Information Notice 1987-39, Control of Particle Contamination at Nuclear Power Plants: Difference between revisions
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{{#Wiki_filter:..-. | {{#Wiki_filter:..-.i V' 'SINS No.: 6835 iN 87-39 UNITED STATES NUCLEAR REGULATORY | ||
COMMISSION | |||
===OFFICE OF NUCLEAR REACTOR REGULATION=== | |||
WASHINGTON, D.C. 20555 August 21, 1987 NRC INFORMATION | |||
NOTICE NQ. 87-39: CONTROL OF HOT PARTICLE CONTAMINATION | |||
AT NUCLEAR POWER PLANTS | |||
==Addressees== | ==Addressees== | ||
:All nuclear power reactor facilities and spent fuel storage facilities | : | ||
All nuclear power reactor facilities | |||
and spent fuel storage facilities | |||
holding an NRC license or a construction | |||
permit.Background | |||
and | |||
==Purpose== | ==Purpose== | ||
:IE Information Notice 86-23 (Reference 1) provided information on events in-volving excessive skin exposures resulting from skin contamination by small,highly radioactive particles with high specific activity (hot particles). | : IE Information | ||
Notice 86-23 (Reference | |||
1) provided information | |||
on events in-volving excessive | |||
skin exposures | |||
resulting | |||
from skin contamination | |||
by small, highly radioactive | |||
particles | |||
with high specific activity (hot particles). | |||
Since that information | |||
notice was issued, there have been more of these events, and a recent report by the Institute | |||
of Nuclear Power Operations (INPO) (Reference | |||
2)provides additional | |||
information | |||
on this subject. This information | |||
notice pro-vides information | |||
on some of the subsequent | |||
events and discusses | |||
degraded fuel and a lack of proper radiological | |||
control during fuel reconstitution | |||
as major sources of hot particles. | |||
Generic licensee lessons learned also are included.It is expected that recipients | |||
will review this information | |||
for applicability | |||
to their facilities | |||
and consider action, if appropriate, to preclude a similar problem occurring | |||
at their facilities. | |||
However, suggestions | |||
contained | |||
in this notice do not constitute | |||
NRC requirements; | |||
therefore, no specific action or written response is required.Discussion: | |||
During the first 6 months of 1987, events involving | |||
hot particle exposures | |||
were reported at nine different | |||
nuclear power stations. | |||
Two events in late 1986 (at V.C. Summer and San Onofre) involved exposures | |||
apparently | |||
exceeding | |||
NRC regula-tory limits. Attachment | |||
1 provides summary descriptions | |||
of eight of these events. More detailed descriptions | |||
can be obtained from the referenced | |||
inspec-tion reports for each event. (Copies of NRC Inspection | |||
Reports are available from the NRC Public Document Room, 1717 H Street N.W., Washington, D.C.)Hot particles | |||
come primarily | |||
from two major sources: degraded fuel and neutron-activated | |||
corrosion | |||
and wear products (e.g., Stellite). | |||
While much of the information | |||
in this notice is pertinent | |||
to both neutron-activated | |||
corrosion and wear product particles (hereafter | |||
referred to as activated | |||
particles) | |||
and | |||
K> QIN 87-39 August 21, 1987 irradiated | |||
fuel particles (hereafter | |||
referred to as fuel particles), a major concern of this notice is extended facility operation | |||
with degraded fuel and the resulting | |||
problems with fuel particle contamination. | |||
On the basis of an NRC review of licensees' | |||
corrective | |||
actions, discussions | |||
with licensees' | |||
operating | |||
staffs, and information | |||
obtained by NRC inspectors, the lessons learned and licensee good practices | |||
resulting | |||
from the events summarized | |||
in Attachment | |||
1 are as follows: 1. Extended power plant operation | |||
with degraded fuel (leaking fuel pins) can result in widespread | |||
dispersal | |||
of fuel particles. | |||
Some plants continue to experience | |||
fuel particle contamination | |||
problems long after leaking fuel pins have been removed because of the residual contamination | |||
of plant systems. Some plants with these problems have started programs to account for missing fuel pellets and fragments | |||
and to identify measures to recover this material.2. Considerations | |||
concerning | |||
the handling of leaking fuel include the following: | |||
a. Special techniques | |||
and precautions | |||
for handling leaking fuel bundles are necessary | |||
to prevent aggravating | |||
the spread of fuel particles. | |||
For example, containment | |||
devices should be used when reconstituting | |||
fuel. The lack of proper radiological | |||
controls and oversight | |||
of the fuel reconstitution | |||
process in the San Onofre 3 fuel pool led to loss of control and dispersal | |||
of numerous fuel particles | |||
into the pool.Fuel particles | |||
then spread through the plant spent fuel systems and to the liquid radwaste systems.b. A damaged, leaking fuel pin that is not properly contained | |||
and segregated | |||
from the common fuel pool area could be a significant, long-term | |||
source of fuel particle contamination. | |||
c. Plants should be aware that NSSS vendors' special refueling | |||
tools and equipment | |||
could be a source of fuel particle contamination. | |||
These tools and equipment | |||
should be carefully | |||
surveyed before they are used and before they are shipped to other facilities. | |||
3. Some plants that have operated for extended periods of time with degraded fuel and plants with activated | |||
particle problems now have instituted | |||
specialized, comprehensive | |||
training programs for plant system maintenance | |||
workers and general employees. | |||
These programs are designed to better inform and prepare the plant staff to cope with the continuing | |||
fuel particle problems. | |||
Additionally, as part of comprehensive | |||
contamination | |||
control programs, special new procedures | |||
to improve surveys for detection | |||
: --..IN 87-39 August 21, 1987 of.hot particles | |||
have been prepared and health physics technicians | |||
have been trained in their use. Decontamination | |||
and dose evaluation | |||
methods and procedures | |||
that focus on hot particles | |||
have been implemented. (See summaries | |||
of events at Trojan and.San Onofre in Attachment | |||
1.).4.. In general, ;licensees | |||
have upgraded their programs for contamination | |||
monitoring | |||
of "clean," laundered | |||
anti-contamination | |||
protective | |||
clothing (PC). However, PC continues | |||
to be a means of transferring | |||
both fuel particles | |||
and activated | |||
particles. | |||
Some facilities | |||
need to consider making their PC monitoring | |||
programs more sensitive. | |||
For example, some licensees | |||
that are using contractor | |||
laundry services found the contrac-tor's alarm on the radiation | |||
monitor (used to screen PC) too high to-detect 0.4 microcurie (VCi) particles. | |||
Moreover, when commercial | |||
laundry services are used, it is possible that PC from a "particle-free" plant* *-can be mixed with PC from a plant with hot particle problems. | |||
Finally, at.leastrone | |||
licensee was relying solely on monitoring | |||
of large bundles of washed PC (bulk surveys) and was not monitoring | |||
samples of individual | |||
PC. For plants with identified | |||
particle problems, individual | |||
PC items may have to be checked before they are reused after cleaning.5. Except for the-Trojan | |||
event discussed | |||
in Attachment | |||
1, to date, no licensee has reported detecting | |||
hot.particles | |||
during airborne sampling.However, as a precaution,,some | |||
licensees | |||
have elected to provide workers with respiratory | |||
protection | |||
for performing | |||
maintenance | |||
on plant systems known to-be a source of hot particles. | |||
===No plant has reported inhalation=== | |||
or ingestion | |||
of hot particles | |||
by any worker.6. Hot particles | |||
in contact with skin.produce | |||
very high dose rates. Diligent personnel | |||
contamination | |||
surveys performed | |||
as soon as practical | |||
after .completing | |||
work involving | |||
contamination | |||
are needed to minimize potential exposure times.-7. Approximately | |||
75 percent of the U.S. power reactor facilities | |||
