IR 05000133/1998004
| ML20195H769 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| Issue date: | 11/20/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20195H767 | List: |
| References | |
| 50-133-98-04, 50-133-98-4, NUDOCS 9811240094 | |
| Download: ML20195H769 (20) | |
Text
,
_
.. _ _ _ _ -. _. _ _.....
_. _
-. _
_ - _ ___
_ _
. _..
.mm_.
..
-
l.
I i
l ENCLOSURE U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
l Docket No.:
50-133 l
[
License No.:
DPR-7 Report No.:
50-133/98-04 l
Licensee:
Pacific Gas and Electric Company (PG&E)
Facility:
Humboldt Bay Power Plant Unit No. 3 Location:
1000 King Salmon Avenue Eureka, California 95503 l
Dates:
September 1 - September 3,1998
'
October 12 - October 17,1998 October 20 - October 22,1998 I
Inspectors:
J. V. Everett, Senior Radiation Specialist j
Fuel Cycle and Decommissioning Branch Division of Nuclear Material Safety L. L. Wheeler, Senior Project Manager Non-Power Reactors and Decommissioning Project Directorate Office of Nuclear Reactor Regulation (
C. E. Johnson, Senior Reactor inspector Maintenance Branch Division of. Reactor Safety Approved By:
D. Blair Spitzberg, Ph.D., Chief Fuel Cycle and Decommissioning Branch Division of Nuclear Material Safety i
i L
i
!
9811240094 981120
~
PDR ADOCK 05000133 l'
O PDR
_.
-_
,
. _ _
. _ _ _ _. _ _ _ _ _ _ _ _ _.
_
__
_. _ _ _... _ _ _ _.. _
-2-l l
EXECUTIVE SUMM ARY Humboldt Bay Power Plant, Unit No. 3 NRC Inspection Report 50133/98-04 An inspection was conducted at the Humboldt Bay site over three weeks during the period September 1,1998 to October 22,1998 to review work activities associated with the removal of l
the 250 foot tall ventilation stack. The first week of the inspection was conducted prior to the l
start of work and reviewed the safety evaluation, work planning, engineering analysis, and radiological controls. The second week of the inspection provided onsite coverage during the
'
cutting of the first section of the stack. The third week of the inspection provided observation of the cutting of the second section of the stack. In addition, programs related to maintenance, l
occupational radiation exposures, radwaste shipping and self assessments were reviewed.
The overall assessment of the licensee's effort to safely remove the ventilation stack was positive. Safety was given a high priority. On occasions where questions or concerns were l
raised by workers, management stopped work until the issues were resolved to the satisfaction
,
of the workers. The importance of performing the work safely was evident through the actions l
of management. Activities were not rushed to meet schedules. Problems were thoroughly evaluated and resolved. Though this approach presented numerous delays in completing work,
,
l I
management continued to place emphasis on worker safety over the meeting of deadlines.
This was considered a strength.
!
Safety Reviews. Desian Chanaes. and Modifications The licensee completed a safety evaluation of the stack removal project and identified a
.
number of administrative controls to offset the potential for and consequences of any credible accidents. An independent assessment of the licensee's safety evaluation by the NRC found the evaluation process used and conclusions reached by the licensee to be acceptable (Section 1).
Decommissionino Performance and Status Review The licensee had adequately incorporated commitments made in the safety evaluation
.
into work procedures. Procedures were detailed and included sign-off sections for key activities. Provisions for contamination control were reviewed and found adequate to minimize the spread of contamination. Safety was mainta ned as a high priority.
,
!
Decisions were not rushed to meet schedules at the risk of inadequate safety practices (Section 2).
The safe load path and exclusion area for the crane was clearly identified. Calculations l
.
l for the weight of each stack section were completed before the cut and verified after the cut. The wallin the liquid radwaste building, adjacent to and below grade of the crane
- pad. was continuously monitored to ensure no distortion was occurring from the weight
of the crane (Section 2).
,
I
!
r i
!
l
-.
.
._
-.
--
.
.
-
._ -
.
.
. - _
_
_
_.. -- --
.-. -
!
l l-3-Several weaknesses were identified by the inspectors regarding attention to detail by the licensee. These issues were determined to be of low safety significance and were
)
adequately corrected by the licensee. However, better attention to detail during the development, review and implementation of the program and procedures should have caught these issues (Section 2).
Maintenance and Surveillance The licensee maintained an active preventive maintenance program for equipment
.
associated with compliance of the plant technical specifications. A system for tracking maintenance activities was being mainta:ned. All required spent fuel pool surveillance tests and preventive maintenance routines had been completed. Plant tours found equipment to be in good operating condition (Section 3).
Occupational Radiation Exposure Occupational exposures for plant personnel were very low for the first half of 1998.
.
These levels were reasonable based on work activities at the site (Section 4).
Solid Radwastc and Transportation The licensee had established procedures and a computerized classification system for
.
handling radioactive waste shipments. Contracts had been established with vendors for receipt and disposal of contaminated material. Characterization of the ventilation stack concrete had been completed identifying the isotopes of concern. Plans had been finalized concerning the packaging and shipment of the stack sections for disposal (Section 5).
