ML20070C823
| ML20070C823 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 02/15/1991 |
| From: | Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NYN-91027, NUDOCS 9102260185 | |
| Download: ML20070C823 (5) | |
Text
New Hampshire-Ted C. Feigenboum M}
Piepdent and CNel Exewtive Officer i
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NYN 91027 February 15, 1991 J
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United States Nuclear Regulatory Commission.
l Washington, D.C.
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i Attention:
Document Control Desk i
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Reference:
Pacility Operating License No. NPP 86,' Docket No. 50 443
Subject:
Inservice Inspection Program Plan, Relief Request IR 6 '
Ocntlemen:
I Enclosed, please find Relief Request IR 6 to the Seabronk Station, Unit 1, First 10-l Year Interval Inservice Inspection-Program Plan, Revision 0.1 tis tellef request addresses hydrostatic testing of Class 1 and Class 2 piping system. and it. submitted purr.uant to j
10CPit$0.55a(g)(5)(ill).
i New llampshire Yankee requests NRC approval of this relief request by May 31.1991 so that it may be implemented during the first refueling outage which is scheduled to begin' i
on July 27, 1991, i,!
Please direct any questions regarding this letter to-Mr. James M. Peschel, Regulatory-
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Compilance Manager at (603) 474 9521 extcusion 3772.
i'l Very truly yours, h&
M4b*
Ted C. Felgenbaum -
Enclosure
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L 9102260185 910215 PDR ADOCK 05000443
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l ' y-New Hompshire Yankee Division of Public Service Company of New Hampshire 1
g, cg P.O. Box 300 = Ses!xook, NH 03874
- Teleplene (603) 474 9521 <
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United States Nuclear Regulatory Commission February 15, 1991 Attention:
Document Control Desk Page two cc:
Mr. Thomas T. Martin Regional Administrator United States Nuclear Regulatory Commission Region 1 475 Allendale Road King of Prussia, PA 19406 Mr. Gordon E. Edison, Sr, Project Manager Project Directora!c l 3 Division of Reactor Frojects U.S. Nuclear Regulatory Commission Washington, DC 20555 Mr. Noel Dudley NRC Senior Realdent Inspector P.O. Box 1149 Seabrook, Nil 03874 4
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ATTACHMENT A Page 1 of 3 RELIEF REQUEST IR-6 Seabrook Nuclear Power Station Unit No. 1 Relief from Inservice InsDection Reouirements Relief Reauest:
IR-6 Component Identification: Class 1 and 2 Ten Year Hydrostatic Tests Code Class:
1 and 2 Examination Cateoorv B-P and C-H Code Reauirement:
For Seabrook Unit No. 1 hydrostatic testing for Class 1 and 2 piping systems shall be accomplished once every 10-years.
This is in accordance with ASME-3 B&PV Code,Section XI, 1983 Edition through the Summer 1983 Addendum'as stated in Table IWB-2500-1-and IWC-2500-1.
Code Relief Reouest:
Pursuantto10CFR50.55(a)drostaticteststoClass1andClass2oystemsfor (g)5(iii)and-(iv),reliefisrequestedfrom performing the 10 year hy Seabrook Unit No. 1.
Basis for Relief:
For Class 1 Systems:
Currently, Seabrook Unit No. 1 is required to perform hydrostatic pressure tests in accordance with IWB-5000. As a minimum, these tests are required to beperformedatleastonceduringeachISIinterval.(i.e.,-every10 years).
Theminimumrequiredtestpressuredecreasesasthetesttemerature(reactor coolant system temperature increases.
In a cold condition temperature <
100'F),minimumtestpracr.,e~isequalto1.10xP,.
P is t e nominal
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operating pressure assoitated with 100% power operation,.
In a hot condition,-
(temperature > 500*F',, the minimum test pressure is reduced to 1.02 x P' Seabrook has a nov:nal operating pressure of 2250 )sia,z therefore, the I'. cold" hydrostatic test pressure would be 2475 psia and tie " hot" test pressure would-be 2295 psia.
