ML20211L359
| ML20211L359 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 10/07/1997 |
| From: | Jabbour K NRC (Affiliation Not Assigned) |
| To: | Reid D VERMONT YANKEE NUCLEAR POWER CORP. |
| References | |
| TAC-M98087, NUDOCS 9710100168 | |
| Download: ML20211L359 (8) | |
Text
I october 7, 1997 Mr. Donald A. Reid Senior Vice 0 resident. Operations-
' Vermont Yankee Nuclear Power Corporation Ferry Road Brattleboro, VT 05301
SUBJECT:
-REQUEST FOR ADDITIONAL INFORMATION REGARDING SAFETY AND RELIEF VALVE SETPOINT TOLERANCE AND POWER OPERATION WITH AN INOPERABLE-VALVE -
VERMONT YANKEE NUCLEAR POWER STATION (TAC NO. M98087)
Dear Mr. Reid:
By letter dated September 11, 1996, Vermont. Yankee Atomic Nuclear Power Corporation submitted proposed changes to the safety cnd relief valve (SRV) j
'setpoint tolerance and power operation with an inoperable SRV.
The NRC staff has reviewed the submittal, and, based on.its review, finds that
- responses to the enclosed request for additional information are needed before we can complete our review.
Please provide your responses within 30 days from the date of this letter.
If
.you have any questions regarding this matter, please contact me at (301) 415-1496.
Sincerely.
ORIGINAL SIGNED BY Kahtan N. Jabbour. Sr. Project Manager-Project Directcrate I 3 Division of Reactor Projects - I/II
-Office of Nuclear Reactor Regulation Docket No 50 271 i
Enclosure:
Request for Additional Information
}-
cc w/ enc 1: See next page
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Distributior)
I Docket..Fi16 OGC TCollins PUBLIC REaton ACRS PDI-3 RF Slittle CCowgill BBoger KJabbour RWessman T> receive a copy of t%le document, indicate in the boa: *C" = Copy without ettechment/ enclosure "E" = Copy with attachment / enclosure *N" = no copy
' C:VAB000R\\M98087.RAI WI
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DATE 10/ 6 /97 M ~
10/ 7 /97 10/G/97 10/07/97 10/V/ i97 0FFICIAL RECORD COPY W
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r Mr. Donald A. Reid Vermont Yankee Nuclear Power Vermont Yankee Nuclear Power Station Corporation i-CC:
~L Mr. Peter LaPorte. Director
, Regional Administrator, Region I ATTN: James Muckerheide U.-S.-Nuclear Regulatory Commission Massachusetts Emergency Management t
475 Allendale Road Agency King-of Prussia, PA 19406 400 Worcester Rd.
P.O. Box 1496 Mr. David-R. Lewis Framingham, MA 01701-0317 Shaw Pittman, Potts & Trowbridge l-2300 N Street, N.W.
Mr. Raymond N.-McCandless L
Washington, DC 20037-1128 Vermont Division of Occusational-and Radiological Healti Mr. Richard P. Sedano, Commissioner Administration Building i
Vermont Department of Public Service Montpelier, VT 05602 120 State Street, 3rd Floor Montpelier VT 05602 Mr. J. J. Duffy Licensing Engineer Public Service Board Vermont Yankee Nuclear Power State of Vermont Corporation 120 State Street 580 Main Street Montpelier, VT 05602 Bolton, MA~ 01740-1398 Chairman, Board of Selectmen Mr. Robert J. Wanczyk Town of Vernon_
Director of Safety and Regulatory P.O. Box 116 Affairs Varnon, VT 05354-0116 Vermont Yankee Nuclear Power Corp.
185 Old Ferry Road Mr. Richard E.- McCullough Brattleboro, VT 05301 Operating Experience Coordinator Vermont-Yankee Nuclear Power Station Mr. Ross B. Barkhurst, President P.O. Box 157 Vermont Yankee Nuclear Power Governor Hunt Road Corporation Vernon, VT 05354 185 Old Ferry Road Brattleboro, VT 05301 G. Dana Bisbee, Esq.