Self Assessments. Auditina. and Corrective Actions The licensee's audit and assessment program was effectively applied to the stack
.
removal project. Several assessnients were conducted which identified numerous work practices that required attention. The level of detail evaluated by the auditors was usually very good. As a result of their attention to small details, they discovered that the wrong crane load rating chart had been provided by the vendor. This error,if not corrected, would have resulted in a decrease in the margin of safety for the crane load activities (Section 6).
l i
.
I
Report Details Summary of Plant Status The Humboldt Bay Power Plant, Unit No. 3 was placed in a SAFSTOR decommissioning status in 1976. Since then the facility has remained in a custodial condition except for two major projects. The first project related to the in-leakage of water into the reactor caisson. This problem was successfully repaired in 1997. The second major project, currently underway, involved the removal of the 250 foot tall plant ventilation stack. The stack was located adjacent to the refueling building. Removing the stack reduced the seismic hazard to the stored spent fuel, plant personnel, and other structures within the radius of the stack. Removing the stack involved cutting the stack into sections using a diamond wire saw. Plans were to cut the stack into approximately 22 sections of varying 'engths from 4.5 feet to 23 feet. This would lower the height of the stack to 28 feet above graN lovel. The cut sections were then cleaned, painted, shrink wrapped, and surveyed prior to stupment offsite to Richland, Washington, for further decontamination and disposal by a contractor.
To replace the old stack, the licensee constructed a shorter steel stack. This new stack
included a filtration system to support future dismantlement activities to the power building, refueling building, reactor caisson, and associated structures. During dismantlement of the old stack, air flow was directed from the old stack into the new stack. This provided for contamination control through the filters of the new stack during cutting.
The in-leakage of ground water into the reactor caisson was confirmed as remaining low. The in leakage was approximately 12 gallons / day. This level had remained steady since the completion of the repair effort in September 1997.
On August 28,1998, the licensee submitted revision 2 to the Humboldt Bay Defueled Safety Analysis Report (DSAR). The DSAR replaced the SAFSTOR Decommissioning Plan.
Safety Reviews, Design Changes, and Modifications (37801)
1.1 Inspection Scope The licensee completed an extensive safety evaluation of the planned work related to the removal of the ventilation stack. This safety evaluation was reviewed by the NRC l
inspectors and headquarters staff to verify that an adequate assessment had been completed and that no safety issues had been overlooked.
1.2 Observations and Findinas The licensee documented the safety evaluation of the stack removal project in Design Change Package DCP M-00431," Unit 3 Ventilation Stack Removal," Revision 0. The licensee evaluated the potential consequences of a number of potential accidents during stack removal. The accidents were either determined to not increase the probability of an accident previously evaluated in the site SAFSTOR Decommissioning Plan or compensating administrative coritrols were established. The licensee's safety
...
.
__
_ - _ -. -.
,
5-evaluation also reviev.ed the work planned to ensure no activities would result in a different type of accident than previously evaluated, increase the probability or consequences of a malfunction of equipment important to safety, or reduce the margin of safety for a Technical Specification.
The safety evaluation considered a number of potential accidents. Since the roof of the refueling building was not structurally capable of withstanding the impact of a heavy load such as a section of stack, damage to the spent fuel in the spent fuel pool was evaluated. The liquid radwaste treatment building, condensate storage /demineralizer water tank, and natural gas line used to provide gas to the Unit 2 boiler were also considered targets. Potential heavy loads that could fall included the crane, a section of the stack being removed, and the work platform. The licensee identified a number of administrative controls to reduce the potential for occurrence and the consequences of the accident. These included establishing a safe loads path and exclusion area for the crane, draining the tanks in the liquid radwaste building to minimum levels, stationing a worker at the cut-off valve for the natural gas pireline, and conducting a crane load test before starting work on the stack.
An independent evaluation of the licensee conclusions was made by the NRC staff, which included personnel with expertise in control of heavy loads, seismic and structural engineering, health physics, and offsite dose predictions. The cvaluation process used and conclusions reached by the licensee were determined to be acceptable.
1.3 Conclusions The licensee completed a safety evaluation of the stack removal project and identified a number of administrative controls to offset the potential for and consequences of any credible accidents. An independent assessment of the licensee's safety evaluation by the NRC found the evaluation process used and conclusions reached by the licensee to be acceptable.
Decommissioning Performance and Status Reviews (71801)
2.1 Insoection Scope The licensee's program for the dismantlement of the ventilation stack was reviewed to verify that commitments in the safety evaluation had baen incorporated into procedures.
The cutting of the first two sections of stack was observed to ensure procedures were properly implemented and controls were adequate for worker safety.
2.2 Observations and Findinas l
a.
Project Plannina and Special Considerations l
l The dcensee planned to remove the concrete ventilation atack by cutting the stack into l
22 sections. The first section removed was a test section to verify the calculations for l
determining the weight of the concrete and to provide an initial verification of the
.
......
..
.
...
.
.
.
...
..
_ - - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
_
6-adequacy of the procedures before a heavy cut was performed. An 8-foot 9-inch long section was removed. The licensee calculated the weight of the section to be 9,359 pounds. The actual weight, as measured by the load cell on the crane, was 9,400 pounds. The next section cut was approximately 23 feet in length and calculated to weigh approximately 28,000 lbs. Adding tha weight of the crane rigging and cable, the total weight was estimated to be 36,277 pounds. The actual weight, as measured t,i'he crane's load cell, was 39,500 pounds. The difference between the estimated weig 't ver.cus the actual weight was due to the slight underestimation in the weight calcu.in of the thickness of the stack wall for this section. The diameter of the stack, the inickness of the stack wall, and the size of the rebar increased as work proceeded from the top of the stack to the bottom. The top of the stack at the 250 foot level was 63 inches in diameter with a wall thickness of 5.5 inches. The last section of stack to be cut at the 28 foot level had a diameter of 183 inches and a wall thickness of approximately 9 inches. Section lengths were shortened from 23 feet near the top to 4.5 feet for the last section to account for the changing size of the stack.
A Skyhorse 11250 crane was used for lowering stack sections to the ground. The capacity of the cone for a boom angle of 60.5 degrees and a boom radius of 160 feet was 53,380 pounds. The licensee had initially planned to use 70 percent of rated capacity for calculating the lengths of stack to be cut. This would result in 22 sections.
Provisions were established in Procedure TP 10/10/98#1, " Cutting, Lifting, and Translation of Stack Sections for Ventilation Stack Removal," Revision 1 A, to allow for cuts up to 85 percent with plant manager approval. Appendix 9.2 of this procedure provided for a 70 percent load capacity for the first five cuts and 80 percent for the remaining cuts. This would reduce the required number of cuts from 22 to 19. The calculated weight included not only the stack section, but also the rigging weight and the weight of the cable. The weight of the rigging and cable ranged from 8,500 pounds to 12,650 pounds, depending on the length of cable used for the lift. More cable was necessary when lif ting the sections closer to the ground.
As the project progressed, the weights of future sections were recalculated based on the actual weight of the section just removed. This ensured that any errors in the calculations for future cuts were minimized. The density of the concrete was determined in Humboldt Bay Calculation No. HB3-EC-431-98-006, " Determination of Concrete Density of the HBPP Stack," dated 10/2/98. The calculations were based on concrete core samples taken to measure the actual density of the concrete. Pacific Gas & Electric (PG&E) Drawing 646224 was used to determine the rebar configuration for the stack. The stack was divided into three areas: bottom, middle, and top. The
~
bottom section included 22.5 feet above grade to 160 feet and had a density of 157 lbs/ cubic foot. The middle section ranged from 160 feet to 200 feet with a density of 154 lbs/ cubic foot. The top section ranged from 200 to 250 feet with a density of 151 lbs/ cubic foot. The differences in density were due to the difference in the size of rebar used in the stack. Rebar ranged from No. 3 at the top to No.10 at the bottom.
The licensee established a safe load path for removal of the ventilation stack. The safe load path restricted the crane from moving the load over the spent fuel pool area.
A drawing showing the safe load path and the exclusion zone was incorporated into procedures. The inspectors concluded through discussions with licensee personnel,
!.
.
...
.
.
.
_ _ _ _ _ _
..
-
.
_ _ -
-
__
-7-review of drawings, and evaluation of the various potential safe load paths, that the licensee had selected the safest path for movement of the load.
The liquid radwaste building was near the location of the crane pad. The nearest wall of the liquid radwaste building was below grade level of the crane pad and was supporting the soil that would be under the crane. The licensee had evaluated the effects of the crane weight on the liquid radwaste wall and determined that the structuralintegrity of the wall was adequate based on the location of the crane and the use of a crane pad to distribute the weight of the crane. The licensee established several monitoring points on the liquid radwaste building wall using strain gauges to verify that the wall was not bulging during the movement of the heavy loads. The wall failure had been computer modeled. The monitoring points were selected based on the most likely failure points on the wall. During the lifting of the first and second sections of the stack, no deflections were measured on the wall. The licensee also established a 10 millicurie (mci) limit for the five liquid radwaste tanks which could be effected by failure of the wall. Prior to removing the first stack section, one tank was emptied and the four remaining tanks were reduced in volume to approximately 6600 gallons with 1.24 mci.
i The activities associated with the stack removal project and the schedule were consistent with the licencee's Post Shut-down Decommissioning Activities Report (PSDAR). The PSDAR, submitted February 27,1998, described the planned activities associated with the stack removal. The PSDAR committed to a new stack with gas monitoring capability to be completed and operational prior to initiating removal of the old stack. The new stack was observed to be operational prior to cutting of the first stack section.
The licensee had compiled a list of commitments from the safety evaluation into a table referred to as the "HBPP Commitments Stack Removal Safety Evaluation." The October 12,1998, revision of the table was r;/! awed to verify that cor-4ments had been incorporated into the implemonting procedures. No omissions or errors were identified. The table provided a cross reference identifying which sections of the procedures contained information intended to meet the safety evaluation commitments. The four procedures discussed in the next section of this report were the primary procedures used by the licensee to document the safety evaluation commitments. A meeting of the plant safety review committee was also observed in which the commitments and their procedural provisions wt re reviewed.
b.
Project Procedures The four primary operational procedures for the stack removal project were reviewed.
These were:
TP 10/7/98#1, Dead Load and Translation Test, Revision 0.
