the radiation exposure
'ist'ory for these employees."
The inspector noted that this was a
conservative approach and concluded that this was an acceptable re-solution of the discrepanc ~
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