IR 05000277/1987003
| ML20212N146 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 03/03/1987 |
| From: | Bicehouse H, Davidson B, Pasciak W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20212N122 | List: |
| References | |
| 50-277-87-03, 50-277-87-3, 50-278-87-03, 50-278-87-3, NUDOCS 8703120375 | |
| Download: ML20212N146 (11) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
j Report Nos.
50-277/87-03 50-278/87-03 Docket Nos. 50-277 50-278 License Nos. DPR-44 DPR-56 Priority
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Category C
Licensee:
Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101 Facility Name:
Peach Bottom Atomic Station Inspection At: Delta,-Pennsylvania Inspection Conducted: January 26-30, 1987 Inspectors:
.b b 3!3
'l H. J. 'Bicehouse, Radiation Specialist date A(.SeL L
alah2 B. S.
avidson, Radiation Specialist date Approved by:
A} L u,1 v 32fEb V. J.(P)isciak,' Chief, Effluents Radiation bath ProtW tion Section Inspection Summary:
Inspection on January 26-30, 1987 (Combined Report Nos. 50-277/87-03; 50-278/87-03).
Areas Inspected:
Routine, unannounced review of the licensee's Water Chemistry Control Program. Areas reviewed included previously identified items, manage-ment controls, plant water chemistry systems, sampling / measurement and implemen-tation of the program.
Results: No violations were noted in the areas reviewed. The licensee appeared to have developed and implemented an adeguate water chemistry control program.
8703120375 870303 PDR ADOCK 05000277 O
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DETAILS 1.
Persons Contacted 1.1 Licensee Personnel
- Mr. R. S. Fleischmann, Manager, Peach Bottom Atomic Power Station Mr. G. R. Barley, Assistant Plant Chemist
- Mr. J. B. Cotton, Superintendent - Plant Services Mr. A. D. Odell, Chemical Engineer
- Mr. D. L. Oltmans, Senior Chemist Mr. M. Satter, Fuel Floor Engineer
- Mr. D. Smith, Superintendent - Operations
- Mr. H. L. Watson, Plant Chemist Other licensee personnel were contacted or interviewed during the course of this inspection.
1.2 NRC Personnel
- Mr. T. P. Johnson, Senior Resident Inspector
- Mr. R. J. Urban, Resident Inspector
- Attended the exit interview on January 30, 1987.
2.
Scope of the Inspection This routine inspection reviewed the licensee's water chemistry control program with emphasis on recent implementation (i.e. 1984-87).
The pur-pose of the. inspection was to review the licensee's program to control corrosion and out-of-core radiation field buildup, ensure long-term inte-grity of the reactor coolant pressure boundary and minimize fuel leakage caused by corrosion-induced failures. The licensee's water chemistry control program was reviewed relative to Technical Specifications, Updated Final Safety Analysis Report (UFSAR), commitments by the licensee regard-ing continued operation of Unit-3 with pipe cracks, NRC Regulatory Guid-ance and industry-consensus standards.
3.
Previously Identified Item (Closed) 25-00-13 TI - Trial Use of Water Chemistry Inspection Modules This inspection completed a series of inspections of 'he licensee's water chemistry control program which involved trial use of' two inspection procedures.
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4.
Management Controls The organization of the licensee's water chemistry control program was reviewed to determine if an effective, documented program for controlling the quality of the primary coolant water in each unit had been developed.
The licensee's Technical Specifications and UFSAR commitments governing organization, procedures, quality assurance / quality control and limiting conditions for operation regarding primary chemistry were used in this review. Guidance provided by the Electric Power Research Institute (EPRI)
Boiling Water Reactor (BWR) Owner's Group Water Chemistry Guidelines Committee, (i.e., EPRI Report NP 3589-SR-LD, April 1, 1984) was also used in the review.
