ML20215G320

Insp Repts 50-266/87-11 & 50-301/87-10 on 870428-0519, Violations Noted:Failure to Properly Train Employees Using Radioactive Source & Failure to Clearly Label Contents of Radioactive Matl in Container

ML20215G320
Person / Time
Site:	Point Beach
Issue date:	06/15/1987
From:	Greger L, Miller D, Paul R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20215G310	List: ML20215G308 ML20215G320
References
50-266-87-11, 50-301-87-10, IEIN-86-023, IEIN-86-23, NUDOCS 8706230213
Download: ML20215G320 (16)

See also: IR 05000266/1987011

Text

E

l

o

.

.

1

U. S. NUCLEAR REGULATORY COMMISSION

REGION III

Reports No. 50-266/87011(DRSS); 50-301/87010(DRSS)

Docket Nos. 50-266; 50-301

Licenses No. DPR-24; No. DPR-27

.

Licensee:

Wisconsin Electric Power Company

231 West Michigan

Milwaukee, WI 53201

Facility Name:

Point Beach Nuclear Plant (PBNP)

Inspection At:

PBNP; Units 1 and 2, Two Rivers, Wisconsin

Inspection Conducted:

April 28 through May 19, 1987

Inspector:

6//5'/B7

_

Date

1

i

0. 8. 7d$v

i

D. E. Miller

9 /#/87

Cate~

)

"

4-

Approved By:

C.

r ge , Chief

(>//f/87

.

Facilities Radiation Protection

Date

Section

1

Inspection Summary

Inspection oli April 28 through May 19, 1987 (Reports No. 50-266/87011(DRSS);

No. 50-301/87010(DRSS))

Areas Inspected:

Routine, unannounced inspection of the radiation protection

program during a refueling outage including:

organization and management

controls; internal and external exposure controls; posting and access

controls; contamination control; two incidents concerning unplanned radiation

exposures; and previous inspection findings.

Results:

Two violations were identified (failure to properly train employees

using a radioactive source - Section 10; failure to clearly label the contents

ofradjoactivematerialinacontainer-Section11).

.

v!P

.

.

DETAILS

1.

Persons Contacted

• R. Bredvad, Plant Health Physicist

• D. Johnson, Project Engineer, Nuclear Plant Engineering

• T. Koehler, General Superintendent

• J. Knorr, Regulatory Engineer, Nuclear Plant Engineering

E. Lipke, General Superintendent, Nuclear Plant Engineering

• J. Reisenbuechler,. Superintendent, EQRS

• J. Zach, Plant Manager

• R. Hague, NRC, Senior Resident Inspector

• R. Leemon, NRC, Resident Inspector

The' inspectors also contacted other plant staff during this inspection.

• Denotes those present at one of the exit meetings held on May 8 and 15,

1987.

2.

General

The onsite inspection which began at 8:00 a.m., April 28, 1987, was

conducted to examine aspects of the licensee's radiation protection

program during a refueling outage.

The inspection included several plant

tours, review of posting and labeling, review of personal internal and

external exposures, and independent inspection efforts by the inspectors.

Also reviewed were selected open items, corrective actions concerning

previous violations, and two incidents concerning unplanned personal

radiation exposures.

3.

Licensee Action on Previous Inspection Findings

(Closed) Open Item (266/86016-01; 301/86015-01):

Failure to initiate a

report form as required by Procedure No. HP 1.11 when portal monitor

containination alarms are initiated.

The licensee has revised HP 1.11 to

better define specific responsibilities for response to portal monitors,

revised Procedure HP 2.1.2 to clarify employee responsibility for frisking

and notification of personnel when contamination is found, and has

initiated a formal training program for security personnel concerning

their responsibility for response to portal monitor alarms.

(Closed) Open Item (266/86016-02; 301/86015-02):

Failure to perform

surveys to ensure workers would not exceed 10 CFR 20.103 limits.

Frequency of radiation and contamination surveys were increased in the

waste evaporator feed cubicle area and other areas subject to changing

radiological conditions.

Procedure HP 2.5 has been revised to ensure

requirements for work activities will be based on timely and adequate

surveys of radiological conditions.

2

--

4'

$

f

t

>

,,

7,

s

q

j

o

..

, y

,

~!

,.

i(Closed) Open-Item (266/85017-01; 301/85017-01): . Developkent-of thel 1

training program for_the RCOs.

The licensee has developed and. initiated

I

an RC0 training' program that is-INP0Lcertified.

l

,

i;

)

(0 pen) Open-ItemL(266/85007-01; 301/85007-01):

Turnover rate of RC0 staff / '

)

and the effect on staff. stability.

