IR 05000295/1989020

Insp Repts 50-295/89-20 & 50-304/89-18 on 890619-0714.No Violations Noted.Major Areas Inspected:Liquid & Solid Radwaste Mgt & Transportation Programs,Including Organization & Mgt Controls & Compliance w/10CFR61

ML20248D740
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	07/28/1989
From:	Gill C, Slawinski W, Snell W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20248D716	List: IR 05000295/1989020 ML20248D714
References
50-295-89-20, 50-304-89-18, NUDOCS 8908110124
Download: ML20248D740 (16)

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U. S.I UCLEAR N REGULATORY COMMISSION

REGION III

l Reports No. 50-295/89020(DRSS); 50-304/89018(DRSS)

-Docket Nos. .50-295;:50-304 ' Licenses'No..DPR-39; DPR-48 Licensee: Commonwealth Edison.Compa'ny Post Office Box 767 Chicago, IL 60690 Facility.Name: Zion Nuclear Power Station, Units 1 and 2-Inspection At: Zion Station, Zion, Illinois I

Inspection Conducted: Jc'1e 19 through July 14, 1989

. Inspectors:- . W. J. Slawinski N~ '

~l-Af-89 Date n C. F. Gill I 7/L8/89 Date Approved By:

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W. Snell, Chief 7/2s/ Radiological Centrols and Date Emergency Preparedness Section Inspection Summary Inspection on' June 19 thr) ugh July 14., 1989 (Reports No. 50-295/89020(DRSS);

No. 50-304/89018(DRSS))

Areas Inspected: Poutine, unannounced inspection of the gaseous, liquid and'

solid radwaste management and transportation programs, including: organization, management controls and trtining (IP 83750, 84750, 84850); gaseous radwaste (IP.84'50); liquid radwaste (IP 84750); solid radwaste including compliance with waste generator requirements of 10 CFR 61 (IP 84750, 84850); radioactive material /radwaste snipping and transportation activities (IP 83750,84850);

an4 audits and appraisals (IP 83750,84750,84850). Also reviewed were

- outstanding items and circumstances related to unplanned releases of gaseous effluent during.CVCS demineralized servicing activities (IP 93702).

Results: The organizational structure staffing and management controls and support for. the radwaste and transport M Ion pr grams appear adequat Overall, the licensee's program for controlling / processing solid radwaste and liquid and gaseous effluents appear generally effective. Nu violations were

8908110124 ADOCK O'500029D, 890801 PDR o PDC

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identified;': however, hcensee identified procedural and training weaknesses -

were'noted in' quantifying unplanned gaseous effluents and a weakness was perceived by the inspectors in QA staff training. Inspector concerns'were also'noted with waste classification methodology and continue to exist for

. operability of process / effluent control instrumentatio .

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L DETAILS Persons Contacted D. Cole, Health Physicist

• K. Garside, Radwaste Shipment Coordinator

• G. Gear, Water Management Supervisor

C. Greaves, Technical Staff Engineer l D. Hemmerle, Lead Chemist

+*G. Kassner, Lead Health Physicist

+P. LeBlond, Assistant Superintendent, Operating R. Palatine, Health Physicist

• Peterson, Regulatory Assurance

• J. Rappeport, Quality Assurance

• T. Rieck, Superintendent, Technical Services

+M. Vincent, Corporate Radwaste Staff J. Winston, Quality Control J. Smith, NRC Senior Resident Inspector

• Denotes those present at the site exit meeting on June 23. 198 + Denotes those contacted by telephone between July 14-17, 198 . General This inspection was conducted to review the licensee's radwaste/

radioactive material shipping and transportation program and liquid, gaseous, and solid radwaste management programs including compliance with waste generator requirements of 10 CFR 20 and 10 CFR 61. The radiological and health physics aspects of unplanned gaseous releases that occurred in May 1989 were also reviewed. The inspection included tours of the radwaste facilities, observation of work, review of representative records, and discussions with licensee personne . Licensee Action on Previous Inspection Findings (IP 92701)

