ML20031C585
| ML20031C585 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/28/1981 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| TAC-12746, NUDOCS 8110070322 | |
| Download: ML20031C585 (7) | |
Text
.
t 4suuo SACRAMENTO MUNICIPAL UTILlW DISTRICT O 6201 S Street, Box 15830. Sacramento, Canfornia 95813; (916) 452 3211 September 28, 1981 e
j
=.
O OCT 0 N b M' DIRECTOR OF NUCLEAR REACTOR REGULATION ATTENTION JOHN F STOLZ CHIEF OPERATING REACTORS BRANCH 4 O, ""Q7 D U S NUCLEAR REGULATORY COMMISSION b
4 WASHP:GTON D C 20555 DOCKET 50-312 RANCHO SEC0 NUCLEAR GENERATING STATION 4] NIT N0. 1 ADEQUACY OF STATION ELECTRIC DISTRIBUTION SYSTEM VOLTAGE
REFERENCE:
Enclosure 1 to Letter from John J. Mattimoe to Robert W. Reid dated February 17, 1981 In response to a telephone request from Mr. Bob White, of Lawrence Livermore Laboratory, we are providing you with a copy of Standing Order 15-79, describing operator actions when the switchyard voltage is less than 216 KV.
Mr. White also requested a completion date for our analysis of MCC overload protection. This study is scheduled for completion by the end of our 1982 re-fueling outage since some field testing may be required.
If you have any further questions, please do not hesitate to call Dave Thorpe, at extension 4992.
ht4 L
ohn J. Mattimoe Assistant General Manager and Chief Engineer Enclosure cc:
M. Padovan B. White hI \\
8110070322 810928 DR ADOCK 05000 as (ttcraic srsitM $1RVING VORf IHAN 600,060 IN 1hl HfApi ni oftil'RNiA
~%
O SACRAMENTO MUNICIPAL UTILITY DISTRICT oFFK:E MEMORANDUM J. King R. Macias D. Zompett!
D. Comstock D. Tipton W. Mo'risawa To:
D. Gouker J. Nichols L. Adkins November 2, 1979 pa7g; B. Spencer M. Hieronimus N. Giroux T. Tucker A. Fraser SO 15-79 W. Ford 4%E]I rmou:
susJECT: 1) Phone communication with NRC
- 2) I&E Bulletin 79-13 Feedline cracking
~
- 3) I&E Bulletin 79-21 Level instrumentation reliability
- 4) Switchyard voltage - operational effects s) Water hammer or other significan line movement
- 6) Air-operated valves, failure mode
- 7) Breaker control power and charging power
- 8) Reactor trips due to surveillance testing
- 9) Reportable Occurrence No. 79-6 and RCP stop criteria
- 10) Reporting of injuries
- 11) Chlorine safety
- 12) Security control for vital areas
- 13) Valve lineups
- 14) Vacation scheduling ENCLOSURES: 1) SMUD letter defining the use of the " red phone"
- 2) SMUD letter in response to ISE Bulletin 79-13
- 3) SMUD letter in response to I&E Bulletin 79-21 4-1 & 2) SMUD/NRC letters concerning reactor trip due to surveillance testing
- 5) SMUD letter on RO No. 79-6
- 6) RPO 79-54, reporting of injuries
- 1) Phone communication with NRC The red phone has undergone a number of changes since first installed and some of the ground rules for its use have been revised.
Contact with the duty person in Bethesda for the MWe or flow transient is the main reporting criteria. As in the past, only hang up the phone when released by the duty person. Log all pertinent information, i.e., name of duty person, reason for call, time, etc. ) is a SMUD letter that resulted from a series of discussions with NRC about the reporting requirements.
Two major changes in reporting are:
- 1) we no longer report these transients to NRC Region V; 2) NRC desired a greater scope of reports.
To accommodate this greater scope of reports, new guidelines need to be established.
If in the Shif t Supervisor's opinion an "off-normal" condition exists, regardless of tne plant operating conditions, I or my designated representative should be contacted for guidance on should or should not the NRC be advised. If I cannot be reached, then P. Oubre', J. McColligan, or R. Rodriguez should be contacted for advice.
An off-normal condition could be a significant increase in letdown activity, air ejector / gland exhaust activity, unexplained increase in reactor building dump s, etc.