are cur-rently using new high-sensitivity | |||
whole-body | |||
contamination | |||
monitors.These state-of-the-art | |||
contamination | |||
monitors increase the probability | |||
of detecting | |||
hot-particles | |||
on plant personnel | |||
while reducing the likelihood | |||
of inadvertently | |||
releasing | |||
particles | |||
from the plant site. To-date, most of-the particles | |||
found on personnel | |||
have:been | |||
detected by these new monitors. | |||
Even with use of the new monitors, a few instances | |||
have oc-curred where hot particles | |||
have inadvertently | |||
been carried home by workers.and have-been | |||
detected in the home or on the worker returning | |||
to the site.No significant ,public exposures | |||
have been reported to date.8. In a recent study for the NRC (Reference | |||
3), it was reported that a plant operating | |||
with 0.125 percent pin-hole fuel cladding defects showed a general five-fold | |||
increase in whole-body | |||
radiation | |||
exposure rates in some | |||
IN 87-39 .August 21, 1987 areas of the plant when compared to a sister plant with high-integrity | |||
fuel (<0.01percent | |||
leakers). | |||
Around certain plant systems the degraded fuel may elevate.-radiation | |||
exposure rates even more. -9. Maintenance-on | |||
valves with Stellite components | |||
can cause introduction | |||
of cobalt-containing | |||
debris with Co-60 as the resultant | |||
neutron activation | |||
product. Some plants have instituted | |||
work controls (e.g., use of contain-ment and post-maintenance | |||
cleaning) | |||
to minimize this input into reactor systems (Reference | |||
4).Health Implications | |||
and Radiation | |||
Protection | |||
Criteria for Hot Particle-Exposures | |||
of Skin: -A hot'particle | |||
on the skin gives a high beta dose to a small area.' Any radia-tion dose to the skin is-assumed | |||
to result in'some increased | |||
risk of skin cancer, although'this | |||
type of cancer is rarely fatal.' Experiments | |||
with animals indicate that highly localized | |||
irradiation | |||
of-the skin'by hot particles | |||
is less likely to'cause skin cancer than more uniform irradiation | |||
by the same quantity of radioactive | |||
material.:- | |||
In addition to any increased | |||
risk of cancer, large doses to the skin from hot particles | |||
also may produce observable | |||
effects such as reddening, hardening, peeling, or ulceration | |||
of the skin-immediately | |||
around the particle; | |||
These effects appear only'after | |||
a-threshold | |||
dose is exceeded. | |||
The doses from hot particles | |||
'equired to-produce | |||
these effects'in | |||
the 'skin are'not known pre-cisely;-Ihowever, -it appears likely, except for a point reddening,-that | |||
these effects will only be seen for doses of hundreds of rems or more.'- No such effects have been seen to date on any workers who have been exposed to-hot particles, even though one exposure has been measured or calculated | |||
as high as 512 rem.Recent reviews of radiobiology | |||
and radiation | |||
protection | |||
criteria for skin, in-cluding considerations | |||
of hot particle exposures, have been provided-by-Wells (Reference | |||
5) and Charles (References | |||
6 and 7). ''The NRC staff recognizes | |||
the need for more'information | |||
on the effects of radiation | |||
on skin and particularly | |||
the effects-of | |||
hot particle irradiation. | |||
The staff has requested | |||
the National Council on Radiation | |||
Protection | |||
and Measurements (NCRP) to. study the health significance | |||
of hot particle exposures and to provisde recommendations- based on the findings of this study. These recommendations | |||
may result in changes in NRC requirements | |||
with respect to hot particle exposures. | |||
However, until these requirements | |||
are changed, IE Infor-mation Notice 86-23 (Reference | |||
1) contains current information | |||
for use in evaluating | |||
doses to skin resulting | |||
from hot particles. | |||
./ ..IN 87-39 August. 21, 1987 Page 5 of S o I specific action or. written response is required by this information | |||
notice.* you have any questions | |||
about this matter, please contact the Regional Admiistrator | |||
'f the appropriate | |||
regional office or this office.e ,.harles E. Rossi, Director Division of Operational | |||
===Events Assessment=== | |||
Office of Nuclear Reactor Regulation | |||
Technwcal | |||
Contact:- | |||
James E..Wigginton, NRR (301) 492-4663 John D. Buchanan, NRR.(301) 492-7293 References | |||
I. JAE Information | |||
Notice 86-23, "Excessive | |||
Skin Exposures | |||
Due to Contamina- tihn With Hot Particles," April 9, 1986.2i. nstitute of Nuclear Power Operations, Significant | |||
Event Report 18-87 (Rev..2), "Radiation | |||
Exposure From Small Particles," July 16, 1987.3,- Hoeller; M. P., :G. F. Martin, and D. L..Haggard, "The Impact of Fuel*- Cladding Failure Events on Occupational | |||
Radiation | |||
Exposures | |||
at Nuclear:PowerPants. | |||
Case Study: PWR During RoutineOperations," NUREG/CR-4485 (PNL-5606), January 1986.H4 Heard, D. B., and R. J. Freeman, "Cobalt Contamination | |||
Resulting | |||
From.`Valve IMaintenance," Electric Power Research Institute, EPRI NP-3220, Final::Report, August 1983. .5.. Welli, 3., "Problems | |||
Associated | |||
With Localized | |||
Skin Exposures," in "Radia-tion Damage to Skin: Fundamental | |||
and Practical | |||
Aspects," Proceedings | |||
of a: .Workshop. | |||
heldat Saclay, France, on October 9-11, 1985, Brit..J3. Radiology, Supplement | |||
No. 19, pp. 146-150 (1986).* .6. Charles, 4.W., "The Biological | |||
Bases of Radiation | |||
Protection | |||
Criteria for Superficial, Low Penetrating | |||
Radiation | |||
Exposure," in "Dosimetry | |||
of Beta Particles | |||
and Low Energy X-Rays," Proceedings | |||
of a Workshop held at-Sacay, Francei October 7-9,-1985," Radiation | |||
Protection | |||
Dosimetry | |||
14 (No.P2),pp. 79-90 (1986).-7. Charles, 14. W., "Skin, Eye, and Testis: Current Exposure Problems and Recent..Advances | |||
in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp. 69-81 (1986).Attachments;.. | |||
..-*. l. EventSummaries | |||
.2.. List-4f Recently Issued NRC Information | |||
Notices | |||
Attachment | |||
1 IN 87-39 August 21, 1987 EVENT SUMMARIES San Onofre 3. Events Durina November 1986 -March 1987, Inspection | |||
Report No. 50-362/86-37 Background: | |||
At the onset of the first fuel cycle, significant | |||
fuel degradation | |||
was evident.The plant continued | |||
to operate with approximately | |||
105 defective | |||
fuel pins. In late 1985 during the first refueling | |||
outage, a fuel pin was inadvertently | |||
pulled apart during the fuel reconstitution | |||
process. Several fuel pellets fell and dispersed | |||
throughout | |||
the fuel pool. Fuel particles | |||
had previously | |||
been detected early on during reconstitution | |||
on fuel handling tools and on the refueling | |||
floors. All the severely damaged fuel pins were then grouped into one fuel bundle and stored in the pool without any containment. | |||
Event Specifics: | |||
From January 2 through February 20, 1987, the licensee's | |||
aggressive | |||
hot parti-cle inventory | |||
and tracking system indicated | |||
that 92 "new" fuel particles (recently | |||
neutron irradiated), 155 "old" fuel particles, 51 ruthenium, 84 crud, and 42 cobalt particles | |||
had been found and analyzed. | |||
Before 1987, no formal tracking program existed.Several incidents | |||
involving | |||
hot particles | |||
have occurred, including | |||
an apparent worker extremity | |||
exposure (hand) of 512 rem during November 1986. As a result, appropriate | |||
NRC enforcement | |||
actions are currently | |||
underway. | |||
Three events involving | |||
the inadvertent | |||
release of hot particles | |||
from the plant site occurred in February 1987. In two of these events, the radiation | |||
dose to the public was determined | |||
to be negligible. | |||
However, the third event involved a 0.2.;Ci particle found by a worker at his home during a self-initiated | |||
radiological | |||
survey. The licensee has not yet estimated | |||
the potential | |||
dose to the worker's family as a result of this occurrence. | |||
In the licensee's | |||
licensee event report (LER No. 86-015, Revision 1) of Febru-ary 22, 1987, the following | |||
program improvements | |||
for detecting | |||
hot particles and controlling | |||