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l ATTACHMENT A Page 2 of 3 RELIEF REQUEST IR-6 Seabrook Nuclear Power Station Unit No. 1 Relief from inservice Inspection Reauirements
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(continued) i Basis for Reliefs (continued)
No additional benefit would be gained by conducting the existing Class I hydrostatic test versus a leak test at normal operating pressure.
Testing l
does not verify the structural integrity nor encompass peak pressures-associated with the limiting design basis upset event (i.e.,1.25 x P,,,t,,).
t Also, no real benefit could be derived from a 1.25 x P,,,i,, pressure test.
This type of hydrostatic test does not consider other stresses, such as thermal and dynamic loads, associated with design basis upset events.
Any-remaining benefits do not out weigh the major problems associated with the performance of a 1.25 x P,,,i,, pressure test.
For Class 2 Systems:
Class 2 ten year hydrostatic pressure tests are conducted in accordance with.
IWC-5000 requirements. A system hydrostatic pressure test:is conducted at 1.10 x Psv for systems with design temperatures < 200*F, and 1.25 x Psv for-systems with a design temperature >.200*F.
Psv shall be the lowest pressure setting amon protection. g the-safety and relief valves provided for over-pressureFor systems, o relief valves P,..t,,
= P,,.
The reasoning associated with the Class 2 hydrostatic tests ~is somewhat.the same as stated for Class 1 systems.
Specific differences exist for Class 2 systems.
Class 2 systems have significantly less number of welds examined by NDE, and are subject to erosion corrosion type problems which have not-manifested themselves in Class 1 systems.
Looking at past industry experience, this experience has shown that leaks and through wall flaws are not found during 10 year hydrostatic tests. Typically, service induced type of problems are found as part of plant operator walkdown:
inspections during normal operation.. Frequent system walkdown inspections at normal operating pressure have proven.to be most effective. This is especially true for erosion corrosion concerns.
A system hydrostatic test i
every 10 years cannot be relied upon to find these type problems.
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t ATTACHMENT A l
Page 3 of 3 RELIEF REQUEST IR-6 l
Seabrook Nuclear Power Station Unit No. 1 Relief from Inservice inspection Reauirements 1
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Proposed Alternative Examinations:
1.
As an alternative for the Class 1 Ten Year Hydrostatic Pressure Test (IWB-5222)specifiedinTableIWB-2500-1CategoryB-P,thefollowing l
shall be performed:
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a.) A system leakage test shall be performed once each inspection interval.
b.) The boundary subject to test presshrization during the system leakage I
test shall extend to all Class 1 pressure retaining components within the system boundary.
c.) Prior to the start of the system leakage test, the system shall be pressurized to nominal operating pressure for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated systems and 10 minutes for noninsulated systems.
The system shall be maintained at nominal operating pressure during.the performance of the VT-2 visual examination, d.)Testtem)eraturesandpressuresshallnotexceedlimitingconditions for the lydrostatic test curve as contained in Technical Specifications, i
e.) The VT-2 visual examination shall extend to all components within the safetyclassboundaryidentifiedin1(b)above.
2.
As an alternative for the Class 2 Ten Year Hydrostatic Pressure Test (IWC-5222) specified in Table IWC-2500-1 Category C-H, the following shall be performed:
a.)Asystemleakagetestshallbeperformedonceeachinspection
- interval, b.) The boundary subject to test pressurization during the system-leakage test shall extend to all Class 2 components included in those portions of systems required to operate or support the safety system function up to and including the first normally closed valve (including a safety or relief valve) or valve capable of autoclosure i
when the safety function is required.
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c.) Prior to the start of-the system leakage test, the system shall be pressurized to nominal operating pressure for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 1
for insulated systems and 10 minutes for noninsulated systems.
The system shall be maintained at nominal operating pressure during the performance of the VT-2 visual examination, d.) The VT-2 visual examination shall extend to all components within the safetyclassboundaryidentifiedin2(b)above.
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