Deputy Attorney General Mr. Gregory A. Maret, Plant Manager 33 Capitol Street Vermont Yankee Nuclear Power Station Concord, NH 03301-6937 P.O. Box 157 Governor Hunt Road
-Resident Inspector Vernon.-VT 05354
. Vermont Yankee Nuclear Power Statir
- U.S. Nuclear Regulatory Commissior Ms. Deborah B. Katz P.O. Box:176 Box 83 Vernon, VT 05354 She11burne Falls, MA 01370 Chief, Safety Unit Mr. Jonathan M. Block, Esq.
Office of the Attorney-General Main Street One Ashburton Place, 19th Floor P.O. Box 566 Boston, MA- 02108 Putney, VY 05346-0566
i f
+-
REQUEST FOR ADDITIONAL INFORMATION BY THE 0FFICE OF NUCLEAR REACTOR REGULATION i
VERMONT YANKEF NUCLEAR POWER STATION
-l 7
R KET NO. 50-271 1
1.
Discuss the original basis for 95% power limitation in technical specifications?
2.
Does Vermont Yankee (VY) Corporation use the GESTAR methodology for reload '
analysis? If not, what is the approved methodology? List the computer codes that are used for reload analysis s.nd confirm that all codes and methodology have been previously approved by NRC. Does the fuel vendor or Vermont Yankee Nuclear Power Corporation perform the reload analysis? Explain the use of the FROSSTEY
,I code and confirm that the use of this code has been approved.
3.
Regarding the main steam isolation valve closure pressurization event, clarify the assumptions regarding the event, including whether credit is taken for the relief mode of aperation for the safety relief valves (SRVs). Are the two SRVs considered operable? Is there any dependence on which SRV is chosen inoperabte?
. It appears that the most conservative case would be to choose the SRV with the lowest setpoint as inopLrable. Please discuss this case.
^
4.
The high pressure systems performance must be evaluated with the proposed -
technical specifications changes. The impact on high pressure coolant injection, j
reactor core isolation cooling, and standby liquid control systems' performance L
must be evaluated, in addition to any other systems with the potential for injection to the vessel at the higher pressures.
5.
Discuss the impact of the proposed changes on any plant specific altemate operating modes (e.g., increased core flow, extended operating domain, etc.)
6.-
From page 19 of submittal, what is base cat,e Peak Clad To:nperature (PCT)? Also, has the main steam line break outside containment been addressed? Has PCT for this event been analyzed with the proposed changes?
- 7. -
Please explain the quote from page 7 of the submittal dated September 11,1996:
i.
"The plant modelis changed to reflect the expected tolerances of the SRVs L
and SVs [ safety valves). As found testing has demonstrated the expected tolerances of the SRVs and SVs to be less than 1% For purposes of l
demonstration of no SV lift with an inoperable SV, a + 1% tolerance is applied L
to the SRVs and a -1 % tolerance to the SVs."
Why are the tolerance assumptions reduced from 3% to 1% for evaluating SRV challenges?
6 ENCLOSURE
)
.w I
2 8.
Page 3 of the cover letter provides the sequence to be followed for imple'menting the relaxed setpoint tolerance. item no. 5 states that subsequent to the 1998 4
refueling outage, all SRVs and SVs will be as-found/as-left tested within 13%I 1% of the technical specification l' nit. Confirm that this statement means that all SRVs/SVs will be tested at least at every 18 months.
3.
One SRV Inoperable implies that the automatic depressurization system (ADS) modo of the SRV would also be Inoperable, is ADS affected in any way by the proposed changes? If so, is there an impact on PCT for any ADS blowdown scenario?
10.
Has the anticipated transient without scram event been addressed for the case of M
one Inoperable SRV? In particular, is the American Society of Mechanical Engineers Code Service Level C value of 1500 psig satisfied for one inoperable SRV?.
11.
