ML19256A749
| ML19256A749 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 12/22/1977 |
| From: | Knapp P, Yuhas G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML19256A739 | List: |
| References | |
| 50-213-77-23, NUDOCS 7901100028 | |
| Download: ML19256A749 (14) | |
See also: IR 05000213/1977023
Text
.
.
U.S. NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
,
Region I
Report No.
50-213/77-23
Docket No.
50-213
License No.
Priority
Category
C
--
Licensee:
Connecticut Yankee Atomic Power Company
P. O. Box 270
Hartford, Connecticut 06101
Facility Name:
Haddam Neck Plant
Inspection at:
Haddam Neck, Connecticut
-
Inspection conducted:
November 1-3, 1977
Inspectors: S Ri _3
' - s. 7 7
.
G.1Y has, Radiation Specialist
date signed
date signed
date signed
_
~
C
(w
l t - 2.7. - T 7
Approved by:
P. J. Knapp, Chief, Wdiation Support
date signed
Section, FF&MS Branch
.
Inspection Summary:
Inspection on November 1-3, 1977 (Report No. 50-213/77-23)
Areas Inspected:
Special, unannounced inspection to review the licensee's
evaluation of an individual's exposure to radiation, including Radiation
Protection Procedures; Surveys; Personnel Training; Exposure Control; Area
Posting and Control and Dosimetry Program. Upon arrival, areas where work
was being conducted were examined to review radiation safety control pro-
cedures and practices. The inspection involved 12 inspector-hours on-site
by one NRC inspector.
Results: Of the six areas inspected, no items of noncompliance were found
in four areas; one apparent item of noncompliance was found in one area
(infraction - failure to control exposure to assum compliance with 10 CFR 20.101(a) - Paragraph 5); and one apparent item of noncompliance was found
in one area (infraction - failure to adhere to Technical Specification 6.13
- Paragraph 5).
Region I Form 12
7901100 2
(Rev. April 77)
.
.
,
i
s
DETAILS
-
L
\\
.
1.
Persons Contacted
,/
'
- Mr. R. Graves, Plant Superintendent
- Mr. R. Traggio, Assistant Plant Superintendent
- Mr. H. Clow, Health Physics Supervisor
- Mr. Q. Billingsley, Engineer
s
- Mr. J. Ferguson, Senior Engineer
Mr. R. Capolupo, Jr., Capolupo and Gundal Building Services
denotes those present at the exit interview.
Other Personnel
,
The individual whose exposure is being evaluated was interviewed by
telephone on November 8,1977, November 17, 1977 and December 8,
1977.
2.
Description of Exposure
On October-22, 1977, a contractor assigned as a decontamination
technician, entered the radiation controlled area under an approved
Radiation Exposure Authorization (REA) about 2:00 PM. He exited
the controlled area about 5:30 PM that evening. About 2230, October
22, 1977, the station health physics staff discovered that the
individual's 0-200 mrem and his 0-1 rem pocket dosimeter were off
scale. The individual was restricted from further access to radia-
tion areas and his thermoluminescent dosimetor (TLD) and film badge
were sent to their respective vendors for evaluation. The TLD
'
result was reported as 22.489 rem pn October 24, 1977. The TLD
vendor also reported the results were unusual in that a large
difference in reading between the individual TLD chips existed and
that radfoactive contamination was found on the TLD holder. That
same day the film badge result of 2.710 rem was reported by the
film processor.
The licensee reported the result of his preliminary evaluation to
the NRC, Region I office by telephone on October 31.
An inspector
was dispatched to the site to review this evaluation on November 1,
1977.
,,
1
+
'
,
-
.
3
.
3.
Inspector Review of Licensee Evaluation
The inspector reviewed the following documentation:
a.
Connecticut Yankee Atomic Power Company (CY) Visitor Dosimetry
Issue Report for the individual involved.
b.
The' individual's NRC Form-4, dated October 15, 1977.
c.
The individual's Indoctrination Checklist, dated October 14,
1977.
d.
