IR 05000312/1987045

Insp Rept 50-312/87-45 on 871207-11.No Violations or Deviations Noted.Major Areas Inspected:Action on Previously Identified Items,Lers & NRC Bulletin Followup

ML20195J184
Person / Time
Site:	Rancho Seco
Issue date:	01/05/1988
From:	Ang W, Miller L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
Shared Package
ML20195J181	List: IR 05000312/1987045 ML20195J178
References
50-312-87-45, IEB-87-001, IEB-87-1, NUDOCS 8801260275
Download: ML20195J184 (6)

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, U. S. NUCLEAR REGULATORY COMMISSION

REGION V

Report No. 50-312/87-45 Docket No. 50-312 License No. OPR-54 Licensee: Sacramento Municipal Utility District P. O. Box 15830 Sacramento, California 95813 facility Name: Rancho Seco Nuclear Generating Station Inspection Conducte f Decerg -11, 1987 Inspection by: [ Ang, P b ect Irispector c Ik Oh Date Signed Approved by: #,

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D'a'e Signed gMiller, Chief,ProjectSection2 t Summary: Inspection on December 7-11, 1987 (Report No. 50-312/87-45) Areas Inspected: Routine unannounced inspection by a region based inspector of licensee action on previously identified inspector items, Licensee Event Reports, and NRC Bulletin follow-up. Inspection Procedures 30703, 92700, 92701 and 92703 were used during this inspectio Results: In the areas inspected, no violations or deviations were identifie ' 8801260275 880108 PDR 0 ADOCK 05000312 DCD

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DETAILS Personnel Contacted

 *8. Croley, Director, Technical Services
 *J. Vinquist, Director, Nuclear Quality
 *G. Cranston, Nuclear Engineering Manager
 *K. Meyer, Licensing Manager
 *P. Lavely, Incident Analysis Group Supervisor E. Gough, Bechtel, Nuclear Engineering Department, Supervisor
 *J. Browning, Incident Analysis Group
 *J. Robertson, Nuclear Licensing Engineer
 * Attended the exit meetin The inspector also held discussions with other licensee and contract personnel during the inspection. This included plant staff engineers, technicians, administrative and clerical assistant . Onsite Follow-up of Written Reports of Nonroute Events (92700) (Clored) Licensee Event Report (LER) 86-30-LO-Inadvertent DHS Isolation The subject LER reported inadvertent isolation of the Decay Heat System (DHS), while in Cold Shutdown and while using the DHS for decay heat removal. The DHS isolation was reported to have occurred during transfer of power source transformers, subsequent loss of bus power and diesel generator star When power was restored to the bus, DHS suction valve HV-20001 closed, per design (auto-closure ,

interlock to prevent over pressurization of the DHS system).

Subsequent licensee review noted that power and control circuitry functioned as designed. The licensee attributed the valve repositioning to the operator's inability to transfer power sources within a five second time limit built into the bus to avoid two sources of power feeding the bus for an extended period of tim The LER noted that placement of a time critical note between procedural steps instead of before the procedural step was a procedure inadequacy that contributed to the reported conditio Lastly, the LER noted that AEOD Report C503, "Decay Heat Removal Problems at U. S. Pressurized Water Reactors," recommended considering removal of DHS auto-closure interlocks to minimize loss of DHS events during decay heat removal, r As corrective action the licensee accomplished the following: l Performed training of operators on bus transfer techniques, i ' Issued a Special Order to stress reading of procedures prior to their us .. .. . _ _

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  't Revised procedures to correct the procedural inadequacy regarding bus transfe '

included in its commitment tracking system a commitment to review the necessity for auto close interlocks for DHS isolation valves (as recommended by AE00 report C503) and accomplish any design changes deemed necessary prior to the end of the next refueling outag The licensee's review and corrective action for this LER appeared to be reasonabl The LER was close No violations or deviations were identifie (0 pen) LER 87-27-LO - Use of Reactor Protection System (RPS) Shutdown Bypass Keys Contrary to Technical Specifications (TS) The licensee reported that RPS Shutdown Bypass Key (s) were determined to have been used during RPS channel calibration in violation of TS 3.5.1.4. The use of the bypass keys were required by Surveillance Procedure I.108A/8/C/0, "Reactor Protection System Channel Test," which was approved by the Plant Safety Review Committee. The licensee reported that the violation occurred on June 21, 1984 and seven additional times between November 6, 1985 and December 5, 1985. The LER concluded that the use of shutdown bypass keys for a channel already in maintenance bypass had no safety consequence, and that the only potential consequence would be an unnecessary reactor trip due to interlocks associated with the use of the shutdown bypass keys and maintenance bypass keys. The shutdown bypass switch enables plant heatup to 1820 PSIG and a Tavg of 525 F without an RPS trip. Channel (maintenance) bypass switches enables a single RPS protection channel to be bypassed without initiating a trip.

l The licensee corrective action consisted of: l (1) Revising surveillance procedure I.108A/8/C/D to be in accordance with TS 3.5.1.4 and to test the "Shutdown Bypass" function only monthly while the reactor is not critica (2) Revising operating procedure B.4 "Plant Shutdown and Cooldown" to test the shutdown pressure setpoint upon shutdown.

l (3) Submit a TS change which will permit the testing of the l shutdown bypau. high pressure setpoint during power operations l providing the same channel is also in a maintenance bypass l condition.