personnel | |||
exposures | |||
from hot particles | |||
were described: | |||
f Extensive, mandatory | |||
use of exceedingly | |||
sensitive | |||
fixed instrumentation (frisking | |||
booths) for the detection | |||
of personnel | |||
contamination; | |||
Special training (including | |||
hands-on laboratory | |||
exercises) | |||
in radioactive | |||
particle characteristics | |||
and survey techniques | |||
for all Health Physics Technicians; | |||
C-. | |||
Attachment | |||
1 IN 87-39 August 21, 1987 Oral and written indoctrination | |||
of all managers, first line super-visors and workers in the special problems associated | |||
with radio-active particles, including | |||
the methods each person must employ to protect himself;Special procedures | |||
to assure detection | |||
and control of radioactive | |||
particles | |||
which feature the establishment | |||
of a clearly identifiable | |||
zone, to demark and contain such particles, surrounded | |||
by clearly identified | |||
buffer zones (or solid physical barriers) | |||
which are surveyed frequently | |||
to verify that control is being maintained; | |||
Maintenance | |||
and wide publication | |||
of a radioactive | |||
particle census during outages to maintain station awareness; | |||
The establishment | |||
of a Task Force to recommend | |||
and implement | |||
action to minimize the future production | |||
and movement of radioactive | |||
particles. | |||
Trojan, April, 1987, Inspection | |||
Report No. 50-344/87-15 Background: | |||
The facility has operated since July 1982 with an estimated | |||
112 fuel pellets unaccounted | |||
for throughout | |||
the reactor and support plant systems. The licensee recovered | |||
or located about 264 pellets of the estimated | |||
376 missing after the 1982 refueling | |||
outage, which occurred because of the baffle jetting problems of the 1981 fuel cycle. (See IE Information | |||
Notice 82-27, "Fuel Rod Degradation | |||
Resulting | |||
From Baffle.Water-Jet | |||
Impingement," August .5, 1982.)Event Specifics: | |||
Shortly after the start of the 1987 refueling | |||
outage in April, a significant | |||
increase in personnel | |||
skin contaminations | |||
occurred. | |||
On April 9, high surface contamination (up to 300,000 dpm/100 cm 2) and high airborne activity levels-.(2E-7 pCi/cc, mixed fission products) | |||
in containment | |||
resulted from the dis-persal of fuel fragments | |||
during reactor vessel. stud removal and stud-hole plugging operations. | |||
The workers in the reactor cavity were wearing respira-tors and no excessive | |||
uptakes of.radioactive | |||
materials | |||
were detected during followup whole-body | |||
counting. | |||
Because of the spread of contamination | |||
to the spent fuel building, the licensee stopped all- reactor building cavity work and all personnel | |||
evacuated | |||
the area that afternoon. | |||
On April 10, a licensee radiation | |||
survey located a hot spot on the cavity floor near a reactor vessel stud-hole | |||
(>100 rad/hr beta and 30 R/hr gamma contact reading using a portable ion-chamber | |||
survey.instrument). | |||
On April 11, another worker located what appeared to be about one-half of a fuel pellet in the flange area at the stud hole. This partial fuel pellet was removed on April 12. | |||
Attachment | |||
1 IN 87-39 August 21, 1987 On April 17, a radiation | |||
protection | |||
technician, after performing | |||
a survey of the lower refueling | |||
cavity, discovered | |||
a fuel particle lodged in his protective | |||
rubber shoe cover. This particle was later determined | |||
to be composed of approximately | |||
50 mCi of mixed fission product activity; | |||
showed readings of 1200 mR/hr with the window open and 250 mR/hr with the window closed. After a careful time-and-motion | |||
study of the technician's | |||
activities, the licensee determined | |||
that no NRC regulatory | |||
dose limits were exceeded. (Licensee | |||
esti-mates were 1.2 rem to whole body; 4.6 rem to skin; 9.6 rem to extremities.) | |||
In general, it appears that the licensee experienced | |||
a programmatic | |||
breakdown that resulted in several workers receiving | |||
significant, unnecessary | |||
radiation exposures | |||
from fuel particle contamination. | |||
In LER No. 87-08'dated | |||
May 8, 1987, the licensee identified | |||
the following | |||
additional | |||
concerns and'corrective | |||
actions. The LER stated in part: Workers entering containment | |||
on April 9 were not-aware | |||
of the fuel particle hazards. As a corrective | |||
measure, all personnel | |||
with access to radiological | |||
control areas were retrained | |||
to be informed of the fuel particle problem and perform hands-on training to demonstrate | |||
competence | |||
in anti-contamination | |||
clothing use. Daily reports are being provided to workers on the status of containment | |||
activities. | |||
Radiation | |||
surveys and record keeping were inadequate. | |||
===As a corrective=== | |||
measure, new procedures | |||
were developed | |||
to specifically | |||
address discrete radioactive | |||
particles. | |||
All radiation | |||
protection | |||
technicians | |||
have been trained on these new procedures... | |||
There was-insufficient | |||
extremity | |||
monitoring | |||
and no procedures | |||
for particle control. As a corrective | |||
measure, procedures | |||
have been prepared to address particle control. Additional | |||
extremity | |||
moni-toring is being utilized.Evaluation | |||
of radiological | |||
events needs to be improved. | |||
A'new-pro'' | |||
cedure will be prepared for documenting | |||
and evaluating | |||
radiologicalj | |||
: events.-Review of radiation | |||
protection | |||
activities.'is | |||
insufficient. | |||
A new separate onsite review committee | |||
will be established | |||
to evaluate radiological | |||
events and to routinely | |||
review the performance | |||
of the Radiation | |||
Protection | |||
Department. | |||
-Insufficient | |||
staffing existed. Increasing | |||
the manpower in both the onsite Radiation | |||
Protection | |||
Department | |||
and the corporate | |||
===Radiological=== | |||
Safety Branch of the Nuclear Safety and Regulation | |||
Department | |||
is being pursued. | |||
Attachment | |||
1 IN 87-39 August 21, 1987 Problems existed due to insufficient | |||
radiation | |||
monitoring | |||
and surveying equipment. | |||
Additional | |||
equipment | |||
including | |||
new portal monitors and radiation | |||
monitoring | |||
equipment | |||
has been procured.There was the potential | |||
for radiation | |||
exposure to individuals | |||
from fuel particles | |||
on anti-contamination | |||
clothing. | |||
An evaluation | |||
for potential exposure is in progress.V. C. Summer, November 1986, Inspection | |||
Report No. 50-395/86-22 After working-in | |||
a "clean" area where no protective | |||
clothing was required, contamination | |||
was detected on the hand of an electrician | |||
who had worked on a control panel for the overhead crane in the fuel handling building. | |||
After measuring | |||
the dose rates (window open and window closed) with a portable survey instrument | |||
the worker's hand was decontaminated. | |||
The contaminant | |||
was not retained for further analysis. | |||
Based on the survey instrument | |||
readings, the dose to the workers hand was calculated | |||
to be about 420 rems (at a depth of 7 mg/cm 2 averaged over an area of 1 cm 2).Salem Unit 2, April 1987, Inspection | |||
Report No. 50-311/87-11 A fuel particle was detected by a whole-body | |||
contamination | |||
monitor on a work-er's arm. The particle was identified | |||
as a fuel particle (about 225 days since in core) by using a gamma-ray | |||
spectrometer | |||
[Ge(Li) detector]. | |||
The licensee believes that the source of the particle was from the last refueling | |||
outage about 8 months earlier.Yankee Nuclear Power Station, May 1987, Inspection | |||
Report No. 50-29/87-10 | |||
A potential | |||
skin exposure of 7.6 rem to a worker's scalp occurred from an activated | |||
particle. | |||
The apparent source of the particle was the worker's PC hood. After its discovery, the particle remained on the worker's scalp for about 78 hours, awaiting medical assistance | |||
to remove the particle. | |||
Prior to medical assistance | |||
