ML17285A881
| ML17285A881 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 12/04/1989 |
| From: | Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17285A882 | List: |
| References | |
| GO2-89-221, NUDOCS 8912140005 | |
| Download: ML17285A881 (11) | |
Text
., ACCELERATED . DI 'TION I DEMONSTRA. ON SYSTEM REGULATORY NFORMATION DISTRIBUTION S EM (RIDS)
ACCESSION NBR:8912140005 DOC.DATE: 89/12/04 NOTARIZED: YES DOCKET
-FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION SORENSEN,G.C. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Application for amend to License NPF-21 re amend to Tech Spec 3.3.7.5 for safety-relief valve position indication.
DISTR1BUTION CODE: AOOID TITLE: OR COPIES RECEIVED:LTR Submittal: General Distribution
/ ENCL L SIZE: (n + I D
NOTES:
RECIPIENT COPIES RECIPIENT COPIES
.ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 l. PD5 PD 1 1 SAMWORTH,R 5 5 h ACRS 'NTERNAL:
6 6 NRR/DET/ECMB 9H 1 1 NRR/DOEA/OTSB11 1 1 NRR/DST 8E2 1 1 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NRR/DST/SRXB 8E 1 1 NUDOCS-ABSTRACT 1 1 OC B 1 0 OGC/HDS2 1 0 REG FILE 1 1 RES/DSIR/EIB 1 1 EXTERNAL: PDR 1 1 NRC PDR 1 1 NSIC 1 1 h
I TOTAL NUMBER OF COPIES REQUIRED: jTTR 27 ENCL 25
C
- i. - lk'H r
t
~ gP~
WASHINGTON PUBLIC POWER SUPPLY SYSTEM F.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 December 4, 1989 G02-89-221 Docket No. 50-397 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
NUCLEAR PLANT NO. 2; OPERATING LICENSE NPF-21 RE(VEST FOR AMENDMENT TO TECHNICAL SPECIFICATION 3.3.7.5 FOR SAFETY RELIEF VALVE POSITION INDICATION
Reference:
- 1) Letter, G02-87-265, GC Sorensen (SS) to NRC dated October 13, 1987
- 2) Letter, G02-88-161, GC Sorensen (SS) to NRC dated July 25, 1988
- 3) NRC SER dated October 16, 1987
- 4) NRC SER dated July 27, 1988 In accordance with the Code of Federal Regulations, Title 10, Parts 50.90 and
- 2. 101, the Supply System hereby submits a request for amendment to the WNP-2 Technical Specifications. Specifically, the Supply System is requesting that the required action for inoperable SRV position indication be revised. A new Action 82 in Table 3.3.7.5-1 will allow one of two indications to be inoperable until the next outage of sufficient duration to effect repairs, provided the remaining position indication and suppression pool temperature is frequently monitored. In addition, this change will allow both indicators to be inoperable on one SRV for 7 days with the same suppression pool temperature monitoring requirements.
The existing action for SRV position monitoring instrumentation requires that the plant be shutdown with one of two monitors inoperable for more than 7 days. On two separate occasions (Reference 1 and 2) the Supply System requested, and was granted (Reference 3 and 4), an emergency Technical Specification change due to the failure of one SRV position monitoring channel. These amendments allowed operation to continue until the next outage of sufficient duration to effect repairs. Without the emergency amendments, a forced shutdown would have been required. The Supply System has made modifications to the acoustic monitors and sesaa4ooo5 89<zoo PDR ADOCK O5000397 P PNU ,0I
I 0
~
1 ~
I
~ t Page Two RE(VEST FOR ANENDNENT TO TS 3.3.7.5 FOR SAFETY RELIEF VALVE POSITION INDICATION changed procedures to increase the reliability of the monitors. However due to the inherent sensitivity of the acoustic monitors future failures of the 'devices are to be expected. As in the previous instances cited above, the repairs could require entry into the drywell with the unit shutdown. To preclude the need for these emergency Technical Specification change requests the Supply System is requesting a permanent change. Absent approval of this request, continued plant operation given similar failures will remain soley dependent on the ability to process Emergency Technical Specification changes.
The operability of the accident monitoring instrumentation is based on providing assurance that sufficient information is available on selected plant parameters (e.g., SRV position indication) 'to monitor and assess important variables following an accident. THI Action Plant Item II.D.3 - Direct Indication of Relief and Safety Valve Position, requires that "Reactor coolant system relief and safety valves shall be provided with a positive indication in the control room derived from a reliable valve position detection device or a reliable indication of flow in the discharge pipe." The Technical Specifications for WNP-2 require two instrumentation channels for providing this information on valve position. One channel utilizes an acoustic monitor, and the second channel utilizes a thermocouple to detect a temperature increase indicative of flow past the valve. The loss of either channel on one or more SRVs does not prevent accurate determination of the position of the associated SRV(s). Further should an SRV open and remain stuck open the resulting transient does not represent the same magnitude of challenge to a BWR (such as WNP-2) as does a stuck open pressurizer relief or safety valve on a PWR. As discussed in the safety analysis of this event (WNP-2 FSAR 15. 1.4) .the operator response to this event is based on a suppression pool temperature alarm not an open alarm from the SRV position indication instruments. The mitigating actions are to attempt to close the open SRV and establish suppression pool cooling within 20 minutes. As discussed in this analysis even if the valve fails to close (worst case) the consequences of the event are mild. Hence the failure of an acoustic monitor causing an operator to review other instrumentation (as listed below) to determine which valve is open does not increase the severity of the transient. The valve can remain open.
Additionally, the loss of one or both channels on any number of SRVs does not affect the capability of any SRV to perform its intended function.