- TP 10/7/98#2, Stack Replacement Project Crane and Crane Operator
Certification inspection Plan, Revision 0
-
8-TP 10/14/98, Stack Section Preparation, Revision 0
-
TP 10/10/98#1, Cutting, Lifting, and Translation of Stack Sections for
=
Ventilation Stack Removal, Revision 1 A Procedure 10/7/98#1, " Dead Load and Translation Test," described the initial testing of the crane. The procedure identified the safe load path and the exclusion area for the crane. The crane was administratively controlled to not allow movement over the area of the refueling building where the spent fuel was stored. The procedure also required the stationing of an operator at the gas shut off valve for the gas line to Unit 2. During a portion of the crane movement, the gas line would be vulnerable if j
the boom fell. The procedure established limitations for crane activities during
]
adverse weather. Sustained winds greater than 25 mph or gusts greater than 35 mph required the test to be terminated, the load lowered, and the crane properly secured.
i The dead load test weight used for implementing this procedure was 43,370 lbs. This weight plus the weight of the cable and rigging provided for 110% of the lift over side" weight limit of the crane. The test was conducted on October 9,1998. The load cell
on the crane was determined to be accurate in providing the weight of the load. The procedure included an appendix which provided for sign-off upon completion of certain activities. The signed and completed attachment was reviewed and found to have the appropriate signatures.
Procedure TP 10/7/98#2," Stack Replacement Project Crane and Crane Operator i
Certifications inspection Plan," Revision 0, provided for verification of the qualifications and certification of the crane operator and riggers, confirmation that the slings met ANSI B30.9 requirements, acceptance of the crane pad, and ad6quacy of the dead load test. The procedure listed the required acceptance criteria for each area evaluated. The procedure, with all required signaturec sud cates, was reviewed and found to be complete.
Procedure 10/10/98," Cutting, Lifting, and Translation of Stack Sections for Ventilation Stack Removal," Revision 1 A provided instructions for the removal of the stack. This procedure included the administrative provisions used to minimize the potential for the work effort to effect the stored spent fuel. Administrative provisions included verification of the crane operator qualifications, verification of the crane certification, identification of the safe load path and exclusion area, completion of the initial dead load and translation test, controls for ensuring the stack sections being removed were within the load capacity of the crane, and limitations on crane operations during bad weather or high winds. Contamination controls to be implemented included maintaining a flow of air from the stack into filters during cutting, applying a sealant to
,
!
the inside of the stack prior to cutting to fix the contamination, covering the ends of the cut section during lowering to the ground, and painting and shrink wrapping the stack
'
sections af ter cutting. A stack cut and stack section removal permit was included as
,
an attachment to the procedure. This permit required verification and sign-off prior to work to ensure certain actions had been completed. Overall, the procedure provided a
!
satisf actory step-by-step process for ensuring all required actions were completed.
.
--
-
-
,
-
w-.
__ _
_-. _. _ _ - - - _. _ -.. _ _ _ _ _ _ _ _ _ _ _
.__...._.
_ - _ _ _... _
l l-9-
Procedure TP 10/14/98, " Stack Section Preparation," Revision 0 provided directions for handling the cut sections of the stack. Procedural steps were provided for actions associated with the lowering the stack section onto the transport trailer, painting, surveying, cutting into smaller sections if necessary, shrink wrapping, and securing the load. This procedure also provided the criteria for determining the DOT shipping classification.
c.
ALARA Review An ALARA review of the work process was completed by the licensee. Because the exposure levels were so low, the emphasis of the project was directed toward contamination control. A number of contamination control measures were identified and implemented. These included:
fixing the contamination inside the stack prior to cutting
drawing air down the stack into a new filter system
placing a cover over the top and bottom stack sections prior to moving the
sections to the ground painting the inside of the removed sections to fix the contamination
shrink wrapping the sections
modifying the radiologically controlled area (RCA) boundary to allow the crane
cab to remain outside the RCA establishing a speciallay down area in the RCA for the stack sections
i enclosing the trailer in a temporary structure during preparation work on the
'
stack sections prior to shipment draining the tanks in the nearby radwaste building to minimal levels to reduce
the potential consequences of an accident
' The ALARA review included not only the stack removal portan of the project, but also the installation of the new stack and modifications to the building internal duct work to connect to the new stack. The estimated total dose for the stack removal project including installation of the new stack was 1.749 rem. Modifications to existing internal duct work for the new stack and stack section preparation for shipping accounted for 1.376 rem of the total estimate.
d.
Plant Tour A tour of the refueling building was conducted on September 1,1998. This included the spent fuel pool demineralizer strainer room, refueling floor, and location of the new
,
stack. Equipment was observed to be in good working condition. Contamination and
..
- - -
.-.__ _ _. _ _ _ _ ___._._ _ _.. ___.__ _ _. _ _ _ _ _ _ _ _ _
-10-radiation levels were consistent with levels found during previous inspections. The new stack was finished and operational before cutting was started on the old stack.
Air was being drawn down the 250 foot ventilation stack into the filters of the new stack to capture any contamination that became loose during the cutting of the stack sections. High efficiency particulate filters were incorporated into the new stack to filter the air.
The status of the in-leakage into the caisson was reviewed. The leak had been repaired September 1997 and was reduced to approximately 15 gallons / day. The leak was currently 12 gallons / day and had remained relatively steady for over a year. At the time repair activities were initiated on the leak in 1997, the leak rate was 6,500 gallons / day.
e.