(Closed) Open Items (295/85040-04; 304/85041-04 and 295/88020-04; 304/88020-04): The former item refers to an issue identified in the Brookhaven National Laboratory Technical Review Report concerning inadequate backup analysis and documentation for the licensee's Interim Radwaste Storage Facility (IRSF) 10 CFR 50.59 evaluation. According to the licensee, an appropriate safety analysis was conducted and is sufficHntly documented for the IRSF project to satisfy the requirements of 10 CFR 50.59. The licensee, however, has not produced documentation and related calculations to show that the IRSF facility design and operation would assure that the radiological consequences of design basis events would not exceed 10% of 10 CFR 100 dose limit _ _ _ _ _ _ . - _ _ _ _ _ _ _ _

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The latter item refers to development of a radiation monitoring program to' monitor sump runoff and airborne conditions in the IRSF during storage of low-level radwaste. Relevant radiation monitoring procedures have been drafted but not submitted for onsite review. The licensee plans to submit a. letter to Region III requesting that further action for these

' open items be held in abeyance because the IRSF is not used nor does the licensee anticipate its use as a radwaste storage facility; the licensee plans no further action for these items at this time. The resolution of these matters will be. tracked as a new itnm pending receipt of notification from the licensee concernira future use of. the facilit (0 pen Item 295/89020-04)

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(Closed) Open Items (295/87022-01; 304/87022-01): Review process and effluent monitor generic operability problems. The licensee contracted the services of a consultant to review the station's process and effluent monitoring system. The consultant's findings, recommendations, and proposed licensee actions are described in Inspection Reports No. 295/89018(DRP); 304/89017(DRP). This matter continues to be of

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concern, remains open and is being tracked under an open item documented-o in the aforementioned inspection repor (Closed) Open Items (295/88020-01; 304/88020-01): Review circumstances surrounding an apparent 500-curie noble gas release from the turbine

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building in May 1988. A 500-curie noble gas (xenon-133) release was quantified from a single routine turbine building gas grab sample collected on May 31, 1988. However, the licensee suspects that the elevated xenon-133 cor. centration identified in the grab sample was produced by high (and fluctuating) background levels in the chemistry

counting laboratory at the time the sample was. counted and did not represent turbine building concentrations. The high background in the counting lab was. attributed by the licensee to boric acid tank leakag Contrary to that previously documented (Inspection Reports No. 295/88020; 304/88020), containment was not vented concurrent with grab sample collection. To correct lab background and related counting problems, the licensee inaugurated a procedure to better track / trend laboratory background and provide enhanced background subtract method (Closed) Open Item (295/88020-02; 304/88020-02): Review status of proposed modifications to install a " seal-in" function on the Unit I discharge canal process radiation monitor (ORT-PRO 5). Based on a recent contractor evaluation of the licensee's process and effluent t

monitoring system, the licensee is considering replacement of the Unit 2 discharge canal monitor (ORT-pR04) with a new monitor similar to Unit 1, and subsequent installation of the " seal-in" function and enhanced flush capability for both monitors. The status of this new proposal will be reviewed during a future inspectio (0 pen Item 295/89020-05)

(Closed) Violations (295/89005-01; 304/89005-01 and 295/89005-02; 304/89005-02): Four Department of Transportation violations for unrelated November 18, 1988 shipping / transportation problem Corrective actions described in the licensee's April 25, 1988 (Natice of Violation)

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4. Organ?zation, Management Controls and Training (IP 83750,84705,8485Q The inspectors reviewed the licensee's organization and management controls for the radwaste and shipping / transportation programs, including: organizational structure and staffing; delineation of I

authosity; management techniques used.to implement the program; and experience concerning self-identification and correction of program implementation weaknesses.

