ML20039B651
| ML20039B651 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 11/30/1981 |
| From: | Bettenhausen L, Chung J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20039B645 | List: |
| References | |
| 50-309-81-29, NUDOCS 8112230345 | |
| Download: ML20039B651 (9) | |
See also: IR 05000309/1981029
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U.S. NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
Region I
Report No.
50-309/81-29
Docket No.
50-309
License No.
Priority
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Category
C
Licensee: Maine Yankee Atomic Power Company
Facility Name: Maine Yankee Atomic Power Station
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Inspection at: Wiscasset, Maine
Inspection conducted:
October 36-30,1981
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Ir.specto rs :
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Jin W. Chung,' Reactor
7'
dat( sicfned
Inspector
Approved by:
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Md4/It-
// don /
L. H.'Bettenhausen, Chief,
date signed
Test Program Section
Inspection Summary:
Inspection on.0ctober 26-30, 1981 (Report No. 50-309/81-29)
Areas Inspected:
Routine, unannounced inspection of cycle 6 post
refueling startup testing, which includes pre-critical tests; critical
test; and power escalation tests. The inspection invo'.ved 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> on
site by one region-based inspector.
Results: One item of noncompliance:
Failure to provide acceptance
criteria, and to provide written procedure - section 4.
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DETAILS
1.
Dersons Contacted
D. Boginton, Reactor Engineer
J. Brinkler, Technical Support Department Supervisur
R. L. Radasch, I&C Department Supervisor
E. Wood, Plant Supervisor
P. Swetland, Resident Inspector
The inspector also interviewed other licensee employees during
the inspection, including Reactor Operators, performance and
support personnel.
denotes those present at the Exit Interview.
2.
Cycle 6 Precritical Test
a.
The inspector reviewed calibration and funct'onal tests and
results to verify the following:
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Procedures were provided with detailed instructions;
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Technical content of procedures were sufficient to
result in satisfactory component calib-ation and test;
Instruments and calibration eq;ipment used were traceable
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to the National Bureau of Standards;
Acceptance and operability criteria were observed in
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compliance with Technical Specifications (TS).
b.
The inspector reviewed the administrative control documents to
verify that the post refueling test sequences were in com-
pliance with the station procedures and Technical Specifications.
The following tests were reviewed:
(1) Functional and Calibration Tests
The inspector reviewed the calibration test of the variable
overpower tvip system, performed May 18, 1981, and verified
that the test was conducted in accordance with the procedure,
3-6.2.1.9, Appendix A.
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The inspector also reviewed the calibration records of the
picoammeters for the Reactivi'y Computer and determined that
the calibrations were perform-<i by qualified technicians in
conformance with the station p (cedures and the TS requirements.
No unacceptable conditions were idencified.
(2) Rod Drop Time
The inspector verified by review of the test results performed
July 11, 1981 that 59 Control Element Assem;11es (CEA) were
tested for the drop times and the individual CEA drop times
were all less than 2.! seconds as required by the TS.
The inspector had no further questions.
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3.
Post - Critical Tests
]
a.
T,est Program Review
The inspector reviewed selected test programs to verify the
following:
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The test programs were implemented in accordance with
Core 5 Refueling and Post-refueling Sequencing Procedures;
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Stepwise instructions of test procedures were adequately
provided, including Precautions, Limitations and Acceptance
Criteria in conformance with the requirements of the
Technical Specifications;
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Provisions for recovering from anomolous conditions were
provided;
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Methods and calculations were clearly spec'fied and the
tests were performed accordingly;
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Review, Approval, and Documentation of the results were
in accordance with the requirements of the Technical
Specifications and the licensee's administration controls,
b.
Low Power Phyrics Tests
The inspector verified by review of the test sequencing
procedure, 11-2, Low Power Physics Tests, Revision 6, that the
test sequences prior to power escalation were specified in the
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procedure and the tests were conducted accordingly, except the
item identified in Section 5.
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4..
The inspector also reviewed the Maine-Yankee (MY) Cycle 6 Core
Performance Analysis, YAEC-1259 and MY Cycle 6 Startup Test
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and Power Escalation Predictions.
(1) Reactivity Computer
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The inspector reviewed the reactivity computer checkout
data to verify that the response of the reactivity
computer was acceptable.
The inspector also verified
,
that the test was conducted in accordance with the
procedure 11.2, Appendix A, Reactivity Computer Checkout.
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The reactivity computer is an important tool to monitor
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the. reactor parameters during the physics tests. Consequently,
a method has to be established to calibrate and to check
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its operability and accuracy. The procedure 11-2, Appendix
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A, compared the reactivity computer response: with the
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wide range Startup Rate (SUR) meters,
)
The inspector noted that the reactivity values from the
SUR and the. computer traces were as much as 20% different,
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with an average of 5% difference.
