ML20035B447
| ML20035B447 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 03/29/1993 |
| From: | Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | |
| References | |
| SECY-93-081, SECY-93-81, NUDOCS 9304010379 | |
| Download: ML20035B447 (7) | |
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POLICY ISSUE-(Information) u March 29, 1993 SECY-93-081 EOR:
The Commissioners FROM:
James M. Taylor Executive Director for Operations t
SUBJECT:
STATUS OF COMANCHE PEAK UNIT 2 LICENSING PURPOSE:
To respond to Commissioners' request for more information from the March 16, 1
1993, discussion on Comanche Peak, Unit 2 full-power operating license-(SRM
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M930316) and to provide an tipdate on plant status and readiness for a full-i power. license.
DISCUSSION:
During a briefing by representatives of public interest groups, the licensee, and the NRC staff, the Commissioners regt.ested further information on the following items:
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- the proposed license exemption for criticality monitoring, licensee use of a computer-based configuration management system, a
cable ampacity derating values and existing margins, and a
requirements for laboratories that perform fire protection tests.
a The staff responded to these items in the enclosure.
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Contact:
Brian Holian, NRR NOTE:
TO BE MADE PUBLICLY AVAILABLE 504-1334 IMMEDIATELY Donna Skay, NRR
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I-After receiving a low-power operating license on February 2,1993, TV Electric completed fuel loading of Comanche Peak, Unit 2 on February 7,1993. Mode change milestones were successfully completed, culminating in entering Mode 2 at 4:25 a.m. (CST) on March 24, 1993. At 8:46 p.m. (CST) on March 24, 1993, Comanche Peak, Unit 2 achieved initial criticality. The licensee completed its low-power physics testing by March 26 and plans to complete test reviews on March 28. The licensee expects to be ready to proceed above 5-percent power by March 29, 1993.
Region IV began around-the-clock coverage of control room and plant activities on March 23, 1993.
In addition, a six-person team from Region IV and NRR began an augmented inspection of Unit 2 critical operations on March 24, 1993.
The NRR/ Region :V Comanche Peak Oversight Panel will review the findings of these two efforts on March 28, 1993. Should the Comanche Peak Oversight Panel find the low-power operations satisfactory, the Regional Administrator's letter to the Director, NRR recommending full-power license issuance would be expected on March 29, 1993.
If the licensee's operations proceed satis-factorily, the staff request that a full-power license be authorized could be sent to the Commission as early as the afternoon of March 29, 1993.
After receipt of the full-power license, the licensee forecasts achieving Mode 1 operations within 2 days, synchronizing to the electrical grid within 5 days, performing required startup testing throughout April and May, performing a planned outage in early June, and beginning commercial operations on June 17, 1993.
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J mes M. Taylor ecutive Director for Operations i
Enclosure:
Response to Commissioners' Questions DISTRIBUTION:
Commissioners OGC OCAA OIG OCA OPP REGIONAL OFFICES EDO SECY
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ENCLOSURE RESPONSE TO COMMISSIONERS' OVESTIONS Item 1:
The proposed license exemption for criticality monitoring.
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Response
This license exemption, which was also approved for Unit 1, is related to the monitoring requirements f.t 10 CFR 70.24 for the movement and storage of fuel in the fuel handling building. The requirements state that in any area in which special nuclear material is handled, tw gamma-or neutron-sensitive i
radiation detectors shall be used to audibly signal if accidental criticality should occur. The regulation does not require underwater monitoring when the fuel is stored beneath a water shield or monitoring of packaged fuel assemblies. -The exemption was approved for Unit 2 based on the fact that procedural controls are in place that will preclude criticality during receipt, inspection, or storage of new fuel. These procedural controls allow only two fuel assemblies to be outside of a shipping container, storage rack, or transfer tube at one time, and require a minimum 12-inch distance between such assemblies.
Invariably, applicants for the Part 70 cold fuel license have requested an l
exemption from the criticality alarm requirements of 10 CFR 70.24. This exemption has been routinely granted for all licensees of power reactors when the request is submitted with specific procedural controls for the handling of new fuel.
In order to reduce the regulatory burden of seeking routinely granted exemptions, a change to 10 CFR 70.24(e) has been proposed that would l
codify both the exemption and the related conditions. The amendment to Part 70 would exempt power reactors from monitoring the dry storage of unirradiated i
fuel if conditions are present that will ensure that the fuel will not become l
critical. The primary basis for the rule change is that the monitors do not perform a safety function to prevent an accident but simply alert personnel that one has occurred. The conditions imposed on applicants as part of the 10 CFR Part 70 licensing review are sufficient to prevent a criticality accident from occurring.