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The organizational structure and staffing for the radwaste operations 5 staff remains essentially as previously described (Inspection Reports N /88020(DRSS); 50-304/88020(DRSS)); the (non-licensed) shift foreman staff remains at five and the radwaste engineering assistant vacancy has been filled. Equipment attendants continue to operate.the radwaste processing systems and report to the (non-licensed) shift forema Radwaste foreman are directly responsible for radwaste shipment preparation and packaging, the waste water treatment plant, and the make-up demineralized system. All radwaste systems are operated by the licensee with the exception of the contractor owned / operated dewatering and solidification equipment. The processing of " wet" solid wastes is, however, supervised by the licensee's radwaste staff. The radiation protection and chemistry staffs are responsible for waste classification, sampling / analysis and completion of shipment documentation. The individuals and organizational entities assigned the responsibility for radwaste management and transportation are procedurally designated and apoear properly delineated. The organization and management controls for the radwaste and transportation programs appear adeq' at TI; inspectors verified that designated radwaste technical staff members attend continuing training to maintain competence in waste processing, packaging and shipping. In 1989, the radwaste shipment foremen attended a three-day "Radwaste Packaging, Transportation, and Disposal" course presented by a waste disposal vendor at the licensee's Production Training Center. A similar course was attended by this individual in 198 Review of the 1989 course manual and discussions with the licensee disclosed the training to be comprehensive. The course also appears beneficial for other station personnel involved in transportation, waste solidification and related activities including health physics and QA/QC staff l l

l Health physics and licensed staff training weaknesses in properly quantifying and classifying unplanned gaseous release events are ]

described in Section 1 No violations or deviations were identifie , Gaseous Radioactive Wastes (IP 84750)

The inspectors reviewed the licensee's gaseous radwaste management j program, including: changes in equipment and procedures; gaseous '

radioactive waste effluents for compliance with regulatory requirements; adequacy of required records, reports and notifications; process and effluent monitors for compliance with operational requirements; and i

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experience concerning identification and correction of programmatic weaknesses. The station's process and effluent monitor operability problems cantinue and are further described in Inspection Reports No. 295/89018(DRP); 304/89017(DRP).

The licensee's gaseous radwaste processing systems, control mechanisms and effluent release paths remain as previously described (Inspection Reports No. 295/87022(DR5S); 304/87023(DRSS)). The majority of gaseous effluents are from batch type releases resulting from release of waste gas decay tanks and from containment vents and purges. The inspector f selectively reviewed gaseous effluent release records and sampling / 1 analysis data for 1989 to date and semi-annual effluent reports and 1 effluent summary / trending data for 1986 to date. There were sever gas decay tank batch releases in 1989 to dat Sampling.and analysis methods 1 appear to meet technical specification requirements; no problems were noted with these batch releases. Unplanned gaseous releases occurred on May 8 and 9, 1989 and are described in Section 1 Semi-annual effluent reports generally show a gradual reduction in the total noble gas effluents since 1985 when about 3800 curies was released. In 1986 and 1987, about 3200 curies and 120 curies was released, respectively. The decrease in 1987 was attributed by the licensee primarily to reactor unavailability, when each unit underwent approximately 3-4 month outages, and to the continued lack of significant fuel and primary to secondary leakage problems. In 1988, nearly 1400 curies were released includira about 500 curies attributed to a single turbine building release in May 1988 (Section 3). In the first half of 1989, about 960 curies of noble gas was release No violations or deviations were identifie . Liquid radioactive Waste (IP 84750)

The inspector reviewed the licensee's liquid radwaste management program, including: liquid radioactive waste effluents for compliance with regulatory requirements; adequacy of required records, reports, and notifications; process and effluent monitors for compliance with operational requirements; and experience concerning identification and correction of programmatic weaknesses. Modifications planned for the two lake discharge tank effluent radiation monitors are described in Section The licensee liquid radwaste system and processitig methods, instrumentation, controls, and release paths remain essentially as previously described (Inspection Reports No. 295/87022(DRSS);

304/87023(DRSS)).

The inspector selectively reviewed radioactive liquid batch release sampling and analysis records for 1989 to date and liquid effluent 1 summary and trending data from 1986 to date. Pre- and post-batch release l l sampling and analysis appear to comply with Technical Specification {

requirements. About 200 lake discharge tank batch releases were made j in 1989 through mid-June; no instance of a release approaching Technical '

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" Wet" solid wastes are either solidified or dewatered onsite by a i

vendor. Class.B and C (radiologically " hot") spent resins and filter sludges are cement solidified by the vendor and shipped to burial sites in large capacity liner Bead resins and activated carbons are dewatered by a vendor and shipped in high integrity containers (HICs). . Wet solid waste burial volumes totalled i

about 4,500 cubic feet in both 1987 and 1988, composed primarily of dewatered resins. In 1989 through May, about 1700 cubic feet of l solidified /dewatered wastes were shipped to low-level waste burial l' site b. Process Control Program (PCP)