See Section 5.

7

"

i

,

I

4.-

Licensee Response to'NRC Concerns

1

.

During a previous inspection (Inspection Report Nos.'266/86016; 301/86015)1 J

j

-programmatic weaknesses concerning health physics coverage, the RWP

'!

~1

program, reuse of protective clothing, the A0 qualification program and

1

other HP practices were identified.

In a letter to the NRC dated'

.]

February 4,.1987, the licensee addressed tris actions that had been, and

y

will be..taken to satisfactorily' correct the identified programmatic

weaknesses; including a commitment to implement full time HP' coverage

within two years.

<

'

5.

Organization, Management Controls, and Staffing

'

The inspectnrs revfewed the= licensee's organization and management

l

controls for radistio protection, including changes in the organizational

l

structure and staffing, effectiveness of procedures and other management'-

techniques ~used to implement the program, and experience concerning

J

self-identification and correction of program implementation weaknesses. *}

l

Region -I6was infonned that a corporata ' staff health physicist will

'

'

assume a newly' created Superintendecit-Health Physics-(S-HP) position at

Point Beach Station effective Jund 1, 1987.

The S-HP reports to.the

3

General' Superintendent with a direct reporting path to< the Plant Manager

33

!

,

as necessary for radiological matters.

The Plar,t Health Physicist and the

!

Radwaste Supervisor will report to the S-HP.

According to licensee

,

representatives, addition of the S-HP is intendedttd aid creation of a

more; professionally oriented radiation protection department.

This

-

cesponds to' observations and recommendations made by NRC inspectors as a

, ,

,

result of past inspections.

)-

',

During two previoun inspections (Ir.cpection Reports No. 266/85007;

301/8500Fand 266/86004; 301/86004), it was notad that the turnover rate

of the technician staff (RCDs and RCOTs) was significantly higher than

the turnover rate of other Region III licensees. . This turnover rate

affected the' qualification and experience level of the RCO staff and

l

. appeared.to diminish the stability and effectiveness of the radiation

'

protection organization.

The cause for this turnover rate was attributed

to the RCOT-selection system and salary differential between RCOs and

I

other plant workers which tended to discourage RCO retention.

Since then,

the licensee ' improved RC0 trainee selection, Jetreased the salary

'

}'

differential between RC0's and other plant workers, increased the HP staff,

and is continuing efforts to build a career HP. staff consisting of 12

or 13 permanent RCOs.

However, the RCO's hoJrly Salary remains l3Wer

,

than senior chemistry technicians, mechanical maintenance workers, and

y

auxiliary operators.

3

..

Eg

<

.

.

'The current radiation protection staff, supplemented by HP contractors,

>

appears adequate to sup' port routine radiation protection coverage.

However,.there remains. insufficient staffing of permanent qualified RCOs

to cover nonroutine functions and the licensee must rely on use of health

physics contractors to supplement;the staff during normal and outage

activities.

The shortage of RCOs appears to have been a factor in an

extremity exposure event discussed in.Section 10.

The apparent staffing shortage and lack of upgrading of RCOs was

discussed at the exit meeting.

(266/85007-01; 301/85007-01)

'

No-violations or deviations were noted.

6.

Internal Exposure Control

The inspectors reviewed the licensee's internal exposure control and

assessment programs, including changes to procedures affecting internal

exposure control and personal exposure assessment; determination whether

engineering controls, respiratory equipment, and assessment of individual

. intakes meet regulatory requirements; planning and preparation for

maintenance and refueling tasks including ALARA considerations; and

required records, reports, and notifications.

The licensee's program for controlling internal exposures includes the use

of protective clothing, respirators, and control of surface and airborne

h

radioactivity.

A selected review of air sample and survey results was

i

made; no significant problems were noted other than those noted in

Section 11.

Whole body count (WBC) data was reviewed for counts performed during the

period August 1, 1986 through March 31, 1987, on company and contractor

personnel.

Several followup counts were performed on the few persons who

showed elevated initial counts.

Followup counting was adequate to verify

that'the 40 MPC-hour control measure was not exceeded.

No problems were

noted.

No violations or deviations were identified.

7.

Personal Contamination Events

The licensee initiates Personnel Contamination Event Reports for

individual personal contamination events.

The report identifies the

individual, date, location of contamination, method of detection,

disposition of the contamination, and possible cause/ source of the

contamination event.

This information is entered into a computer program

which permits summarization and trending of several parameters.

The-licensee periodically generates summary sheets that list individual

events by contractor or employee name, location by body or clothing area,

and method of detection of contamination (routine frisk, checkpoint frisk,

portal monitor, or whole body counter).