arriving on site, the particle was removed by shaving the hair. Earlier in May, the licensee reported that, during fuel assembly move-ment, pieces of fuel rods were seen to have fallen away from the assembly and land on top of the reactor core and in the refueling | |||
cavity area. Fuel recon-stitution | |||
was in progress. | |||
- | |||
Attachment | |||
1 IN 87-39 August 21, 1987 Indian Point Unit 3, May 1987, Inspection | |||
Report No. 50-286/87-18 A maintenance | |||
foreman exiting the containment | |||
after helping to replace steam generator | |||
manway covers received an estimated | |||
4 rem dose to the skin (in back of neck) from an activated | |||
zirconium | |||
particle. | |||
It appears the particle dis-lodged from his PC hood and fell on his neck during temporary | |||
removal of the hood during a work rest-break. | |||
Quad Cities/Dresden/Zion, 1986 and 1987 A special program to investigate | |||
hot particle incidents | |||
has been in place at these Commonwealth | |||
Edison Company facilities | |||
for the last 1-2 years. A total of approximately | |||
100 individual | |||
hot particles | |||
were found on workers' skin or clothing in 1986. Approximately | |||
130 particles | |||
were found in the first six months of 1987. The particles | |||
have been predominantly | |||
Co-60 with activities | |||
ranging from about 0.01 to 1 pCi. Those particles | |||
were analyzed for physical size; the smallest was 20 microns. The licensee investigated | |||
each event and calculated | |||
skin doses. No overexposures | |||
have been reported. | |||
The transfer mechanism | |||
of the particles | |||
to the workers has not been positively | |||
identified. | |||
Callaway Station, 1986 Period, Report No. 50-483/8700 (DRSS)The licensee experienced | |||
ten hot particle skin contamination | |||
incidents | |||
primari-ly during the refueling | |||
outage early during the year. No NRC dose limits were exceeded. | |||
Ineffective | |||
frisking (hand-held | |||
pancake GM-tube) of laundered | |||
PC and potentially | |||
degraded dry-cleaning | |||
fluid quality (leading to cross-contami- nation of PC during cleaning) | |||
were identified | |||
by the licensee as possible contributors | |||
to this contamination | |||
problem. | |||
Attachment | |||
2 IN 87-39 August 21, 1987 LIST OF RECENTLY ISSUED INFORMATION | |||
NOTICES 1987 Information | |||
Date of Notice No. Subject Issuance Issued to 87-38 87-37 87-36 87-35 87-34 87-33 87-32 Inadequate | |||
or Inadvertent | |||
Blocking of Valve Movement Compliance | |||
with the General License Provisions | |||
of 10 CFR Part 31 Significant | |||
Unexpected | |||
Erosion of Feedwater | |||
Lines Reactor Trip Breaker, Westinghouse | |||
Model DS-416, Failed to Open on Manual Initiation | |||
from the Control Room Single Failures in Auxiliary Feedwater | |||
Systems Applicability | |||
of 10 CFR Part 21 to Nonlicensees | |||
Deficiencies | |||
in the Testing of Nuclear-Grade | |||
Activated Charcoal.8/17/87 8/10/87 8/4/87 7/30/87 7/24/87 7/24/87 7/10/87 7/10/87 All nuclear power reactor facilities | |||
holding an OL or CP.All persons specifi-cally licensed to manufacture | |||
or to initially | |||
transfer devices containing | |||
radioactive | |||
material to general licensees, as defined in 10 CFR Part 31.All nuclear power reactor facilities | |||
holding an OL or CP.All nuclear power reactor facilities | |||
holding an OL or CP employing | |||
W DS-416 reactor trip breakers.All holders of an OL or a CP for pressurized | |||
water reactor facilities. | |||
All NRC licensees. | |||
===All nuclear power reactor facilities=== | |||
holding an OL or CP.All NRC licensees. | |||
87-31 Blocking, Bracing, and Securing of Radioactive | |||
Materials | |||
Packages in Transportation. | |||
.: OL =CP =Operating | |||
License Construction | |||
Permit | |||
-.V IN 87-XX August, 1987 No specific action or written response is required by this information | |||
notice.If you have any questions | |||
about this matter, please contact the Regional Administrator | |||
of the appropriate | |||
regional office or this office.Charles E. Rossi, Director Division of Operational | |||
===Events Assessment=== | |||
Office of Nuclear Reactor Regulation | |||
Technical | |||
Contact: James E. Wigginton, NRR (301) 492-4663 John 0. Buchanan, NRR (301) 492-7293 References | |||
1. IE Information | |||
Notice 86-23, "Excessive | |||
Skin Exposures | |||
Due to Contamina- tion With Hot Particles," April 9, 1986.2. Institute | |||
of Nuclear Power Operations, Significant | |||
Event Report 18-87 (Rev. 2), "Radiation | |||
Exposure From Small Particles," July 16, 1987.3. Moeller, M. P., G. F. Martin, and D. L. Haggard, "The Impact of Fuel Cladding Failure Events on Occupational | |||
Radiation | |||
Exposures | |||
at Nuclear Power Plants. Case Study: PWR During Routine Operations," NUREG/CR-4485 (PNL-5606), January 1986.4. Heard, D. B., and R. J. Freeman, "Cobalt Contamination | |||
Resulting | |||
From Valve Maintenance," Electric Power Research Institute, EPRI NP-3220, Final Report, August 1983.5. Wells, J., "Problems | |||
Associated | |||
With Localized | |||
Skin Exposures," in "Radia-tion Damage to Skin: Fundamental | |||
and Practical | |||
Aspects," Proceedings | |||
of a Workshop held at Saclay, France, on October 9-11, 1985, Brit.J. Radiology, Supplement | |||
No. 19, pp. 146-150 (1986).6. Charles, M. W,., "The Biological | |||
Bases of Radiation | |||
Protection | |||
Criteria for Superficial, Low Penetrating | |||
Radiation | |||
Exposure," in "Dosimetry | |||
of Beta Particles | |||
and Low Energy X-Rays," Proceedings | |||
of a Workshop held at Saclay, France, October 7-9, 1985," Radiation | |||
Protection | |||
Dosimetry | |||
14 (No.2), pp. 79-90 (1986).7. Charles, M. W., "Skin, Eye, and Testis: Current Exposure Problems and Recent Advances in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp. 69-81 (1986).Attachments: | |||
1. Events Summaries 2. List of Recently Issued NRC Information | |||
Notices*SEE PREVIOUS CONCURRENCES | |||
C p g /OGCB:DOEA:NRR | |||
z UERidlHBerlinger | |||
RBDE-R R PN n 1 847 4 S8//' 87 8/ /87 RPB:DREP:NRR | |||
*RP:DREP:NRR | |||
R P:NR '*D:DREP:NRR | |||
*PPMB:ARM JEWigginton | |||
JDBuchanan | |||
LJCunningham | |||
FJCongel TechEd 7/28/87 7/28/87 7/28/87 7/28/87 7/28/87 IN 87-XX August, 1987 No specific action or written response is required by this information | |||
notice.If you have any questions | |||
about this matter, please contact the Regional Administrator | |||
of the appropriate | |||
regional office or this office.Charles E. Rossi, Director Division of Operational | |||
===Events Assessment=== | |||
Office of Nuclear Reactor Regulation | |||
Technical | |||
Contact: James E. Wigginton, NRR (301) 492-4663 John D. Buchanan, NRR (301) 492-7293 References | |||
1. "IE Information | |||
Notice 86-23, "Excessive | |||
Skin Exposures | |||
Due to Contamina- tion With Hot Particles," April 9, 1986.2. Institute | |||
of Nuclear Power Operations, Significant | |||
Event Report 18-87 (Rev. 2), "Radiation | |||
Exposure From Small Particles," July 16, 1987.3. Moeller, M. P., G. F. Martin, and D. L. Haggard, "The Impact of Fuel Cladding Failure Events on Occupational | |||
Radiation | |||
Exposures | |||
at Nuclear Power Plants. Case Study: PWR During Routine Operations," NUREG/CR-4485 (PNL-5606), January 1986.4. Heard, D. B., and R. J. Freeman, "Cobalt Contamination | |||
Resulting | |||
From Valve Maintenance," Electric Power Research Institute, EPRI NP-3220, Final Report, August 1983.5. Wells, J., "Problems | |||
Associated | |||
With Localized | |||
Skin Exposures," in "Radia-tion Damage to Skin: Fundamental | |||
and Practical | |||
Aspects," Proceedings | |||
of a Workshop held at Saclay, France, on October 9-11, 1985, Brit.J. Radiology, Supplement | |||
No. 19, pp. 146-150 (1986).6. Charles, M. W., "The Biological | |||
Bases of Radiation | |||
Protection | |||
Criteria for Superficial, Low Penetrating | |||
Radiation | |||
Exposure," in "Dosimetry | |||
of Beta Particles | |||
and Low Energy X-Rays," Proceedings | |||
of a Workshop held at Saclay, France, October 7-9, 1985," Radiation | |||
Protection | |||
Dosimetry | |||
14 (No.2), pp. 79-90 (1986).7. Charles, M. W., "Skin, Eye, and Testis: Current Exposure Problems and Recent Advances in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp.69-81 (1986).Attachments: | |||
1. Events Summaries 2. List of Recently Issued NRC Information | |||
Notices*SEE PREVIOUS CONCURRENCES | |||
D/DOEA:NRR | |||
C/OGCB:DOEA:NRR | |||
