IR 05000155/1979002
| ML19347A517 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 03/13/1979 |
| From: | Fisher W, Schumacher M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19347A516 | List: |
| References | |
| 50-155-79-02, 50-155-79-2, NUDOCS 7905030046 | |
| Download: ML19347A517 (7) | |
Text
-
\\,
-
.
I
-
U. S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCMENT
REGION III
Report No. 50-155/79-02 Docket No. 50-155 License No. DPR-6 Licensee: Consumers Power Company
-
212 West Michigan Avenue
.
Jackson, MI 49201 Facility Name: Big Rock Point Nuclear Power Plant Inspection At: Big Rock Site, Charlevoix, MI Inspection Conducted: February 14-16, 1979 YE k a.w f%-
l, Inspector:
M. C. Schumacher
{
i7,
-
3 /3!77'
Approved By:
W. L. Fisher, Chief Fuel Facility Projects and Radiation Support Section V.,
Inspection Summary:
Inspection on February 14-16, 1979 (Report No. 50-155/79-02)
Areas Inspected: Routine, unannounced inspection of refueling radiation protection Activities,.dncluding: procedures, advanced planning and preparation, training, exposure control, posting and control, material control, and surveys. It also included review of a high radiation evedt!
on the refueling deck that occurred two weeks before shutdown. The inspection involved 24 inspector-hours on site by one NRC inspector.
Results:
No items of noncompliance were identified in any of the eight areas inspected.
.
l (
..
..
.
.
,
970503o0%
p 5,
V
!
._
_ _ _...,. _
_ _.. _ _
. -,. _, _
_
.
.
.
~
~
~
4.
Advance Planning and Preparation The inspector discussed advance planning and preparation with
-
licensee representatives.
Supplies of protective clothing, dosimaters, respiratorspand other items were inventoried before the outage and orders and additional supplies were ordered where needed. No major problems were encount ared, although a temporary laundry outage coupled with late arrival of ordered coveralls had earlier caused shelf stock to run low. No problems were noted by the inspector,at the time of his visit.
The health physicist estimated 240 ran-rems for. the entire outage with the principal exposures anticipated from in-service inspection work in the steam drum area, and removal and replacement of the ring sparger in the vessel. Preparation for the latter job was done by the vendor (GE) and included construction of a mockup of the vessel wall it.to which the new ring sparger and baffle plates could be fitted. The reactor engineer held a training course for the health physics group to explain the work and the procedures to be used.
The health physics department was put on two ten-hour shifts with seven technicians on days and four on nights. The normal comple-ment of seven was augmented by four technicians from the Midland f
plant of whom all but one have no significant nuclear experience.
.
\\
The inexperienced men work under the guidance of a senior technician on the day shift.
No items of noncompliante or deviations were identified.
.
- -
5.
Training
-
The inspector briefly discussed the crientation training for transient workers with a training instructor.
It remains essent'lally as,.previously described /. Selected records of l
temporary employees working in the controlled area were reviewed,'
'
to confirm that training c~onsistent with 10 CFR 19.12 had been given.
No items of noncompliance or deviations were identified.
6.
Exposure Control a.
External Exposure
l Exposure records for the gattsp through February 14, 1979,
'
were reviewed for station employees, nonstation Consumers Power employees, and other vistors. The records reviewed J/ RIII Inspection Report No. 50-155/77-09.
s.
C-3-s.
I
-
.. -
--
- - -
,.- -
- - -
.
.
.
included forms NRC-4, pocket dosimeter records and exposure records from the microfiche system maintai,ned by the licensee's corporate headquarters. The records were satisf actory, but it was noted that the computer based microfiche records for some people showed some minor discrepancies. The licensee representative stated that these problems are recognized and the " bugs" are being eliminated from the relatively new system.
No items of noncompliance or deviations were identified.
b.
Internal Exposure The inspector reviewed licensee practices for control of internal exposures for the outage through February 14, 1979, including records of respirator training, issuance, MPC-hour accu =ulation, air sampling, and bioassay. Satisfactory per-formance was generally indicated. A weakness was noted in iodine air sampling in that no samples were taken during the early phase of the outage, particularly in the reactor cavity during work on head removal February 4-5.
