ML20054F303
| ML20054F303 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 06/11/1982 |
| From: | Mardis D FLORIDA POWER CORP. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 3F-0682-16, 3F-682-16, TAC-12961, YAC-12961, NUDOCS 8206160051 | |
| Download: ML20054F303 (6) | |
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- 3F-0682-16 File: 3-0-3-a-3 Mr. Harold R. Denton, Director Of fice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Crystal River Unit 3 Docket No. 50-302 Operating License No. DPR-72 Nuclear Safety Task Force Followup Actions
Dear Mr. Denton:
Af ter the transient that occurred on February 26,1980, Florida Power Corporation formed a Nuclear Safety Task Force to investigate the overall safety of Crystal River Unit 3. This Task Force made a number or recommendations for safety improvements and made a number of recommendations concerning subjects to be studied in greater detail to evaluate the potential for safety improvements. Af ter the Nuclear Safety Task Force completed its mission, the Nuclear Safety Modifications Control Task Force (NSMCTF) was formed to prioritite outstanding recommendations and to monitor progress to assure timely resolution. This prioritization has been completed and the NSMCTF is continuing l
to track overall progress being made.
l In our letters of March 6,1981, and April 14, 1981, we advised you of the disposition of l
many of the Task Force recommendations and indicated we would provide you a summary of the results of the engineering studies being performed pursuant to Nuclear Safety Task Force recommendations and our plans for further pursuit of these items. By this letter, Florida Power Corporation fulfills that commitment.
As a result of the preliminary engineering studies that were performed, the NSMCTF determined that some of the concerns of the Nuclear Safety Task Force were either unfounded or had no relation to nuclear safety. As a result of this determination, with the concurrence of the NSMCTF, these items have been closed.
The remaining open items will be pursued to completion at a rate commensurate with their safety significance.
Resource commitments for resolution of these recommendations must be determined with full recognition of the relative safety significance of many other projects. The amount of progress made in resolution of these remaining recommendations is heavily influenced by the many other safety significant 8206160051 820611 PDR ADOCK 05000302 1
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General Office 3201 inuty fourin street soutn. P O Box 14042, St Petersburg. Fiorda 33733 e 813-866-5151
Mr. Harold R. Denton June 11,1982 Page 2 Plant additions and modifications currently in the design stage. We do, however, remain committed to the resolution of all Nuclear Safety Task Force recommendations affecting safety.
Attachment I details the current status of each item listed in our April 16, 1981 submittal. We will provide you with another update on the status of these items during the first quarter of 1983.
Very truly yours, 3
- J A
David G. Mardis Acting Manager Nuclear Licensing Attachment AEF:mm cc:
Mr. J. P. O'Reilly, Regional Administrator Of fice of Inspection & Enforcement U.S. Nuclear Regulatory Commission 101 Marietta Street N.W., Suite 3100 Atlanta, GA 30303 l
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ATTACHMENT 1 STATUS OF ENGINEERING STUDIES RESULTING FROM NUCLEAR SAFETY TASK FORCE RECOMMENDATIONS ITEM DESCRIPTION PRELIMINARY STUDY CURRENT STATUS NO.
RECOMMENDATION 1.19 Pursue one of several possible approaches for providing automatic reactor Do nothing Under in-house coolant pump trip.
review to deter-mme concurrence with study recommen-dation.
1.21 On electrical distribution panels - provide controlled drawings in each panel Drawings should be Work proceeding listing panel loads.
provided 3.6 Review loss of ICS and NNI for dif ferent failures and their effect on t' e Formal study should On hold pending components being controlled. Examples include: 1. Decreasing FW tios be dene of potential allocation of while with drawing roos. 2. Mid-scale failures. 3. Examine modifications ICS/NNI failures manpower of ICS to, ontoss of power: A. Fail MFW pump demand to 0. B. Fail MFW block valve closed. C. Fail low-load valve closed. D. Addition of new manual stations on demand to TBV's, ADV's, and SUFW valves. 4. Rod withdrawal limi-l tations.
3.9 Analyze NNI/ICS for failures which will go undetected until needed. Annun-Concern not war-Closed ciate as " trouble." Provide clear indication that a control or indication ranted has been lost.
j 3.10 Investigate whether transferring Tave control from reactor control to feed-Not a safety concern Closed water control improves system transient response.
3.11 Review the reliability of input signals from the NI/RPS system, specifically Not a safety concern.
Closed the RC flow signal.
