IR 05000304/1984017
| ML20127A536 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 06/14/1985 |
| From: | Guldemond W, Hare S, Maura F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20127A511 | List: |
| References | |
| 50-304-84-17, NUDOCS 8506210168 | |
| Download: ML20127A536 (7) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION III
Report No. 50-304/84017(DRS)
Docket No. 50-304 License No. DPR-48 Licensee: Commonwealth Edison Company P.O. Box 767 Chicago, IL 60690 Facility Name: Zion Nuclear Power Station, Unit 2 Inspection At: Zion, Illinois Inspection Conducted: July 2-6, August 29, 1984, and June 10-12, 1985 4h/b-Inspectors:
S. Hare Date F. Maura ([8k Date
.A Approved By:
W. G. Guldemond, Chief
///MI Operational Programs Section Dats Inspection Sumary Inspection on July 2-6, August 29, 1984, and June 10-12, 1985 (Report No. 50-304/84017(DRS)
Areas Ins)ected: Special, announced inspection by region based inspectors of Licensee Event Reports No. 84-005-01 and 84-034-00 and a discussion of the findings with the licensee in an Enforcement Conference in NRC Region III on September 14, 1984. The inspection involved a total of 51 inspector-hours onsite by two NRC inspectors including no inspector-hours during off-shifts.
Results: No violations or deviations were identified, a
PDR G
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DETAILS 1.
Persons Contacted Zion Nuclear Station J. Ballard, QC Supervisor C. Basner, Technical Staff Engineer
- +K. Graesser, Station Superintendent
+T. Kelly, Engineering Assistant, Technical Staff
+W. Kurth, Master Instrument Mechanic
+A. Miosi, Technical Staff Supervisor
- +A. Ockert, Assistant Technical Staff Supervisor G. Plinal, Assistant Superintendent T. Printz, Technical Staff Engineer R. Schultz, Assistant Technical Staff Supervisor W. Stone, QA Supervisor
- N. Valos, Assistant Technical Staff Supervisor The inspectors also contacted other licensee personnel including members of the technical, and maintenance departments.
Commonwealth Edison Company Corporate Staff
+L. DelGeorge, Assistant Vice-President
+B. Stephenson, Manager of Production
+D. Farrar, Manager, Nuclear Licensing
+R. Cascarano, Nuclear Licensing
+F. Lentine, SNED, Zion Project Engineer US Nuclear Regulatory Commission - Region III
+J. G. Keppler, Regional Administrator
+R. Walker, Chief, Operations Branch
+L. Reyes, Chief, Test Programs Section
+N. Chrissotimos, Chief, Reactor Projects Section 2C
+W. Guldemond, Chief, Operational Programs Section
+B. Berson, Regional Counsel
+W. Schultz, Enforcement Coordinator
- +M. Holzmer, Senior Resident Inspector, Zion
- +F. Dunaway, Resident Inspector, Zion
- Denotes persons attending the preliminary exit meeting of August 29, 1984.
+ Denotes per ms attending the Enforcement Conference of September 14, 1984.
Denotes persons attending the exit meeting of June 12, 1985.
2.
LER 84-005-Unit 2 a.
Event On February 15, 1984 the licensee found the equalizing valve on the valve manifold of instrument 2PDT-RV85 open. Since this instrument has its low pressure side open to the auxiliary building, the open
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equalizing valve provided a vent path from the containment to the auxiliary building. The licensee closed the valve immediately and conducted an inspection of all similar manifolds which could generate a flow path from containment. No problems were found with other similar manifolds.
b.
Long Term Corrective Action
'The licensee proposed a modification to replace this five valve manifold with a single isolation valve. The inspector verified that the modification was completed on Unit 2. The Unit 1 change was scheduled for the next refueling outage, in the meantime, the equalizing valve for 1PDT-RV85 was locked wired in the closed position to prevent a reoccurrence. The Unit 1 modification was completed during March 1985.
c.
Effect of Open Valve on Containment Integrity The licensee perfonned a flow test on a similar manifold to determine the magnitude of the leakage through the open equalizing valve. At 47 psig (Pa) a leak rate of 120 scf/hr was reported. The initial LER reported a combined leakage rate (RV-85 plus 1983 Type B and C test results) of 141 scf/hr which is well below the Technical Specification limit of 475 scf/hr at 47 psig. Approximately 10 weeks later, during a unit outage, the licensee performed a test on the actual penetration and obtained an indicated flow rate of 3.5 cfm.