The licensee uses this

information to identify trends, recurrences by individuals, and possible

4

i

{

.

.

1

i

programmatic problems.

During 1987 through May 6, 1987, there were 50

events that met.INP0. reporting criteria.

The licensee does not currently

utilize whole body contamination monitors, relying instead upon " friskers."

The licensee.does have several PCM-1 whole body contamination monitors on

4

order, , Typically, introduction of whole body contamination monitors

increases significantly the. numbers of identified personal contaminations.

The inspectors noted that about half of the personal contamination events

' involved personal clothing.

About one third of the clothing events

,

involved shorts, and one third undershirts and socks.

The inspectors also

i

noted that the licensee's prescribed single set of protective clothing

used for working in contamination levels <30,000 dpm/100 cm2 includes

coveralls with untaped side pocket openings and shoe covers that'do not

cover the ankle area.

It appears that this prescribed clothing

contributes to the potential for contamination of underwear and socks.

l

According to licensee representatives, the licensee plans to soon begin

use of coveralls which do not have side pocket openings.

However, the

inspectors were not apprised of any plans to alter the type of shoe

coverings worn.- This matter will again be reviewed during future routine

radiation protection inspections.

(50-266/87011-03; 50-301/87010-03)

No violations or deviations were identified.

l

8.

E,xternal Exposure Control and Personal Dosimetry

The inspectors reviewed the licensee's external exposure control and

personal dosimetry to meet refueling outage needs.

For the Unit 1 refueling outage it appeared adequate radiation surveys to

identify radiological conditions were performed and sufficient health

physics coverage was available to control jobs.

The inspectors selectively reviewed Radiation Work Permits (RWPs) and

associated radiation surveys and observed work being done in the

containment; no problems were identified.

The inspectors selectively reviewed exposure records including TLD and

self reading dosimetry results.

The records indicate that no person

exceeded regulatory limits.

The occupational external dose for the

station in 1986 was 375 person-rem and through April 1987 it was

approximately 260 person-rem, most of which was due to the Unit I

refueling outage.

No violations or deviations were identified.

9

Preplanning - ALARA

For this refueling outage, health physics personnel were involved in

pre-outage reviews and were aware of the major radiation producing jobs in

advance.

Outage planners were followed.

With the exception of certain

small jobs that were not effectively preplanned, no major difficulties

were encountered.

5

E

.

.

.,

.

.In accordance with Procedure PBNP 3.7.4, radiological reviews were

i

performed for certain routine dose activitier for this' outage in.

accordance with radiological conditions and work to be performed.

The

application of these' reviews are part of the' licensee's exposure reduction

program, and the use of.the reviews are particularly important during

outage conditions for implementing ALARA.

-10.

Radiolouical Incident Involving Unplanned Radiation Exposures

The inspectors reviewed the circumstances surrounding ~an unplanned whole

body radiation exposure to a station employee who unknowingly handled a

i

radioactive source on May 10, 1987.

During the review, the inspectors.

contacted licensee managers and health physics personnel, and interviewed

the individuals involved in the incident.

The inspectors observed

several physical' reenactments of the incident and reviewed the licensee's

investigation findings.

Although no overexposures occurred as a result

of.the incident, the radiation dose to one worker's~ hands was close to

the quarterly extremity dose limit.

The following subsections describe

the event, causes, licensee and inspector followup, and dose assessment.

This matter will be discussed further with the licensee during an

enforcement meeting scheduled' for June 18, 1987, in the Region III Office.

a.

Summary of Event

On Sunday, May 10, 1987, two Radiation Control Operator Trainees

(RCOTs) and a Health Physics Supervisor (HPS) performed functional

tests of two Radiation Monitoring System (RMS) monitors using a

i

cesium-137 source.

On Monday, May 11, 1987, the licensee became

aware that one of the RCOTs may have received an extremity

overexposure while performing the functional tests.

The licensee

informed an NRC resident inspector and a Region III radiation

specialist of the incident on the afternoon of the same day,

and formed a formal investigation committee consisting of the

j

General Superintendent, NPERS, the Superintendent-Training, an

ISI Engineer, a Project Engineer-Radiological, and a Senior Project

j

Engineer-Licensing.

]

The incident occurred while the three workers were performing

functional tests on RMS detectors.

The purpose of the tests was to

expose the detectors to a radiation source of sufficient strength to

actuate containment purge valve trips.

The shielded source container

" pig" used for these tests has a large removable shield plug in one

end which is removed to expose the radiation source.

A nominal 71

millicurie cesium-137 source is attached to the end of a source plug

,

assembly, which is inserted into the " pig" at the end opposite the

shield plug.

The source plug is much smaller in diameter than the

shield plug.