On page 22 of Attachment C to the submittal,it is stated that mechanicalloads on the SRV piping / supports and Torus have been evaluated for the proposed increase in the SRV setpoint tolerance to +/ 3%. The setpoint tolerance of the SVs are
]L-similarly proposed to be increased. Please verify that the loads on the main steam and SV piping / supports have also been evaluated for the increased SV setpoint tolerance, 12.
Please verify that the capability of various motor operated valves (MOVs) to operate open or closed, as necessary during peak transient differential pressure loads, has been evaluated for the proposed increased SV and SRV setpoint tolerance.
~
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k tober 7, 1997
-Mr. Donald-A. Reid LSenior.Vice President. Operations Vermont-Yankee Nuclear Power Corporation Ferry Road Brattleboro.-VT 05301
SUBJECT:
RE0VES1 FOR ADDITIONAL INFORMATION REGARDING SAFETY AND RELIEF VALVE SETP014T TOLERANCE AND POWER OPERATION WITH AN INOPERABLE VALVE -
VERMONT YANKEE NUCLEAR POWER STATION (TAC NO, M98087)
Dear Mr. Reid:
By letter dated September 11, 1996. Vermont Yankee Atom *' "9 clear Power Corporation submitted proposed changes to the safety an; :'ief valve (SRV) setpoint tolerance and power operation with an inoperable MV,
-The NRC staff has reviewed the submittal, and, based on its review.. finds that
-responses to the enclosed request for additional information are needed before we can complete our review.
Please provide your responses within 30 days from the date of this letter.- If you have.any questions regarding this matter. please contact me at (301) 415-1496.-
Sincerely.
4 ORIGINAL SIGNED BY Kahtan N. Jabbour. Sr. Project Manager Project Directorate I-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket No. 50-271
~
Enclosure:
Request for Additional Information cc w/ enc 1:
See next page Distribut' on Docket F11e-OGC TCollins PUBLIC REaton ACRS PDI-3 RF Slittle CCowgill BBoger w.bbour RWessman KJa p
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10/ 7 /97 10/k/97 10/o7/97 10r/ /97 UFFICIAL RtLORD COPY
I 6
Mr. Donald A. Reid
- Vermont Yankee Nuclear Power Vermont Yankee Neclear Power Station Corporation cc:
Mr. Peter LaPorte, Director Regional Administrator, Region I ATTN: James Muckerheide U. S. Nuclear Regulatory Commission Massachusetts Emergency Management 475 Allendale Road Agency King of Prussia, PA 19406 400 Worcester Rd.
P.O. Box 1496 Mr. David R. Lewis Framingham, MA. 01701-0317 Shaw Pittman, Potts & Trowbridge 2300 N Street, N.W.
Mr. Raymond N. McCandless Washington, DC 20037-1128 Vermont Division of Occu)ational and Radiological Healt1 Mr. Richard P. Sedano, Commissioner Administration Building Vermont Department of Public Service Montpelier, VT 05602 120 State Street, 3rd Floor Montpelier, VT 05602 Mr. J. J. Duffy Licensing Engineer Public Service Board Vermont Yankee Nuclear Power State of Vermont Corporation
.120 State Street 580 Main Street Montpelier, VT 05602-Bolton, MA 01740-1398 Chairman, Board of Selectmen Mr. Robert J. Wanczyk Town of Vernon Director of Safety and Regulatory P.O. Box 116 Affairs Vernon, VT 05354-0116 Ver.aont Yankee Nuclear Power Corp.
185 013 Ferry Road
.Mr. Richard E.-McCullough Brattleboro, VT 05301 Operating Experience Coordinator Vermont Yankee Nuclear Power Station Mr. Ross B. Barkhurst, President P.O. Box 157 Vermont Yankee Nuclear Power Governor Hunt Road Corporation Vernon, VT 05354 185 Old Ferry Road Brattleboro, VT 05301 G. Dana Bisbee, Esq.