Work Activity Observations The inspectors observed a significant amount of work activities during the cutting of the first two sections of the stack. Activities observed included:
Verification that the holes drilled in the first stack section for attachment to the
lifting harness were at least 24 inches below the top of the stack.
!
Observation of the instrumentation used to monitor the potential movement of
the liquid radwaste wall and review of the data collected during the heavy load test and first two cut. No wall movement was noted.
Verification that all sign-offs had been completed on procedure TP 10/7/98#1,
"Doad Load and Translation Test."
Discussions with the crane oiler and crane operator on routine maintenance
activities for the crane. Daily maintenance records for the past 7 days were examined and found to be complete. The operator's understanding of the safe toad path and the exclusion area were in agreement with the provisions of the licensee's procedures.
Observation of the morning pre-job meetings which included the sign-off of the
pre-work checklist by all responsible persons before stack cutting activities were initiated.
l Verification that an individual was in position at the shutoff valve for the natural
gas supply line for Unit 2 during the cutting of the first section of stack. The
'
i individual was aware of his responsibilities. The valve locking devices had been removed to facilitate rapid valve operation. Communications with project management via radio was demonstrated.
f The overall assessment of the licensee's effort to safely remove the ventilation stack j
was positive. Proper focus on industrial and nuclear safety was continuously j
observed. Frequent reminders were made to all personnel to be safe, ask questions,
'
and stop work if something doesn't appear right. Project management did not rush i
l
b
.. - -.
.. -,
-
-.
,.
.
, -,. -.
..
I
!
,
-11-
activities or decisions in order to meet schedules. The procedures used were comprehensive and sufficiently detailed to ensure proper sequencing of work activities. The procedures included quality control hold points and sign off sections by responsible project personnel as certain activities were completed.
A slow, deliberate, conservative approach to performing the work activities was observed. Very good coordination among the numerous contractors was evident.
Project management actively sought solutions to problems from the people doing the work. P! ant management maintained a strong safety perspective of the project activities and on several occasions stopped work until all the questions were answered to the satisfaction of the working level personnel.
i Several weaknesses were identified by the inspectors regarding attention to detail by the licensee. These included an error on several equations referencing diameter instead of radius, overestimation of the weight calculation for the crane cable by using
,
l 5 strands instead of the actual number of 4 strands, difficultly in verifying the basis for j
the 150 lbs/ft estimate for the weight of the concrete in the stack, and the use of a i
30 amp electrical circuit when the equipment required a 40 amp circuit. These issues l
were determined to be of low safety significance and were adequately corrected by the
'
licensee. However, better attention to detail during the development, review and implementation of the program and procedures should have caught these issues.
Two elected officials in the California state legislature were known to have an interest l
in the activities at the plant. Based on this information, the NRC inspector made a i
!
courtesy call to the local offices of the two officials. The purpose of the visits was to establish a point of contact for assistance in responding to interests or concerns of the local community and the elected officials. A brief discussion of the NRC role in the
.
current site activities was provided. Meetings were held with Ms. Elizabeth Murgia, l
administrative assistant to Senator Mike Thompson; and Ms. Barbara Ellis, field
'
l representative on the staff of Assembly Member Virginia Strom-Martin. Ms. Murgia was a member of the Citizens Advisory Board for the Humboldt Bay power plant.
Ms. Ellis had recently visited the site.
2.3 Conclusions The licensee had adequately incorporated commitments made in the safety evaluation into work procedures. Procedures were detailed and included sign-off sections for key activitics. Provisions for contamination control were reviewed and found adequate to minimize the spread of contamination. Safety was maintained as a high priority.
Decisions were not rushed to meet schedules at the risk of inadequate safety practices.
The safe load path and exclusion area for the crane was clearly identified.
Calculations for the weight of each stack section were completed before the cut and verified after the cut. The wallin the liquid radwaste building, adjacent to and below grade of the crane pad, was continuously monitored to ensure no distortion was occurring from the weight of the crane.
l
, -.
.
-. -, -
-
- - _ - -
,
- 12-
>
Several weaknesses were identified by the inspectors regarding attention to detail by the licensee. These issues were determined to be of low safety significance and were adequately corrected by the licensee. However, better attention to detail during the development, review and implementation of the program and procedures should have identified these issues.
Maintenance and Surveillance (62801)
3.1 Insoection Scoce The licensee's preventive maintenance program was reviewed to verify the program was being actively implemented and properly documented.
3.2 Observations and Findinas The licensee's preventive maintenance program was described in site Procedure HBAC C-40, " Preventive Maintenance Program." This procedure established responsibilities for implementing the program, defined the three levels of preventive maintenance used at the site, and defined record retention requirements.
The program was developed using reliability centered maintenance concepts to
,
determine which equipment to include in the program as well as the scope and frequency of the preventive maintenance activity.
Level 1 maintenance was performed on all equipment with operating limits or requirements specified in plant technical specifications. Individual surveillance test procedures were developed for this equipment. For the spent fuel pool, this included the water level monitor. Surveillance Test Procedure 3.6.3," Spent Fuel Pool Level Monitor Calibration and Alarm Set Point Verification," Revision 30, had been developed describing the components of the system that required calibration, the calibration acceptance criteria, responsibility for completing the calibration, and detailed instructions for performing the calibration. Level 1 maintenance intervals were incorporated into the master surveillance test schedule.