CY Radiation Exposure Authorization (REA) Serial No. 771787,
dated October 22, 1977.
(This established radiation protection
requirements for the individual's work on October 22, 1977).
e.
The individual's " Pink Exposure Card".
(a card used to record
daily exposure)
f.
Telephone memoranda between the licensee and:
1.
Yankee Nuclear Services (YNS), 1:45 PM, October 24, 1977.
2.
Radiation Management Corporation (RMC), 4:45 PM, October
24, 1977.
3.
RMC, 5:15 PM, October 24, 1977.
4.
RMC, 8:00 PM, October 24, 1977.
(Note:
Film results discussed in this call).
.
5.
YNS,10:30 PM, October 25, 1977.
6.
YNS, 4:00 PM, October 26, 1977.
7.
YNS,1:10 PM, October 27, 1977.
8.
YNS, 4:00 PM, October 27, 1977.
9.
YNS, 12:55 PM, October 28, 1977.
-
.
<
4
10.
RS Landauer, Jr. , Co. , 3:00 PM, October 28, 1977
11.
Northeast Utilities Service Co. (NUSCO), 8:55 PM, October
31, 1977
12.
(NUSCO), 9:00 AM, October 31, 1977
13.
NUSCO, 11:15,AM, October 31, 1977
14.
USNRC Region I, 4:05 PM, October 31, 1977
15.
USNRC Region I, 1:00 PM, November 1, 1977
9
Letter to File from H. Clow, dated October 25, 1977, subject:
"
Personal Investigation - Off-scale Dosimeters
h.
Letter to Yankee Atomic Electric Co., (same as YNS) from licensee,
subject:
Evaluation of Personnel Dosimetry, dated October 25, 1977
i.
Letter to Licensee from Yankee Atomic Power Co., (same as YNS),
dated October 27, 1977, subject:
Evaluation of Personnel Dosimetry
as per your request
j.
Letter to Licensee from Northeast Utilities Service Co., dated
October 31, 1977, subject:
Review of TLD Exposure Report
k.
Radiation Surveys for the controlled areas from October 21, 1977
thru October 24, 1977
1.
Miscellaneous data such as exposure result printouts, test
exposure results, isotopic reports of gama scan of contamina-
tion, etc_.
.
The licensee interviewed the individual and his supervisor in an
effort to establish how such an exposure might have been received.
It was concluded that the individual spent the day performing
normally assigned tasks which included, removing radioactive trash
from the Radiation Control Area (RCA), changing many step-off pads
and attempting to locate some vacuum cleaner parts in the containment.
The individual was usually with someone else throughout the day.
A
review of surveys indicated that the individual was likely to have
passed near areas in which substantial radiation levels existed,
but that the highest dose rates involved were about 700 mrem /hr and
were located in the lower level inner annulus of the containment
near steam generator #1.
No one else on the same REA showed any
~
unusual exposure.
(However, the inspector noted the REA in question
.
.,
5
covered " general access" to the entire RCA and was utilized by 15
individuals for var %us work assignments). The licensee was unable
to establish the cauus of the individual's off-scale dosimeters and
film badge and TLD exposures. The licensee verified that the
dosimeters (Serial Nos. 605540L and 60564H) worn by the individual
had been calibrated in September, 1977.
Resurveys of the contain-
ment on October 23 and 24, 1977, did not reveal any previously
undocumented sources of high dose rate.
The licensee contacted a consultant to discuss the exposure and
salicit recomendations. The licensee requested further informa-
tion and evaluation from the TLD vendor. The TLD vendor reported
that a source of gama radiation located close to the bottom of the
badge could have caused the difference in doses observed on the 4
TLD chips located within the badge.
The TLD vendor made a calcu-
lation in an attempt to estimate the dose that could have been
caused as a result of the contamination discovered on the baage.
This calculation assumed the contamination was present at the time
the badge was loaded and that one third of the contamination re-
mained at the time the contamination was discovered.
(However,the
inspector's review of the vendor's report indicated no basis for
several of the assumptions such as the distribution of contamina-
tion and the subsequent loss of contamination made in the evalua-
tion).