===CERossi CHBerlinger=== | |||
8/ /87 8/10/87*RPB:DREP:NRR | |||
*RPB:DREP:NRR | |||
*AC:RPB:DREP:NRR | |||
*D:DREP:NRR | |||
*PPMB:ARM JEWigginton | |||
JDBuchanan | |||
LJCunningham | |||
FJCongel TechEd 7/28/87 7/28/87 7/28/87 7/28/87 7/28/87 | |||
~' V IN 87-XX August, 1987 No specific action or written response is required by this information | |||
notice.If you have any questions | |||
about this matter, please contact the Regional Administrator | |||
of the appropriate | |||
regional office or this office.Charles E. Rossi, Director Division of Operational | |||
===Events Assessment=== | |||
Office of Nuclear Reactor Regulation | |||
Technical | |||
Contact: James E. Wigginton, NRR (301) 492-4663 John D. Buchanan, NRR (301) 492-7293 References | |||
1. "IE Information | |||
Notice 86-23, "Excessive | |||
Skin Exposures | |||
Due to Contamina- tion With Hot Particles," April 9, 1986.2. Institute | |||
of Nuclear Power Operations, Significant | |||
Event Report 18-87 (Rev. 2), "Radiation | |||
Exposure From Small Particles," July 16, 1987.3. Moeller, M. P., G. F. Martin, and D. L. Haggard, "The Impact of Fuel Cladding Failure Events on Occupational | |||
Radiation | |||
Exposures | |||
at Nuclear Power Plants. Case Study: PWR During Routine Operations," NUREG/CR-4485 (PNL-5606), January 1986.4. Heard, D. B., and R. J. Freeman, "Cobalt Contamination | |||
Resulting | |||
From Valve Maintenance," Electric Power Research Institute, EPRI NP-3220, Final Report, August 1983.5. Wells, J., "Problems | |||
Associated | |||
With Localized | |||
Skin Exposures,' | |||
in "Radia-tion Damage to Skin: Fundamental | |||
and Practical | |||
Aspects," Proceedings | |||
of a Workshop held at Saclay, France, on October 9-11, 1985, Brit.J. Radiology, Supplement | |||
No. 19, pp. 146-150 (1986).6. Charles, M. W., "The Biological | |||
Bases of Radiation | |||
Protection | |||
Criteria for Superficial, Low Penetrating | |||
Radiation | |||
Exposure," in "Dosimetry | |||
of Beta Particles | |||
and Low Energy X-Rays," Proceedings | |||
of a Workshop held at Saclay, France, October 7-9, 1985," Radiation | |||
Protection | |||
Dosimetry | |||
14 (No.2), pp. 79-90 (1986).7. Charles, M. W., Recent Advances 69-81 (1986)."Skin, Eye, and Testis: Current Exposure Problems and in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp.Attachments: | |||
1. Events Summaries 2. List of Recently Issued NRC Information | |||
Notices C/OGCB:DOEA:NRF | |||
CHBerlinger | |||
R i EP:NRR J Eigginton 7/&X/87 RPM :NRR J. an 7/ig/87 A REP:NRR LJC I4nningham | |||
7}(%/87 D:DREP:NRRI | |||
}} | FJCongel-4/ti/8 7 Techd 7/w}} | ||
{{Information notice-Nav}} | {{Information notice-Nav}} |
Revision as of 13:43, 31 August 2018
..-.i V' 'SINS No.: 6835 iN 87-39 UNITED STATES NUCLEAR REGULATORY
COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555 August 21, 1987 NRC INFORMATION
NOTICE NQ. 87-39: CONTROL OF HOT PARTICLE CONTAMINATION
AT NUCLEAR POWER PLANTS
Addressees
All nuclear power reactor facilities
and spent fuel storage facilities
holding an NRC license or a construction
permit.Background
and
Purpose
- IE Information
Notice 86-23 (Reference
1) provided information
on events in-volving excessive
skin exposures
resulting
from skin contamination
by small, highly radioactive
particles
with high specific activity (hot particles).
Since that information
notice was issued, there have been more of these events, and a recent report by the Institute
of Nuclear Power Operations (INPO) (Reference
2)provides additional
information
on this subject. This information
notice pro-vides information
on some of the subsequent
events and discusses
degraded fuel and a lack of proper radiological
control during fuel reconstitution
as major sources of hot particles.
Generic licensee lessons learned also are included.It is expected that recipients
will review this information
for applicability
to their facilities
and consider action, if appropriate, to preclude a similar problem occurring
at their facilities.
However, suggestions
contained
in this notice do not constitute
NRC requirements;
therefore, no specific action or written response is required.Discussion:
During the first 6 months of 1987, events involving
hot particle exposures
were reported at nine different
nuclear power stations.
Two events in late 1986 (at V.C. Summer and San Onofre) involved exposures
apparently
exceeding
NRC regula-tory limits. Attachment
1 provides summary descriptions
of eight of these events. More detailed descriptions
can be obtained from the referenced
inspec-tion reports for each event. (Copies of NRC Inspection
Reports are available from the NRC Public Document Room, 1717 H Street N.W., Washington, D.C.)Hot particles
come primarily
from two major sources: degraded fuel and neutron-activated
corrosion
and wear products (e.g., Stellite).
While much of the information
in this notice is pertinent
to both neutron-activated
corrosion and wear product particles (hereafter
referred to as activated
particles)
and
K> QIN 87-39 August 21, 1987 irradiated
fuel particles (hereafter
referred to as fuel particles), a major concern of this notice is extended facility operation
with degraded fuel and the resulting
problems with fuel particle contamination.
On the basis of an NRC review of licensees'
corrective
actions, discussions
with licensees'
operating
staffs, and information
obtained by NRC inspectors, the lessons learned and licensee good practices
resulting
from the events summarized
in Attachment
1 are as follows: 1. Extended power plant operation
with degraded fuel (leaking fuel pins) can result in widespread
dispersal
of fuel particles.
Some plants continue to experience
fuel particle contamination
problems long after leaking fuel pins have been removed because of the residual contamination
of plant systems. Some plants with these problems have started programs to account for missing fuel pellets and fragments
and to identify measures to recover this material.2. Considerations
concerning
the handling of leaking fuel include the following:
a. Special techniques
and precautions
for handling leaking fuel bundles are necessary
to prevent aggravating
the spread of fuel particles.
For example, containment
devices should be used when reconstituting
fuel. The lack of proper radiological
controls and oversight
of the fuel reconstitution
process in the San Onofre 3 fuel pool led to loss of control and dispersal
of numerous fuel particles
into the pool.Fuel particles
then spread through the plant spent fuel systems and to the liquid radwaste systems.b. A damaged, leaking fuel pin that is not properly contained
and segregated
from the common fuel pool area could be a significant, long-term
source of fuel particle contamination.
c. Plants should be aware that NSSS vendors' special refueling
tools and equipment
could be a source of fuel particle contamination.
These tools and equipment
should be carefully
surveyed before they are used and before they are shipped to other facilities.
3. Some plants that have operated for extended periods of time with degraded fuel and plants with activated
particle problems now have instituted
specialized, comprehensive
training programs for plant system maintenance
workers and general employees.
These programs are designed to better inform and prepare the plant staff to cope with the continuing
fuel particle problems.
Additionally, as part of comprehensive
contamination
control programs, special new procedures
to improve surveys for detection
- --..IN 87-39 August 21, 1987 of.hot particles
have been prepared and health physics technicians
have been trained in their use. Decontamination
and dose evaluation
methods and procedures
that focus on hot particles
have been implemented. (See summaries
of events at Trojan and.San Onofre in Attachment
1.).4.. In general, ;licensees
have upgraded their programs for contamination
monitoring
of "clean," laundered
anti-contamination
protective
clothing (PC). However, PC continues
to be a means of transferring
both fuel particles
and activated
particles.
Some facilities
need to consider making their PC monitoring
programs more sensitive.
For example, some licensees
that are using contractor
laundry services found the contrac-tor's alarm on the radiation
monitor (used to screen PC) too high to-detect 0.4 microcurie (VCi) particles.
Moreover, when commercial
laundry services are used, it is possible that PC from a "particle-free" plant* *-can be mixed with PC from a plant with hot particle problems.
