IR 05000400/1990022
| ML18009A753 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 12/13/1990 |
| From: | Decker T, Seymour D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18009A752 | List: |
| References | |
| 50-400-90-22, NUDOCS 9012210051 | |
| Download: ML18009A753 (15) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
sv. s PiARIETTA STREE1, IvI.L'V.
ATLANTA,GEORGIA 30323 Report No.:
50-400/90-22 Licensee:
Carolina Power and Light Company P. 0.
Box 1551 Raleigh, NC 27602 Docket No.:
50-400 Facility Name:
Shearon Harris Nuclear Power Plant License No.:
NPF-63 Inspection Conducted:
'ovember 13-16, 1990 Inspector:
D. A. Seymour P
Approved by:
T.
R. Decker, Chief Radiological Effluents and Chemistry Section Radiological Protection and Emergency Preparedness Branch Division of Radiation Safety and Safeguards y~Jj~ ro
. Date tgned
/> /8 A'ate igne SUMMARY Scope:
This special, unannounced inspection was conducted in the areas of Spent Fuel Pool water quality; and in count room and chemistry procedures.
Results:
The licensee had started on the clean-up of the spent fuel pools and transfer canals.
The licensee had also issued a Significant Operational Occurrence Report which evaluated the impact to safety caused by the increased activity levels in the spent fuel pools.
The conclusion.of:this reporttI,was'.that,,>this increased activity did not constitute an unreviewed safety"--concern'." >The Corporate Task Force assigned to determine the best methods-foer.:dealincg <with the spent fuel iron oxide deposits had made progress towards this goal.-
They are scheduled to make recommendations to management in;January 1991..
The licensee was considering the possibility of isolating spent fuel received from other sites (Paragraph 2).
The licensee had initiated a
study to qualify the effects of not treating liquid samples with nitric acid prior to compositing and analysis.
The licensee also committed to review applicable procedures to ensure that they were consistent with current operations and. requirements (Paragraph 3).
In the areas inspected, violations or deviations were not identified.
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REPORT DETAILS Persons Contacted Licensee Employees S.
Buch, Environmental and Chemistry Technician
- J. Collins, Manager, Operations D. Elkins, Shipment Director, Spent Nuclear Fuel
- G. Forehand, Manager, guality Assurance/guality Control (gA/gC)
- J. Hammond, Manager, Onsite Nuclear Safety S. Johnson, Chemistry Foreman G. Nathan, Senior Specialist, Chemistry
.."C. Olexik, Yianager, Regulatory Compliance
- G. Olive, Security Specialist
- A. Poland, Project Specialist, Environmental and Radiation Control (ELRC)
- R. Richey, Yice President, Harris Nuclear Project
- J. Sipp, Manager, ERRC D. Tibbitts, Manager, Shift Operations
- M. Wallace, Senior Specialist, Regulatory Compliance
~E. Willett, Manager, Outage/Yiodifications
- W. Wilson, Manager, Spent Nuclear Fuel Other licensee employees contacted during this inspection included engineers, operators, technicians, and administrative personnel.
Nuclear Regulatory Commission
- Yi. Shannon, Resident Inspector
- J. Tedrow, Senior Resident Inspector
- Attended exit interview 2.
Acronyms and Initialisms used throughout this report are listed in the last paragraph.
Spent Fuel Pool (SFP)
(84750)
The inspector met with licensee representatives to discuss the status of the Spent Fuel Shipping Program.
Items discussed with the licensee during this inspection included:
progress'ade by the Task Force in resolving this problem; review of commitments by the licensee to tables in the Final Safety Analysis Report (FSAR); and clean-up of the crud, in Harris's SFP.
As discussed in Inspection Report No.
50-400/90-12, and in Inspection Report No. 50-325/90-28, Harris's SFP has been the recipient of spent fuel from Brunswick Steam Electric Plant (BSEP).
The spent fuel had large
amounts of iron oxide corrosion products (crud) adhering to its outside surface.
