ML20112D438
| ML20112D438 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/08/1985 |
| From: | Domer J TENNESSEE VALLEY AUTHORITY |
| To: | Adensam E Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0588, RTR-NUREG-588 NUDOCS 8501140285 | |
| Download: ML20112D438 (5) | |
Text
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L TENNESSEE VALLEY AUTHORITY i
CHATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II January 8,1985 Director of Nuclear Reactor Regulation Attention:
Ms. E. Adensam, Chief Licensing Branch No. 4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Ms. Adensam:
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
In accordance with the requirement of 10 CFR 50.49(h), we are providing notification of additional equipment on unit 1 at Sequoyah that has been discovered to not meet requirements of NUREG-0588 for qualification. provides the list of componets and their justification for an extension. Enclosure 2 provides the justification for continued operation (JCO) for the componets listed in Enclosure 1.
We are therefore requesting an extension for qualification of these components for unit 1 until the ed of the cycle 3 refueling outage presently scheduled to begin in June 1985. This schedule relief request is the same as that previously granted TVA on April 11, 1984.
If you have any questions concerning this matter, please get in touch with Jerry Wills at FTS 858-2683 Very truly yours, TENNESSEE VALLEY AITIHORITY "J. A. Domer Nuclear Engineer Sworn to and subs % bed before me this day of( L/A w.
1985 Ewassr.La-,
NotarfPublic j_
My Commission Expires #f d' s <
Enclosures (2) oc:
U.S. Nuclear Regulatory Commission (Enclosures)
Region II Attn:
Mr. James P. O'Reilly Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
\\
8501140285 850108 PDR ADOCM 05000327 i\\
P PDR An Equal Opportunity Employer
o.
ENCLOSURE 1 1-ZS-30-8, -10. -15, -20, -50, -52, -56, -58 During a review of an operations and maintenance reminder, it was discovered that NAMCO limit switches manufactured before February 1978 were not environmentally qualified. A review of our documentation concluded that the above NAMCO limit switches were manufactured prior to this date.
1-FCV-90-107 (LS), -11 (LS), -113 (LS), -117 (LS)
During an environmental qualification review, it was discovered that the above limit switches were not qualified for the environment in which they are located. A review of the vendors documentation indicated that the gasket and 0-ring failed when subjected to greater than 1 x 107 rads.
1-FSV-1-147, -148, -149. -150 During field verification of environmental electrical equipment, TVA discovered that the above solenoid valves had not been replaced. These valves have subsequently been replaced with qualified solenoid valves.
0 l
ENCLOSURE 2 JUSTIFICATION FOR CONTINUED OPERATION 1-FSV-1-147, -148, -149, and -150 The control air supply to the above solenoid valves was isolated upon discovering the solenoid valves were unqualified. With the air isolated to the solenoid valves, the main steam isolation bypass valves will remain in their failed-safe position which is closed during normal and adnormal operation. These valves (per our emergency procedures) are not required to mitigate any accident. The solenoid valves have subsequently been replaced.
~
ENCLOSURE 2 (CONT')
JUSTIFICATION FOR' CONTINUED 0?ERATION (JCO)
, Limit rwitches en FCV-90-107, -Ill, -113, -117 The limit switches are in the seal-in (control) circuit for the containment upper and lower compartment sir monitors outboard containment isolation valves. These valves close upon receipt of a containment vent isoaltion signal. After an accident inside containment, the limit 2 witches may fail in the closed position allewing the associated valves to reopen (if open at time of a:cident) when the containment vent isolation signal is reset.
Taking a single failure of the inboard isola tion valve (failing open), a path to
-ouwide. primary -cont ailunent (ir.t_o 'the annulusi would exist.
After a - -
~
loss of coolant accident (LOCA), thg increased containment pressure may cause airborne radioactivity to be released into the annulus, and may also-pressuri e the annulus. We believe that justification for continued operation is provided for the following reasons:
1.
It is highly unlikely that the spring-loaded fail-closed inboard valve (which receives the same signal as the outboard valve) would fail in the open position.
-2.
Resetting the containennt vent isolation signal is included in emergency procedure ES-0.2, "SI Termination." Af ter a large break LOCA, SI (safety injection) will not be terminated until very late in the event.
By this time, containment pressure will be reduced.
to near normal and any radiation leakage into the annulus will be handled by the emergency gas treatment system (EGTS).
3.
ES-0.2 cautions the operator to determine whether, af ter a LCCA, the containment ventilation systems should be returned to normal alignment.
It is highly unlikely that the operato'r vill reset containment vent isolation if there is any significant release of radiation into the containment.
f 5
i E74342.05 SIB-Dac. 10, 1984 12/10 09:la 72091i1
- 03,0F 0?
9 JUSTIFICATION FOR CONTINUCD OPERATION (JCO)
SQNMEF8410 1-ZS-30-8, -10, -15. -20, -50, -52. -56, -58 ^
The limit switches are in the seal-in (control) circuit for the containment purge supply and exhaust isolation valves.
These valves close upon receipt of a containment vent isol.ition signal. After an accident inside containment, the limit switches nay fail in the closed position allowing the associated valves to reopen (if open at tir2e of accident) when the containment vent accident signal is reset. Taking a single failure of the outboard ipolation valve (failing open), a patAto, out s ide -ecn tainment wou11! exist. Although there are isolati6it' ~
valves down' stream which receive the 'same closure signal, there is a rubber expansion joint in the line which is only rated to 3 lb/in2 We believe JC0 is provided until the next refueling outage g
for the following reasons.
1.
It is highly unlikely that a spring-loaded fail-closed valve in -
the annulus (which receives the same closure signal as the inboard valve) would fail in the open pos'ition.
Only one pair of containment prge isolation valves would be open with the unit in modes 1, 2, 3, and 4.
In addition, operation with purge valves opened is limited to less than or equal to 1,000 hrs /yr.
2.
Resetting the containment vent isolation signal is included in emergency procedure ES-0.2, "SI Termination." Af ter a large break loss of coolant accident (LOCA), safety injection (SI) will not be terminated until very late inthe event.
Bz this time, containment pressure will be reduced below the 3 lb/in~g rated limit of the expansion joint. The downstreau isolation valve will he closed, and any radiactive leak-of f in the annulus will be handled by the emergency gas treatment system (ECTS).
3.
After a small break LOCA, SI will be terminated land subsequently containment vent isolation reset) af ter reactor coolant-systers --
(RCS) pressure re-established. The sns11 break LOC., though, will
... pressures of approxiraately 2-3 lb/in}g. which is only rem!'
within the limits of the expansion joint.
4.
ES-0.2 cautions tha operator to determine whether, a f ter a LOCA, the containment ventilation syttems should be returned to norul alignment.
It is highly unli'<ely that the operator will reset containment vent isolation i f t r.n e is rny significtnc re.le.ise of radiation into the cone sinment.
.s.
E74342.05 REB-coe. 10, 1984 to,n on en
-man,ee a66
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