ML19221A849
| ML19221A849 | |
| Person / Time | |
|---|---|
| Issue date: | 08/11/1972 |
| From: | NRC OFFICE OF STANDARDS DEVELOPMENT |
| To: | |
| References | |
| REGGD-01.019, REGGD-1.019, NUDOCS 7907100098 | |
| Download: ML19221A849 (4) | |
Text
Revision 1 August 11,1972 SAFETY GUIDE 19 NONDESTRUCTIVE EXAMINATION OF PRIMARY CONTAINMENT LINER. WELDS A.
Introduction be nondestructively examined using the following procedures:
General Desig, Criterion I,
" Quality Standards and Records," of Appendix A to 10 1.
Nondestructive Examination of Liner CFR Part 50. " General Design Criteria for Seam Welds Nuclear Power Pla n t s,"
requires that a.
For each welder and welding components important to safety be fabricated to quality standards commensurate with the position (flat, vertical. horizontal.
importance of the safety function to be and overhead), the first 10 feet of performed. The leaktight integrity of the weld, and one spot (nct less than primary containment liner and its penetrations is 12 inches in length) in each an important consideration in safety evaluations.
additional 50 foot increment of This guide describes acceptable procedures for weld (weld test unit) or fraction implementing this criterion by the use of thereof should be examined nondestructive methods to examine the welds in radiographically in accordance the liners and penetrations of primary reactor
.with the techniques prescribed in containments of concrete construction.
Section V,
"No nd e st ructive Examination," of the ASME Boiler B.
Discussion and Pressure Vessel Code ( ASME B&PV Code), in any case. a There are no directly applicable industry minimum of 2 percent of all liner codes that cover the nondestructive examination seam welds should be examined by of containment steelliner and penetration welds radiography.
in concrete containments. Current industry b.
Where radiographic examination of practice is generally based upon the application liner seam welds is not feasible or of provisions of Sections 111 and VIII of the where the weld is located in areas ASME Boiler and Pressure Vessel Code and which will not be accessible after ANSI B31.7, " Nuclear Power Piping," for construction, the entire length of comparable welds. Because of the lack of weld should be c 4 mined by the specifically applicable standards, these practices magnetic particle method or by the have differed significantly.
ultrasonic method in accordance Af ter reviewing a number of applications with the techniques prescribed in for construction permits and operating licensesSection V of the ASME B&PV for nuclear power reactors, the AEC regulatory Code for such e xamination staff has developed acceptable standard methods.
procedures for the nondestructive examination c.
All liner seam welds should be of such leaktight membranes. These procedures tested for leak tightness in will provide a uniform quality level consistent raccordance with the following with the safety function of containment liners.
method (or other methods of equivalent sensitivity):
C.
Regulatory Position immediately preceding the Seam welds in the steel liners of test, a soap solution (or other conventionally reinforced or prestressed appropriate solution) should concrete reactor containment structures should be applied to the weld. A 19.1125 072 7 9071000W '
vacuum box containing a penetration and liner, reint'orcing viewing window should be plate and liner, liner insert and placed over the area to be liner, reinforcing plate and frames tested and evacuated to for airlocks and access openings, produce at least 5 psi and liners and frames for airlocks differentisI with the and access openings, should be atmospheric pressure. Leaks in fully examined (1) in accordance welds, if present, should be with paragraph a. above or (2) by j
detected by formation of magnetic p ar ticle, or liquid bubbles. The solution used for penetrant when a non-magnetic the test shouki have bubble weld is used, in accordance with formation properties adequate the te ch niques prescribed in for identification of leaks. The Section V of the ASME B&PV test solution should be Code.
checked every hour with a c.
All welds in bellows type suitable test leak to verify the ex pa nsion joints provided in bubble formation property of p e n e t r a tion assemblies or the solution used.
appurtenances to the containment vessel should be magnetic-particle, d.
Where leak hase-system channels or liquid-penetrant tested when a are instaDeJ over liner welds, nonmagnetic, weld is used, in channel-w4irrer-plate welds should accordance with the techniques
-be tested for leak tightness by prescribed in-Sebtion V of ASME
'pt'essu rizing the channels to B&PV Code fdr'such examination containment design pressure. If methods.
any indicated loss of channel test pressure occurs within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, as evidenced by a test gauge, the 3.
Qualification of Welders and Welding channel-tc>-liner welds 'should be Procedures soap buale tested in accordance with the above procedures.
The qualification of welders, welding machine o pe rators, and welding procedures should be in accordance 2.
Nondestructive Ex a mina tion of with Section IX, " Welding Fene t ra tion, Airlock, and Acce" Qualifications,"'of the ASME B&PV Opesung Welds Code.
a.