The fuel was shipped dry in specially designed casks. It is believed that the shipment of the dry fuel, the heat generated by the fuel, and the vibrations of the shipping process all exacerbated the crud shedding problems.
The crud shedding presented several serious concerns:
crud build up in the bottom of the shipping casks; crud shedding in the SFP itself; and the inability of either site to effectively process the crud due to limitations in their radwaste systems.
After several shipments there was approximately 18 inches of crud in the bottom of one shipping cask, with radiation readings reaching 1260 Roentgens per hour (R/hr).
The crud from this cask was pumped into one of SHNPP's SFPs.
At the time of this inspection there were several areas in SHNPP's SFPs and transfer canals that had large deposits of crud.
The crud is primarily composed of iron-55 and colbalt-60.. It has a particle size of less than 10 microns, with a specific activity of approximately 18 millicuries per gram.
The licensee estimated that there was between 1000 and 4000 pounds of crud in the SFP and transfer canals.
This calculates to a possible total activity of 33,000 curies.
Because of the fine particulate nature of the crud, it becomes a serious airborne problem when dry.
When wet, the crud forms a tenacious coating that is difficult to flush and creates hot spots in the SFP clean-up systems.
An interesting developement was that the crud was remaining suspended in the water for longer periods of
'time.
Initially, water clarity was regained within several hours of fuel movement.
Currently, the water may lose clarity for several days after fuel transfer or movement.
The licensee attributed this to the fine iron oxide particles becoming charged, and as a result, resistant to settling.
The licensee also indicateo to the inspector that previous industrial experience with BWR fuel shipments (approximately 160 shipments)
had not indicated the magnitude of the crud problem that SHNPP would experience.
Table 11.1.7-1 of Shearon Harris Nuclear Power Plant's (SHNPP)
FSAR lists design and normal values for SFP specific activity concentrations for several different nuclides.
Section ll.l. 1 states that maximum fission product activities had been used as design basis source terms for shielding and facilities design, and for calculating the consequences of postulated accidents.
Section 11. 1.7 of the FSAR also states that fuel received. from other sites will not contribute significantly to fuel pool activities.
Discussions with the licensee, and a review of selected analyses results, indicated that as a result of the fuel shipments and the associated crud, concentrations in the SFP had exceeded the limi.ts specified in the FSAR.
Some of these results are listed below:
Activity Concentrati ons in uCi/g FSAR Table 11. 1.7-1 Sample From Nuclide Design Activity.
SFP A,.Taken Oct. 23, 1990 Sample From Transfer Canal 2-3, taken Oct. 23, 1990 Hn-54 Co-58 Co-60 2.6 E-08 1.0 E-06 1.3 E-06 2.7 E-06 7.8 E-06 3.6 E-04 2.4 E-05 7.9 E-06 1.2 E-03 Both of the samples were dip samples of 125 milliliters; the samples were not filtered prior to counting.
The sample concentrations ranged from approximately 10 to 1000 times the design activity concentrations.
The resident inspectors had issued a violation to the licensee for failure to perform a written safety evaluation as required by
CFR 50.59 for a change in the operation of the plant ( Inspection Report No. 50-400/90-21).
The inspector discussed the implications of exceeding the design basis concentrations with the licensee.
During these discussions, the licensee indicated that the responsible managers had assessed the potential impact of exceeding these values, but had not documented these results, as they had not believed that there was an unresolved safety concern.
The responsible managers believed that the crud was primarily an ALARA concern, and possibly a process system concern.
Also, since this problem was under investigation, the managers were delaying making any changes to
'he FSAR unti 1 the full extent of the problem and the impact of the potential corrective actions could be determined.
During this inspection, the inspector reviewed Significant Operational Occurrence Report 90-148.
This~ document evaluated the impact to safety caused by the increased activity levels in the SFP and transfer canals due to the receipt of the BSEP fuel.
The licensee concluded that this event did not constitute an unreviewed safety question because safety was not perceived to be an issue.