Deputy Attorney General Mr. Gregory A. Maret, _ Plant Manager 33 Capitol Street Vermont Yankee Nuclear Power Station Concord, NH- 03301-6937 P.O. Box 157 Governor Hunt Road Resident Inspector Vernon, VT 05354 Vermont Yankee Nuclear Power Station U.S. Nuclear Regulatory Commission Ms. Deborah B. Katz P.O. Box 176 Box 83 Vernon, VT 05354 Shellburne Falls, MA 01370 Chief, Safety Unit Mr. Jonathan M. Block, Esq.
Office of the Attorney General Main Street One Ashburton Place, 19th Floor P.O. Box 566 Boston, MA 02108 Putney, VY 05346-0566
3 REOUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l
VERMONT YANKEE NUCLEAR POWER STATION DOCKET NO. 50-271 1.
Discuss the original basis for 95% power limitation in technical specifications?
2.
Does Vermont Yankee (VY) Corporation use the GESTAR methodology for reload l
analysis? If not, what is the approved methodology? List the computer codes that l
are v*sd for reload analysis and confirm that all codes and methodology have been previously approved by NRC Does the fuel vendor or Vermont Yankee Nuclear l'
Power Corporation perform the reload analysis? Explain the use of the FROSSTEY code and confirm that the use of this code has been approved.
3.
Regarding the main steam isolation valve closure pressurization event, clarify the a:sumptions regarding the event, including whether credit is taken for the relief mode of operation for the safety relief valves (SRVs). Are the two SRVs considered operable? Is there any dependence on which SRV is chosen inoperable? -
It appears that the most conservative case would be to choose the SRV with the lowest setpoint as inoperable. Please discuss this case.
4.
The high pressure systems performance must be evaluated with the proposed technical specifications changes. The impact on high pressure coolant injection, reactor core isolation cooling, and standby liquid control systems' performance must be evalustad, in addition to any other systems w!th the potential for injection to the vessel at the higher pressures.
5.
Discuss the impact of the proposed changes on any plant specific altemate operating modes (e.g., increased core flow, extended operating domain, etc.)
8.
From page 19 of submittal, what is base case Peak Clad Temperature (PCT)? Also, has the main steam line break outside containment been addressed? Has PCT for this event been analyzed with the proposed changes?
. 7.
Please explain the quote from page 7 of the submittal dated September 11,1996:
"The plant modelis changed to reflect the expected tolerances of the SRVs and SVs [ safety valves]. As found testing has demonstrated the expected tolerances of the SRVs and SVs to be less than 1%. For purposes of demonstration of no SV lift with an inoperable SV, a + 1% tolerance is s,pplied to the SRVs and a -1 % tolerancs to the SVs."
Why are the tolerance assumptions reduced from 13% to 1% for evaluating SRV challenges?
ENCLOSURE
-o.
y l
l 8..
Page 3 of the cover letter provides the sequence to be followed for'impleinenting
. the relaxed setpoint tolerance item no. 5 states that subsequent to the 1998 refueling outage, all SRVs and SVs will be as found/as left tested within
- 3%/* 1% of the technical specification limit. Confirm that this statement means that all SRVs/SVs will be tested at least at svery 18 months..
9.
- One SRV inoperable implies that the automatic depressurization system (ADS) mode i
of the SRV would also be inoperable, is ADS affected in any way by the proposed changes? If so, is there an impact on PCT for any ADS blowdown scenario?
10.
Has the ant:.:lpated transient without scram event been addressed for the case of one inoperable SRV? In particular, is the American Society of Mechanical Engineers Code Service Level C value of 1500 psig satisfied for one inoperable SRV?,
=11.
On page 22 of Attachment C to the submittal, it is stated that mechanicalloads on the SRV piping / supports and Torus have been evaluated for the proposed increase in the SRV setpoint tolerance to +/ 3%. The setpoint tolerance of the SVs are similarly proposed to be increased. Please verify that the loads on the main steam and SV piping / supports have also been evaluated for the increased SV setpoint to;erhGCS.
12.
Please verify that the capability of various motor-operated valves (MOVs) to operate open or closed, as necessary during peak transient differential pressure loads, has been evaluateu for the proposed increased SV and SRV setpoint tolerance.