Each plug is prevented from casual removal by a

padlock.

The two padlocks were operated by the same High Radiation

Area key.

For these tests, the large plug is removed to expose the

monitor to a collimated radiation beam emanating from the radioactive

.

source.

'

.

6

I

.

.

Neither the HPS or the RCOTs had previously_used the " pig"; however,

the HPS had observed the use of.the " pig" to test the IRE-211/212

!

detectors on one of.the RMSs.

None of the three employees were

aware or had been instructed that the Cs-137 source was attached to

!

the small plug; they stated that they assumed the two plugs varied

-!

in size to allow for different size radiation beams.

The " pig" was

not marked to identify the radiation hazard associated with removal

of the' source plug.

b.

Chronology of the Incident

On May'.9, 1987, the HPS completed an 11-hour shift at about 5:30 p.m.

At about 8:50 p.m., the HPS, who was the Duty On-Call Supervisor,

received a call from the Duty Radiation Control Operator (RCO) who

was covering the shift with an RCOT.

The RCO stated that he had

to leave the site because of a family emergency.

The HPS contacted

two of the four available RCOs to find one to cover the remainder

,

of the shift; the HPS was unsuccessful.

The HPS then called in an

RCOT to join him and the other RCOT onsite to cover the remainder

of the shift. When the HPS arrived onsite, he became aware that his

'

shift was responsible for conducting the functional trip test of the

Unit 1 containment purge valves.

The two monitors used to trip the

purge valves are the Unit 1 SPING RMS (IRE-305) located in the Unit 1

rod drive room and the Unit 1 PNG RMS (IRE-211/212) located in the

-l

IRE-211/212 cubicle.

Both monitors are exposed to the Cs-137

radiation source for the test.

At about 11:55 p.m., the HPS,

after realizing that he had never conducted or observed a trip test

on the IRE-305 monitor, called an off-duty HPS who provided the

onsite HPS with information concerning the techniques and methods

required to successfully conduct the test; there was no discussion

of use of the Cs-137 source " pig," which the HPS had observed in use

once previously.

At about 12:30 a.m. on May 10, 1987, the three workers arrived at

the Unit I rod drive room to conduct the functional trip test of

IRE-305.

At this point, there are two differing accounts of how the

test was performed, one by the two RCOTs and one by the HPS.

According to the RCOTs, the HPS performed the test at the back side

of IRE-305 by removing the small (source) plug from the " pig,"

setting it on the floor, and directing the open plug end of the pig

toward the shielded IRE-305 monitor.

Based on the HPS recollection

of the performance of the test, the RCOTs successfully conducted the

test on the front side of IRE-305 by removing the large (shield)

plug.

After the control room ir. formed the workers the test was

successful, the plug which had been removed was returned to the pig

and the workers departed the area.

The licensee later demonstrated that if the radioactive plug was on

the floor and not in the " pig" for the test, there would still be

sufficient radiation emitted from the unshielded source to cause the

containment purge valves to trip closed.

These different scenarios

/

described by the HPS and the RCOTs also were noted during physical

,

7

p

.

.

t

reenactments.

Although the discrepancies concerning the performance

of this test are significant in their degree of disagreement, it

appears thatleven if the small plug was removed from the pig as

described by the RCOTs the length of time and manner in which it

,

was handled'would not have caused significant' personal exposure to

the'HPS.

At about 1:00 a.m. , the three employees began the trip test on

channel IRE-212 on the PNG monitor located in the IRE-211/212

cubicle.

To conduct the test, one RCOT positioned himself behind

the monitor.

His job was to position the " pig" to ditect the-

radiation beam from the open end of the pig at channel IRE-212.

The other RCOT was positioned at the side of the monitor near the

first RCOT to physically assist and to make radiation surveys.

The

HPS was located at the front of the monitor and was in radio contact

with the control room.

To begin the test, the first RCOT apparently

renoved the source plug, placed it in front of him on the monitor

support (pallet) and attempted to trip the purge valve by pointing

the open port of the " pig" at the monitor.

After several . failed

attempts to trip the system, the HPS changed positions with the

.

'

second RCOT so he could assist in the " pig" handling.

During the

time the HPS and the second RCOT changed positions, the first RCOT

held the source plug for approximately 30 seconds in each hand. He

stated that he was unaware that either plug was a radioactive source;

he assumed the source plug was merely another shield plug.

The

other RCOT did not recognize the error even though he measured

abnormally high general area radiation levels (200 - 300 mR/hr) when

the " pig" was incorrectly used; he stated he was unfamiliar with

radiation levels to be expected during the evolution.

