ML18153C249
| ML18153C249 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/25/1990 |
| From: | Potter J, Wright F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18153C247 | List: |
| References | |
| 50-280-90-18, 50-281-90-18, NUDOCS 9006140473 | |
| Download: ML18153C249 (11) | |
See also: IR 05000280/1990018
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W .
ATLANTA, GEORGIA 30323
Report Nos.: 50-280/90-18 and 50-281/90-18
Licensee:
Virginia Electric and Power Company
Glen Allen, VA 23060
Docket Nos.: 50-280 and 50-281
License Nos.: DPR-32 and DPR-37
Facility Name: Surry 1 and 2
Inspection Conducted: April 16-20, 1990
Jnspector:~~~/:;fi:_ _______________ _
Approved by:
~----------------------
J.
. Potter, Chief
Scope:
Facilities Radiation Protection Section,
Emergency Preparedness and Radiological
Protection Branch*
Division of Radiatfon Safety and Safeguards
SUMMARY
This unann6unced inspection of radiation protection activities was made to
review activities associated with an airborne radioactivity event in the
licensee's Auxiliary Building (AB) on March 26, 1990. A cursory review of
licensee's on-going As Low As Reasonably Achievable (ALARA) activities was also
made.
Results:
One violation was identified for failure to utilize process or other
engineering controls, to the extent practical, to limit* exposures to
concentrations of radioactive materials in air to levels below the allowable
concentrations specified in 10 CFR Part 20. The inspector determined that the
violation resulted from operation and engin~ering deficiencies. The engineering
and operating procedure problems were reported to _resident .inspectors for
review.
-
Management support and increased management and worker involvement in the
licensee's ALARA program activities appeared to be improving worker awareness
of ALARA objectives. Overall, the licensee's radiation protection staff
appeared to be generally effective in protecting the health and safety of the
workers.
7 -
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REPORT DETAILS
1. Persons Contacted
Licensee Employees
- W. Benthall, Supervisor, Licensing
- R. Bilyen, Licensing Engineer
- M. Biron, Supeivisor, Radiological Engineering
- D. Christian, Assistant Station Manager, Operations and Maintenance
- W. Cook, Operations Supervisor, Radiation Protection
- D. Erickson, Superintendent, Radiation Protection
- E. Grecheck, Assistant Station Manager
~D. Hart, Supervisor, Quality Assurance
- M. Kansler, Station Manager
- J. McCarthy, Superintendent, Operations
- L. Morris, Radwaste Superintendent, Radiation Protection
- T. Sowers, Superintendent
T. Steed, Station ALARA Coordinator
- W. Thornton, Directors Corporate Health Physics and Chemistry
Other licensee employees contacted during this inspection included
engineers, craft, technicians, and administrative personnel.
Nuclear Regulatory Commission (NRG)
- ~. Holland, Senior Resident Inspector
S. Tingen, Resident Inspector
- J. York, Resident Inspector
- Attended exit interview held April 20, 1990
2. Onsite Followup of Events at Operating Power Reactofs (93702)
a.
Background
On March 26, 1990, the inspector, as a member of an on-going
maintenance team inspection (MTI), was touring the licensee's
Auxiliary Building
(AB) reviewing radiological postings and
radiological protection activities.
While the inspector was in the
AB the licensee failed to maintain control of radioactive
contaminati6n on the -2 and 13 foot (ft)_ elevations of the AB.
The
event resulted in the contamination of 10,000 square feet (ft2) of
clean Radiological Control Area (RCA) floor space, three personnel
contaminations, and seven personnel having positive whole body counts
in excess of one percent maximum permissible organ burden (MPOB) but
less than three percent MPOB. The inspector reviewed the licensee's
controls and recovery activities following the event and discussed
the activities and findings with the licensee's staff.
The
licensee's radiation protection staff responded quickly to the event
2
limiting additional contaminated area and personnel contaminations.
During the MTI,.the inspector determined that a series of operational
activities apparently had caused the airborne contamination event. At
a MTI pre-ex it briefing, the 1 i censee was informed that there
appeared to be a violation of NRC requirements for controlling
airborne radioactivity resulting from operational activities on
March 26, 1990.
-
b.
Event Chronology (All Times Are Approximate)
March 23, 1990 _
11: 00 AM - The 1 i censee began transferring the contents of a spent
fuel pool ion exchange filter located in the licensee's AB to a High
Integrity Container (HIC) located in the licensee's Decon Building
(DB). The spent filter resin contained 156 curies of radioactivity,
primarily_from the cobalt-60 radioisotope.
