ML20235P025
| ML20235P025 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/10/1987 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8707200309 | |
| Download: ML20235P025 (5) | |
Text
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l TENNESSEE VALLEY AUTHORITY l
CH ATTANOOG A, TENNESSEE 37401 SN 157B Lookout Place i
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JUL 101987 I
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk
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Washington, D.C.
20555 I
Gentlemen:
In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 1
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SEQUOYAH NUCLEAR PLANT (SQN) - NRC INSPECTION REPORT NOS. 50-327/87-24 j
AND 50-328/87 RESPONSE TO NOTICE OF VIOLATION NOS. 50-327,
-328/87-24-03 Enclosed is our response to Gary G. Zech's June 4, 1987 letter to j
S. A. White, which transmitted the subject Notice of Violation. TVA does l
not recognize any items described herein as commitments.
If you have any questions, please telephone M. R. Harding at (615) 870-6422.
To the best of my knowledge, I declare the statements contained herein are complete and true.
Very truly yours, TENNESSEE VALLEY AUTHORITY J
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R. Gridley, Dir ctor Nuclear Safety nd Licensing Enclosure cc:
See page 2 l
8707200309 G70710 PDR ADOCF. 05000327 g
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An Equal Opportunity Employer (j k
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4 4 U.S. Nuclear Regulatory Commission JUL 10 087 cc (Enclosure):
Mr. G. G. Zech, Assistant Director for Inspection Programs Office of Special Projects U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. J. A. Zwolinski, Assistant Director for Projects Division of TVA Projects Office of Special Projects U.S. Nuclear Regulatory Commission 4350 East West Highway EWW 322 Bethesda, Maryland 20814 Sequoyah Resident Inspector Sequoyah Duclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 l
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ENCLOSURE RESPONSE - NRC INSPECTION REPORT NOS. 50-327, -328/87-24 j
GARY G. ZECH'S LETTER TO S. A. WHITE Violation 50-327. -328/87-24-03 10 CFR 50.72, Immediate notification requirements for operating nuclear power reactors, Section b. 2.(i) and b. 2.(vi), requires that the licensee notify NRC as soon as practical and in all cases within four hours of the occurrence
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of any event that:
(1) was found while the reactor is shutdown, that, had it been found4 while the reactor was in operation, would have resulted in the nuclear power plant, including its principal safety barriers, being seriously degraded or being in an unanalyzed condition that significantly compromises plant safety.
(2) is related to the health and safety of the public or onsite personnel, or protection of the environment, for which a news release is planned or will be made.
Such an event may include an onsite fatality or inadvertent release of radioactively contaminated materials.
Contrary to the above requirements, no report was made relative to an April 29, 1987 event which involved the spilling of several thousand gallons of reactor coolant system (RCS) water into containment through an inadvertently opened pressurizer spray line vent valve.
This occurred when th3 RCS was being refilled following steam generator repair work.
Information pertaining to this event was made available for release to the news media by TVA as an input to TVA's wire service.
In this instance, the " event" is the
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leak itself, not the precursor of a misaligned valve.
Had a water spill of i
this magnitude and volume occurred at power, it would have constituted a small break loss of coolant accident (LOCA).
This is a Severity Level IV violation (Supplement I).
Admission or Denial of the Alleged Violation TVA denies the violation.
Reason For Denial (Example 1)
For the example cited under 50.72.b.2.1 on the misaligned valve and subsequent leak, this rule does not apply because:
a.
pressurizer vent valve configuration could not exist at power.
Control room alarms, annunciators, and indicators, as in the April 29, 1987 event, would alert operators of an open RCS system.
Full temperature and pressure could not administratively be achieved with the configuration of the vent valve, blind flange, and hose, as in the April 29, 1987 event.
Reason For Denial (Example 1) (c ontinu ed )-
Therefore, the misaligned valve is not an event found during shutdown that could exist at power'.
b.
Leak was within the bounds of makeup system.
