IR 05000312/1974008
| ML19319D838 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/15/1974 |
| From: | Dodds R, Garvin L, Andrea Johnson NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML19319D832 | List: |
| References | |
| 50-312-74-08, 50-312-74-8, NUDOCS 8003250826 | |
| Download: ML19319D838 (7) | |
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U. S. ATOMIC ENERGY COBCIISSION
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DIRECTORATE OF REGULATORY OPERATIONS
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REGION V
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50-3i2/74-08 RO Inspection Report No.
Docket No.
50-312 Sacramento Municipal Utility District Licensee License No. DPR-54 6201 S. Street, P. O. Box 15830
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Sacramento, California 9'5813 Priority Category B
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Facility Rancho Seco Location Clay Station. California
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Type of Facility Routine, Announced & Unannounced Type of Inspection
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Dates of Inspection Seotember 15,16, 24 and 25,1974 v
Dates of Previous Inspection August 14,19, 20 and
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i Se tember 3-5 and 11-13,1974
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wvh Principal Inspector
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T. D. J hnson, Reactor Inspector
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- A Accompanying Inspectors.
,Date L.J.garvin,IIIR'eactorInspector ff* W
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date J. D.
'essner, feactor Inspector
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Other Accompanying Personnel: None
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d Reviewed by,
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_ R."T.' Dodds,' Reactor Inspector
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SUMMARY OF FINDINGS
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Enforcement Actions
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None.
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Licensee Action on Previously Identified Enforcement Items
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Not applicable.
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Unusual Occurrences
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The licensee's report of the events and circumstances associated with abnormal occurrence 74-4 (imbalance function generator setting less conservative than required by the Technical Specifications) was confirmed by examination of relevant records and through discussions with licensee representatives.
(Subsequently reported to Licensing by letter dated September 30, 1974),
Other Significant Items 1.
The initial approach to critical test was performed pursuant to
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approved procedures and criticality was achieved on September 16, 1974 at 4:10 a.m.
The control rod configuration and baron con-(Qj eentration of the primary coolant system were substantially in agreement with predictions.
(Paragraph 2ofDetails.)
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The results of the simulated control rod ejection test showed a reactivity worth substantially greater than predicted.
(Paragraph 3 of Details.)
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An expanded test program has been initiated to determine the source of a metal-to-metal random noise in the primary coolant system when the "A" primary coolant pump is operated alone. The noise has not been identified under other pump operating sequences.
(R0:V Daily Report dated 9/23/74)
Management Interview The inspectors met with Messrs. D. Raasch and R. Rodriguez and other members of the licensee's staff at the conclusion of the inspection on l
September 18, 1974. The lice..see representatives made the following commitments.
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The source of noise identified during operation of the "A" primary
coolant pump will be determined and, if necessary, appropriate act, ion initiated prior to commencement of the power ascension program.
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.2.. Appropriate administrative procedures will be formulated and
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3bAwrittenreportofthevariationbetweenthepredictedandmeasured
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reactivity values of a single inserted control rod will be submitted
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to the Comission in accordance with Section 6.12.2.B of the
, Technical Specifications.
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. REPORT DETAILS
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Persons Contacted
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Sacramento Municioal Utility District
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R. Rodriguez, Manager, Nuclear Operations P.~ Oubre', Assistant Plant Superintendent, Operations
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J. McColligan, Assistant Superintendent, Technical Support R. Colombo, Technical Assistant D. Whitney, Plant fluclear Engineer
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R. Dietrich, Nuclear Engineer l
B. Spencer, Shift Supervisor S. Anderson, Nuclear Engineer L. Schwieger, QA Director J. Jewett, QA Engineer
J. Sullivan, QA Engineer
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Babcock and Wilcox Comoany E. Logan, Site Operations Manager R. Matheson, Nuclear Engineer 2.
Initial Acoroach to Criticality On September 15 and 16 the inspectors witnessed the preparations,
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approach to critical and criticality of the Rancho Seco reactor. The
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reactor achieved criticality at 4:10 a.m. on September 16, 1974.
The control rod configuration and baron concentration of the primary coolant at criticality were in substantial agreement with predictions.
Based on the inspector's examination of related records and observations the following was noted.
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Zero power physics test procedure, TP 710/Rev.1, was available a.
and being used as the document to control the activities related to performing the initial approach to criticality test. The shift test engineer was responsible for compliance with the procedure.
The checklists and signature signoffs contained within TP
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710/Rev. I were examined and verified.
Implementation of the procedural requirements was also found to be consistent with
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the applicable provisions of the Technical Specifications
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for the station.