03:00 Prt. -
Following the resin transfer, the licensee began
dewat.ering the HIC in accordance with licensee procedures. During the
dewatering process, the licensee's dewatering pump discharged into a
floor drain, in an area the licensee calls Ion Exchange Alley (Ix
Alley), on the -2 ft elevation of the 1icensee's AB.
The Ix Alley
was located along the north wall of the AB and contained the shielded
pl ant ion ext hanger filters for primary systems.
The dewateri ng
continued throu~hout the weekend.
09:00 PM - An entry was.made into the Ix Alley to conduct a survey
and attach a reach rod back onto a valve. A radiological survey made
during the entry showed contamination levels up to 16 million
disintegrations per minute (dpm) per 100 square centimeters (cm 2 ) on
the floor. The measured airborne radioactivity was at a concentration
1.1 times the applicable maximum permissible concentrations (MPCs)
specified in 10 CFR Part 20, Appendix B, for.a weekly exposure of
40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br />.
March 26, 1990
10:-00 AM - The licensee was rece1v1ng new fuel into the Fuel Handling
Building (FHB). The activity required the licensee to open an
external roll-up door of the building. The outside temperature was
cool and the fuel handling personnel requested operations provide
building heating.
..
3
10:35 AM - Operations ~tarted a FHB ventilation supply fan (l-VS-F-6)
to provide requested heating. The operator did not start additional
exhaust fans.
~
02:45 PM - Health Physics (HP) Technician and Planner entered the Ix
Alley in the AB for a pre-job inspection for repairing valve reach
- rods.
03:00 PM - A Decon Technician, assigned to maintain the clean area
outside the gate to Ix Alley, during the pre-job *inspection, measured
radioactive *contamination up to 200,000 dpm on a large area swipe
(masslinn cloth) and notified the HP Shift Supervisor. HP_ personnel
were dispatched *to assess the radiological conditions and secure
access to any contaminated areas. Initial surveys found contaminated
clean areas on the -2 and 13 ft elevations of the licensee's AB.
03:20 PM - Affected areas were barricaded and posted.
03:25 PM - HP Technician and Planner left the Ix Alley.
- 04:30 PM -
FHB ventilation supply fan 1-VS-F-6 stopped as requested
by HP.
04:40 PM - Dewatering of the HIC was stopped.
05:00-06:00 PM - Licensee began preparation for decontamination
efforts for the -2 foot elevation of the AB.
c.
Radiation Protection Activities for Entry into Ix Alley on March 26,
1990
On March 26, 1990, the licensee activated Radiation Work Permit (RWP)
90-1-0014 for entry ,into the Ix Alley.
A Planner required access to
the area for a pre-job walk down, to repair valve reach rods. The
Planner was accompanied by a HP Technician *
The most recent radiation surveys of the Ix.Alley had been made three
days earlier on a March 23, 1990 entry. The licensee's surveys showed
the contamination levels were elevated and the airborne radioactivity
was higher than normally measured. The measured radioactive
contamination was up to 1.6 E7 dpm/100 cm2 and the measured airborne
radioactivity was 1.1 times the MPC.
The contamination levels in the
Ix Alley measured in previous months had varied from 1.5 E5 to 2.0 E6
dpm/100 cm2 * The airborne radioactivity in the area was usually less
than MPC and had only exceeded MPC values twice in recent months. The
highest airborne radioactivity measurement in the area in 1990 was
7.5 times MPC, measured in January. While these activities were
elevated, they were not significantly greater than those found there
occasionally.
4
The RWP required full dress protective clothing with an outer hot
particle suit and tight fitting full face piece respirator for the
task. The respirator chosen provided a protection factor of 50 for
airborne radioactive particulates. The licensee's RWP requirements
appeared to be adequate for radiological conditions and the planned
task. The licensee held a pre-job briefing and the workers were
advised of the radiation levels (50-500 millirem per hour) and
contamination levels (1.6 E7 dpm/100 cm 2 ).
On March 26, 1990, when the HP Technician and the Planner entered the
Ix Alley (approximately 2:45 PM), they entered through Gate 2 where
the licensee had a plastic air lock constructed inside the Ix Alley.
The licensee reported that it was standard practice to assign a
Decon Technician to maintain the clean area outside Gate 2 to prevent
the spread of contamination on the -2 foot elevation of the AB. The
licensee set up a buffer zone at the gate and a Decon Technician was
dressed in paper coveralls, rubber shoe covers, and rubber gloves.