After the HPS haa exchanged positions, the first RCOT apparently

re-installed the small (source) plug in the pig and removed the

larger (shield) plug so the test could be performed using what he

assumed to be a larger beam size.

After additional monitor

manipulation with the large plug removed and the small plug

positioned in the pig, the control room reported the purge valve

. tripped closed; the large plug was subsequently returned to the pig.

The workers departed from the area assuming that although they

encountered some difficulty in tripping the valves, the tests were

'

successfully completed and no unusual incidents or circumstances

had occurred.

The licensee became aware of the radiation exposure problem on

Monday, May 11, 1987, when the two RCOTs were casually discussing

their weekend work activities with other members of the health

physics staff.

During these discussions, some staff members

realized a significant radiation exposure may have occurred; they

so informed health physics management personnel.

The licensee then

formed a formal investigation committee to review the incident.

The

committee conducted several physical reenactments of the events,

interviewed all personnel involved in or with the event, and

performed radiation dose assessments.

'

8

j

{

.

~

,

f4

10 CFR 19.12 requires that workers receive instruction in

'

precautions or procedures to minimize exposure and in the purposes

and functions of protective devices employed.

The failure to-

(

instruct the workers.in the proper use of the cesium-137 shielded

H

source container is a violation of 10 CFR 19 requirements.

!

.(50-266/87011-01; 50-301/87010-01)

l

c.

Dose Assessment

.

.

a

The licensee calculated whole body and extremity exposures _for each

!

of the workers involved in the incident.

The dose assessments were

l

calculated based on reenactments (witnessed by NRC inspectors),

sourc'e output and configuration, time of exposure to the source, and

location of the source relative to the workers,

j

,

For the whole body, the results of the calculations indicate the

highest dose was approximately 660 mrem to the knees of the RCOT who

performed the tests on RE-211/212.

Adding previous doses, the RCOT's

whole body exposure was less than 900 mrem for the calendar. quarter;

no regulatory whole body dose limit was exceeded.

The inspectors

agree with the licensee's whole body dose assessments.

The only significant extremity dose was_to the hands of the RCOT who

held the source.

The licensee calculated this individual's

extremity dose using a modified "QAD". computer code which divides

the volume source into multiple point sources then calculates dose

_

l

from each point source to the skin.

The licensee calculated a

maximum contact dose of approximately 17.5 rem based on the specific

source characteristics, a 33-second exposure time, and 7 mg/cm2 dead

skin layer.

Independent NRC calculations based on generalized

source characteristics and the remaining assumptions utilized by the

license resulted in an approximate maximum contact dose of 18.75 rem.

,

Assuming the correctness of the licensee's computer code, their

calculation should be more accurate than the NRC derived value,

which was based on approximate source characteristics.

Based on the

realistically conservative assumption that the individual's hand was

in contact with the surface of the cylindrical source and using the

contact dose rate distribution derived by the licensee's computer

code, the maximum dose to 1 cmi of skin tissue at a depth of 7 mg/cm2

is approximately 15 rem.

(While technical arguments may be made to

utilize less conservative assumptions than 1 cm2 skin area and

7 mg/cm2 dead skin layer, these values are specified by NRC as noted

in IE Information Notice No. 86-23.

The applicable NRC dose limit is 18.75 rems per quarter.

Although

the extremity dose in this incident (15 rem) did not exceed

regulatory limits, such outcome appears fortuitous rather than

having derived from licensee planning, training, or precautions.

9

J

b;

-

.

.

' d .' - ' Factors' Contributing to' Incident's Occu'rrence

As a result'of the.. licensee's investigation and the inspectors'

review ~of the incident, several major factors were identified which

appear.to have contributed to the source handling incident.

-The source container (pig) had no caution markings to identify -

the radiation hazard associated with the removal of the source

plug.

The two plugs are similar by outward appearance, with

only the plug diameters differing.

Both plugs are locked by

similar key locks that are opened by the same key.

The HPS and the RCOTs were untrained and inexperienced in the

use of the source container and in the function and calibration

of the RMS.

The HPS was unable to provide sufficient technical

information to the RCOTs concerning the job they performed,

used poor judgement in performing a job for which he was

unqualified, and may have been fatigued.

The relatively low

number of qualified RCOs available to provide health physics

coverage also appears to have been contributary.

There were no procedures covering the use of the source for

functional testing of the RMS channels.

Although the licensee

recently developed a formal training plan which covers the use

of the source container, none of the three participants had

attended the training sessions.

11.

Hot Particle Incident

On April 21, 1987, two contractor health physics technicians were assigned

to move bags of radwaste from one temporary storage location to another.