All welds in penetrations, airlocks, and access openings that are not 4.
Qualification of Nondeshuctive backed by concrete, such as welds Exzmination Per,sonnel between penetrations and flued fittings, and flued fittings and pipe Nondestructive exami. stion should be lines, should be fully examined in performed by personnel designated by accordance with the examination the licensee or his agent and qualified methods of NE-5120 of Section ill in accordance with the provisions of of t he A SM E, B&PV C#
Sdion V of th'e ASME B&PV Code.
e m plo y ing the techniques prescribed in Section V of that Code.
5.
Selection of Spots for Radiographic b.
All wends in the vicinity of Examination i
penetrations, airlocks. and access openings that are backed by The spots of liner seam welds to be concrete, such as welds between radiographically examined should be penetration and reinforcing plate' randomly selected but no two spots in adjacent weld test units shou!d be closer than 10 feet and their locations
' Thnkened liner inwrt which proudes loul remforcement.
should be recorded.
'm iu
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6.
Time of Examination and liquid penetrant methods m NE-5120 of Section 111.
All examinations should be performed as soon as practicable after the lineal 8.
Repair and Reexamination increment of weld to be examined is a.
Containment Uner Seam Welds completed.
Examined by R diography 7.
Acceptsace SW When a radiographed spot fails to a.
Contamment Uc:e Sam:a Welds meet the specified acceptance Examined by.Rsdiography standards, two additional spots should be radiographically Where a spot in the seam weld is examined in the same weld test judged acceptable in accordance unit at locations at least one foot with the referenced standards of removed (on each side) from the NE-5120 of Sectbn III of the original spot. The locations of ASME B&PV Code, the entire weld these additional spots should be test unit represented by this spot determined by the examiner using radiograph is considered the same procedure followed in the acceptable..
selection of the original spot for examination and the examination b.
Contunnecat Ucer Seam Welds results should determine the Exarnined by Ultrasonic or fallowing corrective actions:
Magnetic Particia (1) If the two additional spots examined meet the specified Seam welds examined by accept a nce standards, the ultrasonic or magnetic particle entire weld unit represented e
methods are considered acceptable by the three spot radiographs provided the examinations meet is considered acc:ptable.
the a c c e p t a nce standards However, the defective referenced for such examination welding disclosed by the first methods in NE-5120 of Section 111 of the 'three radiographs of the ASME BAPV Code-should be repaired by welding.
(2) If either of the two aeditional c.
Soap Bubble Leak Tests of sp ts examined fails to meet Containtnent Uner Welds the specified a cceptance standards, the entire weld test Liner welds are considered anit is considered acceptable provided no leakage is unacceptable. The entire weld detected by soap' bubble tests (or should be removed and the by other methods of equivalent j int should be rewelded or, sensitivity).
optionally, the entire weld unit may be completely d.
Penetration. Afriock, and Access radiographed and clefective Opening Welds welding only need be repaired.
Penetration, airlock, and access (3) Repair welding should be opening welds are considered performed using a qualified acceptable provided the procedure as specified under examinations meet the acceptance regulatory position.t. above.
standards referenced in NE-5120 The weld repaired ireas in of Section 111 of the ASME B&PV each weid test unit should be Code. Welds in bellows type spot radiographed at one 9l expansion joints are considered selected location to meet the 5 074 accevtaace criteria erecified in acceptable if the examinat regulatory position 7.a.
or meet the acceptance stand referenced for magnetic particle 8.a.( 1 ) above.
19.3
b.
Containment Limr beam Welcs reexaminea Dy soap.ibble leakage Examinect by Ultrasonic or re testing.
~
d.
Pirectration Airlock, and Access When a weld wiich has been Opening Welds examined' does not comply with the specifiid' acceptance standards, V' elds judged unacceptable m the weld should be repaired and accordance with regula tory reexaminei in acconiance with the positien 7.d. should be repaired provisions of Section til of the and reexamined in accordance with ASME B&PV Code, the provisions of Section 111 of the ASME B&PV Code.
t Soap Bub':de Tests of Containment 9.
ReccMs c.
Liner Welils Records of radographs and other Welds judged unacceptable because non&structive examinations including leakage ia, detected by the soap those for repaired defective welds bubble tett (see regulatory position shou!d be retained by the licensee in 7.c., abos e) should be repaired.
compliance with the provisions of Repair welding should be Section XVil. " Quality Assurance pe rform ed u sing. a qualified Reccrds," of Appendix B to 10 CFR procedure as specified under Part 50. "Quahty Assurance Critena for regulatory position 3. above. The Nuclear Power Plants and Fuel weld repaired anas should be Reptocessing Plants."
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9 19.4 125 075
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