Waste stabilization operations are conducted by a vendor in accordance with NRC (generically) approved vendor solidification / dewatering topical reports. The processes are implemented by plant specific vendor PCP procedures that have been approved through the licensee's onsite review process. The operations are conducted under the licensee's supervision using vendor personnel and equipment. The inspector's reviewed the vendor's PCP implementing procedures for dewatering bead type ion exchange resin and activated carbon and for operation of the vendor's cement solidification system. Procedure acceptance and sampling criteria appear consistent with 10 CFR 61 and applicable commi:,sion branch technical position papers. QC hold points contained in the PCP procedures were discussed with a station QC inspector. Inclusion of QC hold points appears to be a good practic No significant problems were identified with implementation of either PCP procedur c. 10 CFR 61 The inspectors reviewed the licensee's solid radwaste program for compliance with waste generator requirements of 10 CFR 20.311, 61.55 and 61.56. This review included examination of waste manifests, waste classification and stabilization methods /

procedures, and the station's QC program to meet 10 CFR 20.311(d)

requirements. The QC program is discussed in Section Except as noted below, the licensee determines radionuclides concentrations in specific waste streams by direct measurement and by inferential measurement whereby concentration of radioisotopes which cannot be readily measured are projected through ratioing to concentrations of radioisotopes which can be measured. For gamma emitting nuclides, waste classification is determined directly by licensee (in-house) isotopic analysis of actual waste strear. samples collected from each batch of lic,uid system waste prior to solidification or dewaterin Certain isotopic concentrations which cannot be readily measured by gamma spectral analyses, such as pure beta emitters, are calculated using vendor derived scaling factors ratioed to concentrations of gamma emitting nuclides that are measured by the licensee. The scaling factors are derived by a vendor from analysis of plant specific waste streams, normally

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l collected by the licensee and submitted to the vendor on an annual basis. However, unlike the application of beta emitting nuclide scaling factors, alpha emitting transuranic nuclide waste stream contributions are determined ;:ing the latest vendor analyses without rationing to cor.centrations of radioisotopes that are measured by the licensee. The inspector expressed concern that transuranic concentrations cannot necessarily be assumed to reiaain constant from waste batch to batch and can be altered by reactor operations. The licensee was unsure of the. uncertainties and reliability at ociated ith vender derived tran: uranic scaling factors and committed to evaluate their current methodology for determining transuranic concentrations and develop enhanced waste classification methods, if deemed appropriate. According to the licensee, transuranic nuclides do not normally affect the waste classification to any significant extent. This matter was discussed at the site exit meeting and in telecons with the licensee on July 14 and 17, 1989 and will be reviewed further during future inspection (0 pen Item 295/89020-01)

Waste classification is determined by a station health physicist using Station Procedure ZPR 1430- The procedure was reviewed by the inspectors and found to be consistent with 10 CFR 61.55, except as noted above. Waste classification calculations for selected 1989 shipments were reviewed for accuracy and adherence to the procedure; no problems were identified. Waste ranifests for radwaste shipments made in 1989 to date were selectively reviewed and appear to meet 10 CFR 20.311 requirement The licensee has generated Class A, B and C wastes. The majority of waste, however, is Class A waste shipped to burial sites as solidified stable waste or dewatered waste stabilized in H1Cs. The HICs currently used by the licensee to provide waste stability pursuant to 10 CFR 61.56 were verified by the inspectors to be approved by the burial site state, or that state issued certificates of compliance were maintained by the licensee as appropriat No violations or deviations were identified; however, one unresolved item was note . Transportation of Radioactive Material and Radwaste (IP 83750, 84850)

The inspectors reviewed the licensee's transportation of radioactive materials program, including: determination whether written implementing procedures are adequate and acceptably implemented; determination whether shipments are in compliance with NRC and DDT regulations and the licensee's quality assurance program; determination if there were any transportation incidents involving licensee shipments; adequacy of required records, reports, shipment documentation, and notifications; and experience concerning identification and correction of programmatic weaknesse ______ _ __ - _- _ - _ N