After the task was done and their protective coveralls drycleaned, hot

particles were found in the breast pockets of the coveralls they had

worn.

The licensee performed a followup investigation to determine the

activity of the hot particles, the isotopes in the particles, and the

length of time the particles were in the pockets.

The inspectors

interviewed.the participants in the incident, reviewed the licensee's

investigation results and calculational methods, and performed

,

independent calculations.

No overexposures occurred as a result of the

incident, and no items of noncompliance with regulatory requirements were

identified; however, weaknesses were noted.

The licensee's investigation

j

appeared timely and thorough.

This matter will be discussed further with

i

the licensee during an enforcement meeting scheduled for June 18, 1987,

in the Region III Office.

a.

Sequence of Events On April 21, 1987, unusually high contamination

,

levels were found on two pairs of protective coveralls while frisking

j

them after dry cleaning.

No other contaminated PCs were found nor

was any significant contamination found in the laundry room or the

dry cleaning system.

The PCs were apparently worn by two

technicians while moving bags of radwaste in the radwaste building

earlier that day.

The contamination was subsequently identified as

several discrete fuel particles.

10

i

{

. .

.

Direct radiation and contamination surveys of the health physics.

' station, locker. room, maintenance shop, radwaste truck access, and

radwaste ATCOR areas were made to identify the source of the

contamination and determine if'any contamination had been spread to

clean areas.

No significant activity was found except in a portion

of the ATCOR area of.the radwaste building where the two contract

technicians had worked earlier that day.

After reporting to work on the morning of April 21, 1987, the senior

and junior contractor health physics technicians were instructed to

!

remove bagged radwaste materials from behind a temporary shield wall

in the ATCOR area of the radwaste building; the bags were to be

transferred into a shielding cask'in the nearby truck. bay.

The bagged

materials had been placed behind the shield wall over the preceding

two and a half years because their elevated radiation levels and/or

radioisotopic composition dictated a need for special packaging.

The bags were being moved so that the area could be used to store

other_radwaste.

The two contractor technicians, who were working

under the direction of the chemistry group radwaste supervisor, were

to move the bags and provide their'own health physics job coverage.

At about 0750 hours0.00868 days <br />0.208 hours <br />0.00124 weeks <br />2.85375e-4 months <br /> on April 21, 1987, the senior contractor

technician initiated a Radiation Work Permit (RWP) for the bag

handling.

The radiological conditions he entered on the RWP *:!ere

based on a survey he had performed in the general area on April 7,

i

1987.

The general area survey did not include dose rate or

i

contamination levels within the temporary shielded area even though

entry into that area would be required.

One set of protective

clothing was prescribed.

Extensive dosimetry for the chest area,

hands, and forearms was prescribed including integrating alarming

dosimeters (set at 65 mR) to be worn on the chest area of each

technician.

No respiratory protective devices were worn or

prescribed.

The proper RWP authorizing approvals were obtained.

At about 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> the technicians donned the prescribed protective

clothing, attached their dosimetry, proceeded to the work area,

posted a copy of the RWP at the work site, and unlocked the High

j

Radiation Area (HRA) gate at the shielded storage room in which the

temporary shielded area is constructed in a corner.

The temporary

shielded walled area is about six feet high and is built of solid

concrete blocks supported / braced with scaffolding; the scaffolding

is so arranged that a person can climb in and out and bags can be

suspended from a horizontal scaffolding railing that is slightly

higher than the block wall.

j

Using an extended probe radiation survey instrument, the senior

technician surveyed the shielded storage room while entering to

verify the exposure rates.

He then looked into the temporary

shielded storage area and saw about eight bags of waste, three of

which had attached ropes that were tied to a horizontal scaffolding

railing above the block wall. The technicians discussed possible

11

f

-

.

handling methods,. assembled plastic bags, and contacted the control

room to inform them that bags with high radiation readings would be

handled and transported.

l

The senior. technician then pulled out one tied-off bag, transferred

it to the step-off pad (SOP) at the HRA gate where the junior

technician (on the clean side of the SOP) had a plastic bag ready

to " bag-out" the transferred bag.

The junior technician then taped

>

the outer bag and monitored the radiation level on the bag.

The,

senior technician removed his low-cut shoe covers and cotton gloves

.'

':

at the S0P, donned clean cotton gloves, and carried the bag to the

shielding cask in the truck bay.

This process was repeated for the

other two tied-off bags.

The senior technician then surveyed the

general radiation fields inside the temporary storage area, while

.

standing.on-scaffolding, using the extended probe survey instrument-

1

the general area radiation exposure rate was80-100 mR/hr.

The

t

senior technician then climbed into the temporary storage area,

handed the remaining four bags over the wall to the junior technician,

-

,

then climbed out.

