ML20155G233
| ML20155G233 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/06/1988 |
| From: | Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 87-742A, NUDOCS 8810140142 | |
| Download: ML20155G233 (5) | |
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VIMOIN A Ex.ncTunc Ann Powan Coxprxy HicuMoxo,Vamoixta unun October 6, 1988 l
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t United States Nuclear Regulatory Comission Serial No.
87-742A Attention:
Document Control Desk N0/JDH:Jmj l
Washington, D.C.
20555 Docket Nos.
50 338 i
50 339 i
License Nos. NPF 4 i
NPF 7 t
P Gentlemen:
11RENIA ELEGIBIC_MOREILCOMPE NQR]lLANNA POWER STAIIDH UNITS 1_AN(L2 f20 POSED TECliNICAL SPECiflGAUON CHANGE.. SUPPLEMENT REACIOR COOL ANT SYSTIM LEAllAGE DETECTION SYSTEN On July 20, 1988, we submitted a proposed Technical Specification change for North Anna Units 1
and 2
to clarify the requirements of Technical
[
Specification 3.4.6.1 regarding RCS leakage detection systems.
We request l
that the proposed change be treated as an exigent request in accordance with 10CFR50.91(a)(6).
The basis for our request is discussed in the enclosure, i
t if you require additional information or have any questions, please contact us imediately.
t Very truly.yours,
/
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W. R. Cartwrt(ht Vict President Nuclear j
Enclosure kM
$*$$$i!S$$8$$$
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cc:
U. S. Nuclear Regulatory Comission i
101 Marietta Street, N.W.
Suite 2900 I
Atlanta, GA 30323 Mr. J. L. Caldwell NRC Senior Resident inspector r
North Anna Power Station Comissioner Department of Health i
Room 400 109 Governor Street Richmond, Virginia 23219 1
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BASIS.JOR EXIGENT REQUEST 10CFR50.91(P' equires the licensee to explain an exigent request and why it cannt ned. The regulation also requires NRC to use its normal procedures i' nir.es that the licensee failed to use its best effort to make a time;
. ion for the amendment to create the exigency and take advantage o,
.adure. These issues are discussed below.
Backarousj On July 20, 1988, Virginia Power submitted a proposed Technical Specifications change, for Nurth Anna Units 1 and 2, to clarify the requirements of Technical Specification 3.4.6.1 regarding RCS leakage detection systems.
The limiting condition for operation (LCO) was revised to require 1) the containment atmosphere particulate and gaseous radioactivity monitoring system, and 2) the cratainment sump level and discharge flow measurement system to be operable.
The current LC0 was difficult to understand because it was interpreted to require two leakage detection systems to be operable, whereas the associated action statement wa:, interpreted to require three separate and independent methods to be operable.
Regulatory Guide 1.45 requires three separate detection methods of which two of the methods should be 1) the containment particulate radioactivity monitoring system and 2) the containment sump level and discharge flow measurement system.
Regulatory Guide 1.45 also requires a third method which is satisfied by the containment gaseous radioactivity monitoring system.
The proposed change :larifies the specification such that the containment particulate and gaseous monitoring system are considered as two separate detection methods but are nqt considered as two indepen.'ent systems.
Specifically, the monitors share a common piping system, power supply and piping arrangement that do not make them truly independent.
Therefore, the action statement was modified to achieve consistency with the LC0.
Specifically, if either of the two required leakage monitoring systems are inoperable, a compensatory leakage measurement using the RCS water inventory balance method is specified instead of obtaining grab samples.
The current specification docs not require a compensatory leakage measurement if the containment sump discharge measurement system is inoperable whereas the revised specification does.
This compensatory leakage measurement along with a fully operable leakage detectior system is the basis for extending the action statement from six hours to 40 days when o;.e leakag7 detection system is inoperable.
The surveillance requirements have also oeen rewritten to require a periodic calibration of the containment sump level monitor.
The proposed Technical Specification changes are consistent with the regulatory position of Regulatory Guide 1.45, "Reactor Coolant Pressure Boundary Leakage Detection Systems" and NUREG 0452, "Westinghouse Standard Technical Specifications".
Specifically, three separate detection methods are provided but they are grouped as two separate and redundant detection systems.
The loss of a single system would not result in the loss of detection capability.
Therefore, regulatory position #9 of Regulatory Guide 1.45 is fully met.
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Basis for Reauest l
The action statement of Technical Specification 3.4.6.1 has been entered twice in the last few weeks.
On September 22, 1988, the saal on the particulate filter housing was leaking.
Because the two monitors share a common piping system, the containment particulate and gaseous monitoring system was declared inoperable.
The system was returned to operable status when a temporary seal was put on the filter housing. On October 3, 1988, the purge inlet S0V to the containment particulate and gaseous monitor failed causing the control power fuses to the monitors to blow rendering the system inoperable.
The SOV was electrically isolated, the fuses were replaced, and power was restored.
The system was returned to service.
In both cases, the current specification require us to enter into a six hour action statement.
This action can result in undue pressure on operations and l
maintenance personnel to conduct troubleshooting / repair activities on a highly accelerated schedule.
If the actions are unsuccessful, it can also result in unnecessary challenges to plant systems to respond to an unplanned, rapid rampdown to meet the action statement requirements.
The action statement in the proposed specification would permit a 30 day - rather than six hour -
period to take appropriate actions for the events described above.
Certain compensatory actions are also required.
Need for Prompt NRC Action Currently, a temporary seal has been installed on the filter hout ng.
9e S0V has been electrically isolated and the fuses were replaced.
Additional corrective action appears warranted.
For example, further testing of the pump i
motor seems prudent.
- However, the current specification effectively discourages such activity by the time constraints imposed.
We believe that a request to process the Technical Specification change in an exigent manner is justified to support maintenance actions that are timely, but not hurried.
In addition, until the additional corrective actions can be effectively implemented, the possibility exists that adverse conditions may develop necessitating additional entries into the overly-restrictive action statement.
1 Avoidina the Exiaent Reauest We have considered several alternatives to this exigent request:
requesting an emergency TS change, requesting discretionary enforcement, and taking no further action.
Although we consider that the circu'nstances described above warrant prompt action by NRC, the concern does not meet the criterion in 50.91 for an emergency Technical Specification change in that a plant shutdown or derating is not imminent.
Discretionary enforcement is not appropriate to the circumstances.
The current specification can be met, if necessary.
This request centers on the recognition that alternatives preferable to promptly shutting down an operating unit are available.
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If no exigent action is taken, the proposed Technical Specification would be processed in normal fashion.
Other regulatory issues could take priority in NRC's review and approval process.
If a situation similar to those discussed above were to disable a sampling method resulting in less than the required number of systems, both we and NRC would again be forced into a reactive mode on a short time frame.
Licensee Best Efforts Toward A Timely Acolication One alternative to the exigent request not discussed above was our proactive 1
effort in July 1988 to identify and submit for NRC review and approval the 1
clarification of Technical Specification 3.6.4.1.
At that time, we believed we were taking appropriate actions that would improve the specifications and prevent the type of occurrence currently being discussed.
We also believe that this request is timely in that we recognize that the possibility exists for additional problems on the RCS leakage detection systems.
On two previous occasions, minor problems could have had consequences out-of-proportion with their significance.
We believe that this application reflects that recognition and proposes action in a timely manner to preclude recurrence.
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