IR 05000206/1981023
| ML20009B741 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/01/1981 |
| From: | Book H, Wenslawski F, Yuhas G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20009B727 | List: |
| References | |
| 50-206-81-23, NUDOCS 8107170111 | |
| Download: ML20009B741 (9) | |
Text
FOR DCS PROCESSING
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Original document not available t NRC.$ b;N b ch U. S. :;UCLEAR REcUL\\ TORY Cole.ISSIO:t 0FFICE OF I!!SPECTI0tt A iD E iFORCEME!rr
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REGI0:1 V
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Report ::o. 50-206/81-23 Docket ::o.
50-206 License to.
DPR-13 Safeguards Group Licensee:
Southern California Edison Company P. O. Box 800 2244 Walnut Grove Avenue Rosemead, California 91770 Facility ::a=e: San Onofre Unit 1 (SONGS-1)
Inspection at: Camp Pendleton, California Inspection conducted: June 1_3, 1981,
Inspectorsy [
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G. P. Yuhas, Radiation Specialist date Signed Date Signed
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Date Signed
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- n.JApproved by:
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F. A. Wenslawski, Chief, Reactor Radiation
'Date Signed Protection Section-
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H. E. Book, Radiological s'afety Branch
/Date Signed
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Summary:
Inspection on June 1-3, 1981 - Report No. 50-206/81-23 Areas Inspected:
Special unanneunced inspection by a regional based inspector to review the licensee's action regarding discovery of low level radioactive material contamination of beach sand in an area adjoining an inactive tsunami wali penetration.
The inspection involved 36 inspector hours on site.
Results: Of the areas inspected, no items of noncompliance were identified at this time, however final determination of compliance remains unresolved pending completion of the licensee's action.
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DETAILS, 1.
Persons Contacted Licensee Representatives:
- J Curran, Station Manager
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E. Morgan, Assistant Station Manager, Operation
- K. Barr, Health Physics Manager
- J. Dunn, Project Quality Assurance Supervisor
- G. Mcdonald, Quality Assurance / Quality Control Supervisor
- D. Duran, Radwaste Supervisor R. Warnock, Health Physics Supervisor (SONGS 1)
C. Appleford, Supervisor Construction Engineering
- F. Briggs, Compliance Engineer B. Graham, Chemistry / Radiation Protection Engineer
- R. Mcrgan, Radwaste Foreman Non Licensee Representatives:
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D. Bunn, Health Physicist, California Department of Health Services T. Crockett, Radiochemist, General Atomics
- Denotes those individuals attending the exit interview on June 3, 1981.
In addition to the individuals noted above, the inspectors met with and
interviewed other members of the licensee's and contractor's staffs.
2.
Discussion One committment Fouthern California Edison made regarding development of Units 2 and 3 was to construct a beach passageway thru the Exclusion Area connecting the northern and southernly portions of San Onofre State Beach.
Construction of the first section, which will run parallel with, and in close proximity to, the Unit 1 tsunami wall, began in late March of this year.
As a result of the Unit 2/3 barge loading facility substantial accretion of sand resulted in an approximate three foot overburden near the tsunami wall.
This build up of sand also effectively caused the mean high water line as surveyed in January 1963 to move westward away from the tsunami wall creating about 150 feet width of beach.
Early construction activity on the beach passageway involved excavation of the overburden and original beach in order to place an appropriate foundation. This action is necessary to support the passageway when the Unit 2/3 barge loading facility is removed and erosion returns the beach to the 1963
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-2-By early May, 74cavation had removed most of the overburden within thirty feet of the tsunami wall. On Sunday, May 10, 1981 a Health Physics Technician performing a routine weekly radiation survey of the beach area noted that an 18" drain line penetration of the tsunami well located about 60' north of the south Guard Tower had been uncovered.
The penetration closure device, a flapper, had been knocked off and the line was full of sand. The technician surveyed the area and recorded a maximum reading of 0.2 mr/hr at contact with the pipe and general area readings of 0.018 to 0.02 mr/hr.
On Monday, May 11, 1981 the Supervisors of Health Physics and Radwaste inspected the area and had a sample collected from within the pipe for radioactivity analysis.