4.1 Management Policies The licensee's management policies relative to the water chemistry control program were reviewed to determine if the licensee had pro-vided a management commitment to and support for, an effective water chemistry control program. The BWR Owner's Group Water Chemistry Guidelines Committee recommends that corporate management establish policies and procedures and provide the resources necessary to support and enforce those policies. The licensee's Electric Production Department established requirements and guidelines for chemistry pro-grams in " Requirements and Guidelines (R&G) No. 22, Chemistry Program,"
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Revision 1, (October 20, 1986) signed by the Vice President, Electric Production Department. Although an explicit policy statement wasn't provided in the document, it was clear that corporate management was committed to an effective water chemistry control program.
Require-ments and Guidelines No. 22 appeared to meet the EPRI Guidelines for establishment of policies and procedures and provision of resources necessary to support and enforce those policies.
4.2 Corporate Chemistry The role of the corporate chemistry group in providing technical support to the station chemistry group was briefly reviewed. The corporate chemistry laboratory participates in the Chemistry Steering Committee which meets monthly to discuss and resolve chemistry prob-lems at Peach Bottom and Limerick. The committee includes represen-tations from the two stations and Engineering (in addition to the Corporate Chemistry Laboratory personnel).
In addition, an Overview Committee meets quarterly to provide chemistry policies for the two stations.
Representatives from the Corporate Chemistry Laboratory, Engineering, Station and contracted consultants make up this second committee.
Both committees are relatively new and their activities and responsibilities are being defined. A corporate chemistry computer program is used for recording and trending plant chemistry data.
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4.3 Station Chemistry The Station Chemistry group reports to the Senior Chemist. The Senior Chemist reports through the Superintendent Operations to the Station Manager. A 1985-1986 reorganization separated the chemistry group from the Health Physics organization and changed its reporting relationship to the Superintendent Operations. This change appeared to have_ strengthened the station's chemistry operations evidenced by the attention to high purity water, trending of chemical measurements and innovative sampling / monitoring activities noted during the inspec-tion.
4.4 Procedures Selected chemistry analytical (CA) procedures were reviewed for conformance to the licensee's Technical Specifications 3/4.6.B.
" Coolant Chemistry," and EPRI NP 3589-SR-LD Guidelines. Administra-tive (A) procedures governing control of chemicals onsite, (i.e.,
A-96 program) were also reviewed and discussed with the licensee's representatives.
Within the scope of this review, the following items were noted; routine chemical sampling and analyses were provided satisfying
Technical Specification requirements; chemistry goals and actions were described in procedures which
were generally consistent with the EPRI Guidelines; and Administrative controls for and reviews of chtmicals used onsite
were provided.
4.5 Resources The inspector reviewed station chemistry staffing relative to the identified duties and responsibilities of the chemistry group. The licensee appeared to have sufficient staff to provide the necessary sampling, analysis and surveillance activities described in the licensee's procedures.
The inspector also reviewed analytical capabilities relative to the EPRI Guidelines and general Region I utilities' capabilities. The licensee appeared to have adequate sampling, in-line instrumentation and laboratory analytical capabilities. The inspector noted that new in-line conductivity cells and special crack growth monitoring capa-bilities had been added to the licensee's en tsting progra.
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4.6 Quality Assurance (QA)/ Quality Control (QC)
The licensee's program to identify and correct chemical control deficiencies was reviewed to determined if a program to identify, investigate, document, report, track, close and trend discrepancies in the water chemistry control program had been developed. The inspector reviewed the licensee's audit program (as it related to water chemistry control) under the Technical Specifications, QA Plan and UFSAR commitments.. Annual Audit No. AP86-36 HPC, "PBAPS Chemistry /
Radiochemistry Program," was reviewed. The audit covered adherence to procedural controls including control of chemical reagents, cali-bration, Technical Specification requirements and document control.
Occasional surveillances of the chemistry operation are also under-taken by the licensee's QA group.
The inspector reviewed a surveil-lance of the A-96 program completed January 13-20, 1987.
In addition, completed detailed monitoring checklists (QC inspections) were also reviewed for five (5) routine chemistry activities. Within the scope of these reviews, the licensee appeared to be implementing an effec-
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tive QA/QC program relative to water chemistry control program activities.
5.