The iodine constant air monitor (CAM) on the southwest corner of the refueling deck, approximately 25 feet away, showed no anomalies, although it was in the general direction of air movement as determined by smoke tests, according to licensee representatives. They also pointed out that the work was done in supplied air hoods
'
(
and that iodine releases had not increased during the period and that no elemental iodine had been observed on GeLi analysis of particulate filters.
No items of noncompliance or deviations were identified.
7.
Posting and Control
..,
i The inspector observed postings of materials storage areas, radiation and high radiation areas,%gnd airborne radioactivity areas.
Licen $e proce'duhes for. controlling access to and work in controlled areas remain as previously" described.2/ The inspector reviewed %
five RWP's written for the outage. They covered work done on the reactor deck related to removal and replacement of the ring sparger and baffle.
No items of noncompliance or deviations were identified.
~2/ lbid.
%:
-4-i
.
s'
(
..
..
'z
--
.
.
-
- -.
.. -
.-...
a.. -
,.- --
_
,
,
8.
Material control
.
Licensee control of contaminated clothing, tools and equipment, and dry wastes were observed.
It appeared that contamination boundaries and tool checkout procedures were being observed.
No significant accumulations of trash were observed and house-keeping in the tool decontamination area was satisfactory. The occurrence of facial contamination on three sen who handled plastic bags containing contaminated coveralls was documented in the Health Physics log.
Followup action of decontamination and whole body counting appeared satisfactory.
No items of noncompliance or deviations were identified.
9.
Surveys Records of routine daily, weekly, and monthly radiation and con-ta=ination surveys, special survays entered in the health physics log, and personal contamination sheets were reviewed for the period January 30 - February 15, 1979. The daily surveys indicated that the dirty side - clean side distinction is being satisfactorily maintainedonthereactordeckleyel. Dirty side contamination up to a maximum of 30,000 dpm/100 cm was recorded; levels greater than 400 dpm/100 cm2 on the clean side are decontaminated. Approx-imately 20 occurrences of low-level personal contamination were noted, indicating that a problem observed during an earlier inspection
>
,
may still exist. This aspect of the outage will receive further review during a subsequent inspection.
'
No items of noncompliang or deviations were identified.
- 10.
High Radiation Occurrence at Fuel Pool. January 18, 1979
.
- .,
Licensee personnel notified the inspector of an item of possible generic interest discovered in the investigation following the occurr,nce of anomalously high radiation levels on the refueling e
deck at approxi1mately 0138 on January 18, 1979. A hot spot reading greater than 1000 R/hr at contact was found on a portion of cord, '.
from an underwater observation light hanging a: about foot level from the refueling bridge rail. They believe it was caused by a contamination fragment, flushed from an empty sipping can during operation training sessions conducted during the week of January 8,1979, which became attached to a slack portion of cord in the water. Shortly before the alarm sounded on January 18, an operator who crossed over the bridge may have dislodged the cord knot on the rail, permitting the cord to slip and' bring the slack out of the water and onto'the edge of the bridge.
.
.
(
'
.
.
..
_,.
',- k.I
.
.,
,
,
. -.
-
.-
- - - -
,
-
.. -.
.. -,
.
.
.
The alarm on the fuel pool monitor (caused by a 45 mR/hr reading)
caused the evacuation of two operators and the shift supervisor.
g
.
Surveys of the area by the operator before the alarm had apparently
-
indicated nothing unusual. During this period one of the operators went to the bridge, turned on underwater lights, and crossed over the bridge. The operator afterward indicated that he may have inadvertently loosened the knot in the light cord holding a light suspended from the west side of the bridge. The alarm sounded a few minutes after he crossed the bridge.