Specifically:
It had no impact on the margin of safety as defined in the basis for the TSs.
It had no effect on safety which was not bounded by previous analyzed accidents.
It did not increase the probability or consequences of any previously analyzed accidents.
It did not introduce the possibility of a new accident that was not bounded by previously analyzed accidents.
This document contained several calculations covering SFP -accidental releases based on realistic assumptions, as well as conservative estimates which assumed all of the crud activity was suspended uniformly through the
SFP, and/or assumed that selected portions of the SFP were empty.
These calculations showed that even in the most conservative,
"worst," case, a
release from the SFP would be bounded by a release of= 4,000 gallons from the. waste evaporator concentrates tank.
This release, using activities listed in the FSAR, would release 12,600 curies, and was evaluated in the FSAR.
The inspector also reviewed internal correspondance, dated October 31, 1990, which requested cognizant personnel to study the potential impact of the spent fuel crud on the Harris Licensing and Design Bases, and to identify and initiate any required crud-related changes to these bases and
'upporting documentation.
A memorandum dated November 13, 1990, in reply to the first memorandum, detailed the areas that would be reviewed.
These included shielding, zone maps, KVAC filtration, fuel pool cleanup system, and the potential for on-and off-site releases.
This review was expected to be completed by the second quarter of 1991, prior to the next scheduled shipment of spent fuel from BSEP.
A corporate level Crud Task Force was established on June 28, 1990, to investigate the crud problem and to propose to management methods for its mitigation.
The recommenoed methods should minimize cost and man-rem from a shipment and plant operations perpective.
The Task Force was chartered with developing milestones, estimating costs, and recommending assignments of responsibility for the chosen solution.
The inspector discussed the progress of the Task Force in finding a solution for this problem.
The Task Force had considered several potential solutions, including chemical decontamination and ultrasonic cleaning.
One potential solution that was being given serious consideration was the proposal of placing the fuel bundles in large cannisters fitted with suction pumps and filtration systems.
The fuel bundles would be mechanically cleaned through a flushing process similiar to low pressure hydrolazing.
The flushed material would be collected in trickle-bed design filters, which would have alternate layers of charcoal and resin.
The plan would include having the vendor come in and, clean several hundred bundles of fuel at one time.-
This flushing could occur at either end of the shipment.
The Task Force did not want the spent fuel to be cleaned off any more than was necessary to mitigate the crud shedding problem because of fuel bundle integrity concerns, and also because of the difficulty and expense in disposing of the material.
The Task Force planned on recommending to management that they implement the selected option prior to the,.receipt of additional fuel from BSEP.
SHNPP planned on receiving fuel from'obinson in the interium.
However, since Robinson is a pressurized water reactor, its fuel is not expected to cause a similiar crud problem.
The Task Force was scheduled to present its findings and recommendations to management in January 1991.
During this inspection, the inspector reviewed selected portions of
'a procedure covering the clean-up of the SFP and transfer canal areas.
This procedure,'itled
"Removal of Radioactive Particulate within the Fuel Pools and Transfer Canal System,"
was dated November 14, 1990.
The inspector also observed the clean-up of a portion of a transfer canal by
use of the method described in the procedure.
The system used an underwater vacuum head attached to an aluminum handling pole for manuverabi lity, and was connected to a
submersible pump.
The pump discharged into one of two 24-inch diameter, 68-inch tall pressure vessels submerged in the SFP.
The pressure vessels were filled with activated charcoal which acted as a mechanical filter to remove particles down to
'.5 microns in size.
The pressure vessels discharged into the SFP.
The pressure vessels were equipped with pressure guages to indicate differential pressure across the charcoal beds, and a flow indicator.
At the time of the inspection, the inspector also noticed a submerged rate meter which indicated radiation readings off the outside of the cannister.
The inspector noted a radiation reading of 6 R/hr during the vacuuming process.