The licensee performed an experiment in an attempt to determine the
response of the dosimetry packet to a nearby point source of gama
radiation.
The results, as would be expected, showed a decrease in
dose on each dosimeter dich was proportional to the inverse square
of the distanca between source and the dosimeter. Attachment A
contains data from this experiment.
The licensee requested a review of the event by Northeast Utilities
Service Company (NUSCO). NUSCO performed an independent review in-
cluding an interview with the individual involved.
NUSCO concluded
that the individual received an exposure of greater than one rem on
October 22, 1977, that the individual had entered high radiation
areas near the steam generator loops, and that, in the opinion of
the reviewer, the TLD holder had been contaminated internally since
the time it was loaded.
NUSCO recomended that the TLD reading be
disregarded and the film badge exposure be entered on the man's
occupational exposure record.
(The inspector noted that no basis,
other than the unsupported opinion regarding TLD contamination, was
given to sustain this recomendation.
Shown in Attachment A, is a
calculation that indicates that less than 1 rem would have been
deposited on one TLD chip based on the amount of contamination
discovered and the time the TLD badge was loaded).
.
.
.
6
,
4.
Telephone Contacts with Individual Involved
The inspector interviewed the individual by telephone on November
8, 17 and December 8, 1977.
The individual was cooperative and attempted to recall all infor-
mation revelant to his exposure.
5.
Inspector Findings
These findings are the result of a review which included independent
inspection of work areas, observation of the licensee's exposure
control technique, evaluation of pertinent data, and discussions
with the health physics staff, contractors, and the exposed indi-
vidual.
The individual had sucessfully completed the licensee's indoctrina-
.
tion training on October 14, 1977.
He had no previous experience
as a radiation worker prior to October 15, 1977.
'
The following items of apparent noncompliance were revealed.
A.
Technical Specification 6.18, states,
"In lieu of the ' control
device' or ' alarm signal' required by paragraph 20.203(c) (2)
of 10 CFR 20:
Each High Radiation Area in which the intensity of radia-
tion is greater than 100 mrem /hr but less than 1000
'
mrem /hr shall be barricaded and conspicuously posted as a
High Radiation Arca and entrance tnereto shall be controlled
by issuance of a Radiation Exposure Authorization and any
individual or group of individuals permitted to enter
such areas shall be provided with a radiation monitoring
device which continuously indicates the radiation dose
rate in the area."
Contrary to this requirement the individual stated to the
inspector that he entered the inner anulus area lower
level near the bottom of the steam generators and reactor
coolant piping on the afternoon of October 22, 1977 alone
and without a radiation monitoring device which continuously
indicates the radiation dose rate in the area.
Licensee
surveys indicate whole body dose rates up to 700 mrem /hr
in this area. The lack of the required monitoring device
constituted noncompliance with Technical Specification
s
6.13A.
(50-213/77-23-02)
_
%
e
7
B.
Technical Specification 6.11 states, " Procedures for personal
radiattan protection stall be prepared consistent with the
requirement of 10 CFR Part 20 and shall be approved, maintained
and adhered to for all operations involving personnel exposure."
Pursuant to this Technical Specification, Connecticut Yankee
developed and implemented Administrative Procedure No. ADM
1.1-37, Radiation Exposure Authorization, Flow Control.
The individual was working under a Radiation Exposure Authori-
zation (REA) number 771787. This REA stated " Continuous
Health Physics Coverage Required." The individual stated to
the inspector that during entry into the inner anulus area on
October 22, 1917, to remove the blotter paper used during
steam generator work he was not accompanied by a health physics
technician.
This failure to follow prgcedure is covered in the report of
Inspection 77-21.
-
.
Administrative Procedure No. ADM 1.1-37 requires that, "The
job supervisor shall enter the exposure received (dosimeter)
on the " white copy" of the REA (posted at HP Control Point)
upon completion of job."
Contrary to this requirment the individual stated to the in-
spector that he, rather than the job supervisor, entered
"0"
exposure received on REA 771787.