Finally, at.leastrone
licensee was relying solely on monitoring
of large bundles of washed PC (bulk surveys) and was not monitoring
samples of individual
PC. For plants with identified
particle problems, individual
PC items may have to be checked before they are reused after cleaning.5. Except for the-Trojan
event discussed
in Attachment
1, to date, no licensee has reported detecting
hot.particles
during airborne sampling.However, as a precaution,,some
licensees
have elected to provide workers with respiratory
protection
for performing
maintenance
on plant systems known to-be a source of hot particles.
No plant has reported inhalation
or ingestion
of hot particles
by any worker.6. Hot particles
in contact with skin.produce
very high dose rates. Diligent personnel
contamination
surveys performed
as soon as practical
after .completing
work involving
contamination
are needed to minimize potential exposure times.-7. Approximately
75 percent of the U.S. power reactor facilities
are cur-rently using new high-sensitivity
whole-body
contamination
monitors.These state-of-the-art
contamination
monitors increase the probability
of detecting
hot-particles
on plant personnel
while reducing the likelihood
of inadvertently
releasing
particles
from the plant site. To-date, most of-the particles
found on personnel
have:been
detected by these new monitors.
Even with use of the new monitors, a few instances
have oc-curred where hot particles
have inadvertently
been carried home by workers.and have-been
detected in the home or on the worker returning
to the site.No significant ,public exposures
have been reported to date.8. In a recent study for the NRC (Reference
3), it was reported that a plant operating
with 0.125 percent pin-hole fuel cladding defects showed a general five-fold
increase in whole-body
radiation
exposure rates in some
IN 87-39 .August 21, 1987 areas of the plant when compared to a sister plant with high-integrity
fuel (<0.01percent
leakers).
Around certain plant systems the degraded fuel may elevate.-radiation
exposure rates even more. -9. Maintenance-on
valves with Stellite components
can cause introduction
of cobalt-containing
debris with Co-60 as the resultant
neutron activation
product. Some plants have instituted
work controls (e.g., use of contain-ment and post-maintenance
cleaning)
to minimize this input into reactor systems (Reference
4).Health Implications
and Radiation
Protection
Criteria for Hot Particle-Exposures
of Skin: -A hot'particle
on the skin gives a high beta dose to a small area.' Any radia-tion dose to the skin is-assumed
to result in'some increased
risk of skin cancer, although'this
type of cancer is rarely fatal.' Experiments
with animals indicate that highly localized
irradiation
of-the skin'by hot particles
is less likely to'cause skin cancer than more uniform irradiation
by the same quantity of radioactive
material.:-
In addition to any increased
risk of cancer, large doses to the skin from hot particles
also may produce observable
effects such as reddening, hardening, peeling, or ulceration
of the skin-immediately
around the particle;
These effects appear only'after
a-threshold
dose is exceeded.
The doses from hot particles
'equired to-produce
these effects'in
the 'skin are'not known pre-cisely;-Ihowever, -it appears likely, except for a point reddening,-that
these effects will only be seen for doses of hundreds of rems or more.'- No such effects have been seen to date on any workers who have been exposed to-hot particles, even though one exposure has been measured or calculated
as high as 512 rem.Recent reviews of radiobiology
and radiation
protection
criteria for skin, in-cluding considerations
of hot particle exposures, have been provided-by-Wells (Reference
5) and Charles (References
6 and 7). The NRC staff recognizes
the need for more'information
on the effects of radiation
on skin and particularly
the effects-of
hot particle irradiation.
The staff has requested
the National Council on Radiation
Protection
and Measurements (NCRP) to. study the health significance
of hot particle exposures and to provisde recommendations- based on the findings of this study. These recommendations
may result in changes in NRC requirements
with respect to hot particle exposures.
However, until these requirements
are changed, IE Infor-mation Notice 86-23 (Reference
1) contains current information
for use in evaluating
doses to skin resulting
from hot particles.
./ ..IN 87-39 August. 21, 1987 Page 5 of S o I specific action or. written response is required by this information
notice.* you have any questions
about this matter, please contact the Regional Admiistrator
'f the appropriate
regional office or this office.e ,.harles E. Rossi, Director Division of Operational
Events Assessment
Office of Nuclear Reactor Regulation
Technwcal
Contact:-
James E..Wigginton, NRR (301) 492-4663 John D. Buchanan, NRR.(301) 492-7293 References
I. JAE Information
Notice 86-23, "Excessive
Skin Exposures
Due to Contamina- tihn With Hot Particles," April 9, 1986.2i. nstitute of Nuclear Power Operations, Significant
Event Report 18-87 (Rev..2), "Radiation
Exposure From Small Particles," July 16, 1987.3,- Hoeller; M. P., :G. F. Martin, and D. L..Haggard, "The Impact of Fuel*- Cladding Failure Events on Occupational
Radiation
Exposures
at Nuclear:PowerPants.
Case Study: PWR During RoutineOperations," NUREG/CR-4485 (PNL-5606), January 1986.H4 Heard, D. B., and R. J. Freeman, "Cobalt Contamination
Resulting
From.`Valve IMaintenance," Electric Power Research Institute, EPRI NP-3220, Final::Report, August 1983. .5.. Welli, 3., "Problems
Associated
With Localized
Skin Exposures," in "Radia-tion Damage to Skin: Fundamental
and Practical
Aspects," Proceedings
of a: .Workshop.
heldat Saclay, France, on October 9-11, 1985, Brit..J3. Radiology, Supplement
No. 19, pp. 146-150 (1986).* .6. Charles, 4.W., "The Biological
Bases of Radiation
Protection
Criteria for Superficial, Low Penetrating
Radiation
Exposure," in "Dosimetry
of Beta Particles
and Low Energy X-Rays," Proceedings
of a Workshop held at-Sacay, Francei October 7-9,-1985," Radiation
Protection
Dosimetry
14 (No.P2),pp. 79-90 (1986).-7. Charles, 14. W., "Skin, Eye, and Testis: Current Exposure Problems and Recent..Advances
in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp. 69-81 (1986).Attachments;..
..-*. l. EventSummaries
.2.. List-4f Recently Issued NRC Information
Notices
Attachment
1 IN 87-39 August 21, 1987 EVENT SUMMARIES San Onofre 3. Events Durina November 1986 -March 1987, Inspection
Report No. 50-362/86-37 Background:
At the onset of the first fuel cycle, significant
fuel degradation
was evident.The plant continued
to operate with approximately
105 defective
fuel pins. In late 1985 during the first refueling
outage, a fuel pin was inadvertently
pulled apart during the fuel reconstitution
process. Several fuel pellets fell and dispersed
throughout
the fuel pool. Fuel particles
had previously
been detected early on during reconstitution
on fuel handling tools and on the refueling
floors. All the severely damaged fuel pins were then grouped into one fuel bundle and stored in the pool without any containment.
Event Specifics:
From January 2 through February 20, 1987, the licensee's
aggressive
hot parti-cle inventory
and tracking system indicated
that 92 "new" fuel particles (recently
neutron irradiated), 155 "old" fuel particles, 51 ruthenium, 84 crud, and 42 cobalt particles
had been found and analyzed.
Before 1987, no formal tracking program existed.Several incidents
involving
hot particles
have occurred, including
an apparent worker extremity
exposure (hand) of 512 rem during November 1986. As a result, appropriate
NRC enforcement
actions are currently
underway.
Three events involving
the inadvertent
release of hot particles
from the plant site occurred in February 1987. In two of these events, the radiation
dose to the public was determined
to be negligible.
However, the third event involved a 0.2.;Ci particle found by a worker at his home during a self-initiated
radiological
survey. The licensee has not yet estimated
the potential
dose to the worker's family as a result of this occurrence.
In the licensee's
licensee event report (LER No.86-015, Revision 1) of Febru-ary 22, 1987, the following
program improvements
for detecting
hot particles and controlling
personnel
exposures
from hot particles
were described:
f Extensive, mandatory
use of exceedingly
sensitive
fixed instrumentation (frisking
booths) for the detection
of personnel
contamination;
Special training (including
hands-on laboratory
exercises)
in radioactive
particle characteristics
and survey techniques
for all Health Physics Technicians;
C-.