Plant Water Chemistry Systems 5.1 Plant Descriptions Units 2 and 3 are virtually identical 3,293 MWt General Electric BWRs.
Each unit has a design power level of 1,151 MWe.
Unit 2 was issued an operating license on October 25, 1973 and began commercial operation during July 1974. Unit 3 was issued an operating license on July 2,1974 and began commercial operation during December 1974. Both units have experienced large diameter primary system pipe cracking (intergranular stress corrosion cracking or IGSCC).
Unit 2 replaced its recirculation and residual heat removal piping during a 1984-85 outage. Unit 3 is currently operating with weld overlay repairs to its cracked pipe under an NRC order requiring close control of primary water quality and shutdown for unidentified leaks exceeding two (2) gallons per minute (gpm).
Both units employe condensate filter demineralizers,1% flow '.<eactor Water Cleanup (RWCU) systems and Admiralty Brass condensers, and receive cooling water from the Susquehanna River.
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5.2 Primary Water System i
BWRs may experience water chemistry transients caused.by intrusion
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of contaminants at points relatively remote from the reactor.
Each unit's condensate system was reviewed for familiarization with major components.and to identify potential flow paths for the ingress of contaminants into the reactor feedwater. Sampling and in-line instru-mentation was reviewed for representativeness and early detection of the possible failure of condenser tubes, air inleakage through the condenser, condensate pump seals and turbine gland seals, escape of
. condensate filter demineralizer resins and organic contaminants via the radwaste system.
Within the scope of this review, no unique problems or concerns were noted.
5.3 Operation Operating schemes employed for the units' condensate filter demine -
ralizer and RWCU systems and radioactive waste (radwaste) water recycle were reviewed..The licensee discards filter _demineralizer resins on differential pressure buildup.
RWCU system resins are discarded on either conductivity or silica breakthrough.
Radwaste resins are discarded on silica breakthrough.
Both units draw their control rod drive (CRD) cooling water from processed, demineralized condensate rather than from the condensate storage tanks. This operating scheme limits ingress 1of impurities via the CRD cooling water by ensuring passage through the filter demineralizers prior to use.
Both units return feedwater (FW) heater drains to the hotwells.
Forward pumped FW heater drains have been shown to be a source of contaminants in other plants which this licensee has avoided.
The units have established conductivity, pH, total organic carbon, silica and chloride limits for radwaste water recycle to the Conden-sate Storage Tanks.
Radwaste water recycle is conditional on chemistry approval. The licensee appeared to have developed an operating scheme for radwaste water recycle responsive to concerns raised in NRC Information Notices Nos. 82-32 and 83-49 and Institute of Nuclear Power Operation (INPO) guidanc __
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5.4 Radiation Field Bui1 dup The primary long-term source of radiation fields in BWRs is cobalt-60.
The presence of high ccbalt-containing alloys (e.g.; Stellite) in'the primary system in the hard-facing alloys used in applications requir-ing resistance to mechanical wear have been associated with general radiation field buildup in BWRs.
EPRI studies have shown that valve wear is the dominant out-of-core source of cobalt and in-core cobalt sources, (i.e, cobalt alloys in pins and rollers-of BWR control blades)
contribute up to 75% of-the total cobalt-60 inventory.
Both units were reviewed for matierials of construction containing high cobalt alloys.. Both units contained control rod roller and FW control valve materials with high cobalt content.
For over 10 years, the Nuclear Steam Supply System (NSSS) vendor, (i.e. General Electric Company) and the BWR Owner's Group have col-lected data on radiation field buildup in the BWR Radiation Assessment and Control (BRAC) program.
EPRI studies have shown that the BRAC
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data could be interpreted to fall into four (4) patterns for radia-
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' tion field buildup. The licensee participated in the BRAC program and the pattern of radiation field buildup at Peach Bottom for both l
units was determined to be " generic." Generic buildup plants'are characterized by buildup curves throughout their operating years that can be mathematically described as approximating either the logarith-
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mic'or parabolic functional form.
Incorporation of soluble radio-
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isotopes from the reactor water during t h general corrosion of stain-
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les steel appears to be the controlling mechanism.