This failure to follow procedure is covered in the report of-
Inspection 77-21.
C.
The inspector attempted to locate facts that might substantiate
levels of contamination on the individuals TLD badge which
could have resulted in the dose recorded by that dosimeter.
The amount of cot.tamination discovered by the TLD vendor would
- not have caused the reported exposure (see Attachment A).
If '
the badge had been contaminated to a level sufficient to cause
the reported exposure the individual might have discovered the
contamination when surveying himself.
The individual stated
to the inspector that he had checked himself at the hand and
foot counter when leaving the containment building at least
-
,
-
.
8
four times on the ofternoon of October 22.
He then surveyed
himself and his dosimetry packet again after removing his
anti-contamination clothing in the change room on the same
four occasions. He stated ~ that during the week of October 15
thru October 22 he never discovered any contamination on his
dosimetry packet and he never caused the hand and foot counter
to alarm.
Another possible indication of substantial contamination on
the TLD bage would have been the exposure results recorded on
the 0-200 mrem pocket dosimeter which was located in his
dosir:etry packet. However, the exposures recorded for this
dosimeter from October 15 through October 17 do not indicate
any unexplained accumulation of exposure that might be attrib-
uted to contamination in the dosimetry packet.
Neither the licensee or the TLD vendor have reported finding
substantial contamination that may have come from the.TLD
badge or the individuals dosimetry packet.
-
At this tirre sufficient evidence to disregard the TLD badge
results on the basis of contamination to the holder has not
been presented by the licensee or been discovered by the in-
spector.
s
D.
The distribution of dose among the individual's TLD chips,
film badge and pocket dosimeters is consistent with an exposure
to a point source of gamma radiation no closer than a few
centimeters in front of the bottom of the TLD badge.
See
Attachment A for details.
10 CFR 20.101(a), " Exposure of individuals to radiation in re-
stricted areas" requires that no licensee shall cause any in-
dividual in a restricted area to receive in any period of one
calendar quarter a dose in excess of 7-1/2 rem to the skin of
the whole body.
'
The inspector noted that, in the absence of additional facts
and data to permit a more precise determination and in view of
the fact that the employee's dosimeter readings were consistent
with localized exposures in excess of the quarterly limit for
skin exposures, this finding represents noncompliance with 10 CFR 20.101(a) (50-213/77-23-01).
.
9
.
Several possible examples of how the individual may have been
exposed to a source of radiation were presented to the in-
spector:
1.
The individual stated to the inspector that he did not
survey the anti-contamination clothing that he wore at
the facility. On at least two occasions workers dis-
covered specks of contamination reading 200 mrem /hr in
,
the clean anti-contamination clothing.
(however,the
exact intensity is not known due to detector location and
geometry).
2.
The individual stated to the inspector that in the week
of October 15 thru October 22 he lost his entire dosimetry
-
packet for about a half hour.
The packet was located in
a drum of used anti-contamination cloth'ing.
Since the
individual did not inform the licensee of this event no
effort was made to evaluate the dose to the dosimeters in
the packet.
3.
The individual stated that as far as he knew the materials
.
he collected from the containment such as blotter paper
(sheets of absorbant material used to minimize the spread
of contamination), were not surveyed prior to his removing
them from the work areas on the afternoon of October 22,
1977. The individual worked about two hours removing
materials from the containment lower level inner anulus.
No specific instance could be identified as the cause of this
exposure.
6.
Additional Item
On November 3, 1977, the inspector observed that the Guard House
Portal Monitor Serial No. 184 did not have a current calibration
sticker affixed. The licensee demonstrated that the portal monitor
was functioning properly according to the calibration procedure PM
9.6-1.13 but could not locate the documentation required by the
procedure.
.
-
.
10
This matter is covered in the report of Inspection 77-21.
7.
Exit Interview
The inspector met with licensee representatives (denoted in para-
graph 1) at the conclusion of the inspection on November 3, 1977.