While the Planner and HP Technician performed their work in the Ix
Alley the Decon Technician performed a contamination survey of the
clean area outside the gate using a masslinn mop to take a large area
swipe. The Decon Technician detected radioactive contamination up to
2.0 ES dpm on the masslinn cloth. The Decon Technician notified the
HP Shift Supervisor who sent a HP Technician to evaluate the
situation.
The licensee had secured and posted access to the 13 and -2 foot
elevations of the AB by 3:20 PM and all personnel were evacuated from
the two floors, except for the Planner and HP Technician, who exited
the Ix Alley at approximately 3:25.
d.
Radi~tion Protection Activities Following the Event.
The licensee's initial response to the event was timely and orderly.
The licensee's radiation protection personnel evacuated all persons
on the -2 and 13 ft elevations and barricaded, posted, and restricted
access to affected areas. Personne 1 contaminations were quickly
attended to and internal assessments were made in accordance with
licensee procedures. Access to the Ix Alley was cancelled until
licensee personnel completed initial investigation of the event.
The radiological surveys made by the licensee's staff, during the
entry into the Ix Alley, detected contamination levels up to
4.6 E7 dpm/100 cm2 and air activity 99.3 times the allowable MPC of
10 CFR Part 20, Appendix B for a 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> exposure.
The radiological surveys made by the licensee's staff, in clean areas
on the -2 foot elevation of the AB, detected contamination levels up
to 119,000 dpm/100 cm2 and airborne radioactivity 3.3 times the
allowable MPC of 10 CFR 20, Appendix B.
7
higher than most resin processed at the facility .and contained 156
curies, most of which was cobalt 60.
On the evening of March 23, 1990, a licensee represent~tive, who had
made an entry into the Ix Alley to perform a radiological survey,
observed that the floor drain in the Ix Alley had apparently backed
up, puddled, and drained. Licensee representatives reported that the
drain had contained a sock type filter that had apparently restricted
the floor drains ability to drain all of the liquid initially
de 1 i vered to the drain from the dewa teri ng pump in the DB. The
highest level of contamination found during the March 23, 1990
radiological survey was 1.6 E7 dpm/100 cm2 * On March 26, 1990, the*
licensee detected up to 4.6 E7 dpm/100 cm2 *
The licensee concluded, that highly contaminated radioactive liquids
from the spent resin dewatering hose overflowed the AB floor drain
in the Ix A 11 ey and became the source for the airborne materi a 1
detected there on March 26, .1990.
The inspector inquired about an engineering evaluation for the rubb~r
hose that was used as the dewatering *drain. The licensee was unab,le
to find any engineering evaluations or documentation on installation
and. acceptability of using a 300 foot rubber hose used in draining
high radioactivity liquids between the DB and AB. However, the
insp~ctor was told that the hose had been used for at least 15 years.
The inspector determined that the licensee was aware of the
r~diological problems that existed with a hose discharging highly
contamin~t~d fluids from a 300 foot rubber hose into a floor drain
for a period of 15 years. However, at the time of the March 26, 1990
event, the licensee had no planned changes for the dewatering drain.
Following the March 26, 1990 contamination event, the licensee
planned to install a permanent drain line for dewatering activities.
The resident inspector was briefed on the matter for further review.
g.
Building Ventilation Activities
As stated in the previous paragraph, the licensee's Decon, Fuel
Handling, and Auxiliary Buildings are all connected with a pipe
tunnel. The licensee's ventilation systems were designed to maintain
these buildings at a negative _pressure to ensure air leakage was
always into the buildings to prevent unfiltered air from escaping
into the environment. Ventilation airflow was designed to move air
within the buildings from area~ least likely to be contaminated to
areas having a higher probability of contamination to reduce the
probability of spreading radioactive material to cleaner areas.
The inspector determined that the 1 icensee has had contamination
control problems with the -2 ft elevation of the licensee's AB for
years and the Ix Alley also has been a high radiation area. The high
radiation in the area had prevented the licensee from recovering or
decontaminating the Ix Alley floor space on the -2 foot elevation. To
8
contain the radioactive contamination from the Ix Alley and connected
pipe tunnel, the licensee had sealed off some of the ventilation air
flow paths at gates connecting the pipe tunnel to the FHB, DB, and
AB. The licensee sealed or air-dammed HP Gate 22 in the DB and
erected a plexiglas wall across the north end of the AB on* the
-2 foot elevation.
-
The inspector requested a review of the 1 i censee' s engineering
evaluation for the plexiglas wall, to see if it had addressed the
walls effect on the building's ventilation systems. The licensee
reported that there had not been an engineering evaluation on the
wall and that it was constructed in 1985 with a plant work request.