The inspector corrected the indicated flowmeter reading to its calibration pressure and standard atmospheric pressure. The true flow rate was 7.167 scfm or 430.0 scf/hr.
It was determined that the original test of 120 scf/hr was incorrect because no pressure correction factor had been applied to the flow measurements made.
The pressure at the flowmeter was not measured during the first test.
The licensee wrote a revised LER on May 3, 1984 stating that the overall leakage (451.8 scf/hr) had not exceeded the Technical Specification limit.
10 CFR 50, Appendix J, Section II F, defines Type A tests as tests intended to measure the primary reactor containment overall integrated leakage rate. Therefore, it is the NRC's position that in. order to determine the overall containment leakage rate, the measured leakage rate from RV85 must be added to the last known overall containment leakage rate, that being the last Type A test results (June 1980), corrected to accident pressure, and corrected to account for any measured degradation in penetration leakage rate.
The inspector reviewed the results of the licensee's test on the RV85 penetration and performed the necessary corrections to obtain the overall containment leakage rate at the time of the event as noted below:
1980TypeAtestresultsatPt=Ltm=pgg(g/ day 1980 Type A test results at Pa = Lam -
- 0.0113 wt%/ day where,Lt=0.062wt%/dayasdetermineddurNgthepreoperational test performed in 1973 at Pa and Pt.
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La = 0.1 wt%/dag 475 scf/hr, therefore, Lam = 0.0113 x g = 53.6 scf/hr From Type B and C tests performed in 1980 and 1984 the following deterioration was noted:
1980 Type B and C "as left" = 6.93 scf/hr 1984 Type B and C "as found" = 28.81 scf/hr
Deterioration 1980 to 1984 using minimum pathway leakage
= 1/2 (28.81) - 1/2 (6.93) = 10.94 scf/hr.
Overall containment leakage rate at time of event = measured RV85 leakage rate + 1980 Type A test at Pa + Type B and C 1980-1984 deterioration = 430.0 + 53.6 + 10.9 = 494.5 scf/hr, whcie the maximum allowable containment leakage rate, La, is 475 scf/hr.
Therefore, it was the NRC's position, at that point in time, that with the equalizing valve open the licensee had violated containment integrity requirements as stated in the Technical Specifications, paragraphs 3.9.5.A, 1.0.C.5., 3.10, and 4.10.
d.
Length of Time Equalizing Valve was Open The last time the valve was clearly demonstrated to be closed was during the June 1980 integrated leak rate test. A review of more recent records showed that the instrument was last calibrated on March 9, 1983 and a valve lineup was last performed on May 5, 1983.
The instrument calibration date is not meaningful in that the instrument is disconnected from the manifold for calibration. The valve lineup required the valve to be closed; however, the LER states that the valve "...was extremely hard to operate due to possible' internal stem binding.", therefore, placing the May 5,1983 verification in question.
In summary, all that can be stated is that:
(1) The valve was positively closed during the June 1980 ILRT.
(2) The valve may have been closed on May 5, 1983 and opened for some unknown reason during the period of May 5,1983 to
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February 15, 1984.
3.
Enforcement Conference On September 14, 1984, an Enforcement Conference was conducted between members of NRC Region III and the licensee's staff denoted in Paragraph 1.
The licensee presented the sequence of events and the corrective actions that have been taken to prevent a repetition of the event.
Final corrective action on Unit 1 was planned for the early 1985 refueling outage. The licensee's presentation was in agreement with the inspection findings. The licensee presented the results of new testing performed since August 29, 1984 which, in their opinion, demonstrated that:
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the actual measured leakage rate from similar manifolds is approximately 230 scf/hr.
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independent calculations agreed with the measured leakage rate.
c.
the reported leakage rate of 430 scf/hr is in error due to suspected leakage in the plumbers plug used to connect the test instrumentation to the penetration being tested.
The licensee stated that a corrected LER with the results of all the testing done since August 29, 1984 would be submitted to the NRC.
In addition the licensee agreed to submit the independent calculations performed to verify the measured results.