The inspector summarized the purpose and the scope of the inspec-
tion and the findings. The licensee indicated the dose assessment
was still in progress.
Followup telephone calls to the licensee on November 16 and 17,
1977, advised him that subsequent findings after review of the
data, indicated that all dosimeter readings were consistent with
exposure of the individual to a point source of radiation located
within a few centimeters of the body.
.
I
.
.
,
11
ATTACHMENT A
I.
Licensee
["'"'---~-------~~3
Experimental
!
\\
Personnel Dosimetry {
-
-
Packet
t
. Pocket Dosimeter -
I
fi
i
-
.
'
'
Plastic Bag
Film Badge
f
-
'
!
/
l
O
U
TLD Badge
'
C
D
<
j
TLD Chip
.
.
q/
.
,
\\
s
O
"
A
B
.'
.
i
Y~
e
~ ~ ~ ~
60
5.86 met Co source
60
A 5.86 mei Co
source was placed about 1/4" from the right corner
of the packet. The exposure time was 64 minutes.
Test Results
Film badge 1.8 rem (1 remy , .8 rem 9;
Beta possibly due to scatter)
dosimeter 660 mrem.
.
.
.
.
.
12
.
II. NRC estimate of possible dose to TLD chip due to contamination.
Given:
TLD Vendor located Ex103 dpm on TLD holder.
The TLD chips are located 2.5 cm apart vertically and
1.9 cm apart horizontally.
The TLD chips were loaded for 35 days according to the
TLD vendor.
Assume:
The source of activity emitted one gamma of one mev
per disintegration.
(A qualitative isotopic identification
by gamma spectroscopy indicated thirteen isotopes pre-
sent, the licensee used .7 mev per disintegration).
,
All the contamination was located 1 millimeter from one
TLD chip..
-
The contamination was present for the entire period the
badge was loaded.
2
Then:
6x103 dpm x 4.5x10-10 mci x .5 mrem /hr x (100 cm1 x 600 hr
dpm
mci
(.1 cm)'
= 810 mrem exposure to 1 chip.
The TLD chips are arranged as shown below.
If chip A
received 810 mrem an inverse square calculation indicates
,
that chips B, C and D would have received doses that
may not have been detectable.
.
A
B
A
810 mrem
B 2.24 mrem
C 1.25 mrem
C
D
D
.8 mrem
-
.
.
13-
III.
.Possible location of source.
The following data for each chip within the individual's TLD
badge was provided by the licensee on December 6,1977.
NG-67
G-7
Chip 1
Chip 1
12.45 rem
15.34 rem
NG-67
G-7
Chip 2
Chip 2
23.50 rem
22.49 rem
The licensee stated that the film badge could have been located
up to 31/4 inches from the lower chips (NG-67 Chip 2, G-7
Chip 2) and still have been in the heavy plastic dosimetry
packet worn by all monitored personnel.
To demonstrate that a single point source of radiation could
have caused the readings observed on each dosimeter within the
-dosimetry packet, assume that the source was located between
-
NG-67 chip 2 and G-7 chip 2 and about 3 cm in front of the TLD
badge.
This would mean that NG-67 chip 2 and G-7 chip 2 would have
been 3.1 cm from the source.
NG-67 chip 1 and G-7 chip 1 would have oeen 4.0 cm from the
source.
The film badge could have been 8.8 cm from the source.
The 1 R pocket dosimeter could have been up to 10.6 cm from
the source. The 200 mR pocket dosimeter could have been no
further aw /.
Using the inverse square relationship, the dose to each of the
above dosimeters located within the individual's packet would
have been:
NG-67 Chip 2, G-7 Chip 2
23 rem
NG-67 Chip 1, G-7 Chip 1
13.8 rem
Film badge
2.8 rem
1 R pocket dosimeter
1.9 rem (off scale)
accordingly, the 200 mR pocket dosimeter would have been off
scale.
.
.
.
14
.
This source would have caused a reading of about 240 mrem /hr
at a distance of one foot. Such a source might have missed in
a cursory survey in a 700 mrem /hr field.
,
e
e
4