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The radiation protection / health physics staff coordinates all radioactive material and radwaste shipments, performs package and vehicle surveys, determines waste classification, curie content, and adequacy of shipping L papers and package marking / labeling. The radwaste operations. staff and'

radwaste. shipment. coordinator prepare- and package all radwaste shipment The warehouse / stores group is responsible for transportation arrangements and package transfers involving miscellaneous limited quantity radioactive r

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material shipments and those shipped common carrier that do not require vehicle placarding or special loading arrangements. Station QA/QC reviews all' outgoing shipments for ccepliance with selected procedures and DOT requirements, In.1988, the licensee made about 75 radioactive material and about 35 radsaste shipments. The radwaste shipments consisted primarily of dewatered or solidified (Class A stable) resins transferred to the Barnwell,. South Carolina disposal site. Cumulative radwaste burial volumes shipped to low-level waste disposal sites in 1988 was about 11,500 cubic feet. In 1989 to date, about 38 radioactive material and 16 radwaste shipments were made. The 1989 radioactive material shipments consist primarily of protective clothing sent to a laundry vendor and shipped as LSA material.in large." strong tight" metal bins. Cumulative-radwaste burial volumes shipped to low-level waste disposal sites in 1989 through May is about 5,500 cubic fee Previous radioactive material transportation problems experienced by the licensee are described in Inspection Reports No. 295/89005(DRSS);

304/89005(DRSS). Corrective actions for these problems are described in the referenced report and Section 3 of this report. According to the licensee, no significant problems have been identified with their radwaste shipments to low-level waste burial sites within the last several year No violations or deviations were identifie . Audits and Appraisals (Ip 83750, 84750, 84850)

The inspectors reviewed reports of radwaste and transportation program audits and surveillance conducted by the licensee including audits l required by Technical Specifications. Also reviewed were management techniques used to implement the audit programs, and experience concerning identification and correction of r, programmatic weaknesse In addition to inspections of each outgoing radioactive material /radwaste shipment, the licensee's QA department conducts annual audits of the station's radwaste and transportation program and at least quarterly surveillance of various radwaste activitie Technical Specification required audits of the PCP and implementing procedures for solidification of radwaste are normally included in the annual radwaste/ transportation program review. QC audit requirements of 10 CFR 20.311(d) appear to be satisfied by- the annual radwaste program audits and quarterly activity surveillanc !

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The last station QA audit of the radwaste/ transportation program was conducted on November 23 through December 1, 1988. The purpose of the audit was to verify implementation of the station's QA program related to radwaste and included review of radioactive material and radwaste shipment records and aspects of vendor radwaste solidificatio activities and compliance with waste generator requirements of 10 CFR 6 No significant problems / concerns were identified in the audit report; howeser, inspector concerns associated with the depth of this audit and auditor training were noted and are described belo The inspectors reviewed the station QA organization and QA auditor experience / training related to radiation p otection/radwaste. The station currently has 11 auditors including the QA supervisor. Of these 11 auditors, six ore considered qualified to audit radwaste program areas; however, none of the auditors appear to possess extensive radiation protection /radwaste experience at an operating plant. The radwasta auditor qualification requirements consist of informal, primarily on-the-job training in selected aspects of titles 10 and 49 of the Code of Federal Regulations and one year assignments at an operating station with some experience in radioactive material shipment and solidification activities or on-the-job participation in two radioactive material vehicle inspections and surveillance and one radwaste audit. Inspector review of the report and auditor field notes for the previously discussed annual radwaste/ transportation program audit revealed an apparent weakness in auditor experience / qualifications related to 10 CFR 61 program area The review of waste stability compliance status appeared superficial and not properly directed indicating apparent auditor experience and/or training deficiencies. The desirability to enhance auditor training in radwaste generator program areas was discassed at the exit meetin The inspectors reviewed records of selected radwaste surveillance conducted in 1988 and 1989 to date and discussed the surveillance program with several QA auditors. The 1988 surveillance consisted primarily of radwaste and radioactive material shipment observations and review of related records; no significant problems were identified during these surveillanc In 1989, QA surveillance have expanded to include in process observation of radwaste solidification / dewatering activities using a revised surveillance checklist that includes verification of waste classification calculations and test documentation to demonstrate waste stability pursuant to 10 CFR 61.56. The licensee is encouraged to continue these expanded surveillanc No violations or deviations were identified by the inspecto . Unplanned Gaseous Effiuent Release Events (IP 93702)