. A review of the licensee corrective action confirmed that procedure changes and a proposed TS change had been issue The validity of the licensee's evaluation for safety significance would be reviewed by the normal NRC TS change review proces However, the inspector noted that the licensee had not provided an evaluation and ccrrective action for the fact that neither the surveillance l-l l _ - . - . .-- -. - -- -- .- .-. - . . .- . . . . .

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procedure originator, reviewer and approver (3 people), the , approving Plant Safety Revies Committee (4 people), the shutdown bypass key issuing reactor operator (8 instances) nor the operations shift supervisor (8 instances) had recognized the TS violation. In further discussion with the licensee, the Incident Investigation and Review Group supervisor stated that a root cause analysis for the LER reported TS violation was already scheduled for a later dat The inspector requested the licensee to assure that this analysis addressed corrective action for this aspect of the LER. Pending licensee completion of its corrective action, the LER was left ope No additional violations or deviations were identifie . NRC Bulletin Followup (92703) (Closed) NRL Bulletin 87-01 - Thinning of Pipe Walls in Nuclear Power Plants NRC Bulletin 87-01 provided licensees a brief summary of the results of the investigation conducted regarding the Surry Unit 2 feedwater pipe failure, and requested licensees to provide information regarding its pipe wall thickness monitoring program for carbon steel condensate, feedwater, steam and connected high energy piping systems. The Bulletin requested licensees to report its piping design and construction codes and standards, its wall thickness , inspection criteria, the results of inspections that have been performed, and its corrective action The licensee provided the information requested by the Bulletin via letter GCA 87-536 dated September 16, 1987. The inspector reviewed and discussed the licensee's response with the NRR reviewer for the Bulletin. The inspector and the NRR reviewer concluded that the licensee response provided the information requested by the Bulleti The licensee response to the Bulletin reported that it had a program to monitor pipe wall thinning in high energy single phase and two phase carbon steel piping and also reported the results of recent inspections (July 87) performed. The licensee's program and the recent inspections were reviewed and discussed with the lead engineer for the pipe wall thickness monitoring program. The inspections identified the current pipe wall thicknesses and attempted to predict the wall thickness remaining at the next refueling outage by determining the wall thickness wear rate based on hours of usage of the piping inspected. The acceptance criteria for both the measured wall thickness and predicted wall thickness was based on a minimum wall thickness provided by the Nuclear Engineering Departmen An inspection of the basis for the minimum wall thicknesses used revealed that the Nuclear Engineering Department did not keep , documented calculations for the minimum wall thicknesses used in the inspections. However, a sampling recalculation of minimum wall thicknesses performed by the licensee, in response to the _ , - - , - _ _ _ _ . ._- __

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inspector's request, indicated that for the inspector's samples, the minimum wall thicknesses used were correct. The Nuclear Engineering

 . Department. Manager committed to document its minimum wall thickness calculations for all the piping inspecte The licensee's response identified that four nonconforming reports (NCRs) were written as a result.of the recent pipe wall thickness inspection. The piping involved in three of the NCRs were replaced and the piping identified in the fourth NCR (S6776) was determined by the licensee to be acceptable until the next inspection cycl NCR 56776 documented acceptability of the piping on the basis tsf (1)

the difference between normal operating pressure (1100 psi) and the design pressure (1300 psi), (2) the measured wall thickness (.890") and (3) the consideration that the thinner wall was limited to a 45 sector of the pipe circumferenc The inspector questioned the licensee regarding the effect of piping stresses in the thinner wall area of the piping. The licensee reviewed the piping analysis and determined that the piping stresses in the thinner wall pipe segment had an approximately 25% margin between its code allowable stresses and the stresses calculated by the piping analysi The Nuclear Engineering Manager committed to document the stress margins as further justification for piping acceptabilit Since the licensee response to the Bulletin provided the information requested and since the response appeared to have been representative of its program, NRC Bulletin 87-01 was close No violations or deviations were identifie . Foilow-up of Previous Inspection Items (92701) (Closed) Inspector Follow-up Item 85_-04-02 - Licensee Review and Verification of Past Commitments and Design Implementation This item had been previously inspected and the inspections documented in NRC Inspection Reports 50-312/86-38 and 87-1 The item was left open pending completion of the licensee's commitment management procedure and subsequent NRC review. The licensee , subsequently prepared and issued Rancho Seco Administrative Procedure (RSAP) 0902 - Regulatory Correspondence and Commitment Control and RSAP 0904 - Regulatory Commitment Management. The procedures established authority and responsibility for regulatory commitments and provides controls by the Coordinated Commitment Tracking System. The system appeared to provide adequate controls to assure fulfillment of commitments. A monthly management commitment statistical report is issued by the licensing department to the Chief Executive Officer, Nuclear and the various Department Manager The December 3, 1987 report was reviewed and discussed with the licensee. The inspector noted that the report appeared to be a good manageirant tool for identifying accountability for commitments. However, the inspector noted that one of the higher management level department heads had an 85.71 percent (6 of 7

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items) overdue commitment rat Although the overdue commitments were non-restart items, the inspector requested licensee attention to overdue commitments. The licensee reiterated that overdue commitments are a continuing subject of licensee management meeting , held by the Chief Executive Officer,. Nuclea .On the basis of the issued procedures and implementation of the procedures, the follow-up item was close No violations or deviations were identifie Exit Interview The inspection scope and findings were summarized on December 11, 1987,

 .with those persons-indicated in paragraph 1 above. The inspector described the areas inspected and discussed in detail the inspection findings. Licensee representatives acknosledged the inspector's findings.

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