Some plants, (termed "midlife change" plants by EPRI), have demonstrated generic buildup behavior for their first several years and then, coincident in time with significant fuel failure experience, exhibited linear increases in the buildup of cobait-60 on the recirculation system piping. Although not yet proven, the behavior is thought to result from' accelerated corrosion induced by plateout of metallic copper.
Both units have Admirally' Brass condensers and filter demineralizers l
_ with copper in their FW systems and could be at risk for "midlife
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change" phenomena. Neither plant has exhibited linear increases in
radiation field buildup to date. However, the licensee did not have a systematic survey program to monitor the radiation field buildup on recirculation piping.
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The licensee electropolished the replacement recirculation pipe in Unit 2 prior to_ its installation.
The effectiveness of the treatment
in passivating the pipe has not been determined since the unit hadn't completed its first post pipe replacement cycle.
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EPRI recommends maintaining FW quality as'high as possible with parti-cular attention to minimizing corrosion product ingress during opera '
j tion.. EPRI also. recommends maintaining reactor water conductivity
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i below 0.2'microSiemen per centimeter (pS/cm).
Review of Unit 2 water data showed an improving trend on. total corrosion product inventory in the.FW and reactor water conductivities between 0.1 and 0.2-pS/cm.
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- Sampling / Measurement
'The~ licen:,ee's sampling and in-line measurement program for. determining possible chemical contaminants in high purity reactor water and systems supplying makeup and cooling water was reviewed relative to commitments in the UFSAR,. justifications.for Unit 3 operation with cracked pipe and industry-consensus recommendations and guidelines, (e.g., EPRI Guide-
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lines and American Society for Testing and Material (ASTM)). The review te included frequency of surveillance of control room monitors and process
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' monitoring stations, sample stream temperature control, quality control
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of.in-line instrumentation accuracy, acceptance and correction criteria
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l for conductivity measurements and the ranges of in-line instrumentation.
6.1 Routine Sampling:
Sample panels for Units 2 and 3 were ot, served and discussed with' the
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licensee. The inspector noted that the sampling design was consist-j-
ent with 1970's vintage plants reflecting guidance from ASTM of that era. As mentioned earlier, the licensee was replacing conductivity cells with improved conductivity instruments with better temperature control and/or compensation.
Hotwell leak detection panels were also
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observed and discussed with the licensee. Continuous flow was noted
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ensuring " representative" sampling for the sample panels.
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Within the-scope of this review, no concerns were noted. The licen-
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see appeared to have provided an adequate sampling program.
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comparison of in-line instrumentation and laboratory instrumentation was a licensee-identified weakness which was being corrected.
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6.2 CAVS Units
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Following approximately seven (7) years of development, the NSSS vendor offered a Crack Arrest Verification System (CAVS). The CAVS
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was designed to monitor BWR structural components. Tha CAVS consists
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of a set of fracture mechanics specimens enclosed in an autoclave that is attached to the recirculation system (or other systems to be monitored) by a sample line. The specimens, designed to be represen-tative of structural components, (e.g. 304 or 316 stainless steel)
are monitored for crack growth. Crack growth increments of approxi-mately 1E-3 inches can be detected and crack growth rates of approxi-mately 1E-6 inches per hour can be monitored. The CAVS is coupled
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with simultaneous water temperature, conductivity, dissolved oxygen, pH and electrochemical potential (ECP) measurements. The licensee
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installed a CAVS unit in Unit 3's recirculation line to monitor the (
behavior of the cracked recirculations inlet safe ends and to provide data to show that the incremental crack growth was similar to or less than that. predicted by analysis.
Additional CAVS units were being used to monitor Unit 2 crack growth before and after the introduction of hydrogen water chemistry on i
Unit 2.
Two CAVS units were in place during the inspection, (i.e.,
Recirculation and RWCU water) and a third, (i.e. feedwater system)
was being installed.
Pending NRC-NRR approval, hydrogen water chemistry (HWC) has been planned for introduction on Unit 2 to
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growth rates before and after HWC initiation.