The junior technician then followed the 50P

procedure and the four bags were transferred to the shielding cask

"

in the same manner at the first three.

The HRA gate was relocked,

and the shielding cask surveyed to assure adequate postings and

access controls.

It is the licensee's practice when one set of protective clothing'is

l

worn that the low cut rubber shoe covers remain on the hot side of

f

the SOP, the cotton gloves are placed in a receptacle at the SOP,

and the coveralls and low cut plastic shoe covers are worn back to

l

the access control area where the coveralls are surveyed to see if

l

they.are acceptably clean to be placed in the wearer's controlled

!

side locker for reuse.

The plastic' shoe covers are discarded.

The

'

technicians followed this practice.

As the junior technician

approached a portable frisker with his hands, the alarm (set at

100 cpm above background) alarmed; the technician switched the

frisker meter range from the X1 to the X10 range and began surveying

i

the arms of the coveralls when the alarm sounded again.

Both

technicians then discarded their coveralls in the dirty laundry

'

container and began whole body frisking with portable friskers.

The

junior technician identified about 200 cpm on his left wrist,

300 cpm on his shorts, 200 cpm on his socks and 3000 cpm on his

shoes.

The senior technician identified about 200 cpm on the heel

of one shoe.

The technician then followed normal decontamination

"

and documentation procedures.

The personal contamination

documentation was taken to a health physics foreman who reviewed the

documentation.

The technicians did not tell the RCOs that their

protective coveralls contained highly elevated contamination levels

i

when placed in the dirty laundry drum.

As previously stated, the technicians wore extensive self-reading

dosimetry on their chest and wrists including an integrating

,

alarming dosimeter on the chest of each technician.

The highest

reading thus recorded was 80 mR to the right wrist of the senior

12

(

.c

.

i

contra'ctor technician who had performed the majority of the handling

of._the radwaste bags.

The indicated exposures appeared reasonable

for the job performed.

l

b.

Source and Isotopic Content of Contamination (Hot Particles).

During surveys performed in the shielded storage room and vicinity

on the afternoon of April 21, 1987, and on April 22, 1987, several

" hot" particles were identified on the floor of the storage room,

and one on the ladder'used while placing the radwaste bags in the

shielding cask.

No additional particles were found in areas

traversed by the technicians during or after performance of the

radwaste bag handing.

The " hot" particles read up to 40 R/hr when

-

measured at one inch with an R02A survey meter with the beta-

,

!

. window closed.

The particles were small but generally visible with

the naked eye.

The licensee collected samples of the particles for

,

isotopic analysis.

Licensee representatives removed the bags from the shielding cask

where they were placed by the contract technicians.

The bags were

observed to see if any had been breached.

The licensee noted that

the inner bags (three layers), containing a small filter, appeared

to be slit.

The representative took a contamination swipe of the

area surrounding the slits in the inner bags.

The swipe was retained

for isotopic analysis. According to the contract technicians, the

plastic bags containing the small filter were the last handled and

transferred to the shielding cask.

The licensee performed further surveys on the two pairs of coveralls

that were retained because of contamination levels.

The~ licensee

found two hot particles in the breast pocket of each pair.

There

was total radioactivity of 14.2 pCi in the pocket of one pair of the

coveralls and 2.8 pCi in the other.

~

According to the licensee, the subject filter is a "swarp" filter

from a portable underwater cleaning system.

The filter is

essentially a stainer through which circulated water flows while

cleaning underwater debris.

The filter sits in a hose coupling

fitting and is under water when the cleaning system is in use.

The

filter is cylindrical, about three inches in diameter, five inches

high, has a handling bail on top, and has a thin metal flange

seating surface on the bail end.

The licensee believes that the

filter was used during the Unit 2 outage in 1985 to remove debris

'

from the reactor vessel, and has probably been in the shielded

storage area since November 1987.

Using gamma analysis techniques, the licensee determined that the

isotopic content of the hot particles found in the coverall pockets,

floor of the shielded storage area, and swipe taken on the bag

containing the "swarp" filter was mainly Ce-144, Pr-144, Rh-106,

,

Ru-106, and Cs-137; the relative abundance of the isotopes was

similar.

The isotopic content indicates that the original source

of the particles was past failed fuel, particles of which were

i

collected in the "swarp" filter during incore cleaning.

13

p

.

.

i

c.

Calculated Dose to Contractor Technicians

Skin doses were calculated by NRC using the VARSKIN computer code

(draft NURGEG/CR 4418 at a skin " depth" of 7 mg/cm2 averaged over

2

1 cm .(IE Information Notice 86-23).