Item 2:
Licensee use of a computer-based configuration management system.
Response
This issue was raised during a discussion of a weakness discovered by the Operational Readiness Assessment Team (0 RAT) when it inspected the area of configuration control. The Regional Administrator explair,ed that the weakness dealt with valve misalignments found during the inspection. The ORAT report stated that the misalignments were the result of the failure of operators to document valve manipulations. The staff found the corrective actions, which included revision of the system status control procedure, acceptable;- through
-j followup inspections, the staff confirmed that TU Electric has adequately addressed these issues.
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Subsequent to this discussion, a question was raised as to whether the licensee had a computerized system to aid in configuration management.
Discussions with TV Electric revaaled that a computer aided design (CAD) i system is used as a drafting tool to store and retrieve plant drawings. The licensee stated that the scope of the computerized system has been limited to i
vital station drawings (i.e., system flow diagrams) of critical systems to I
make the best use of resources and to maintain system efficiency and speed.
This system assists in making timely updates to important drawings, which enhances the plant's configuration management.
l Item 3:
The specific cable ampacity derating values and existing margins.
Response
Cables enclosed in electrical raceways that are protected with fire barrier I
materials are derated because of the insulating effect of the fire barrier i
material. Among the other factors that affect ampacity derating are cable i
fill, cable loading, cable type, raceway construction, and ambient temperature. The National Electrical Code, Insulated Cable Engineers Association (ICEA) publications, and other industry standards provide general ampacity derating factors for open air installations, but do not include derating factors for fire barrier systems.
Historically, ampacity derating i
factors for raceways enclosed with fire barrier material have been determined i
for specific installation configurations by testing.
In SSER 26, the staff discussed concerns it has with inconsistent ampacity derating test data, but recognized that the ampacity derating concern is an aging issue rather than an immediate operability issue.
In SSER 26, the staff documented TU Electric's interim ampacity derating factors, and acknowledged that TU Electric had performed a calculation to evaluate the acceptability of a 40-percent cable tray derating factor.
Accordingly, the staff:
(1) documented TU Electric's commitment to complete
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plant-specific ampacity derating testing by the completion of the first refueling outage and (2) concluded that the use of TU Electric's interim j
l ampacity derating factors was acceptable.
j After SSER 26 was issued, TU Electric conducted a series of ampacity derating tests for Thermo-Lag fire barrier configurations at Omega Point Laboratories (OPL) in San Antonio, Texas from March 3 through March 13, 1993. NRC staff observed test preparation and testing from March 2-7, 1993. The first test i
group, conducted from March 2 to March 3, 1993, consisted of a 3/4"-diameter conduit with a single 3/C #10 AWG 600-volt copper cable and a 2"-diameter conduit with a single 3/C #6 AWG 600-volt copper cable. The second test group, conducted from March 5 to March 8, 1993, consisted of a 24"-wide x 4"-
deep x 12-feet-long cable tray filled to a 2.95-inch depth with 3/C #6 AWG 600-volt copper cables and a free air drop (small) made of a single 3/C #6 AWG 600-volt copper cable. The final test group, conducted from March 10 to 14, 1993, consisted of a 5"-diameter conduit with four 1/C #750 MCM volt copper cable and a free air drop (larr,e) made of three 1/C # 750 MCM volt copper cable. The ampacity derating factor test results are summarized below.
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> j The ampacity derating test procedure used for all test articles was performed in two steps, as follows:
(1)
An ampacity product (or derating) test was conducted with the Thermo-Lag material configured around the test article.
(2)
The baseline test was conducted on the same instrumented article without the Thermo-Lag product.