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Implementation
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The licensee's implementation of the water chemistry control program was reviewed relative to Technical Specifications, commitments in support of Unit 3's continued operation and recommendations and guidance in NRC Regulatory Guides, NRC Information Notices and industry consensus standards.
7.1 Surveillance Activities Reactor coolant chemistry surveillances under Technical Specification 3/4.6.B were reviewed for selec'
months during the period 1984-86.
General chemistry sampling and ana' lysis records were also reviewed.
The inspector noted that Unit 3 had experienced reactor water conduc-tivities exceeding the Technical Specification limit of 10 pS/cm on September 14, 1986 and October 30, 1986.
Licensee Event Reports (LERs) No. 3-86-19 and 3-86-22 were issued for those occurrences and the LERs were reviewed in NRC Combined Inspection Report Nos. 50-277/
86-19; 50-278/86-20.
Both events occurred as condensate filter demineralizers were returned to service following maintenance activi-ties and the probable cause was the introduction of resin into the primary system. As a result of the September 14, 1986 event, the licensee modified procedures to flush condensate filter deminera-lizers prior to returning the unit to service. As a result of the October 30, 1986 event, the licensee added visual inspection, (i.e.,
"boroscopic" examinations), to procedures to further reduce the likelihood of resin introduction.
The actions appeared responsive to minimize resin " hideout" in condensate filter demineralizers.
Reviews of routine sampling and analysis activities showed that the licensee was implementing an effective sampling program in conformance with licensee procedures.
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10 7.2 CRUD-Induced Localized Corrosion (CILC)
Since 1979, fuel cladding corrosion failures at some BWRs have been associated with heavy plant corrosion product (CRUD) scale deposits with high copper concentrations. These crud-induced localized corro-sion (CILC) failures have been limited to plants with copper alloy condenser tubes and filter demineralizer condensate cleanup systems.
Unit.3 experienced fuel failures in 1984-85 causing a reduction in power to about 90% to reduce high offgas release rates.
Examinations during the 1985-86 outage showed that approximately 40 bundles showed evidence of corrosion failures.
The licensee's program to minimize the risk of fuel failures was reviewed. Trends of copper levels in the FW system and in the reactor coolant were reviewed for both units. Copper levels appeared generally consistent with fuel. warranty
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requirements. The licensee also had acquired fuel especially manu-factured to minimize the risk of corrosion-induced failure. General corrosion buildup was also being monitored, trended and controlled.
These actions by the licensee appeared to be responsive to minimize concern over CILC failures.
7.3 Turbine Corrosion Review of licensee examinations of the low pressure turbines (LPT)
during the 1984 Unit 2 outage and the 1985 Unit 3 outage showed no objective evidence of LPT problems resulting from carry over of corrosive materials in the Units' system. Deposits were not noted at the wet-dry zone, (i.e. " Wilson Line) and no evidence of corro-sion cracking was noted on buckets and wheels.
7.4 Chemical Control Program Review of the chemical / material control program (under Administrative Procedure No. 96) showed that the licensee had established a program controlling the purchase, issue, use and disposal of potentially harm-ful chemicals and materials. Spot checks of chemicals found in use in the two units showed that those chemicals had been evaluated prior to issue by the chemistry group.
7.5 Valve Maintenance Procedures EPRI studies have shown that lapping and grinding hard-fm sd valve seats can contribute 10% of total cobalt input from debris left after standard cleanup procedures are completed.
EPRI indicated that post-maintenance cleaning procedures can effectively remove the debris.
Although visual QC inspections of valve internals following mainte-nance is required by the licensee, special procedures to ensure reasonably complete retention and removal of debris were not included in valve maintenance procedures.
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Exit Interview-The' inspector met with'the 1tcensee's' representatives (denoted in Detail 1) at the conclusion of the inspection on January 30, 1987.
During
- the meeting, the inspector summarized the purpose and scope of the inspec-tion and identified findings as' described in this report.
At no time during this inspection was written material provided to the licensee by the inspector. No information except from disclosure under 10 CFR 2.790 is discussed in this report.
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