Attachment
1 IN 87-39 August 21, 1987 Oral and written indoctrination
of all managers, first line super-visors and workers in the special problems associated
with radio-active particles, including
the methods each person must employ to protect himself;Special procedures
to assure detection
and control of radioactive
particles
which feature the establishment
of a clearly identifiable
zone, to demark and contain such particles, surrounded
by clearly identified
buffer zones (or solid physical barriers)
which are surveyed frequently
to verify that control is being maintained;
Maintenance
and wide publication
of a radioactive
particle census during outages to maintain station awareness;
The establishment
of a Task Force to recommend
and implement
action to minimize the future production
and movement of radioactive
particles.
Trojan, April, 1987, Inspection
Report No. 50-344/87-15 Background:
The facility has operated since July 1982 with an estimated
112 fuel pellets unaccounted
for throughout
the reactor and support plant systems. The licensee recovered
or located about 264 pellets of the estimated
376 missing after the 1982 refueling
outage, which occurred because of the baffle jetting problems of the 1981 fuel cycle. (See IE Information
Notice 82-27, "Fuel Rod Degradation
Resulting
From Baffle.Water-Jet
Impingement," August .5, 1982.)Event Specifics:
Shortly after the start of the 1987 refueling
outage in April, a significant
increase in personnel
skin contaminations
occurred.
On April 9, high surface contamination (up to 300,000 dpm/100 cm 2) and high airborne activity levels-.(2E-7 pCi/cc, mixed fission products)
in containment
resulted from the dis-persal of fuel fragments
during reactor vessel. stud removal and stud-hole plugging operations.
The workers in the reactor cavity were wearing respira-tors and no excessive
uptakes of.radioactive
materials
were detected during followup whole-body
counting.
Because of the spread of contamination
to the spent fuel building, the licensee stopped all- reactor building cavity work and all personnel
evacuated
the area that afternoon.
On April 10, a licensee radiation
survey located a hot spot on the cavity floor near a reactor vessel stud-hole
(>100 rad/hr beta and 30 R/hr gamma contact reading using a portable ion-chamber
survey.instrument).
On April 11, another worker located what appeared to be about one-half of a fuel pellet in the flange area at the stud hole. This partial fuel pellet was removed on April 12.
Attachment
1 IN 87-39 August 21, 1987 On April 17, a radiation
protection
technician, after performing
a survey of the lower refueling
cavity, discovered
a fuel particle lodged in his protective
rubber shoe cover. This particle was later determined
to be composed of approximately
50 mCi of mixed fission product activity;
showed readings of 1200 mR/hr with the window open and 250 mR/hr with the window closed. After a careful time-and-motion
study of the technician's
activities, the licensee determined
that no NRC regulatory
dose limits were exceeded. (Licensee
esti-mates were 1.2 rem to whole body; 4.6 rem to skin; 9.6 rem to extremities.)
In general, it appears that the licensee experienced
a programmatic
breakdown that resulted in several workers receiving
significant, unnecessary
radiation exposures
from fuel particle contamination.
In LER No. 87-08'dated
May 8, 1987, the licensee identified
the following
additional
concerns and'corrective
actions. The LER stated in part: Workers entering containment
on April 9 were not-aware
of the fuel particle hazards. As a corrective
measure, all personnel
with access to radiological
control areas were retrained
to be informed of the fuel particle problem and perform hands-on training to demonstrate
competence
in anti-contamination
clothing use. Daily reports are being provided to workers on the status of containment
activities.
Radiation
surveys and record keeping were inadequate.
As a corrective
measure, new procedures
were developed
to specifically
address discrete radioactive
particles.
All radiation
protection
technicians
have been trained on these new procedures...
There was-insufficient
extremity
monitoring
and no procedures
for particle control. As a corrective
measure, procedures
have been prepared to address particle control. Additional
extremity
moni-toring is being utilized.Evaluation
of radiological
events needs to be improved.
A'new-pro
cedure will be prepared for documenting
and evaluating
radiologicalj
- events.-Review of radiation
protection
activities.'is
insufficient.
A new separate onsite review committee
will be established
to evaluate radiological
events and to routinely
review the performance
of the Radiation
Protection
Department.
-Insufficient
staffing existed. Increasing
the manpower in both the onsite Radiation
Protection
Department
and the corporate
Radiological
Safety Branch of the Nuclear Safety and Regulation
Department
is being pursued.
Attachment
1 IN 87-39 August 21, 1987 Problems existed due to insufficient
radiation
monitoring
and surveying equipment.
Additional
equipment
including
new portal monitors and radiation
monitoring
equipment
has been procured.There was the potential
for radiation
exposure to individuals
from fuel particles
on anti-contamination
clothing.
An evaluation
for potential exposure is in progress.V. C. Summer, November 1986, Inspection
Report No. 50-395/86-22 After working-in
a "clean" area where no protective
clothing was required, contamination
was detected on the hand of an electrician
who had worked on a control panel for the overhead crane in the fuel handling building.
After measuring
the dose rates (window open and window closed) with a portable survey instrument
the worker's hand was decontaminated.
The contaminant
was not retained for further analysis.
Based on the survey instrument
readings, the dose to the workers hand was calculated
to be about 420 rems (at a depth of 7 mg/cm 2 averaged over an area of 1 cm 2).Salem Unit 2, April 1987, Inspection
Report No. 50-311/87-11 A fuel particle was detected by a whole-body
contamination
monitor on a work-er's arm. The particle was identified
as a fuel particle (about 225 days since in core) by using a gamma-ray
spectrometer
[Ge(Li) detector].
The licensee believes that the source of the particle was from the last refueling
outage about 8 months earlier.Yankee Nuclear Power Station, May 1987, Inspection
Report No. 50-29/87-10
A potential
skin exposure of 7.6 rem to a worker's scalp occurred from an activated
particle.
The apparent source of the particle was the worker's PC hood. After its discovery, the particle remained on the worker's scalp for about 78 hours9.027778e-4 days <br />0.0217 hours <br />1.289683e-4 weeks <br />2.9679e-5 months <br />, awaiting medical assistance
to remove the particle.
Prior to medical assistance
arriving on site, the particle was removed by shaving the hair. Earlier in May, the licensee reported that, during fuel assembly move-ment, pieces of fuel rods were seen to have fallen away from the assembly and land on top of the reactor core and in the refueling
cavity area. Fuel recon-stitution
was in progress.
-
Attachment
1 IN 87-39 August 21, 1987 Indian Point Unit 3, May 1987, Inspection
Report No. 50-286/87-18 A maintenance
foreman exiting the containment
after helping to replace steam generator
manway covers received an estimated
4 rem dose to the skin (in back of neck) from an activated
particle.
It appears the particle dis-lodged from his PC hood and fell on his neck during temporary
removal of the hood during a work rest-break.
Quad Cities/Dresden/Zion, 1986 and 1987 A special program to investigate
hot particle incidents
has been in place at these Commonwealth
Edison Company facilities
for the last 1-2 years. A total of approximately
100 individual
hot particles
were found on workers' skin or clothing in 1986. Approximately
130 particles
were found in the first six months of 1987. The particles
have been predominantly
Co-60 with activities
ranging from about 0.01 to 1 pCi. Those particles
were analyzed for physical size; the smallest was 20 microns. The licensee investigated
each event and calculated
skin doses. No overexposures
have been reported.
The transfer mechanism
of the particles
to the workers has not been positively
identified.
Callaway Station, 1986 Period, Report No. 50-483/8700 (DRSS)The licensee experienced
ten hot particle skin contamination
incidents
primari-ly during the refueling
outage early during the year. No NRC dose limits were exceeded.
Ineffective
frisking (hand-held
pancake GM-tube) of laundered
PC and potentially
degraded dry-cleaning
fluid quality (leading to cross-contami- nation of PC during cleaning)
were identified
by the licensee as possible contributors
to this contamination
problem.
Attachment
2 IN 87-39 August 21, 1987 LIST OF RECENTLY ISSUED INFORMATION
NOTICES 1987 Information
Date of Notice No. Subject Issuance Issued to 87-38 87-37 87-36 87-35 87-34 87-33 87-32 Inadequate
or Inadvertent
Blocking of Valve Movement Compliance
with the General License Provisions
of 10 CFR Part 31 Significant
Unexpected
Erosion of Feedwater
Lines Reactor Trip Breaker, Westinghouse
Model DS-416, Failed to Open on Manual Initiation
from the Control Room Single Failures in Auxiliary Feedwater
Systems Applicability
of 10 CFR Part 21 to Nonlicensees
Deficiencies
in the Testing of Nuclear-Grade
Activated Charcoal.8/17/87 8/10/87 8/4/87 7/30/87 7/24/87 7/24/87 7/10/87 7/10/87 All nuclear power reactor facilities
holding an OL or CP.All persons specifi-cally licensed to manufacture
or to initially
transfer devices containing
radioactive
material to general licensees, as defined in 10 CFR Part 31.All nuclear power reactor facilities
holding an OL or CP.All nuclear power reactor facilities
W DS-416 reactor trip breakers.All holders of an OL or a CP for pressurized
water reactor facilities.