Basically, if a condition isn't normal and it could lead to
t Y
SO 15-79 Page 2 November 2, 1979 or indicates an unsafe condition for the public, personnel or plant, promptly contact licensed plant management for advice.
- 2) 1&E Bulletin 79-13 feed line cracking ) is SMUD response to I&E Bulletin 79-13.
This bulletin required a program of evaluating the integrity of all feedwater piping, a reevaluation of our feedline rupture procedure and reactor building leak detection.
D.13, Steam Supply System Rupture, was written to provide guidance to the operator for any line break downstream of the last-off main feedwater check valves. This procedure is in the process of a rewrite to include:
1) con-sideration of the line failure upstream of the OTSG, 2) consideration of an auxiliary feedwater line failure, 3) criteria that recognizes the effect on the RCS due to a feedwater line break is not the same as the break of a steam line.
It is important to recognize that should the line failure (steam, feed or auxiliary feed) occur in the reactor building, reactor building gas activity will vent through the break to the affected side steam header. This could result in an unmonitored release and, therefore, must be isolated and monitored with portable activity monitors.
All operators are well versed in evaluating reactor building leak rates.
3)
I&E Bulletin 79-21 Level instr,umentation reliability This bulletin addressed the concern that various level transmitters in the reactor building would not provide reliable information during accident conditions (extreme building environment).
SMUD's letter of explanation of the anticipated effects was based on an analysis by Bechtel. As you can see from Enclosure 3), the various le7e1 indicators located in the reactor building are not significantly af fected by their environment except for the pressurizer level, and then only when RCS pressure is less than 600 psi.
The most important thing to remember would ba that if a level device is affected, it would most likely be by a reduced reference leg.
The level indicator would falsely indicate a higher than actual level.
The emergency procedures that address RCS leakage all caution the pressurfas5 level is not to be relied on when the coolant is <50 F subcooled.
If RCS pressure is <600 psi under LOCA/ steam leak conditions, this caution would l
also apply.
OTSG levels could also possibly read high due to effects en their reference legs which could affect actual OTSG secondary level. By ensuring feed rates provide adequate RCS subcooling, the specific OTSG level is not a critical parameter.
m._
~
O SO 15-79 Page 3 November 2, 1979
- 4) Switchyard voltage - operational effects During a recent reactor / turbine trip, the switchyard voltage was reduced to 214 KV.
This condition persisted for some time.
Generation Engineering hac performed an analysis that indicates the initiation of an SFAS condition during this low voltage condition places the equipment in some jeopardy of failing to start due to low voltage. Some basic plant responses will be modified to help relieve this condition. These changes will be detailed in a subsequent SO.
To ensure SEAS equipment is never placed in a condition that starting due to low system voltage is questionable, the following action is required:
1.
When switchyard voltage reaches 218 KV, advise the dispatcher that further grid voltage drops could affect your continued operation.
Request he contact PG&E to ensure voltage goes no lower.
2.
Should switchyard voltage reach 216 KV, start both auxiliary diesels and parallel them to their respective buses. Separate the 4A and B buses from their respective SU transformers and adjust 4A 'and B bus voltages to 4160 Vac.
3.
Advise me or my designated representative of the plant condition.
4.
When switchyard voltage is >218 KV and stable, transfer the 4A and B buses back to the S.U. transformers and place the diesels in SFAS standby.
- 5) Water hammer or other significant line movement Longterm SO section 18 is a discussion of action required following a water hammer in any fluid system. We also have a commitment to evaluate various snubbers in the plant following any such transient or following an earth quake of 0.19G or greater.
If you experience a water hammer on any system or an indicated earthquake
>0.19G, initiate a work request to inspect snubbers in accordance with
" applicable surveillance procedures." This will ensure inspection doesn't fall through the cracks.
Should you experience an earthquake, the requirements of C.41, Earthquake, still apply.
- 6) Air-operated valves, failure mode Recently we were required to change our operating mode by leaving the reactor building isolated and the equalizing line stops closed. The clearance placed on SFV-53610 removed the control power but not the motive power. This resulted in the valve "failing open."
Just the opposite of the desired position. Proper action would have been to secure the air to the valve, leave the solinoid power on.
This would provide indication and prevent valve operation.
. ~.. _
o SO 15-79 Page 4 Novem'ber 2, 1979 When placing any valve under clearance, be particularly s,ure you are aware of its operating aaracteristics.