Following evacuation and determination that there were no anocalies indicated on control room readouts, save for higher than normal readings on the fuel pool monitor and two other nearby monitors (21 and 6 mR/hr), reentry was made. Surveys by the shift supervisor showed fields ranging from 50 to 350 mR/hr and locally high readings to greater than 5 R/hr near the northeast end of the fuel pool in the vicinity of the bridge, which runs north-south across the pool. A vacuum hose nearby was erroneously thought to be the source and an attempt was made to sink it by tying one end of a rope to the hose and the other end to the bridge rail to permit recovery, and then weighting the rope to sink the hose. A rope that was hanging over the rail and partially floating in the water was used. After tying off the line on the bridge rail, the operator left the bridge and observed that the hairline of his 200 mR self reader was offseale but still within view. The shif t supervisor, who was monitoring the work, then observed that the radiation level near the bridge rail was greater than 5 R/hr and everyone left the area. The chemical and fi radiation protection supervisor was notified at home at 0248.
-
Reentry was made several hours later by day shift health physics technicians. At this time the hot spot reading greater than 1000 R/hr at contact was found at the edge of the bridge near foot level.
The affected portion of the cord was lowered into the pool.
A, second source was then located approximately six feet away from the y
first, attached to the end of the rope used to tie off the vacuum
-
hose to the bridge rail. This source read 300 R/hr at contact and was identified as a piece of metal handle from a control rod drive blade which.had been stored in the fuel pool.
Licensee memos describing and evaluating the event were reviewed and discussed with licensee health physics personnel. Special processing of TLD badges worn by the shif t supervisor and the two operators indicated doses ascribable to this occurrence of 112, 93, and 12 millirems.
The licensee considered extremity dose to the operator who had been on the bridge. Their review indicated that he had touched neither the spot on the 14ht cord nor the source end of the rope.
The operator stated he had tied'the rope to the rail with a knot in the bight and was not aware of the source on the end. The operator's time on the bridge was astimated at less than 15 seconds.
These assumptions, together with the combined source reading
,
f (36 mR/hr net) on the fuel pool monitor 29 feet away, led the
\\
'
.-
licensee to estimate extremity doses less than the 18.75 rem limit.
og-7-
.,.
._
_ _ _
.
. -
..
__ _ _
__
.
~
.
The inspector's estimates based on these assumptirn3 and a prscum:d two-inch distance to the source were a hand dose of 100 millrems
.
A second l
beta and a 4 rems gamma, and a foot dose of 4 rems gam =a.
estimate of foot dose made based on the difference in TLD dose to the operator (112 mil irems) and the shif t supervisor (93 millirems),
whose feet were never in close proximity to the source, gave 10 rems.
It assumed source-foot and source-badge distances of two inches and 48 inches, respectively. The accuracy of these estimates is uncertain, owing to uncertainty regarding duration and distance of closest approach to the sources. The inspector also took into account the inhomogeneous exposure conditions in estimating a maximum dose to the body and blood forming organs of between 200 and 400 millirems.
Licensee representatives stated that a correction would be made to the individual's NRC-5 to account for the nonuniform exposure.
This event was discussed with licensee personnel during this review, at the exit interview and by telephone on February 23 and 26,1979.
Also discussed was the need for a system of rope control procedures to prevent haphazard use of ropes in the pool, the failure of shif t personnel to accurately identify the sources by survey, and the use of the occurrence in training of RWP exe=pt personnel, particularly The licensee stated that operators and health physi s technicians.
these matters were being iarsued. The licensee also stated that an additional monitor for the fuel pool area would be installed nearer the pool to give better warning of such occurrences.
No items of noncompliance or deviations were identified.
,
>
11.
Exit Interview The inspector discussed".the results of the inspection at a meeting with licensee representatives (Paragraph 1) on
February 16 and by telephone on February 23 and 26,1979.
.
- ,,
The licensee described several actions being taken to avoid
.
recurrence of the hot particle problem on the refueling deck (Paragraph 10), including an improved system of rope control,
,
purchase of a new; monitor for the fuel pool area, and stressing
of the occurrence in radiation protection training for RWP exempt S A corrected whole body dose will be entered for the personnel.
operator.
The inspector acknowledged the apparent absence of an iodine exposure problem owing to good fuel and use of supplied air l
'
for in-cavity work but stated that the CAM location nede it unrepresentative and that iodine samples should have been taken to confirm the absence of-a problem.
v.
Licensee representatives acknowledged these remarks and agreed to take such samples in the future.
.
-8-
[
,
.
,
.
s'
s
.,
l l
t