Sheilding provided by clothing

was measured by the licensee to be 27 mg/cm2 for one of the workers

2 for the other.

Gamma doses were assumed to be

and 39 mg/cm

negligible.

Through discussions, re-enactments, and determination that the hot

particles were released while the technicians handled the last bag

removed from the temporary shielded area, the licensee estimated

that the hot particles were in the technicians' coverall pockets for

a maximum of 15 minutes while the coveralls were being worn.

Because the hot particles were in a coverall pocket and not

2 can be

stationary on the skin the maximum calculated dose to 1 cm

halved based on a conservative estimate of lateral movement of the

coveralls, and further reduced because the coveralls were reasonably

not always in contact with the technician's skin.

By conservatively

estimating that the coverall pocket was one centimeter from the

skin for half of the 15 minutes, a dose reduction factor of about

15 results for 50% of the exposure time.

Based on these assumptions

and the licensee determined particle activities 14.2 pCi and 2.8 pCi

and isotopic compositions, the calculated skin doses to the two

workers were 4.5 rem and 0.75 rem, respectively.

The licensee's calculated skin doses, based on a licensee modified QAD

computer code and the above assumptions, were 3.5 rem and 0.5 rem,

respectively.

The licensee and NRC calculations are in reasonable

agreement.

The applicable NRC dose limit is 7.5 rems per quarter.

Although the

maximum skin dose in this incident (4.5 rem) did not exceed

regulatory limits, such outcome appears fortuitous rather than

having derived from licensee planning, training, or precautions.

No violations were identified.

d.

Apparent Programmatic Weaknesses Associated with this Event

During the inspectors' review of this incident, several associated

matters appeared to contribute to the incident's occurrence, its

severity, and the eventual promptness of followup investigations.

These matters include:

The "swarp" filter was used during vacuuming of a reactor

vessel and contained readily dispersible highly radioactive

particles, yet it was not packaged so there would be a low

probability of package damage and resulting contamination

spread.

14

i

{

.

.

<

The "swarp" filter is estimated to have read approximately

25 R/hr when removed from the reactor vessel and transported to

the temporary storage area, yet the bag was apparently not well

marked / identified nor was the outside of the temporary shield

area posted with an instructional posting to indicate its

relative hazard.

The method of handling during transport to

the storage area could not be established.

There was no inventory of the contents of the temporary

shielded area even though the contents were placed there

i

.

because of the need for special handling and disposal.

The contractor senior technician prescribed a single set of

protective clothing with no respirator even though he was

unaware of the contents of the bagged material.

He apparently

assumed proper past handling of the bagged material and

anticipated that no handling problems would arise.

The technicians knew that one set of coveralls was contaminated

to a significantly greater extent than would be expected for

the work they performed, but did not so inform the RCOs.

Such

information would have prompted an earlier start to the

investigation.

Had hot particles been deposited on the cold

side of the S0P during the bag-out procedure, earlier followup

would have reduced the potential for contamination spread.

It is noteworthy that until about April 1, 1987, there was no firm

requirement for individuals to survey protective coveralls before

placing them in their controlled zone locker, and to place them in

the laundry hamper if contamination levels exceed 2,000 cpm using

an HP-210 probe.

At the request of NRC Region III, the licensee

instituted the coverall frisking policy and revised Procedure HP 2.7

" General Use of Protective Clothing" to include the requirement.

Had this policy not been changed the contaminated PCs would have

probably been reused with resultant greatly increased personal

exposures.

Failure to identify the package contents with a clearly visible

)

label or readily available record providing sufficient information

to permit individuals handling the package to take adequate

precautions to minimize their exposure is a violation

j

with 10 CFR 20.203(f) requirements (Violation 266/87011-02;

301/87010-02).

12.

Exit Interview

The inspectors met with licensee representatives (denoted in Paragraph 1)

at the conclusion of the inspection and summarized the scope and findings

of the inspection activities.

The inspectors also discussed the likely

informational contents of the inspection report with regard to documents

or processes reviewed by the inspectors during the inspection.

The

licensee did not identify any such documents or processes as

'

proprietary.

In response to the inspectors' comments, the licensee:

15

$

.

. . -

..:

.

i

~ Acknowledged the inspectors comments ~concerning the. identified.

a.

weaknesses which. contributed to unplanned personal exposures

.(Sections 10 and 11).

"'

b .-- -Stated that results of the_ investigation and dose evaluations

concerning the personal unplanned exposures would be made available

to Region:III_(Sections 10_and'11).

c.

Stated-that efforts will be' continued to increase the' number off

permanent RCOs on the Radiation Department staff (Section 5).

j

i

..

!

I-

16

i<