The Health Physics Manager notified the NRC Region V Office by telephone that they had uncovered an old storm drain penetration in the tsunami wall which read 0.2 mr/hr at contact.
The licensee representative stated that the storm drain system had been modified several years ago such that this penetration was no longer in use.
He also indicated that a sampling program and evaluation of the situation had begun.
On May 18, 1981 the inspector contacted the Health Physics Manager to review developments regarding their evaluation. The licensee reported that construction activities in the immediate vicinity of the storm drain penetration had been stopped, samples of sand inside the penetration indicated activity of 430 pCi/- due primarily to cesium 137 with a small contribution from cesium 134 and cobalt 60.
The drain line leading to the penetration was cleared of sand and the concrete plug visually inspected.
The sand removed from the pipe was treated as radioactive waste and samples had been collected on the beach. On May 20, 1981 the licensee informed Region V that analysis of beach sand samples indicated a maximum activity of 200 pCi/g, that SCE construction workers were informed that the radiological evaluation of this low level contamination found that no radiation protection measures were required to process the material, and that the licensee was evaluating disposition of the contaminated sand.
On May 22, 1981 the licensee informed Region V that they intended to excavate the contaminated sand and dispose of it as low specific activity material.
3.
Review of Licensee Actions On June 1,1981 the inspector accompanied by a representative of the California Department of Health Services performed an unannounced inspection and radiation survey of the beach adjacent to Unit 1.
- The inspection also involved visual observatioh of construction activities, and beach use by members of the public.
The radiation survey was performed using an Eberline PRM-7, micro "R" meter, NRC Property No. 006383 due for calibration by March 30, 1982 and an Eberline E-520.ith HP 260 Gieger-Mueller detector, NRC Property No. 008253 due for calibration by July 15, 1981.
In addition, four samples of sand from the beach were collected by NRC and three by the State for independent laboratory analysis.
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-3-The radiation survey indicated natural background levels of 5-7 ur/hr away from the facility. The dose rate ranged from 7 to 18 ur/hr on the wet beach and 7 to 25 ur/hr on the dry beach adjacent to the tsunami wall. Considering the operational configuration of the facility and directionality of radiation field the inspector determined that the dose rate measured above background was the result of direct and scatter gamma radiation from within the restricted area.
The excavation was appr3ximately 25 feet along the wall extending about 30 feet west and about 9 feet deep.
The area was cordoned and posted as an industrial safety hazard on two sides.
The background radiation levels in the area of the excavation ranged from 10 to 15 ur/hr. A detailed survey of 30 points within the excavation indicated a range of 10-15 ur/hr general area with maximum contact readings of 30 ur/hr five feet below the penetration on the tsunami wall and 20 ur/hr on contact with the floor of the excavation.
One square meter sand samples were collected on the floor of the excavation below the penetration and at the highest observed meter reading in the excavation.
The radiation survey results indicate the licensee has reduced the average dose rate on the beach by a factor of two since the inspector's December 15, 1980 survey (Inspection Report Nos. 50-206/81-02,81-11).
Other beach sand samples were collected on the wet sand area adjacent to the tsunami wall and north west of the plant on San Onofre State Beach. The samples were analyzed for gamma activity using NRC's Region V
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intrinsic germanium counting system.
The results are included in Attachment A.
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At the conclusion of the survey the inspector and state reptesentative
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met with licensee representatives. The licensee representatives described the status of their cleanup efforts and responded to questions presented by the State Representative. At the conclusion of this meeting the i
State Representative terminated his onsite inspection effort.
The following chronology of licensee actions was developed from discussions
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with licensee representatives and review of survey and sample data.
i Date Point of Interest Source 5-10-81 Initial discovery Weekly radiation survey 5-11-81 Excavation stopped on passageway. Discussions and sample NRC informed.
Samples taken.
data sheet.
5-13-81 Tsunami wall penetration verified Discussion and sample plugged, 14 sand samples data sheet.
collected, dose rate on empty penetration 50-60 ur/hr.
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-4-Date Point of Inf rest Source 5/13-18/81 Sand samp; s analyzed onsite and Sample data sheets.
four samples '_nnt to an independent laboratory for pure beta -
confirmatory analysis.