The licensee planned to switch cannisters on high differential pressure or when the radiation levels reach 300 R/hr.
The vendor who designed this system'or SHNPP will lift the filled cannisters into a
shielded bell for dewatering and preparation for shipment.
The licensee planned on completeing the SFP clean-up by the end of January 1991, although they noted that the clean-up could be delayed by the receipt of fuel from Robinson and SFP rerack activities.
In conclusion, the licensee's near term plans included completing the cleanup of the SFPs and transfer canals, and completing the licensing and design basis reviews.
Long term plans were to determine a method for cleaning the spent fuel, either prior to, or after shipment; to perform regular cleanups of the SFPs; and -to consider isolating Harris spent and new fuel from fuel shipped from other sites.
The licensee's progress in addressing these and other related concerns will be reviewed during subsequent inspections.
No violations or deviations were identified.
Count Room and Chemistry Procedures (84750)
Technical Specification (TS) 6.8. 1 requires written procedures to be established, implemented and maintained for the guality Assurance Program for effluent and environmental monitoring.
On October
and 26, 1990, one of the resident inspectors observed licensee technicians sample and analyze two different liquid samples, as required by TSs.
The resident inspector noted that strict adherance to applicable procedures was-not followed in that the licensee technicians neglected to add nitric acid to these samples as specified by the procedures.
Nitric acid is added to liquid samples to prevent plateout, over time, of radionuclides on the sides of the sample container.
This plateout could have the potential of affecting count results.
The licensee stated that although the nitric acid was forgotten, the omission should not have affected sample results because the sample was counted
shortly after acquistion.
The licensee indicated that typically most samples w'ere counted shortly after acquistion.
The licensee was issued a violation as a result of these two observations (Violation. 50-400/90-21-01
Failure to properly implement a
radiochemistry procedure).
Details of the resident inspector observations and the resultant violation can be found in Inspection Report No. 50-400/90-21.
During the current inspection, a regional inspector discussed this topic with-cognizant li.censee personnel and determined what corrective actions had been taken by the licensee.
Part of the corrective actions involved the performance of a study where steam generator samples were counted at different time intervals using intrinsic germanium detectors.
One of the samples was treated with nitric acid, and one of them was not treated with nitric acid.
The results are summarized below:
Date Time Total Activity (microcuries per milliliter)
w/o acid w/acid 10/31/90 11:55 1.84 E-06 1.83 E-06 10/31/90 16:08 9.97 E-07 1.00 E-06 11/Ol/90 09:34 9.60- E-07 8.96 E-07 The sample population was too small to allow rigorous statistical analysis to determine whether the differences observed were significant.
Given the inherent uncertainties of gamma spectroscopy, there are not any, apparent di"fferences between these two sets of numbers.
The inspector questioned the licensee about their, composite samples.
Several sampling points require composited samples, including:
the secondary waste sample tank, the treated laundry and hot shower tank, waste monitor tanks, and the waste evaporator condensate tanks.
Liquid samples from these sampling points are composited monthly for gross alpha determinations, and composited quarterly for iron-55, strontium-89, and strontium-90 determinations.
The inspector determined, during conversations with the licensee, that the monthly composite, samples were acidified after makeup.
However, there was some question of whether or not the samples from which the composites were drawn were acidified when they were first obtained.
There was the potential for these samples to experience plate-out in the time interval between,acquistion
.and the monthly compositing.
The licensee decided to perform a study, similiar to the one detailed above, which would attempt to qualify the effects of not acidifying the samples from which the monthly and quarterly composites were drawn.
The results of this study will be reviewed during a
subsequent inspection.
The licensee performed other corrective actions to prevent future recurrences of these events, including a group meeting of the responsible technicians to discuss the importance of procedure conformanc rt
TS Table 4.4-4 specifies that the sampling and analysis of reactor coolant for the determination of gross radioactivity shall occur at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
These tests are performed as a method for evaluating and
'rending fuel integrity.