To support the operator in'etermining exist in addition to the channels described if any SRV may be open, the following above:
I) Numerous plant parameters are affected by an open SRV such as steam/feedwater flow mismatch, main turbine governor valve position change, generator output decrease, steam flow increase and reactor pressure perturbation.
Page Three RE(}UEST FOR AMENDMENT TO TS 3.3.7.5 FOR SAFETY RELIEF VALVE POSITION INDICATION
- 2) Cross talk due to noise pickup from acoustic monitors on SRV's adjacent to the SRV with the failed monitor. This capability has been demonstrated to be reliable and accurate on several occasions in the past.
- 3) Su~pression Pool temperature indication is available and is set to alarm at 85 F. An increase in suppression pool temperature could indicate an open SRV.
- 4) Suppression Pool level indication is available and is set to alarm at +0.5" and -I" of normal level (466'3"). An increase in suppression pool level could indicate an open SRV.
In addition to these independent indications, the requested action for one SRV position indication instrument channel inoperable includes a requirement to frequently monitor the remaining position indication channel. This provides sufficient capability to determine the SRV position to allow operation to continue. With this diversity and capability to assess the SRV position, the current action which requires a shutdown in 7 days is overly restrictive and may cause unnecessary transients during the resulting forced shutdown. The requested allowance to operate for up to 7 days with both indication channels inoperable is justified based on the remaining diverse parameters discussed above to support the operator's determination of actual SRV position. This 7 days allows time to attempt repairs or to schedule an outage to allow drywell entry for repairs not possible during operation.
The Supply System has evaluated this amendment request per 10CFR 50.92 and determined that it does not represent a significant hazard because it does not:
I) Involve a significant increase in the probability or consequences of an accident previously evaluated.
The SRV position indication channels are not assumed to function in the initiation of any analyzed accident. The inoperability of these indication channels does not affect the ability of the SRVs to function to relieve pressure nor dothey affect ADS operation of the SRVs. The analysis for an ~
inadvertent opening of an SRV (FSAR Section 15. 1.4) assumes the function of these alarm-'only instrument channels for the purpose of having the operator assess the need for commencing suppression pool cooling with RHR. As
~ ~
k'%
Page Four REQUEST FOR AHENDNENT TO TS 3.3.7.5 SAFETY RELIEF VALVE POSITION INDICATORS discussed above, the operator has many diverse indications available to indicate the need for commencing suppression pool cooling as a result of an open SRV and the SRV position indication is not the primary indication.
Loss of one or more SRV position indication channels will not adversely affect the operator's ability to respond to this event as assumed in the analysis. Therefore, this change will not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2) Create the possibility of a new or different kind of accident from any accident previously evaluated.
SRV operation, including the ADS function, remains unaffected. No new modes of operation of any equipment results due to this change. Sufficient diverse indication remains available to adequately determine whether an SRV is inadvertently open, therefore this change will not result in a failure to assess the need for suppression pool cooling. This change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3) Involve a significant reduction in a margin of safety.
As discussed above, the operator has many diverse indications available to indicate the need for commencing suppression pool cooling. Loss of one or more SRV position indication channels will not adversely affect the operator's ability to respond to this event as assumed in the analysis. The additional surveillances to monitor the remaining operable position indication channel and to monitor the suppression pool temperature while operation continues with an channel(s), as proposed in Action 82, will compensate for the lossinoperable of position indication channel(s). Therefore, this change will not involve a significant reduction in the margin of safety.
As the note on Page 3/4 3-71 is no longer applicable its deletion is considered an administrative matter and, as such, is not addressed in the above analyses.
As discussed above, the Supply System considers that this change does not involve a significant hazards consideration, nor is there a potential for significant change in the types or significant increase in the amount of any effluents that may be released offsite, nor does it involve a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10CFR 51.22(c)(9) and therefore, per 10CFR 51.22(b), an environmental assessment of the change is not required.
~~
Page Five e
RE/VEST FOR AHENDHENT TO TS 3.3.7.5 FOR SAFETY RELIEF VALVE POSITION INDICATIONS This Technical Specification change has been reviewed and approved by the WNP-2 Plant Operations Committee (POC) and the Supply System Corporate Nuclear Safety Review Board (CNSRB). In accordance with 10CFR 50.91, the State of Washington has been provided a copy of this letter.
Regulatory Programs PLP/bk Attachments cc: JB Hartin - NRC RV NS Reynolds - BCP&R RB Samworth - NRC DL Williams - BPA/399 NRC Site Inspector - 901A C Eschels - EFSEC
STATE OF WASHINGTON)
Subject:
T. S. Amendment for Safety
) Relief Va ve Posi ion n ication COUNTY OF BENTON )
I, R. Latorre, being duly sworn, subscribe to and say that I am the Nanager, Corporate Licensing and Environmental, for the WASHINGTON PUBLIC POWER SUPPLY SYSTEN, the applicant herein; that I have full authority to execute this oath; that I have reviewed the foregoing; and that to the best of my knowledge, information, and belief the statements made in true.
it are DATE / , 4 , 1989 R. Latorre, Manager Corp. Lic. 5 Environmental On this day personally appeared before me R. Latorr e, to me known to be the individual who executed the foregoing instrument, and acknowledged that he signed the same as his free act and deed for the uses and purposes herein E<<d mentioned.
d I li ~d ~D 1989.
Notary ublic in and or the STATE OF WASHINGTON Residing at Guà Ny commission expires 7 1 91
~ 0 I l v'" *4
- =
'k J
<<) r t
3 J
'r 4'
J
~