- 7) Breaker control and charging power Reportable Occurrences 79-10 and 11 resulted from 1) a safe ty features breaker control power improperly switched off and 2) a safety features breaker closing power switch improperly switched off.
In each case it was discovered by the alertness of the coerators. All the l
operators are familiar with the importance of these switches but not everyone in the switchgear rooms are operators.
Review with all watch standers the need for vigilance in monitoring all back-lighted pushbuttons as the indicator for breaker control power and ensuring all individual breakers are checked each shif t for proper position of closing power switches.
- 8) Reactor trips due to surveillance testing Enclosures 4-1 and 4-2 provide an insight into the types of reports being made to NRC by Nuclear stations. A review of Enclosure 4-2 makes it clear that any one initiating event can cascade quickly into chaos. Rancho Seco has had its share of " sequential failures."
Whenever surveillance work is done, there is always a chance of operator /
equipment-initiated events. Only attention to details can reduce this probability.
- 9) Reportable Occurrence No. 79-6 and RCP stop criteria, Reference Enclosure 5)
All licensed operators have received instruction by me on the B&W small break analysis and the requirement of stopping RCP's within 2 minutes of auto initiation of the HIP (low RCS pressure start). Pertinent operating procedures have been rewritten to reflect this action.
I continue to get questions such as, "What action is required if HPI is started manually?" All licensed operators must be aware that if you start HPI in anticipation of an automatic low pressure start (assumes SFAS 1A and 1B pushbutton start), two conditions must exist or the RCP's must be stopped;'
- 1) subcooling is at or approaching 50 F and 2) RCS pressure stable or increasing.
A second point can be made--if the operator detects RCS pressure dropping and can start HPI manually before auto start, it is most likely a small break LOCA does not exist.
- 10) Reporting of injuries ) is an RPO letter discussing reporting of injuries. Shift Supervisors should ensure the Plant Superintendent is notified of all onsite injuries brought to your attention. This can best be done by calling 340 and leaving word with the secretary.
e SO 15-79 Page 5 November 2, 1979
- 11) Chlorine safety a
To requote SO 15-78, "It is strongly recommended that when operators are performing any task with the chlorine system other than normal operation of the Wallace-Tiernan equipment, the SS, SCO or CO be present to ensure proper safety precau* ions are taken."
- 12) Security control for vital areas Some ground rules are necessary to make this system workable. They are not a
listed in order of 1mportance.
1.
Vehicles / personnel access to the site at the need of Generation Engineering shall not be approved by the SS.
Ron Lawrence or his deg. rep. must be contacted by the requesting party.
2.
SS only authorizes operators or Nuclear Operations persons on site at the SS request (callout) to enter vital areas (if required, you can authorize access for the site nurse).
3.
If a genuine emergency situation exists that requires persons tc enter vital areas for which they are not routinely cleared:. Call the Watch Commander, identify yourself as the duty Shift Supervisor, state "an emergency exists. Unrestricted entry is required for Vital area (s) now." Give him your phone number and wait for his confirming call. He will instruct his guard (s) to release those areas requested and they will pass all "V" badged persons to the areas (s) you requested.
Be sure to advise the Watch Commander when the unlimited entry is no longer required.
4.
If any debate arises between operators and Security, it should be resolved between the Watch Commander and the Shift Supervisor.
s 5.
Operators entering / leaving a vital area mfat develop patience with the system. Time is lost due to the checkin/out. This time must be factored into all of your work assignments.
- 13) Valve lineups.
Recently a valve lineup was reviewed shortly after the system lineup was made.
Three specific errors were found i.e.,
three valves were not positioned properly. Review with all. operators the tremendous importance of accurate, thorough performance of all system lineups.
1 As you are well aware, one of TMI-2's major errors aas an operator error 4
in a valve lineup."
i S0 15-79 Page 6 November 2, 1979 y
- 14) Vacation scheduling Refueling is presently scheduled to start about the second week of January, 1979. At present it would look like late March for return to power.
Persons with 30 days' vacation on the books now should make some plans to take time off or risk losing vacation by next spring.
Your initials above will indicate you have reviewed thi's entire SOl WJF: jim es:
J. McColligan R. Colombo J. Mau M. Carter D. Blachly w/o: R. Rodriguez 3
~, - -
~
.