However, the procedure
neither specified the acceptance criteria nor the subsequent
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corrective steps.if the reactivity computer responses
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were not acceptable.
This raised a concern regarding
validity of the reactivity computer traces obtained
during the subsequent tests.
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The inspector determined that the 5% difference on the
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average did not alter the results of the physics testing
This failure to provide the acceptance criteria to evaluate
the test results constitutes an example of noncompliance
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summarized in Section 4.
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(2) Criticality
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The inspector reviewed the procedure 11-2, Appendix B and
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the test data performed July 13, 1981, and verified that
the critical baron concentration was measured five times
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consecutively, and values were within 5 ppm of the average
as specified in the procedure.
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The critical boron concentration was 1153 ppm and was
within the acceptable value of 1197 + 95.1 ppm.
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The inspector had no further questions.
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(3) Temperature Coefficients
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The inspector determined by review of the results of-
the reactivity computer traces that the Isothermal
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Temperature Coefficient (ITC) and the Moderator Temperature
Coefficient (MTC) were measured with the CEA Group 5 at
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169 steps on July 12, 1981 in accordance with the procedure
11-2, Appendix'C.
The results were:
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ITC. 10 Arho/'F
MTC. 10 arho/'F
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measured
0.312
0.481
predicted
0.13 + 0.5'
O.30 + 0.5
The results were within the requirements specified in TS.
No unacceptable conditions were identified.
(4) Shutdown Margin (SDM)
Technical Specification 3.10.A.3 stated that when the
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reactor was critical, the available shutdown reactivity
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margin (SDM) with the_ strongest CEA struck out would be no less
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t % 3.2%, and the CEA insertion would be permitted only
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'f the SDM was no less than 2*J during the icw power
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physics testing,
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The inspector found that:
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An SDM demonstration procedure was neither established
nor included in the post refueling startup test
sequencing procedure; and
The SDM was not demonstrated during the cycle 6
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startup tests.
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During the subsequent discussions with a cognizant engineer
and the review of the previous cycle performance reports,
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the inspector determined that the SDM's for the previous
,
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cycles were demonstrated by the computer predictions for
the Beginning Of Cycle (BOC) and the End Of Cycle (E0C),
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and that the selected parameters contributing to the
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reactivity margin were measured during the startup physics
tests to verify the computer model. However, the inspector
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verified that such computer calculations (equivalent to
table 4.2 of the cycle 5 performance analysis report)
were not provided for cycle 6.
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Upor. request by the inspector, SDM calculations were
provided on October 28, 1981.
The results did not include
the built-in calculational uncertainty and the conservatism
given in the previous SDM calculations.
The inspector determined that the SDM was greater than
the 3.2's margin required by TS. A licensee representative
stated that a SDM demonstration procedure would be developed
and be incorporated into the Low Power physics testing
program.
The failure to provide a written procedure and to implement
this demonstration during the post refueling testing
program constitutes an example of noncompliance summarized
in Section 4.
(5) CEA Worths
The inspector verified by review of Procedure 11.2,
Appendix D, and the test data that the maximum ejected
rod (rod 34) worth was measured during the boration and
the dilution processes.
The measured ejected rod worths
were 0.072?sArho during boration and 0.0622?sarho during
dilution. The acceptance criteria requires less than
0.083?s.
The regulating rod worth was measured on July 13, 1981
and was 3.0648"JArho. The acceptance value was 3.076+0.307?JArho.
The inspector had no further questions.
c.
Power Escalation Tests
The power ascension was initiated at a rate of lis/hr up to 10?s
power and 2?s/shif t thereafter, as specified in Table 1, Appendix
A - Power Level Changes, procedure 11-3.
The procedure specified that the azimuthal power tilt and the
power peaking be monitored using the ir a re detectors (INCA
Tilt Monitor) for the power level 5?e-4U:
it approximately 30?s
power, the process computer developed problems, and subsequently
the Reactor Protection System (RPS) excore detector readings were employed
to monitor the tilt trends as per a letter to NRR dated July 24, 1981.
The inspector verified by review of the INCA printouts and the
excore trend readings that the INCA tilts were less than 2.2*s
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prior to the computer failure at 30*J power. The inspector
also determined by review of the excore detector readings an.d
their trends that the tilts were within the required 3.0?;
during the computer failures and up to the computer restoration.
