2CAN129012, Provides Update Re Commitment on One of Two Compensatory Actions Concerning RCS Leak Detection Insp.Util Believes That Periodic Containment Entries & Performance of RCS Leak Detection Insp No Longer Necessary
| ML20065R794 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 12/11/1990 |
| From: | James Fisicaro ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 2CAN129012, NUDOCS 9012190176 | |
| Download: ML20065R794 (3) | |
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December 11, 1990 2CAN129012 U.S. Nuclear Regulatory Commission Document Control. Desk Washington, D.C. 20555
Subject:
Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Reactor Coolant System Leak Detection Inspection Gentlemen:
In an Arkansas' Nuclear One - Unit 2 (AN0-2) letter dated August 12,-
1988, (2CAN088801),." Licensee Event Report No. 50-368/87-003-01",
interim compensatory actions were imp 1 rented until final-pressurizer repairs could be completed at the :~csequent refueling outage.
ANO is' providing an update regarding its commitment on one of the two compentatory actions.
The initial condition was identified as a small leak from a' Reactor Coolant System (RCS) pressurizer heater sleeve caused by-the failure of a heater sheath.
The RCS leakage subsequently:
resulted in boric acid induced corrosion of the pressurizer shell.
The-damaged area was repaired'using a temporary weld. Additionally, several f
pressurizer features were removed and temporary plugs welded into their sleeves._ An interim commitment was made to perform containment building inspections while ANO-2 was at power unless-prohibited by ALARA considerations due to abnormal containment conditions.
The inspection r
specifically included. examinations of the pressurizer lower head where temporary plugs welded to sleeves were installed.
The primary purpose
~
of the entries was to conduct an_ inspection of the accessible areas-of-1 the:'co_ntainment b~ilding-to identify and assess RCS leaks until a u
permanent repair of the_ pressurizer was completed.
3 The pressurizer vessel permanent repairs were completed during th'e 2R6-D
' refueling._ outage in early 1988.
Subsequent to the-outage, the inspections were_ continued on.a quarterly-basis..Since the permanent-repairs were completed, some minor leaks have been identified which were 3.-
not'related:to boric' acid induced co_rrosion.
Performing the subject' inspection at power po'ses several industrial safety, concerns. regard _ing heat stress, oxygen deficient atmospheres,. lighting,' communications and j
other personnel safety matters.
In addition, other processes and
. procedures have been implemented which were not in place in 1987.
Some of these are':
1.
Procedure 2305.02D,L i' Reactor Coolant System Leak Detec.f on",
contains a trigger mechanism established on the leak rate-form to perform an investigation if the unknown leakage exceeds the seven 00bl
'9012190176 901211 PDR ADOCK 05000368 g
PDR j y,
-e U.S. NRC December 11, 1990 Page 2 day average by.3 GPM.
The RCS leak rates (known and unknown) and any leakage within the containment building are plotted in the control room to enhance the capability to more readily recognize changes and trends in the data.
An auto leak rate program has been incorporated in the plant computer which has resulted in a smoother leak rate calculation.
This has led to a higher credibility of the deta and therefore a quicker response by plant operations and management.
2.
Upon completion of a plant shutdown to hot standby, Procedure 2102.10, " Plant Shutdown and Cooldown", requires the performance of a RCS structural integrity inspection.
This inspection is a more thorough and time consuming surveillance than the "at power" containment inspection because it also requirea the cavity areas be inspected.
3.
Af ter completion of an RCS heat-up to hot standby, Procedure 2102.002, " Plant Startup", requires the performance of an RCS structural integrity inspection, and determine an RCS leak rate-prior to power operations.
This inspection airo requires engineering standards to evaluate the leakage and determine its acceptability.
AN0's May 27, 1988 (OCAN058813) response to Generic Letter 88-05 discusses the actions to address boric acid' corrosion consistent with the NRC guidance.
This letter does.not alter AN0's existing guidelines which include design methods to minimize the potential for RCS leakage and maximize the ability.to detect RCS leakage.
AN0 management believes the periodic containment entries and performance of RCS leak detection inspection, as previously committed, is no longer
-necessary.
Current procedural requirements and leakage detection
-systems are sufficient to identify and assess RCS leaks. We believe it is prudent to make containment building power entries to investigece l.
elevated RCS leakage if necessary but not on any specific frequency.
l This change has been discussed with members of the NRC staff Should you.have any-questions please contact me.
L Sincerely, pW.S*
l James J Fisicaro L
Manager, Licensing JJF/RJK/mmg cc: Mr. Robert Martin U. S. Nuclear Regulatory Commission Region IV l
611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 l
U.S. NRC Decemb?r 11,-1990 Page 3 cc: Thomas W. Alexion NRR Project Manager, Region IV/ANO-1 U. S. Nuclear Regulatory Commission NRR Mail Stop 11-B-19 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852 NRC Senior Resident Inspector Arkansas Nuclear One - ANO-1 & 2 Number 1, Nuclear Plant Road Russellville, AR 72801 Ms. Sheri Peterson NRR Project Manager, Region IV/ANO-2 V. S. Nuclear Regulatory Commission NRR Mail Stop 11-B-19 One White Flin. North 11555 Rockville Pike Rockville, Maryland 20852 i
l l