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The revised procedure had been approved in accordance with the provisions of the QA program for operations.
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Chemistrt
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/The recorded quality.of the reactor coolant was found to be within the limits prescribed by the Technical Specifications.
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1During deboration of the primary coolant, analyses of coo an samples to determine boron concentrations were performed on aWith
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1600 ppm boron, dilution of the primary coolant system was
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stopped for approximately one hour to check the uniformity As criticality was approached, of boron in the coolant.
samples were being analyzed on about a seven minute interval.
At the time criticality was reached, the baron concentration of the coolant was 1484 ppm. The predicted value was 1496 ppm.
Prior to the initial approach to critical test, the inspectors verified that the gaseous and liquid radiation monitors were The calibration of these monitors had previously in service.
been verified by an R0:V Radiation Specialist during an inspection
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on September 3-5,1974.
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l Procedural and Plant System Prerecuisites c.
i The test procedure outlined the conditicqs to be satisfied These prior to commencing the approach to critical test.
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-conditions included verification of system conditions through l
use of pertinent procedure checklists to assure (1) calibration
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of instrumentation, (2) valve lineups and (3) operability of The inspectors observed that the safety required systems.
feature system was in service, nuclear instrumentation was i
responding as expected and that the routine operations startup procedures with accompanying checklists were being implemented by the licensed operators.
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The records showed that the nuclear instrumentation and special
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instrumentation required by STP 710/1 had been recently calibrated.
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The detectors had been source checked and the signal-to-noise i
In addition the reactor trip setpoints of the test performed.
instrumentation were verified to have been lowered to the proper levels for the approach to critical test. The inspectors also verified that the count rate on each channel was above the
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miriimum specified value.
During the approach to criticality, subsequent to each boron
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, analysis of the primary system coolant, the inverse multiplication
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of the core was plotted by two individuals using data from two The plots were observed to provide an early
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, extrapolation to show that baron concentration at criticalityCriticality
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would be approximately 1500 ppm.
a concentration of 1484 ppm.
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Crew performance T.h.e inspector verified the following during the test period.
(1) Senior Reactor operators and reactor operators werecond
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(2)~ Both SMUD and B&W technical support personnel were at the site and available to assist.
(3) The crew working time was nine hours with one hour used
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as overlap.
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~(4) Shift turnover was observed to have been conducted in an
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.(5)Procedureswereobservedtobeusedasrequiredanddata j
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was evaluated in a timely manner, 3.
Preoperational Test Procedures and Data The inspectors examined the procedures with the accompanying raw data for the following tests:
Control rod drop times
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Pressurizersprayeffectivenesg i
Temperature coefficient at 300 F.
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- Psuedo rod ejection d.
Calibration and neutron response check of source range e.
monitors With the exception of the psuedo rod ejection test, the recorded l
data were found to oe within the limits prescribed by the Technical Specifications and consistent with the information submitted in the
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Results of the psuedo Safety Analysis Report for the facility.
._ rod ejection test indicated that the reactivity worth of the selected rod (No. 8 of Group 7 in the H-2 core position) was 1.24% deltaGroups 6 and 7 K/K with rod groups 1, 2, 3 and 4 at 100% withdrawn. full-in The boron Groups 8 and S were 36% and 16.7% withdrawn, respectively.
concentration in the coolant was 1196 ppm.
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An additional test was performed under the same conditions execpt with i
a boron concentration of 1242 ppm and Group 5 at the 505 withdrawn The reactivity worth of the selected rod was measured and
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found to be 0:80% delta K/K.
In both cases the rod drop measurement technique was used to determine reactivity worth. The physics predictions for the above conditions, except that Group 5 was considered to be at the full in position, provided a reactivity value of 0.87% delta K/K for the pseudo ejected rod.
30, 1974, the licensee informed the inspector that the On September predicted value was in error and reevaluation of the physics calculations indicated the maasured worth of 1.24% delta K/K should And, further, with Group 5 fully inserted have been anticipated.
the reactivity worth of the rod was predicted to be approximately 1.9% delta K/K. The safety analysis in the FSAR, Section 14.2.2.4.5, states that a reactivity addition of 1.52% delta K/K during a rod eject accident is required to release the necessary energy to cause deformation of the reactor pressure vessel.
Section 3.5.2 of the Technical Specifications prohibits operation of the unit with a single control rod of an inserted group having a reactivity war '- axcess of 0.65% delta K/K at rated power or
..ca K/K at a hot zero power condition. Therefore, greater than the licensee.._s issued Standing Order 50-30 specifically prohibiting
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going or being critical at less than 50% withdrawn on Group 5.
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