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The inspector further reviewed the data from tests performed July 18-25,
T
1981 for the total peaking factor (F (R)) and the linear heat
generation rate (LHGR), as summarized in the following:
Measured
Acceptance
T
F (R)
1.579
A 1.897
LHGR,KW/ft
2.411
513.5
(1) Power Distribution and Anomaly
The inspector reviewed the INCA measurements of the power
distribution, performed July 25, 1981 at 47.3?s power and
August 12, 1981 at 95.0?4 power.
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The inspector determined that the measurements were
performed in accordance with the procedure 11-3, Appendix
B, and that the differences between the INCA measurements
and the PDQ predictions were all less than 10?;, including
the measurements for the edge assemblies.
No unacceptable conditions were identified.
(2) Excore Nuclear Instrumentation (NI)
The inspector verified by review of the data from the calibration
performed July 25, 1981 that the RPS Excore Nuclear Instrurrentation
(NI) channels were calibrated as per procedure 3-6.2.2.16, Daily
Calorimetric Adjustment, Revision 5.
No unacceptable conditions were identified.
(3) Core Thermal Power
The procedure 12-5, Plant Calorimetry, kevision 2, established
various computation 61 methods for estimating the core
thermal power, which included AT power, INCA Power,
Excore Power, Steam Flow Power, and Feed Flow Power
Calculations.
The inspector was informed that the calorimetric cal-
culations employing the feed flow information was the
most accurate method since three calibrated venturi
sensors could measure the feed flow accurately.
The inspector reviewed the data from the test performed August 3,
1981, and verified that the hand calculation of the core
thermal power was accurate to within 1.5% and 0.5% of the
computer calculations by the Feed Flow and the Steam Flow
methods respectively.
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.The inspector had no further. questions.
(4) Temperature Coefficients
The inspector verified by review of the reactivity computer
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traces and the data sheets of July 25, 1981 that the ITC
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and the MTC were 0.0018% Arho/'F and 0.00036% Arho/'F
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respectisel; at the moderator temperature of 554.3'F.
No unacceptable conditions ware identified.
4.
. Noncompliance
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The inspector identified one item of noncompliance in the activities
related to quality and safety.
Technical Specification 5.8.1 specifies the requirements of establishing,
implementing, and maintainf rg written procedures for the testing
activities.
10 CFR 50, Appendix B, Criterion XI requires that all
testing be performed in accordance with written procedures which
incorporate acceptance criteria for the satisfactory completion of
the testing.
Contrary to the above, the following findings were identified as
detailed in 3.b(1) and 3.b(4):
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Details in item 3.b(1):
Procedure 11.2, Appendix A, provided
neither acceptance criteria nor subsequent corrective action
if the test failed to meet ;he acceptance requirements. The
reactivity computer checkout data performed during the cycle 6
post refueling startup testing were not evaluated against
established acceptance criteria.
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Details in item 3.b(4): A procedure to demonstrate the SDM
was neither established nor implemented in the post refueling
startup test program, and the SDM was not demonstrated during
the cycle 6 startup testing.
Upon request of the inspector,
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the SDM was' demonstrated on October 28, 1981.
The inspector
independently determined that the SDM met the requirements
specified in TS 3.10.A.3.
The licensee representative stated that the acceptance cri-
teria for the reactivity computer checkout would be established
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and that the cycle 6 physics test results would be evaluated
again by December 1, 1981. The licensee further stated that
the necessary procedure revisioia and the corrective actions
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to the findings would be implemented prior to the r. ext startup
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testing.
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The above failures to meet the requirements specified in
TS 5.8.1 and 10 CFR 50, Appendix B, Criterion XI collectively
constitute an item of-noncompliance (50-309/81-29-01).
5.
Post Refueling Startup Precedures
The inspector reviewed the test sequencing procedures, 11-2, Low
Power Physics Tests, Revision 6, and 11-3, Power Escalation Tests,
Revision 6, which stated that the acceptance criteria were specified
in RE-LP-6.1 and RE-PE-9.1 respectively.
1
The inspector verified that the forms RE-LP-6.1 and RE-PE-9.1 were
merely blank data summary sheets.
The inspector was informed that
test specifications from the cycle management report.should have
been listed on the data forms. The licensee representative stated
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that the procedures 11-2 and 11-3 would be revised prior to the
next cycle testing and that the proper specifications or the references
would be included.
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This is an unresolved item pending the procedure revisions and
subsequent NRC:RI inspection (50-309/81-29-02).
6.
Unresolved Items
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Unresolved items are those items for which further information is
required to determine whether they are acceptable or items of
noncompliance. An unresolved item is identified in Section 5.
7.
Exit Interview
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Licensee management was informed of the purpose and scope of the
inspection at the entrance interview.
The findings of the inspection
were periodically discussed and were summarized at the conclusion
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of the inspection on October 20, 1981. Attendees at the exit
interview are denoted in Paragraph 1.
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