5/20/81 Surveyor laid out detailed grid Sample grid map and of affected beach area for data sheets discussion.
sampling program.
Samples are collected, 10 CFR 19.12 training given to SCE construction personnel.
5/22/81 Contaminated sand is moved from Survey results and the beach to inside the restricted discussion.
area and packaged as Low Specific Activity (LSA) waste for disposal in a licensed burial facility.
5/23 - 6/3/81 Packaging and shipment of Survey records and contaminated waste continues.
direct observations.
6/3/81 Licensee concludes further Observation.
excavation may not be practicable.
Detailed survey and radiological evaluation is initiated to prepare radiological impact letter.
Review of the 172 sample results from SCE and 42 performed by a representative of an independent laboratory indicates the maximum activity observed for a single beach sample of sand removed from the excavation was:
2.5 E-4 uCi/g 137-Cs, 1.2 E-5 uCi/g, 134-Cs, and 6.6 E-6 uCi/g 60-Co.
The average activity of sand excavated appears to'be 2.0 E-5 uCi/g due to 137-Cs. The samples collected by the licensee on the stretch of wet sand adjoining the facility did not indicate any radioactive material above the minimum detectable activity of 4.5 E-8 uCi/g.
Water samples taken from the construction well used to depress the ground water in the excavation area indicated less than 3.95 E-8 uCi/ml i
of gross activity.
Samples collected in the excavation on June 2,
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1981 and analyzed by the licensee indicated a maximum activity of 2.46 E-6 uCi/g 137-Cs and 1.9 E-7 134-Cs.
Environmental Technical Specification 3.2.5 " Beach" requires that l
sand will be collected semiannually from the beach 0.5 mile south I
of the station, at the surfing beach north of the station, at the southern extent of San Onofre State Beach and near flewport Beach.
The results of these samples are summarized in the Annual Operating Report.
Review of the Annual Operating Report of San Onofre riuclear l
Generating Station Unit 1 for 1980 indicates 137-Cs activity in beach l
sand averaged 6.0 E-8 uCi/g with a maximum observed activity of 1.2 l
E-7 uCi/g.
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The Technical Specifications do not require samples of sand from the beach directly in front of the tsunami wall. As of the inspection, no evaluation of historical iadiological environmental data had been made regarding the beach contamination according to the licensee representative.
The licensee representative stated that they had intended to remove all sand contaminated above natural background levels as noted in the Annual Operating Reports.
However, after extensive excavation, levels of 2.4 pCi/g were still considerably greater than the average background of 0.06 pCi/g.
The licensee decided to stop further excavation and make a more sophisticated determination of residual activity and the consequences of proceeding with construction without further removal.
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The licensee representative stated they were considering submission
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of an application for alternate disposal of this material as permitted by 10 CFR 20.302.
The inspector observed laborers packaging the contaminated sand into new 55 gallon 17H drums lined with heavy plastic bags for shipment.
The licensee had made 15 shipments containing 66 drums each
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to the licensed burial facility. The licensee estimated that this is about 40% of the sand to be processed.
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The inspector reviewed the documentation for two of these shipments, SW-43 and SW-46.
The licensee has used the highest observed activity to classify and document these shipments. The activity: 2.5 E-4 uCi/g 137 Cs, 1.2 E-5 uCi/g 134 Cs, 6.6 E-6 uCi/g 60 Co is quite conservative in view of other sample data. All shipments have been
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made as LSA pursuint to 49 CFR 173.392.
Although the licensee's evaluation of the source of this contamination was incomplete, the inspector noted that a document search was under;y
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to review the yard drain system's input and design changes since cc istruction.
The licensee interviewed 13 individuals with familiarity of the plants operating history. No conclusive information had'been developed indicating the source of the activity.
The Health Physics Supervisor performed an evaluation of 137 Cs to 134 Cs concentrations observed in reactor coolant and liquid effluent waste stream. This evaluation indicates the activities observed on the beach are consistent with a source that had been deposited no later than 1975.
