ML17321A387
| ML17321A387 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 01/10/1985 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML17321A386 | List: |
| References | |
| NUDOCS 8501280753 | |
| Download: ML17321A387 (7) | |
Text
SAFETY EVALUATION REPORT REQUEST FOR RELIEF FROM SECTION XI HYDROSTATIC TEST REQUIREMENTS INDIANA & MICHIGAN ELECTRIC COMPANY D.
C.
COOK UNITS 1 & 2 I.
BACKGROUND INFORMATION 10 CFR 50.55a requires that inservice examinations and tests be performed in accordance with the requirements of the applicable edition and addenda, of Section XI of the ASME Code unless such requirements are impractical to perform and relief from those requirements are granted, by the Commission.
By letter dated July 23, 1984, Indiana and Michigan Electric Company requested relief from the 1004F minimum temperature and four-hour holding time requirements of the 1974 Edition through Summer 1975 Addenda of Section XI for D.
C.
Cook Units 1 & 2.
The letter also contained information supporting the request.
Pursuant to 10 CFR 50.55a(g)(6)(i), this information has been reviewed and evaluated with the necessary findings made to grant relief from the Code requirements as requested.
II.
RELIEF RE VEST Relief is requested from the 100 F minimum temperature requirement during hydrostatic tests of Class 2 systems and the four-hour hold time for noninsulated systems.
III.
CORE REIEOIRRIIEOI EERIE EOI I 4
The system hydrostatic test shall be conducted at a test temperature not less than 100'F except as may be required to meet fracture tough-ness criteria applicable to ferritic materials.
The test pressure and temperature shall be maintained for at least four hours prior to the performance of the examinations.
850i280753 850ii0 PDR ADOCK 05000315 P
IV.
LICENSEE'S BASES FOR RE UESTING RELIEF (Generally quoted from licensee s
u y etter The basis for requesting code relief from the temperature requirements is that heating these systems to, and maintaining 100 F minimum test temperature will be impractical, extremely difficult and costly to achieve.
Me believe the 100'F minimum temperature as specified by the 1974 Code Edition does not have a firm technical basis.
The 100'F temperature was chosen as a rounded-off number that would be substan-tially above the ductile to brittle transition temperature of ferritic I
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steels used in nuclear piping systems.
In subsequent editions of Section XI, including the 1980 Edition through 1981 Minter Addenda which has been adopted by 10 CFR 50.55 for plants currently starting their next ten-year interval, the 100 F minimum test temperature limit has been dropped for Class 2 systems.
In the 1980 Edition through 1981 Minter Addenda, IMC-5230(b) states that in systems containing ferritic steel components for which fracture toughness requirements were neither specified nor required in the construction of the components, the system test temperature shall be determined by the owner.
Later Codes permit the owner to select the hydrostatic test temperature for those plants (such as the D.
C.
Cook Plant) that have not been constructed with fracture toughness requirements.
Materials used in construction of the D.
C.
Cook Plant piping systems have a silicon content specified in the ASHE SA material standards.
This silicon content indicates that semi-killed or killed ingots were used as the starting material, and that the ductile to brittle transition temperature would be below 60 F.
The only materials used in construction of the Cook Plant piping systems subject to ISI that do not have a specified silicon content are SA-181 and SA-333.
SA-181 material is used as flanges primarily on two systems - service water and component cooling water.
Service water operates at ambient temperature which is close to the tempera-ture of Lake Michigan and during winter months has been as low as 34 F.
Since this system is subject to low temperatures for a sub-stantial part of the year, we propose to test this system at the ambient temperature at the time of testing.
Component cooling water, l
and any other systems with SA-181 flanges, are relatively low-pressure systems (less than 150 psig),
and the probability of brittle failure is remote at whatever temperature is used for the pressure test.
Many systems are below six-inch nominal pipe size or below 5/8-inch nominal thickness which the ASME B&PV Code Section III considers to be of such a size that brittle fracture is not possible and, therefore, excludes these sizes from fracture toughness requirements.
These
- systems, or segments of systems, will be individually evaluated and an appropriate temperature specified for the pressure test.
The ice condenser glycol piping was const ucted from material that is intended for use at low temperature, including SA-333, and therefore, testing at ambient temperature is satisfactory.