Level 2 maintenance was performed on all equipment that supported the operating limits or requirements specified in the technical specifications. Level 3 maintenance was performed on equipment required to be maintained operational during SAFSTOR, as listed in Table 3 of the DSAR. The spent fuel poolliner.avel instrumentation consisted of Level 2 and 3 components, such as the level bubbler, remote level indicator, level recorder, alarm switch, and level transmitter. Procedures for performing Level 2 and level 3 maintenance could be either a detailed task description in a Systems Application and Program Planned Order, a plant manual volume 5 maintenance procedure, or a specific section of the manufactures instruction manual.
The Systems Application and Program system provided notification when activities were due.
.
F.
-. - -
-...-
i
.
-13-Equipment that was not included in the Level 1 through 3 categories was not included in the preventive maintenance prograrn and was maintained through corrective maintenance. The spent fuel pool demineralizer system was in this category.
All spent fuel pool related surveillance tests and preventive maintenance routines had been completed. There was no maintenance backlog for Level 1 or 2 equipment. The program appeared to be well documented and implemented for the normal maintenance activities associated with Unit 3. During plant tours, equipment was typically observed to be in good operating condition.
3.3 Conclusions
.The licensee maintained an active preventive maintenance program for equipment associated with compliance of the plant technical specifications. A system for tracking
'
maintenance activities was being maintained. All required spent fuel pool surveillance j
tests and preventive maintenance routines had been completed. Plant tours found j
equipment to be in good operating condition.
'
Occupational Radiation Exposure (83750)
4.1 Inspection Scope
Personnel exposures were reviewed for the first half of 1998 to verify occupational exposures at the facility were reasonable for the level of work activities underway.
4.2 Observations and Findinas For the first and second quarter of 1998, there were 82 employees and contractors badged. The total dose for this group was 0.225 rem. There were also a number of visitors badged. Of the visitors, several PG&E Wdquarters engineering support personnel had been onsite. Their total dose was 0.051 rem. The highest dose received by any one individual was a radiation protection technician with 0.121 rem.
Of the 82 employees and contractors badged, only 11 had received measurable exposures. There had been no personnel contamination incidents for the first two quarters of 1998 other than problems that could be contributed to radon.
Conclusions Occupational exposures for plant personnel were very low for the first half of 1998.
l These levels were reasonable based on work activities at the sit,
- - - - - - - - - - - -..- - - -
,
.
- 14-
Solid Radwaste and Transportation (86750)
5.1 Inspection Scope The licensee's radioactive waste shipping program and procedures were reviewed.
Special emphasis was placed on radwaste activities associated with the stack removal project.
5.2 Observations and Findinas On September 2,1998, the licensee completed their first radioactive waste shipment for 1998. The shipment included four low specific activity (LSA) boxes, four limited quantity boxes, and one drum of LSA. The LSA boxes consisted of sludge from the No. 3 waste recirculation tank and concrete from the suppression pool repair project.
The limited quantity boxes contained soil excavated from around the fire main. Low levels of Cesium-137 (Cs-137) were present. The LSA drum contained water from the suppression chamber mixed with concrete. Completion of the final survey of the truck prior to leaving the site was observed by the inspector. The radiation protection technician was very thorough in conducting the survey. The highest reading detected was a small area half way back on the bottom of the trailer. A reading of 160 mR/hr contact dose was measured. This was within the 49 CFR 173.441 limit of 200 mR/hr.
The training and qualification of the staff responsible for radwaste shipments was reviewed. The licensee had established a training category called " DOT Radwaste Shipment Qualification." This included 4 courses covering 49 CFR, First Responder Awareness (HAZWOPER), Department of Transportation (DOT) radioactive shipping requirements, and site specific radwaste requirements. Eight site personnel had completed the program.
The licensed procedures for handling and shipping radioactive waste were reviewed.
These included:
HBRCS-12," Radioactive Material and Waste Shipments," dated 1/11/97
PCP-6C," Shipment of Solid Radioactive Waste," dated 11/10/97
RCP-6E, " Radioactive Material / Waste Curie Content Calculations, dated 8/4/98
RCP-6F," Burial Site Disposal Criteria and Classification of Radwaste," dated l
6/25/98
!
RCP-6J," Radioactive Material / Waste Nuclide Fractions and Correlation Factor
Determination," dated 8/4/98 I
,
,
. _ -.
-
..
-
-
_
_..
.
!
-15-RCP-6L," Receiving, Loading, and Releasing of Transport Vehicle for
Radioactive Material / Waste Shipment," dated 11/10/97 i
RCP-6P, Radioactive Material Shipments," dated 4/8/98
Selected sections of the revised 49 CFR requirements were compared to the licensee's procedures. The procedures had been revised to incorporate the new 49 CFR requirements.
Three vendors had been selected by the licensee for receipt of various contaminated materials from the site. Contaminated items and equipment would be sent to Hake, Inc. in Memphis, Tenn. Sludge, soil, and concrete would be sent to ATG Richland Corporation in Richland, Washington. Low level radwaste and soil would be sent to Envirocare in Utah. Hake, Inc. and ATG would perform decon and volume reduction services. The licenses for the three vendors were reviewed. ATG Richland Corporation's current license was Revision No. 6 to License No. WN-10393-1. This was a state of Washington license which expires September 30,2004. The current license for Hake, Inc. was R-79171-101 which expires September 30,2001.