The inspector discussed these analyses with the licensee, and determined that the licensee was using a proportional counter to determine the gross radioactivity measurements.
Typically, gross radioactivity measurements for a nuclear power plant include gross beta and gross gamma components.
Proportional counters can not be used to accurately quantify gamma emmiting radioisotopes.
The inspector reviewed procedures covering the gross radioactivity measurements.
Procedure RCP-713, titled
"Gross Radioactivity", dated May 23, 1990, defined gross radioactivity as "the gross beta activity of all the beta emitting radioisotopes in a
depressurized reactor coolant liquid sample (as determined by a
beta proportional counter)."
Procedure RCP-720, titled "Operation of the Tennelec LB5100 II," dated October 18, 1990, referred to the Tennelec proportional counter as an instru'ment used for gross alpha and gross beta
.
analysis.
A review of the licensee's Radiochemistry Laboratory Analysis Request Form indicated that gross beta activity was being recorded on the gross radioactivity portion of the form.
The inspector also reviewed correspondence from Nuclear Reactor Regulations (NRR) to the licensee that referred to a
"gross beta/gamma count...
as being obtained using a
proportional counter."
Discussions with several licensee representatives indicated that most cognizant personnel considered the measurement being performed on the proportional counter as being a gross beta measurement.
Some individuals did consider the measurement to be a "gross beta/gamma count."
The inspector did find supporting documentation, from a source independent of the licensee, that indicated that proportional counters could be used to indirectly detect gamma radiation.
The primary purpose of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> gross radioactivity measurement is to track and trend any degradation of fuel performance.
Degradation of fuel should be readily detectable by using a proportional counter for a gross beta measurement.
The licensee stated that they would review their procedures to determine if they were consistent with their operations and requirements, and that they would resolve any inconsistencies discovered.
The inspector also reviewed pertinent procedures covering sampling and analysis of the spent fuel pool water.
Table 9.1.3-3 of the SHNPP FSAR listed spent fuel storage pool water chemistry limits -for several parameters.
Procedure CRC-001, titled
"Environmental and Chemistry Sampling and Analysis Program,"
dated April 26, 1990, listed the frequencies of these measurements.
Two of the parameters, calcium and magnesium, were listed as being required to be measured monthly, except during fuel movement, at which time they would be measured weekly.
The
,inspector also reviewed Chemistry Data Management System Status/Exception Reports for selected portions of 1989 and 1990.
These reports listed the results of sampling and analyses performed for these chemistry parameter The inspector compa'red these reports to a log which indicated when fuel had been received or shuffled in the SFPs.
The analyses for calcium and magnesium had not been performed weekly, as required by procedure, during fuel movement in, the SFP.
The inspector discussed this apparent discrepancy with the licensee and determined that the requirement for the weekly testing had been included to protect the reactor core from scaling deposits during fuel movements into and out of the core and SFPs.
This requirement was included in the procedure prior to the company's knowledge of receiving and shuffling of fuel from other CP&L sites.
The licensee stated that they would revise their procedures to reflect'urrent practices.
No violations or deviations were identified.
5.
Exit Interview The inspection scope and results were summarized on November 16, 1990 with those persons indicated in Paragraph 1.
The inspector described the areas inspected and discussed in detail the inspection results as listed in the summary.
Proprietary information is not contained in this report.
Dissenting comments were not received from the licensee.
Acronyms and Initialisms ALARA - As Low As Reasonably Achievable BSEP - Brunswick Steam Electric Plant CFR - Code of Federal Regulation CPKL - Carolina Power and Light ESRC - Environmental and Radiation Control FSAR - Final Safety Analysis Report HP - Health Physics NRC - Nuclear Regulatory Commission NRR - Nuclear Reactor Regulations QA - Quality Assurance QC - Quality Control R/hr - Roentgen per hour SFP - Spent Fuel= Pool SHNPP - Shearon Harris Nuclear Power Plant TS - Technical Specification uCi/g - microcurie per gram w/ - with w/o - with out
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