Each ampacity test was performed by raising the conductor temperature from ambient (i.e., 40' C) to its rated temperature limit (i.e., 90' C), al'uring the test article to reach thermal equilibrium, ai.d then measuring the final carrent or ampacity value for the test article. The ampacity derating factor was calculated as follows:
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Ampacity derating factor = 1 -
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I I, - Ampacity value for product test l
1, - Ampacity value for baseline test TV Electric performed a series of calculations to establish the existing design margin for cable ampacity derating. These calculations were performed for the cables fed from the various switchgear, as follows:
Calculation Cables Calculated Excess Ampacity Marain 40%
- EE-CA-0008-3097 From 6.9 kV Cable tray Conduit
- 40%
- 2-EE-CA-0008-3038 From 480 V Cable tray - 38%
Conduit
- 23%
- 2-EE-053 All other Cable tray - 40%
Conduit 35%
- 16345-EE(B)-140 Air drops Cable tray - 39%
35%
Conduit On March 10 and March 23, 1993, TU Electric sent letters to NRC containing preliminary information about both TU Electric's calculated excets ampacity margin and the test results for the plant-specific ampacity derating tests.
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The following table summarizes the preliminary test data, and provides the ampacity derate margin (calculated excess ampacity margin minus the actual i
test data):
Raceway Amoacity derate Excess amgatity test value derate maroin 3/4" conduit 9.1%
25.9%
2" conduit 6.5%
23.5%
5" conduit 10.7%
12.3%
24" cable tray 31.4%
6.6%
Small air drop 23.0%
12.0%
i Large air drop 31.7%
3.3%
The NRC staff finds that the preliminary ampacity test results provided by TU Electric are acceptable since the test derate factor data are bounded by the calculated (design) ampacity margins. However, the NRC staff.is still reviewing TU Electric's plant-specific ampacity derating program.
The NRC staff will complete its review of the plant-specific test _ program and results a
after.TU Electric submits the final test reports (consistent with the schedule r
published in SSER 26).
t Item 4:
Clarification on requirements for laboratories that perform fire protection tests and how such requirements are determined to be met.
Resocr.2e Section 9.5-1 of the Standard Review Plan uses the phrase " nationally recognized testing laboratory," which was adopted from terminology used in the past by the National Fire Protection Association (NFPA). The'SRP does not define the phrase and the NFPA subsequently dropped the phrase from all of its published documents.
In its fire Protection Handbook,.the NFPA stated that it dropped the phrase because there was always a doubt abor ~ exactly what.
constituted a " nationally recognized testing laboratory.
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The NRC does not have codified requirements or guidance for evaluating the acceptability of fire testing laboratories to perform fire protection tests.
The staff does, however, apply its fire protection engineering expertise and judgment and ensures that such laboratories have the facilities, equipment, personnel, and experience needed to conduct such tests.
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3 - a Early in its review of the Thermo-Lag issues, the staff asked the National Institute of Standards and Technology (NIST) to identify attributes for evaluating fire testing laboratories. NIST stated that suitable laboratories l
would have the following attributes:
The facilities and equipment needed to conduct tests in accordance with-national consensus standards such as American Society of Testing and l
Materials (ASTM) and the National Fire Protection Association (NFPA).
t For the purposes of testing raceway fire barriers, this includes a full-l scale floor furnace that conforms to all of the requirements of ASTM E-119.
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Knowledgeable and experienced staff such as full-time permanent staff I
i trained in running ASTM E-Il9-type tests and a responsible test officer authorized to sign the test reports.
(Although not essential, NIST stated that participation on ASTM or NFPA fire testing standards committees offers additional evidence of laboratory competence. Omega i
Point Laboratories participates on these committees.)
Experience in conducting fire endurance tests for more than one client.
Acceptance of the laboratory's ASTM E-119 test results by the U.S. model' building code organizations and other authorities having jurisdiction over fire protection, such as insurance companies and Federal, State,'
i and local agencies responsible for fire safety.
NIST independently reviewed Omega Point Laboratories (OPL) against these
. i attributes and found that it was suitable for conducting raceway fire barrier tests. This conclusion is documented in a letter from NIST to K.S. West, NRC, dated November 5, 1991.
t As a fundamental part of its review of the Comanche Peak Thermo-Lag fire
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barrier program, the staff evaluated OPL during visits to the laboratory. The staff observed all aspects of the laboratory's work on full-scale fire barrier tests and reviewed its fire test reports. The staff concluded that OPL was equipped and qualified to conduct raceway fire barrier tests.
An additional inspection of Omega Point Laboratory was conducted in March 1993 by the Vendor Inspection Branch (VIP). Again, no specific criteria were used to qualify the laboratory. The inspection report is not complete, however, t
the initial findings did not reve" any significant technical deficiencies.
Discussions with the VIB indicate that none of.the inspections findings affect the NRC's assessment that OPL is qualified to perforn raceway fire barrier tests.
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