Envirocare has two licenses. The state of Utah License No. UT 2300249 expired February 28,1996, and was under timely renewal. The NRC special nuclear material License No. SMC-1SS9 expires November 30,2003. The material and levels of contamination planned for shipment to the three vendors were found to be within the limits of their respective licenses.
The licensee used a computerized system called Integrated Shipping and Inventory Program to classify the radioactive material and waste for shipment and disposal. The system also generated the required documents for shipping. The system had recently undergone an extensive validation and verification process which was documented in a report dated July 1,1998.
The work associated with the stack removal project would result in contaminated material requiring shipment as radwaste. Radiation exposure levels were low. Typical levels were less than 0.2 mR/hr on contact with the stack. At the bottom of the stack,
smearable contamination levels were 30,000 dpm/100 cm. F xed contamination
levels were 700,000 dpm per probe area of 20 cm The depth of the contamination was determined to be less than % inch. At the 100 foot height above grade, the
contamination level was 1,000 dpm/100 cm removable. No 'ixed contamination was found.
To fix the contamination to the inside of the stack during dismantlement, the licensee used a technology called " capture coating." This technique involved fogging the inside
!
of the stack with a sticky solution of sugar and starch compounds. The aerosol l
covered the surface of the inside of the stack with a thin film of sticky solution. This was considered a temporary fixing of the contamination that would last through the dismantlement work. The technology had previously been successfully demonstrated at Hanford on a Department of Energy dismantlement project. Smearable
contamination levels at the bottom were reduced to less than 1,000 dpm/100 cm i
'
-16-Before a section of stack was cut, a cover was placed over the top and airflow down the stack to the filters was verified. After the cut was cornpleted, a cover was placed over the bottom of the cut section prior to movement to the ground. The stack section was then placed on a trailer and moved into a covered structure where the inside of the stack was painted with an enamel paint to seal the contamination. Surveys and
,
inspections were completed. The stack section was then shrink wrapped in plastic.
"
The first shipment was completed on October 22,1998 and was shipped to ATG Richland Corporation in Richland, Washington, as limited quantity (LO). Future sections of the stack will be larger in diameter and some will require segmenting the stack lengthwise into smaller sections before shipping. On November 6,1998, a i
conference call was held between the NRC, DOT, and the licensee to discuss the use of limited quantity as the shipping category. The classification of surface contaminated object (SCO) better described the shipments being made by the licensee. As of the date of the conference call,5 shipments had been made as LO.
,
As a result of the conference call, the licensee determined that future shipments would i
be made using the SCO category.
Characterization of the contamination on the stack was performed by Thermonuclear j
Corporation on February 24,1998. The primary isotopes identified were:
l lSOTOPE QUANTITY I
l Cs-137 6 x10'3 uC /gm i
Co-60 3.4 x10 pCi/gm Am-241 1.5 x10~7 uCi/gm Sr-90 2.3 x10" uCi/gm The stack contamination levels were relatively low and consisted of isotopes that were expected by the licensee. Standard radiological precautions and techniques were effectively used by the licensee for handling the stack sections.
Procedure RCP-6A," Release of Material from Restricted Areas," dated July 25,1995, was also reviewed. This procedure provided requirements for release of material from the radiologically controlled area. The procedure established a limit of no detectable for material being free released from the radiologically controlled area. The criteria in Regulatory Guide 1.86," Termination of Operating License for Nuclear Reactors," was used as the minimum acceptance criteria for instrument sensitivity for conducting surveys. For beta / gamma surveys, an HP-210 or HP-260 probe or equivalent was used. A background limit of 150 counts / minute was established for survey areas.
.
5.3 Conclusions L
l The licensee had established procedures and a computerized classification system for
!
handling radioactive waste shipments. Contracts had been established with vendors for receipt and disposal of contaminated material. Characterization of the ventilation j
,
,
..._ __ _ _. _ _
_ _ _ _ _ _ _ _ _ _ _ _ _. _. _ _. _ _ _ _ _. _ _ _
,
l
.
17-
-
l stack concrete had been completed identifying the isotopes of concern. Plans had been finalized concerning the packaging and shipment of the stack sections for disposal.
- 6 Self Assessment.s, Auditing, and Corrective Actions 6.1 Inspection Scoce l
The licensee's internal audit program conducted audits and assessments of the
'
various site program to verify compliance with regulations and company policies.
Several selected audits and assessments, including assessments of the stack removal l
project, were reviewed to determine the level of detail and adequacy of the scope of
,
l the audits.
6.2 Observations and Findinos j
A review was completed of severalinternal audits and assessments that had been conducted by the licensee's Nuclear Quality Services organization for the stack removal project, corrective action program, and radiation safety program.
l Audit 981320263, conducted June 19,1998, through June 30,1998, review all quality problem job orders initiated between August 6,1996, and June 9,19%.
'
Sixteen closed nonconformance issues were reviewed. Severalissues related to l
handling of sources and properly characterizing quality problems were identified as possibly needing additional attention by management. The audit concluded that the licensee's corrective action program was being effectively implemented.