The class "A" piping of the spray line is separated from the class "B" vent valve by a 3/8-inch flow restrictor, The makeup flow rate from one centrifugal charging pump is adequate to sustain a pressurizer level at 2,250 psia for a break through a 3/8-inch-diameter hole.
Even in the unlikely event of a failure of the vent valve and blind flange, the rate of loss of reactor coolant would be bounded by the 3/8-inch flow restrictor, c.
Leak was not a LOCA as defined by 10 CFR 50.46.
Paragraph c(1) of 10 CFR 50.46 states ".
. Loss-of-coolant accidents (LOCA's) are hypothetical accidents that would result from the loss of reactor coolant, at a rate in excess of the capability of the reactor coolant makeup system, from breaks in pipes in the reactor coolant pressure boundary up to and including a break equivalent in size to the double-ended rupture of the largest pipe in the reactor coolant system." As stated above, this leak was not in excess of the makeup system.
d.
Leaks of this nature have been analyzed and addressed in the Final Safety Analysis Report (FSAR).
FSAR chapter 15.3 states that small break LOCAs are those breaks of greater than 3/8-inch-diameter hole. This leak was through a 3/8-inch flow restrictor.
l The FS R further states that the charging system is designed to maintain pressurizer level and pressure for leaks of i
3/8-inch-diameter or less.
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Compliance with technical specifications.
Limiting Condition for Operation '(LCO) 3.4.6.2 (operational leakage) states that RCS leakage shall be limited to 1 gal / min unidentified l
leakage. This limit is verified on an every-shift basis with an RCS inventory taken every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
If such a leak occurred at power, compliance with the LCO would be I
met by licensed operators by reducing the leakage to within the limit l
within four hours or be in HOT STANDBY within the next six hours.
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.. Reason For Denial (Example 1) (continued) f.
Covered by Emergency procedures.
If such a leak were to occur at power, the problem would be immediately identifiable by operators from alarms, annunciators, and indicators such as:
(1) high containment moisture, (2) ice condenser door open, (3) high radiation levels in lower containment, and (4) increased charging flow. Upon identifying the leak from the RCS, operators would refer to the appropriate procedures and take the necessary actions to maintain control of the unit.
Operators would utilize Abnormal Operating Instruction (AOI)-6, e
"Small Reactor Coolant System Leak," and if necessary, Emergency Instruction E-0, " Reactor Trip or Safety Injection."
Reason For Denial (Example 2)
For the second example cited under 50.72.b.2.vi for notification of NRC of the event TVA does not consider this rule to apply because a formal press release was not planned or made. TVA's definition of a press release is a written announcement issued directly to all of the news media. TVA's Knoxville news tape is a recorded message used to provide optional information to the news media on the status of TVA's nuclear plants and daily activities of interest. TVA has previously provided to the Public Affairs Office and the Regional Office general information on the news tape in L. M. Mills' letter to James p. O'Reilly dated January 12, 1984.
Reporters may or may not choose to call for information on the news tape.
In contrast, TVA's formal news releases are typed and hand-carried or mailed to local and regional news media. TVA did not issue a formal news release on the spill.
Information was provided on the news tape so TVA could informally answer potential rumors that could be received by the media.
Additional Information TVA realizes'the sensitivity and importance of maintaining good communications with NRC.
Daily, the resident inspectors are provided all control room logs and potential reportable occurrences (pros). Also, the daily plant staff meetings are open to the residents so they can stay abreast of the latest plant status, upcoming issues, and major work activities planned. Weekly. TVA upper management calls the Regional Office and Special projects Office to discuss plant status, the restart schedule, and other pertinent events and issues.
In addition, the Manager of Nuclear power keeps NRC's Director of the Office of Special projects and other key NRC personnel appraised of major issues and items of interest.
In summary, TVA will continue to make a major effort to maintain open and forthright communications with NRC, as well as a proactive attitude in meeting the 10 CFR reporting requirements.
In consideration of the subject event, TVA in the future will try to keep the Commission better informed; however, given the circumstances, this violation is denied.
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