Could be combined with item 3.6.
3.12 Study whether single failures can be handled so they do not cause loss of both Combined with item Closed automatic and manual control of a single component.
3.6 l
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ITEM DESCRIPTION PRELIMINARY STUDY CURRENT STATUS NO.
RECOMMENDATION 3.13 Remove mixtures of power supplies where possible. The signal conditioners Maintain existing Closed should be powered from the same source as indicator and transmitter.
design and revise procedures to align switches to NNI-X powered inputs.
3.21 In order to assure having means of relieving pressure during loss of one Preliminary study channel of NNI, the pressurize spray control should be powered / controlled still in progress from dNerse sources.
3.22 Item 1.2 recommends setting NNI signal select switches to make the Not a safety concern Closed "A" loop powered from (X) and the "B" Loop powered from (Y). Certain features of the present NNI arrangement prevent this and r lust be changed.
3.23 Change pressurizer level compensation from temperature compensation to Not a safety concern.
Closed pressure compensation. This concern is based on level error caused by Do nothing.
inherent time delays in the RTD sensors measuring pressurizer temperature.
3.24 Review interlocks which can fail on loss of a power suply to determine if Detally study should Under in-house bypasses are needed to allow normal shutdown or to accommodate emergency be performed.
review procedures.
5.35 Investigate multiple channel display capability for identifying failed signals Not a safety concern Closed before transferring to ICS control.
5.36 Provide a diesel backup air compressor (considering loss of offsite power Existing temporary Work proceeding event).
diesel air compressor should be made perma-nent.
5.49 Consider expanding the range of RC pressure indication to approximately 0-3000 Existing RC pressure On hold pending psig. Consider expanding ranges of other instrumentation such as T Hot, transmitters should be allocation of man-recalibrated.
power.
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ITEM DESCRIPTION PRELIMINARY STUDY CURRENT STATUS NO.
RECOMMENDATION 5.54 Identify and implement discrete changes in FW system to improve reliability Not a safety concern.
On hold pending and reduce safety system challenges.
Two modifications allocation of man-recommended for Plant power.
reliability upgrade.
5.65 An inadvertent actuation of B ESFAS with A pump running could cause destruc-Should be pursued Work proceeding tion of A MU pump (closure of MUV-64) unless operator acts. (Could cause failure of two pumps). Consider a suction pressure switch which will be de-feated on a full ESFAS signal.
3.75 Investigate various means for assuring reference legs for steam generator Diverse type sensors On hold pending levels - pressurizer levels, RC drain tank level, and makeup tank level.
should be used on allocation of man-Provide past documentation on the subject or additional work if necessary.
some level measure-power ments.
5.76 Replace Bailey Meter Co. model BY transmitters with Rosemount trans-Transmitters impor-Closed mitters. (Have high failure rate with pressurizer level, all BY'S tend to shift tant to safety have zero.)
been or soon will be replaced. No further action needed.
5.82 Investigate placing bypass valve around MSIV's or slow opening of MSIV's for Should be pursued Work proceeding equalizing pressure to prevent steam hammer.
5.95 Plant electrical auxiliaries are powered from startup transformer during opera-Preliminary study tian. If loss of offsite power occurs, Plant trips because FW, CD, etc., pumps still in progress trip. Should auxiliaries be powered from Plant auxiliary transformer, so that on loss of offsite power, Plant remains on-line (since auxiliaries would not be affected)?
5.105 Evaluate the sump systems for all safety-related rooms to ensure that flood-Concern not war-Closed ing from internal or external sources is adequately addressed.
ranted. Do nothing.
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3.106 Perform a detailed review of the communication paths between redundant safety-Concern not war-Closed
.related equipment to assure against common mode failure of steaming, fire, ranted. Do nothing.
and flood.
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1 ITEM DESCRIPTION PRELIMINARY STUDY
. CURRENT STATUS RECOMMENDATION NO.
5.113 The existing design of the ESFAS system causes start of the decay heat pumps Concern not war-Closed at 1500 psi. DH pumps cannot pump into the system until approximately 400 ranted. Do nothing.
psig is.eached. The pumps will sit on recirc for a significant length of time. Should there be a separate setpoint for DH pump actuation?
6.7 Design / install backup power sources (AC and DC) for NNI-(Y) channel.
Should be pursued Detailed study in progress 6.8 Review fuse coordination for all vital bus feeds.
Should be pursued Detailed study in progress i
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