On May 8 and 9,1989, unplanned but monitored gaseous effluent releases occurred during Chemical Volume and Control System (CVCS) mixed bed demineralized (MBD) resin fill and return to service operations. Details are described below and focus on the radiological aspects of the event The operational and maintenance aspects of these events are described in Inspection Reports No. 295/89015; 304/8901 _-____ _ - - - - -

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, Event No'. 1 On May 8, 1989 at approximately 0945 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.595725e-4 months <br />, operating radwaste ;

personnel prepared to fill the 1A CVCS MBD with resin. Pursuant to station Procedure 501-70, the IA MBD-inlet and outlet valves were closed and: tagged out-of-service and its vent and drain valves were

, opene Upon opening the vent and drain valves, the auxiliary building vent stack monitor (0RE-0014) alarmed high in the control ~

-room and a decrease in the U-1 VCT level was noted. By about 0955, the licensee determined the probable cause of the problem to be leakage through the MBD inlet and/or outlet valves, thereby allowing RCS letdown wat.er to enter the bed and escape through its vent and drain valves. Immediate actions were taken in accordance with Procedures A0P 1.1, " Excessive RCS Leakage" and A0P 5.1,!High Radiation Alarms," including closure of the vent and drain valves and securing the auxiliary building exhaust and supply fans to reduce vent stack flow. The leakage, therefore, was isolated after about ten minutes and the licensee estimated that 200-300 gallons of RCS-letdown water was released to the auxiliary building. At about 1005 hours0.0116 days <br />0.279 hours <br />0.00166 weeks <br />3.824025e-4 months <br />, process monitors for the U-1 pipe chase and auxiliary building vent monitors downstream of ORE-0014 alarmed high. The auxiliary building was subsequently evacuated and declared an exclusion-area. ~ Radiation protection personnel validated the alarm and took local samples in accordance with A0P 5.1. Gas samples were taken in the Unit 1 VCT room, on the til7' elevation Aux Building general _ area, and on the 642' elevation Aux Building level (in the vicinity of Monitor ORE-0014). At 1100, additional samples were taken on the Aux Building Vent Monitors 1RT and 2RT-PR25, and on the particulate and iodine. monitors for Aux Building flow, 10PR038 and=20PR038 . Two radiation protection technicians (RPTs) working in the containment spray pump cubicles were externally contaminated by noble ga The RPTs were given whole body counts and were found to have no significant intarnal depositions. The release was quantified by the station's health physics staff and showed that the maximum instantaneous release rate initially exceeded the threshold for a GSEP Alert classification but thereafter decreased to a rate commensurate with an Unusual Even However, the initial release rate calculations were later discovered by the licensee's HP shff to be inaccurate and the actual release rate never exceeded the threshold for Unusual Event classification. An Unusual Event was initially declared at 1111 hours0.0129 days <br />0.309 hours <br />0.00184 weeks <br />4.227355e-4 months <br /> and terminated at 1245 after the calculational error was discovere Root Cause(s)

The uncontrolled release was apparently the result of RCS letdown leakage through the MBD inlet and outlet valves and subsequently tnrough the open 1A MBD vent and drain valvas. This pathway leads to the auxiliary building equipment drain tank and ultimately provides a path for gasses through the vent stacks. The station's maintenance department is in the process of determining the cause of the leakage and repairing the valve _ _ _ _ _ _ _ - _ _ - _