The inspector reviewed the following drawings with SCE identification
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nos. 567774-10, 567784-0, 568649-6 and 5104342-2 describing the old yard drain system. These drawings indicate that until Design Change 73-30, " Modification of the Yard Drainage Collection and Drainage System" wa*, implemented it was possible for contaminated liquid from above the Auxiliary Building to be directed to the yard drain system.
Drain points near the Refueling Water Storage Tank also could have resulted in contamination of the yard drain system.
In addition, the yard area is graded such that a spill of contaminated material outside the Controlled Area could have delivered radioactive maters 1 to the yard drains. Design Change 73-30 terminated the 18 inch ts
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-6-wall discharge. A yard drain sump was constructed and pumps installed to discharge the volume collected to the circulating water discharge.
In response to IE Bulletin 80-10, " Contamination of Nonradioactive Systems and Resulting Potential for Unmonitored, Uncontrolled Release of Radioactivity to Environment" the licensee began a sampling regime and schedule to install an inline radiation monitor in the yard drain system.
During the survey of the excavation the inspector observed a four inch open penetration about three feet below and twelve feet south of the 18 inch line in the tsunami wall.
The licensee representative was unable to conclus'.vely explain the purpose of this pipe and could not locate as-built drawings of the tsunami wall or yard drain system while the inspector was on site.
The licensee has complied with applicable regulations of 10 CFR 19.12, 10 CFR 20.105 and 10 CFR 71.5 since the May 10, 1980 discovery of this apparently uncontrolled release of radioactive materials. On June 16, 1981 the inspector notified the licensee's Compliance Engineer that NRC had not yet received a written followup report to the initial notification made on May 11, 1981 on discovery of this apparent uncontrolled
or unplanned release of radioactivity from the station as required in Section 5.6.3 of Appendix B to the Technical Specifications.
The licensee's evaluation of the source and time of release is incomplete.
Review of the licensee's actions which resulted in the release remains unresolved pending development of additional information (50-206/81-23-01).
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Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable, items, items of noncompliance, or deviations. Unresolved items disclosed during the inspection are discussed in Paragraph 3.
5.
Exit Interview The inspector met with licensee representatives (denoted in Paragraph 1)
at the conclusion of the inspection on June 3,1981.
The inspector sumnarized the scope and fir. dings of the inspection.
The inspector stated that it does not appear that any significant threat to the health and safety of the public has occurred during excavation
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and removal of the contaminated sand.
That the licensee's actions i
are consistent with regulatory requirements and the "ALARA" criterion.
However, since the licensee's evaluation is incomplete and has not yet resolved such issues as:
the source of contamination; radiological
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environmental inpact at the time of the leak; accurate determination of the amount of activity originally released; how much will remain; and the significance of future erosion exposing residual activity, l
a determination of compliance with regulatory requirements remains I
ooen.
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-7-The licensee representative stated that in their opinion virtually all the contaminated sand had been removed, however since some residual activity remained they intended to submit an application pursuant to 10 CFd 20.302 which would' authorize them to terminate their clean up effort.
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i ATTACHMENT A SAMPLE RESULTS
.Thre: samples of beach sand from in front of San Onofre Nuclear Generating Stat sn Unit 1 and one sample from the northern portion of San Onofre State Beach were collected on June 1-3, 1981 by scraping a surface area of square meter to a depth of about one centimeter. ~ The accumulated sand was mixed
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in the field and a portion of samples 1, 2 and 3 provided to the State of Cali fornia. The four samples noted below were analyzed at the NRC's Region V Mobile Laboratory.using an intrinsic germanium detector.
Samole Description Isotopes Observed Activity Counting Error Other than Naturally uCi/g in Percent
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Occurring Radioactivity
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1. San Onofre State Beach
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(northern section west of
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turnaround)
2. SONGS 1 (base of 137 Cs 1.5 E-6 4.4%
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excavation at tsunami wall)
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3. SONGS 1 (base of 134 Cs 1.7 E-7 24%
excavation at highest 137 Cs 4.3 E-6 2.5%
radiation measurement)
i 4. SONGS 1 (NW of tsunami
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wall on active tidal beach)
- The lower limit of detection for 134 Cs and 137 Cs in sand was 7 E-8 uCi/g
based on a 100 minute count of 200 grams of dry sand.
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