The inspector discussed the findings with the resident inspector for
review.
On morning of March 26, 1990, the licensee Wis receiving new fuel
into the FHB; The ambient temperature was cool and the receiving
operation required a roll up door be opened. The-workers receiving
the new fuel requested operations provide some heat to the FHB.
Operations responded and began operation of l-VS-F-6, a heating
supply of the FHB Ventilation System.
Operating Procedure OP-21.2.5, Placing Fuel Building .Ventilation
System In Service; revision dated October 27, 1983, stated, in part,
not to operate area supply fans unless associated area exhaust fans
are operating. The licensee's investigation of t~e event determined
that when 1-VS-F-6 was started, no additional exhaust fans were
started. That action caused an increased pressure in the FHB which
subsequently increased pressure in the connecting pipe tunnel and its
effluents, which included the Ix Alley. It appeared that the
increased pressure in the Ix Alley provided a motive air stream for
transporting the radioactive contamination in the tunnel and Ix Alley
areas. The inspector did not investigate or assay the adequacy of
operations actions but did discuss the event with the NRC Resident
Inspector for further review.
The licensee was also aware that positive air pressures from the
connecting tunnel caused radioactive material to migrate from
enclosures in the auxiliary and decontamination buildings. The
licensee had processed Engineering Work Request (EWR)89-492 in July
1989, which requested the employment of an outside contractor,
experienced in balancing ventilation systems, to correct AB flow
imbalance. Additionally, Health Physics Staff initiated EWR 89-701 in
August 1989, requesting that an air dam be. installed in the
connecting pipe tunnel to redute contamination migration from the Ix
Alley.
h.
Licensee Investigation, Short Term Corrective Actions, Long Term
Corrective Action Recommendations, and Root Cause Conclusions for the
March 26, 1990 .A.irborne Radioactivity Event
9
The licensee documented the event in Station Deviation Report
Sl-90-477. In the licensee's final report, the licensee reported that
the loss of contamination control resulted from the high levels of
radioactive contamination behind Gate 2 becoming airborne due to the
increased turbulent flow from the FHB ventilation fan 1-VS-F6 and the
opening of Gate 2. The contributing factors to the event were:
0
0
A temporary HIC dewatering flow path backed up causing gross
contamination of surrounding floor area.
A pre-~xisting ventilation system flow imbalance between the AB
and the Spent Fuel Building.
The licensee initiated the following short term corrective actions
following the event:
0
0
Engineering prepared a RCA ventilation matrix for use by
operators to ensure that RCA ventilation flows are always
properly balanced.
RWPs issued for movement of radioactive materials with temporary
hook-ups would require safety reviews.
The licensee developed the following long term corrective actions
following the event:
0
0
Licensee initiation of a Engineering Work Request to correct
ventilation flow imbalances.
Purchase and utilize continuous air monitoring equipment as the
equipment becomes available.
The licensee's radiation protection staff submitted a request for an
EWR requesting the installation 6f an air dam in the FHB pipe tunnel
before the event. The licensee approved a Engineering Work Request to
install an air dam April 19, 1990.
i. Regulatory Evaluation and Conclusion
10 CFR Part 20, Section 103(b)(l) requires that the licensee, as a
precautionary procedure, use process or other engineering controls,
to the extent practicable, to limit concentrations of radioactive
materials in air to levels below those which delimit an airborne
radioactivity area as defined in 10 CFR 20.203(d)(l)(i i).
10
CFR Part 20, Section 203(d)(l)(ii) defines an airborne
radioactivity area as any room, enclosure or operating area in which
airborne radioactive material composed wholly or partly of licensed
material exist in concentrations which, averaged over the number of
hours in any week during which individuals are in the area, exceed
10
25 percent of the amounts specified in Appendix B, Table I, Column 1
of Part 20.
Contrary to the requirements specified a.bove, the licensee failed to
utilize process or other engineering controls to the extent
practicable to limit airborne radioactivity material below 25 percent
of the amounts specified in Appendix B, Table I, Column 1, in that,
on March 26, 1990, the licensee's use of a floor drain for
radioactive waste dewatering activities enabled highly contaminated
fluids to become a source for airborne radioactive material arid the
licensee's building ventilation configurations and inadequate
.ventilation operating procedures provided the motive force for moving
loose surface radioactive material from the Ix Alley throughout the
licensee's -2 and 13 ft elevations of the AB as airborne radioactive
material. The subsequent airborne radioactivity caused licensee
personnel to be exposed to concentrations of airborne radioactivity
two times. the activities specified in Appendix B, Table I, Column 1,
of Part 20, in an airborne radioactivity area of the licensee's AB,
having a concentration 99 times the specified Appendix B limit while
wearing a respirator having a protection factor of 50.