Two audits relating to the radiaten nrotection program were reviewed.
Audit 96191008 was performed July 4,1996, through August 9,1996.
l Audit 972100007 was conducted August 815,1997. The audits concluded that the
radiation protection program. was being adequately implemented. Findings included issues related to procedure content, source inventory records, calibration documentation, and labeling of LSA boxes in the radwaste handling building.
Two assessments were reviewed related to the stack removal project.
I Assessment 982470028 was conducted August 12-28,1998. Assessment 982750007 was conducted August 28,1998, through October 15,1998. These two assessments l
reviewed a number of areas including the ventilatior' duct removal effort, fastahation of the new stack, and preparations for removal of the ventilation stack. A number of good observations were made by the Nuclear Quality Services auditors. The observations related to lack of craft supervisory personnel monitoring work activities, uce of unapproved drawings in the field, lack of a field change concerning the anchors in the concrete base for the new stack supports, lack of torque requirements for selected anchor bolts, inadequate rebar scanning prior to drilling, incorrect rebar installation, procedure compliance errors, and numerous other failures by the
,
contractor to comply with site procedures and programs.
i
d
,, -
.-,
,
.,,-,--n
.. --,.
,
-
, - - - - -,,
- _. _ _ _ _ _ -. ~ _ _ _ _ _. _.. _ _ _ _
-18 A significant finding was made by the Nuclear Quality Services Auditors in
,
l Assessment 982470028. During the review of the crane load rating chart and maintenance records provided by the cranc contractor, the auditors observed that the
'
crane loading chart was for a Skyhorse Model 11320 crane. However, the crane planned for use on the stack removal project was a Skyhorse Model 11250. The Model 11250 rating for loads was approximately 30 percent less than the Model 11320. This finding was significant in that miscalculating the loads for the crane could have resulted in serious potential consequences related to the stability of the crane.
6.3 Conclusion The licensee's audit and assessment program was effectively applied to the stack removal project. Several assessments were conducted which identified numerous work practices that required attention. The level of detail evaluated by the auditors was usually very good. As a result of their attention to small details, they discovered that the wrong crane load rating chart had been provided by the vendor. This error, if l
not corrected, would have resulted in a decrease in the margin of safety for the crane load activities.
Follow-up of Open items (92701)
7.1 (Closed) Insoection Followuo item 50-133/98001-02: Dosimetry issuance Durina Radioloaical Emeraencies As a result of an emergency drill conducted by the licensee on November 14,1998, a maintenance team dispatched to the top of Boiler No. 2 to report the condition of the reactor fuel building roof did not have dosimetry. The area that the team responded to was outside the restricted area and therefore did not require dosimetry during normal operations. The licensee identified the problem of emergency personnel responding to areas outside the restricted area but still having the potential to receive radiation exposure during the accident. The issue was entered into the licencee's tracking system as job Order C017216. Emergency Plan Implementing Procedure R-4 was l
revised to require dosimetry to be issued to all emergency personnel during a declared I
emergency, even if they were responding to problems outside the restricted area.
Alt Meeting The inspectors presented the inspection results to members of the licensee management at the exit meeting on October 22,1998. The licensee acknowledged the findings presented. The licensee dio not identify as proprietary any information provided to, or reviewed by, the inspector.
}
!
.
h
-,,--,
-
-
, _ - - - -
,
, -.
,
_ _ _. - - _ _.
-
AlTACHMENT PARTIAL LIST OF PERSONS CONTACTED Licensee J. Albers, Senior Radiation Protection Engineer (Radiation Protection Manager)
J. Bramble, Maintenance L. Claytor, Senior Radwaste Engineer V. Jensen, Nuclear Quality Services Engineer E. Kahier, Decommissioning Project Manager T. Moulia, Plant Manager R. Snyder, Radwaste Engineer D. Sokolsky, Senior Licensing Engineer T. Tyler, Maintenance
.
Burns & Rge
'
B. Morgan, Project Manager INSPECTION PROCEDURES USED 37801 Safety Reviews, Design Changes, and Cost Controls 40801 Self-Assessments, Auditing, and Corrective Actions 62801 Maintenance and Surveillance 71801 Decommissioning Performance and Status Review 83750 Occupational Radiation Exposure 86750 Solid Radioactive Wasto Management and Transportation ITEMS OPENED, CLOSED, AND DISCUSSED Opened None Closed 50-133/96001-02 IFl Dosimetry issuance During Radiological Emergencies Discussed None
.
i.
!
'
l
.. _.
['-,
?
!
-.
2-LIST OF ACRONYMS ALARA as low as reasonably achievable CFR Code of Federal Regulations DSAR Defueled Safety Analysis Report HBPP Humboldt Bay Power Plant
' LSA low specific activity LO limited quantity.(designation used by 49 CFR for shipping)
mci.
millicurie mR milliroentgen
,
'
NRC Nuclear Regulatory Commission PG&E.
Pacific Gas & Electric PSDAR Post Shutdown Decommissioning Activities Report SCO surface contaminated object (designation used by 49 CFR for shipping)
'.
!
!
!
!
l r
.
t
2
-
U n
-
I
'
.
.
..
..
..
,
.
-..
. -. _.,
-
.
.
w