In the second relief request covering holding time at pressure, the basis for the 4-hour holding time at pressure is that an insulated system requires sufficient time to permit the fluid from a leak to saturate the insulation and be detectable.
Since this requirement is not applicable to noninsulated
- systems, we propose that the time at pressure be 10 minutes which is in accordance with the 1980 Edition of Section XI, IWC-5213(d).
We will maintain the pressure (and tempera-ture) for four-hours on insulated systems.
V.
ALTERNATIVE EXAMINATIONS AND TESTS PROPOSED Class 2 systems will be tested generally at 60 F minimum temperature except the service water, component cooling water, and the ice con-denser glycol piping.
The hydrostatic test temperature of systems where the 60'F minimum may be impractical to achieve will be based on sound engineering judgment.
The ten-minute holding time for noninsulated systems in accordance with the 1980 Edition of Section XI will be used.
1 VI.
STAFF EVALUATION AND CONCLUSIONS The staff has reviewed the information supporting the licensee's requests for relief from the 100 F minimum temperature and four-hour hold time requirement of the 1974 Edition of Section XI'for Class 2 systems during hydrostatic testing.
The 100'F temperature is impractical to achieve in most Class 2 systems or to maintain for the duration of the test.
The requirement was incorporated in the Code to cover conservatively Class 2 ferritic steel com-ponents from brittle fracture during the test since fracture toughness requirements were not specified or required in the con-struction of the components.
The materials used in the construction of Class 2 systems at D.
C.
Cook Units 1 8 2 were specified for low temperature service or have a ductile-to-brittle transition tempera-ture far below the 100' minimum test temperatur e requirement.
The 1980 Edition of Section XI does not impose a minimum temperature requirement during hydrostatic tests but allows the test temperature to be determined by the licensee.
The purpose of the four-hour hold time is to allow leakage froa a source sufficient time to penetrate insulation and thereby become detectable during the visual inspection of the systems.
For noninsulated
- systems, a four-hour hold time is
~f 5
not necessary because a source of leakage is not hidden and therefore easily detected visually.
The four-hour hold time requirement for noninsulated systems in the 1974 Edition was changed to ten minutes in the 1977 Edition of Section XI in recognition of this fact.
Based upon the above, the staff finds that the requirements are impractical and if imposed upon the licensee would not increase the safety margins of D.
C.
Cook Units 1 8 2 or enhance the effectiveness of the hydrostatic tests.
The alternatives proposed by the licensee will provide assurance of the structural integrity of the Class 2
piping and components.
We therefore conclude that relief from the requirements may be granted as requested.
4kà 7
fgeg DOCKET NO(S) 50-315/316 Mr. John Dolan, Vice Presf&ent, Indfana and Michigan Electric Company c/o American Electric Po>ter Ser,v,ce Cor poratfon 1 Riverside Plaza
- Columbus, Ohio 4321$
SUBJECT:
INDIANAAND MICHIGAN ELECTRIC COMPANY DONALD C.
COOK NUCLEAR PLANT, UNITS 1
AND 2 DIST ION ile w/o encl.
ORB¹l Rdg /w/o encl.
CParrish w/encl; :,
DWigginton w/encl.
The following documents concerning our review of the subject facility are transmitted for your information.
CI Notice of Receipt of Application, dated C3 Draft/Final Environmental Statment, dated C3 Notice of Availabilityof Draft/Final Environmental Statement, dated CI Safety Evaluation Report, or Supplement No.
, dated Cj Notice of Hearing on Application for Construction Permit, dated CI Notice of Consideration of Issuance of Facility Operating License, dated CI Monthly Notice; Applications and Amendments to Operating Licenses Involving no Significant Hazards Considerations, dated Application and Safety Analysis Report, Volume O Amendment No.
to Application/SAR dated C3 Construction Permit No. CPPR-
, Amendment No.
dated D Facility Operating License No.
, Amendment No.
D Order Extending Construction Completion Date, dated IXI Other(SpecifyJ Monthl Notice co e n
'for hearfn re uests and coments Janua 3
, dated
Enclosures:
As stated Dfyfsfon offLfcensfng, ORB¹1 Office of Nuclear Reactor Regulation cc: w/enclosures OP,'FICE+
SURNAML+
ORB¹1: DL CParrish; aATs>
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NRC FORM 318 (1/84) NRCM 0240
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