ML20245A126
| ML20245A126 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/14/1989 |
| From: | Black S Office of Nuclear Reactor Regulation |
| To: | Kingsley O TENNESSEE VALLEY AUTHORITY |
| Shared Package | |
| ML20245A128 | List: |
| References | |
| TAC-R00398, TAC-R00399, TAC-R398, TAC-R399, NUDOCS 8904250059 | |
| Download: ML20245A126 (3) | |
Text
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UNITED STATES i
NUCLEAR REGULATORY COMMISSION i
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' April 14, 1989 Amjgertently enhrnittnA with March 14th date.
DocketNos.50M/328 Mr. Oliver D. Kingsley, Jr.
Senior Vice President Nuclear Power Tennessee Valley Authority'
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l 6N 38A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801
Dear Mr. Kingsley:
SUBJECT:
CORESHUTDOWNMARGIN(TACR00398,R00399)-SEQUOYAHNUCLEARPLANT, UNITS 1 AND 2 By letter dated July 14, 1988, the Tennessee Valley Authority (TVA) submitted a Licensee Event Report (LER 50-328/88-030) on the effects of excessive reagtor cooldown following a reactor scram on shutdown margin in the cores for 1
Sequoyah, Units 1 and 2.
This LER applied to Unit 1 Core 4 and Unit 2 Core.3.
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Unit I was preparing to begin Cycle 4 operation and Unit 2 was in Cycle 3 operation. The number assigned to the core for each unit is the Cycle the unit is currently in or preparing to enter when the unit returns to power.
t The staff conducted an inspection on this subject during July 11-14, 1988, j
reviewed the above LER and reviewed TVA's letter of August 31, 1988.
The
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staff concluded in its letter dated September 30, 1988, that the compensatory 1
measures put in place by TVA adequately addressed the effects of excessive j
cooldown on shutdown margins and that no unresolved safety issue exis*ed. This conclusion was only for the short term in that it was limited to Unit 2 Core 3 1
operation and to the restart of Unit 1 Core 4 in November 1988.
This was because TVA relied on operator action to compensate for known deficiencies in plant design or maintenance.
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This letter will address the long-term operation of the Unit 1 Core 4 and the current restart of Urif t 2 from its Cycle 3 refueling cutage.
By letters dated October 5 and 14, 1988, TVA provided details of its long-term corrective action program.to assure that a reactor cooldown from a scram does 3
not result fa a violation of the requirements in the Technical Specifications on minimum core shutdown margin.
TVA also addressed this program in the LER 50-327/88-045-01 dated January 25, 1989 on the reactor cooldown following the scram of Unit 1 on November 18, 1988.
Based on the enclosed Safety Evaluation (SE), the staff concludes that the
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procedural, hardware and training enhancements implemented and comitted to by
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TVA will provide reasonable assurance that adequate shutdown margin will be maintained at Sequoyah.
This conclusion is predicated on the successful and 8904250059 890414 ADOCK0500g7 f0 DR i
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.i Mr. Oliver D. Kingsley, Jr.
2-p prompt completion of the additional longer-tern corrective actions discussed in the enclosed SE and on continuing successful performance in maintaining coolant temperature after future trips.
The staff notes that certain other commitments in the broader areas of post. trip review, LER review, control and review of vendor documents and review of emergency operating procedures were made in TVA's various submittals and presentations on shutdown margin. Although these commitments are not directly relevant to the technical resolution of the immediate issue and are not discussed above, their implementation is considered part of the. corrective action necessary to resolve the Notice of Violation on this subject issued by the NRC on September 12, 1988.
This closes out the' staff review of this shutdown margin issue. You are requested to inform us, within 30 days of complation, when you have completed the additional longer term corrective actions discussed in the enclosed SE and have implemented the connitment areas of post-trip review, LER review, control and review of vendor documents and review of emergency operating procedures.
The reporting and/or recordkeeping requirements contained in this letter affect fewer then ten respondents; therefore OMB clearance is not required -
under P. L.96-511.
Sincerely, M
%j Suzanne C. BlacW, Assistant Director for Projects TVA Projects Division Office of Nuclear Reactor Regulation
Enclosure:
Safety Evaluation cc w/ enclosure:
See next page Distribution N
LWatson NRC PDR MSimms Local PDR JDonohew 6
OGC ADSP Reading BGrimes DCrutchfield EJordan BDLiaw ACRS(10)
SBlack GPA/CA RPierson SQN Rdg. File E
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'DATE :4/d/89
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' 0FFICIAL RECORD COPY j.
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Mr. Oliver O p sley, Jr.
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General Counsel Regional Administrator, Region II Tennessee Valley Authority U.S. Nuclear Regulatory Commission-l 400 West Suinnit Hill Drive -
101 Marietta Street, N.W.
E11 B33 Atlanta, Georgia 30323 Knoxville, Tennessee -37902 Resident Inspector /Sequoyah NP Mr. R. L. Gridley c/o U.S. Nuclear Regulatory Consission Tennessee Valley Authority 2600 Igou Ferry Road SN 1578 Lookout Placa Soddy Daisy, Tennessee 37379 Chattanooga, Tennessee 37402-2801 Mr. John T. LaPoint Mr. Michael H. Mobley, Director Tennessee Valley Authority Division of Radiological Health Sequoyah Nuclear Plant T.E.R.R.A. Building, 6th Floor P.O. Box 2000 150 9th Avenue North Soddy Daisy, Tennessee 37379 Nashyfile, Tennessee 37219-5404 Mr. M. Burzynski Dr. Henry Myers, Science Advisor Tennessee Valley Authority Committee on Interior.
Sequoyah Nuclear. Plant and Insular Affairs P.O. Box 2000 U.S. Peuse of Representatives Soddy Daisy, Tennessee 37379 Washington, D.C.
20515 1
Mr. D. L. Williams Tennessee Valley Authority Tennessee Valley Authority Rockville Office 400 West Summit Hill Drive 11921 Rockville Pike W10 885 Suite 402 Knoxville, Tennessee 37902 Rockville, Marylandi 20652 County Judge Hamilton County Courthouse
- Chattanooga, Tennessee 37402 1
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