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The error in calculating the release rate was caused by misapplication of the GSEP noble gas release calculation procedure (EPIP 350-1). Details concerning quantification of tha release are described in the " radiological aspects" subsection below. An additional problem was identified by the licensee in implementing procedure (AOP 1.1), which requires releases to be classified using the EPIP procedure based on the instantaneous release rate; however, neither procedure provides adequate guidance or designates responsibility for release quantificatio Although station practice has generally been for the HP staff to perterm the calculation., the licensee considers this unacceptable for timely classification of the even Radiological Aspects of Event As documented above, release rate calculation errors were caused by misapplication of the calculation procedure (EPIP 350-1) which represents vent stack flow rates in units of cc/second. The health physicist performing the calculation used the EPIP procedure in conjunction with another work sheet which is based on the procedure but is not approved and is intended for use in a different application. This work sheet uses a value for stack flow rate in cc/ minute (rather than cc/second) and was erroneously applied to the EPIP procedure. Also, the work sheet assumes a (conservative) 100% xenon-133 isotopic mix instead of the EPIP recommended xenon-133/ krypton-85 90%/10% mix, this introduced an additional overestimate in the release calculatio The maximum instantaneous release rate at about 0945 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.595725e-4 months <br /> was initially calculated at 174 E6 uti/second which (minutes later)

reduced to 1.37 E5. This maximum release rate exceeded the threshold for an Alert Classification, the latter rate was below the Alert level but above the Unusual Event level. About 30 minutes later, the HP staff discovered the calculational error and recalculated the release based on measured stack flow rates and a more repr.esentative isotopic mix. The recalculation showed that the maximum instantaneous release rate was 4.14 E3 uC1/second, below the Unusual Event threshold. After terminating the event, health physics personnel used an isotopic analysis of reactor coolant samples from that morning to verify accuracy of the isotopic mix and release rate estimate. The release rate was quantified at 0.01% of 10 CFR 20 (Technical Specification) dose limits for iodine and 4.67% of 10 CFR 20 limits for noble gases. The total activity released during the event was 9.6 curies. The release quantification methods, assumptions and calculations were reviewed by the inspectors and appeared correc The inspectors also reviewed the station's radiological response to the event including evacuation of the auxiliary building and selected aspects of the routine and emergency air sampling progra No significant problems were identified with the licensee's radiolnaical response to the even !

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Corrective Actions The corrective actions taken or planned by the licensee for this event are as follows:

(1) HP staff tailgate sessions have been held to review proper release quantification methods using the current EPIP procedur (2) Revise the A00 procedure to designate responsibility for assessing and classifying abnormal release (Targeted for

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completion by September 1989)

(3) Revise Procedure JPIP 350-1 to simplify release quantification method (Targeted for completion by September 1989)

(4) Train licensed shift supervisors and the health physics staff on the use of EPIP 350-1. The lead health physicist plans to assist the site training department in development of lessen p' as for the HP staf (Targeted for completion by

ptember 1989)

(5) The licensee's corporate emergency preparedness group plans to investigate release rate quantification methods implemented at other Commonwealth Edison Stations and provide guidance for event classification.

) (6) Consider providing operations with an appropriate correlation between radiation monitor count rate and effluent release rate (under worst case flow conditions) to provide upper bounds to ensure tnat initial release rate estimates are reasonabl The radiological aspects of this event including the corrective actions delineated above were discussed at the site exit meeting and in telecons with the licensee on July 14, 1989. The implementation status of the corrective actions will be reviewed during a future inspectio (0 pen Item 295/89020-03)

b. Event No. 2 On May 9,1989, operating personnel were precaring to return the IB MBD to service folicwing the unplanned release on the previous day. Both the 1A and IB demineralizers had been isolated from the RCS letdown since the May 8 event by closure of the cation bed bypass valve and placement of the three-way demineralized bypass valve in the divert position. The 1A bed was out of service and empty at this time and its inlet and outlet valves were closed and l

known to be leaking since the May 8 event. However, to facilitate maintenance repairs, the 1A bed's vent and drain valves were open.