The corrected LER was submitted on October 2, 1984. The LER states a test (without a plumber's plug) performed on the Unit 1 RV-85 manifold, using threaded connections, measured a leakage rate of 241 scf/hr at 47 psig. The theoretical calculations performed by Sargent and Lundy Engineers were received by the Region on October 15, 1984 and gave results similar to the Unit 1 measurements (232 scf/hr). The inspectors performed independent calculations using the equations and tables of data given in Crane Company Technical Paper No. 410, and valve internal dimensions and configuration obtained from the Zion Instrument Department. Although our results were higher than those supplied by the licensee, they were below the magnitude required to exceed the Technical Specification limits on containment integrity. Therefore, this item is no longer considered to be a violation of the Technical Specifications.
4.
LER 84-034 a.
Event During a routine reivew of Appendix J requirements conducted by the Station Technical Staff the licensee found that Type B testing of the containment airlocks was not being performed in accordance with the requirements of Paragraphs III.D.2(B)(ii) and (iii) of 10 CFR 50, Appendix J.
The licensee reported the finding to the NRC by LER 84-034, dated November 2, 1984.
b.
Cause of Event The inspector determined that the primary cause of the event was the licensee's failure to update the station procedure based on the NRC denial of an exemption request as described below.
On August 5, 1975 the NRC requested the licensee to determine if Zion Units 1 and 2 were in full compliance with the requirements of Appendix J and to identify planned actions to attain compliance. By letters dated September 26, 1975, January 31, 1977, May 17, 1977 and July 7, 1980 the licensee requested, among others, an exemption from l
the testing requirements of containment airlocks.
I By letter dated September 30, 1981 (Eisenhut to DelGeorge) the NRC denied the licensee's exemption request on airlock testing due to the fact that the Appendix J airlock testing requirements had been revised (relaxed) on October 22, 1980. Therefore, beginning on
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October, 1981 the licensee was expected to comply with the revised airlock testing requirements of Appendix J.
c.
Existing Test Program Prior to the finding of noncompliance t'y the licensee in October,1984, the Type B test program for the personnel and emergency airlocks consisted of the following:
NRC Requirement Personnel Airlock Emergency Airlock Every 6 months test at Pa Complied Complied After periods when containment integrity is not required, test at Pa (1) Following refueling Complied Complied outages (2) Other than refueling outages Did not comply Did not comply After use, when containment Used penetration Used penetration integrity is required, test pressurization pressurization seals within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> at Pa system. Flow system zone or as stated in Technical meter and alarm sensitivity Specifications sensitivity was does not satisfy satisfactory.
NRC requirements.
Following the finding of noncompliance the licensee tested the emergency and personnel airlocks for each unit. The inspector determined that the test results satisfied the Station Technical Specifications and Appendix J requirements.
d.
Corrective Action The inspector verified that:
(1) Current airlock test requirements have been incorporated into Procedure TSS 15.6.10C, Revision 5, dated October 11, 1984.
(2) Station Procedure ZAP 5-51-7, Revision 6, dated January 1985, requires shift notification whenever the emergency airlock is used. The procedure also requires testing of the airlock be performed after its use per PT-14.
(3) Modification M22-1(2)-85-44 is being issued to install a flow transmitter, with a high flow alarm in the control room, to monitor penetration pressurization system flow into the emergency airlock seals. The new flow transmitter and alarm will be similar to the system which now exists in each personnel airlock.
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(4) A formal system for tracking regulatory changes has been implemented to ensure their incorporation into appropriate documents.
(5) The licensee also has a system to keep track of exemption requests and take whatever action is necessary to comply with the results; however the system depends on the site receiving from its corporate office the results of the NRC review. The Zion Station claims.they never received a copy of the September 30, 1981 NRC letter rejecting the airlock surveillance exemption request.
No violations or deviations were identified.
5.
Exit Interview The inspectors met with licensee representatives (denoted in Paragraph 1)
at a preliminary exit cn August 29, 1984, at the Enforcement Conference of September 14, 1984 and at the conclusion of tt.e inspection on June 12, 1985, and summarized the scope and findings of the inspection. The licensee acknowledged the inspectors' statements. During the Enforcement Conference the licensee disagreed with the method used by the Region to determine the overall containment leakage rate and was informed they should pursue the issue with the Office of Nuclear Reactor Regulation.
The inspectors also discussed the likely informational content of the inspection report with regards to documents reviewed by the inspectors during the inspection.
The licensee did not identify any such documents as proprietary.
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