The inspector informed licensee management that failure to use
process or other engineering controls for radioactive waste to limit
exposures to airborne radioactive material was an apparent violation
of 10 CFR Part 20, Section 103(b)(l) (50-280, 281/90-18-01).
The inspector concluded that the licensee's root cause assessment
appeared to be correct and the licensee's proposed corrective actions
could help prevent a similar event. Violations of NRC requirements
for protecting workers from airborne radioactivity were identified;
however, there did not appear to be problems in the licensee's
radiation protection program.
The violations were created from
ventilation problems that the licensee had been experiencing for
several years and operating procedures that were not specific enough
to prevent excessive building ventilation supply without appropriate
exhaust.
One violation was id~ntified.
3.
Surveys, Monitoring, and Control of Radioactive Material
10 CFR 20.201(b) requires each licensee to make or cause to be made such
surveys as (1) may be necessary for the 1 i censee to comply with the
regulations and (2) are reasonable under the circumstances to evaluate the
extent of radioactive hazards that may be present.
The inspector reviewed the plant procedures which established the
licensee's radiological survey and monitoring program and verified that
the procedures were consistent with regulations, Technical Specifications,
and good HP practices.
..
..
11
The inspector reviewed selected records _of radiation_ and contamination
surveys performed in March and April, 1990 and discussed the survey
results with licensee representatives. During tours of the plant the
inspector observed health physics technicians performing radiation and
contamination surveys.
The inspector performed independent radiation surveys in the AB and
verified that the areas were properly posted.
No violations or deviations were identified.
4.
Program for Maintaining Exposures As Low As Reasonably Achievable (ALARA)
10 CFR 20.lc states that persons engaged in activities under licenses
issued by the NRC should make every reasonable effort to maintain
radiation exposures ALARA.
The recommended elements of an ALARA program
are contained in Regulatory Guide 8.8, Information Relevant to Ensuring
that Occupationa 1 Radiation Exposure at Nuclear Power Stations wi 11 be
ALARA, and Regulatory Guide 8.10, Operating Philosophy for Maintaining
Occupational Radiation Exposures ALARA.
5.
The inspector attended a monthly Surry Station ALARA Committee meeting
held Apri 1 16, .1990. In addition to routine activities and reviews. of
ALARA goals, initial Department Exposure Reduction Plans were submitted to
the Committee. The plans were submitted by Maintenance, Radiological
Protection, Operations, and Site Services Departments. The plans were
schedu_l ed for implementation in December, 1990. The Exposure Reduction
Plans appeared to be aggressive and workable. Management support for the
ALARA program was evidence by those plans and commitments.
No violations or deviations were identified.
Exit Interview
The inspection scope and findings were summarized on April 20, 1990, with
those persons indicated in Paragraph 1. The inspector described th~ areas
inspected and discussed in detail the inspection results listed below.
Dissenting comments were- not received from the licensee. Proprietary
information is not contained in this report.
The inspector reported that the Radiation Protection-Staff's response to
the airborne radioactivity event that occurred on March 26, 1990, appeared
to be appropriate and effective in protecting the health and safety of the
workers. The inspector reported that worker awareness of ALARA objectives
appeared to be improving through increased staff participation and
involvement in the ALARA program.
The inspector reported that engineerini controls and records of engineer
reviews for use of a temporary radioactive waste drain and constructing of
plant containments affecting ventilation systems and operating procedures
12
for proper opera ti on of venti 1 at ion systems appeared to be a program*
weaknesses.
Two apparent violations were discussed at the exit meeting. One of the
violations, concerning the selection of respiratory protection equipment.
to meet the requirements of 10 CFR Part 20.103(c) was reviewed and
withdrawn.
During a telephone conversation on May 25, 1990, between
F. Wright of the NRC and D. Erickson of Virginia Electric and Power
Company, the licensee v,*as informed there would not be a violation issued
for failure to select respiratory protection equipment providing a
prot~ction factor greater tha*n the multiple of airborne radioactivity
exceeding the quantities specififed in Appendix B, Table I, Column 1 of
Part 20 because the airborne radioactivity concentrations the licensee
workers were exposed to on March 26, 1990, were not expected by the
licensee.
The second violation is summarized below.
Item Number*
50-280, 281/90-18-01
Description and Referen~~
Violation - Failure to use process and other
engineering .controls to limit exposures to
airborne radioactivity (Paragraph 2) .