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At 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />, operating personnel performing the partial clear opened the cation bed bypass valve and the IB MBD outlet valve to allow letdown flow into the B bed; however, this sequencing also established a flow path from the RCS letdown to the 1A MBD

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(through its leaking valve (s)) and cut this bed's drain / vent valves to the auxiliary building equipment drain _ tank which

. ultimately vents to the vent stack. This was the same release path

. as the previous day. This caused a decrease in VCT level and an l

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increase in activity detected by Aux Building Vent Stack Monitar ORE-001 At 1705, the shift foreman (SF) involved in the operation contacted the control room and was told that all indications looked norma The decrease in VCT level had been expected as a result of opening the IB MBD cutlet valve. The control room was unaware at this time that the 1A MBD vent and drain valves were still open. The SF then closed the 1A MBD vent and drain valves, per the partial clear; concurrently, the unit operator initiated makeup flow to restore VCT level. At this time, VCT recovery was reportedly more rapid than expected and in order to return the unit to a presumably safe configuration, operating personnel decided to return all valves to their original out-of-service lineu This was done at about 1715 hours0.0198 days <br />0.476 hours <br />0.00284 weeks <br />6.525575e-4 months <br /> and involved closing the cation bed bypass and IB MBD outlet valves, and opening the 1A MBD vent / drain valve When the vent and drain valves were opened, the vent stack monitor alarmed high. This alarm was caused by the release of gasses from the draining /ventirg of RCS water which had collected in the 1A MB Subsequent planned flushing, draining and venting of the 1A bed later that day, in preparation for inlet / outlet valve repairs, produced further (but controlled) release The health physics staff quantified the maximum instantaneous release rate dering all evolutions on May 9, 1989 at 3.92 E3 uCi/sec. The licensee's release calculations and assumptions were reviewed by the inspectors and appeared correct. Total noble gas activity released during the May 9 evolutions, which began at 1710 hours0.0198 days <br />0.475 hours <br />0.00283 weeks <br />6.50655e-4 months <br /> and ended at about 2300, was 4.7 curies. No technical specifications dose limits were approached as a result of the May 9, event ,

Root Cause and Licensee Corrective Actions The unplanned release appears to have been caused by a combination of inadequate job planning and communications during the return to service operations. The job plan for the partial clear of the MBDs did not include proper actions (i.e.,' valve sequencing) to ensure '

that the 1A bed's vent drain alves were closed'before unisolating the beds. Also, the possibility of backfi,lli.ng the 1A b'ed by~ reverse flow though its leaking outlet valve was not addressed in the job plan. Although radio communications were apparently

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established between the operating shift foreman (working in the auxiliary building at the valve panel) and the control room, the communications were inadequate in that the control room operators were not aware of specific valve positions throughout the evolutio Corrective actions taken or proposed by the licensee are as I follows: 1 (1) Revise station administrative procedures to require that specific sequencing be addressed in job plans when executing clearing operation (2) Revise relevant station procedures (S01-70) to add caution statements to alert operators to the potential for unplanned effluent releases during evolutions involving MBD (3) Conr:uct tailgate ussions with operations and maintenance staffs to discuss the specific problems related to the event anc the potential for releases during other similar evolutior The operations and maintenance aspects of these events has been reviewed by the Zion NRC Resident Inspectors Office and is described in Inspection Reports No. 295/89015(DRP); 304/89015(DRP); one violation related to this event was identified in the repor No violations or deviations concerning the radiological response to this event were identified by the inspectors. Several weaknesses were identified by the licensee as described in Section 10(a).

1 Exit Meeting (IP 30703)

The inspectors met with licensee representatives (denoted in Section 1)

at the conclusion of the onsite inspection on June 23, 1989 and further discussed the May 8 and 9 gaseous effluent release events (Section 10)

in telecons with the licensee on July 14, 1989. The inspectors summarized the scope and findings of the inspection and discussed the likely informational content of the inspection report with regard to documents and processes reviewed by the inspectors during the inspection. The licensee did not identify any such documents or processes as proprietar The following matters were discussed specifically by the inspectors: Inspector concern regarding the methodology for low-level wast'

classification involving transuranic nuclide (Section 7) Inspector concern regarding station QA auditor radwaste/ health l

physics experience and training. (Section 9) The radiological aspects associated with the unplanned gaseous effluent releases on May 8 and 9,1989 and the status of corrective actions for the licensee identified training and procedural l weaknesse (Section 10) Continued inspector concerns with process and ef fluent monitor operabilit (Section 3)

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