All NRC licensees.
All nuclear power reactor facilities
holding an OL or CP.All NRC licensees.
87-31 Blocking, Bracing, and Securing of Radioactive
Materials
Packages in Transportation.
.: OL =CP =Operating
License Construction
Permit
-.V IN 87-XX August, 1987 No specific action or written response is required by this information
notice.If you have any questions
about this matter, please contact the Regional Administrator
of the appropriate
regional office or this office.Charles E. Rossi, Director Division of Operational
Events Assessment
Office of Nuclear Reactor Regulation
Technical
Contact: James E. Wigginton, NRR (301) 492-4663 John 0. Buchanan, NRR (301) 492-7293 References
1. IE Information
Notice 86-23, "Excessive
Skin Exposures
Due to Contamina- tion With Hot Particles," April 9, 1986.2. Institute
of Nuclear Power Operations, Significant
Event Report 18-87 (Rev. 2), "Radiation
Exposure From Small Particles," July 16, 1987.3. Moeller, M. P., G. F. Martin, and D. L. Haggard, "The Impact of Fuel Cladding Failure Events on Occupational
Radiation
Exposures
at Nuclear Power Plants. Case Study: PWR During Routine Operations," NUREG/CR-4485 (PNL-5606), January 1986.4. Heard, D. B., and R. J. Freeman, "Cobalt Contamination
Resulting
From Valve Maintenance," Electric Power Research Institute, EPRI NP-3220, Final Report, August 1983.5. Wells, J., "Problems
Associated
With Localized
Skin Exposures," in "Radia-tion Damage to Skin: Fundamental
and Practical
Aspects," Proceedings
of a Workshop held at Saclay, France, on October 9-11, 1985, Brit.J. Radiology, Supplement
No. 19, pp. 146-150 (1986).6. Charles, M. W,., "The Biological
Bases of Radiation
Protection
Criteria for Superficial, Low Penetrating
Radiation
Exposure," in "Dosimetry
of Beta Particles
and Low Energy X-Rays," Proceedings
of a Workshop held at Saclay, France, October 7-9, 1985," Radiation
Protection
Dosimetry
14 (No.2), pp. 79-90 (1986).7. Charles, M. W., "Skin, Eye, and Testis: Current Exposure Problems and Recent Advances in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp. 69-81 (1986).Attachments:
1. Events Summaries 2. List of Recently Issued NRC Information
Notices*SEE PREVIOUS CONCURRENCES
C p g /OGCB:DOEA:NRR
z UERidlHBerlinger
RBDE-R R PN n 1 847 4 S8//' 87 8/ /87 RPB:DREP:NRR
- RP:DREP:NRR
R P:NR '*D:DREP:NRR
- PPMB:ARM JEWigginton
JDBuchanan
LJCunningham
FJCongel TechEd 7/28/87 7/28/87 7/28/87 7/28/87 7/28/87 IN 87-XX August, 1987 No specific action or written response is required by this information
notice.If you have any questions
about this matter, please contact the Regional Administrator
of the appropriate
regional office or this office.Charles E. Rossi, Director Division of Operational
Events Assessment
Office of Nuclear Reactor Regulation
Technical
Contact: James E. Wigginton, NRR (301) 492-4663 John D. Buchanan, NRR (301) 492-7293 References
1. "IE Information
Notice 86-23, "Excessive
Skin Exposures
Due to Contamina- tion With Hot Particles," April 9, 1986.2. Institute
of Nuclear Power Operations, Significant
Event Report 18-87 (Rev. 2), "Radiation
Exposure From Small Particles," July 16, 1987.3. Moeller, M. P., G. F. Martin, and D. L. Haggard, "The Impact of Fuel Cladding Failure Events on Occupational
Radiation
Exposures
at Nuclear Power Plants. Case Study: PWR During Routine Operations," NUREG/CR-4485 (PNL-5606), January 1986.4. Heard, D. B., and R. J. Freeman, "Cobalt Contamination
Resulting
From Valve Maintenance," Electric Power Research Institute, EPRI NP-3220, Final Report, August 1983.5. Wells, J., "Problems
Associated
With Localized
Skin Exposures," in "Radia-tion Damage to Skin: Fundamental
and Practical
Aspects," Proceedings
of a Workshop held at Saclay, France, on October 9-11, 1985, Brit.J. Radiology, Supplement
No. 19, pp. 146-150 (1986).6. Charles, M. W., "The Biological
Bases of Radiation
Protection
Criteria for Superficial, Low Penetrating
Radiation
Exposure," in "Dosimetry
of Beta Particles
and Low Energy X-Rays," Proceedings
of a Workshop held at Saclay, France, October 7-9, 1985," Radiation
Protection
Dosimetry
14 (No.2), pp. 79-90 (1986).7. Charles, M. W., "Skin, Eye, and Testis: Current Exposure Problems and Recent Advances in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp.69-81 (1986).Attachments:
1. Events Summaries 2. List of Recently Issued NRC Information
Notices*SEE PREVIOUS CONCURRENCES
D/DOEA:NRR
C/OGCB:DOEA:NRR
CERossi CHBerlinger
8/ /87 8/10/87*RPB:DREP:NRR
- RPB:DREP:NRR
- AC:RPB:DREP:NRR
- D:DREP:NRR
- PPMB:ARM JEWigginton
JDBuchanan
LJCunningham
FJCongel TechEd 7/28/87 7/28/87 7/28/87 7/28/87 7/28/87
~' V IN 87-XX August, 1987 No specific action or written response is required by this information
notice.If you have any questions
about this matter, please contact the Regional Administrator
of the appropriate
regional office or this office.Charles E. Rossi, Director Division of Operational
Events Assessment
Office of Nuclear Reactor Regulation
Technical
Contact: James E. Wigginton, NRR (301) 492-4663 John D. Buchanan, NRR (301) 492-7293 References
1. "IE Information
Notice 86-23, "Excessive
Skin Exposures
Due to Contamina- tion With Hot Particles," April 9, 1986.2. Institute
of Nuclear Power Operations, Significant
Event Report 18-87 (Rev. 2), "Radiation
Exposure From Small Particles," July 16, 1987.3. Moeller, M. P., G. F. Martin, and D. L. Haggard, "The Impact of Fuel Cladding Failure Events on Occupational
Radiation
Exposures
at Nuclear Power Plants. Case Study: PWR During Routine Operations," NUREG/CR-4485 (PNL-5606), January 1986.4. Heard, D. B., and R. J. Freeman, "Cobalt Contamination
Resulting
From Valve Maintenance," Electric Power Research Institute, EPRI NP-3220, Final Report, August 1983.5. Wells, J., "Problems
Associated
With Localized
Skin Exposures,'
in "Radia-tion Damage to Skin: Fundamental
and Practical
Aspects," Proceedings
of a Workshop held at Saclay, France, on October 9-11, 1985, Brit.J. Radiology, Supplement
No. 19, pp. 146-150 (1986).6. Charles, M. W., "The Biological
Bases of Radiation
Protection
Criteria for Superficial, Low Penetrating
Radiation
Exposure," in "Dosimetry
of Beta Particles
and Low Energy X-Rays," Proceedings
of a Workshop held at Saclay, France, October 7-9, 1985," Radiation
Protection
Dosimetry
14 (No.2), pp. 79-90 (1986).7. Charles, M. W., Recent Advances 69-81 (1986)."Skin, Eye, and Testis: Current Exposure Problems and in Radiobiology," J. Soc. Radiol. Prot. 6 (No. 2), pp.Attachments:
1. Events Summaries 2. List of Recently Issued NRC Information
Notices C/OGCB:DOEA:NRF
CHBerlinger
R i EP:NRR J Eigginton 7/&X/87 RPM :NRR J. an 7/ig/87 A REP:NRR LJC I4nningham
7}(%/87 D:DREP:NRRI
FJCongel-4/ti/8 7 Techd 7/w