ML20202C363
| ML20202C363 | |
| Person / Time | |
|---|---|
| Issue date: | 05/15/1997 |
| From: | Bagchi G NRC (Affiliation Not Assigned) |
| To: | Coffman F NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20202C086 | List:
|
| References | |
| FRN-62FR63892, RULE-PR-50 AE26-1-018, AE26-1-18, NUDOCS 9802120226 | |
| Download: ML20202C363 (4) | |
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] NUCLEAR REEULATERY 03MMISSION
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+,,,,,* May 15, 1997
/2D b REVISED NOTE TO: Franklin Coffman, RES/DET/GSIB FROM: Goutam Bagchi, Chief. ECGB/DE ' '
SUBJECT:
ComENTS ON 10 CFR 50.55a - CODES AND STANDARDS RULE The attachment contains our connents on (1) the Proposed Rule Revision, and (2) the Draft Regulatory Analysis, cc w/ attachment:
B. Sheron G. Lainas J. Strosnider R. Wessman W. Norris L. Shao J. Cralg A. Murphy G. Millman l
Contact:
Hans Ashar, ECGB/DE/NRR 415-2851 Thomas McLellan, ECGB/DE/NRR 415-2716 21 226 980206 50 62FR63892 PDR QTp7/2Of2h _ .
M REVISED NOTE To: Franklin Coffman, RES/DET/GSIB FROM: Goutam Bagchi, Chief. ECGB/DE/NRR Original signed by G. Bagchi
SUBJECT:
COPMENTS ON 10 CFR 50.55a - CODES AilD STANDARDS RULE The attachment contains our connents on (1) the Proposed Rule Revision, and (2) the Draft Regulatory Analysis, cc w/ attachment:
- 8. Sheron i
G. Lainas J. Strosnider
- R. Wessman W. Norris L. Shao i J. Craig
- A. Murphy G. Millman ,
Contact:
Hans Ashar. ECGB/DE/NRR 415-2851 Thomas McLellan, ECGB/DE/NRR 415-2716 DISTRIBUTION FILE CENTER ECGB RF
- DISK /D0CUMENT NAME: G:\ASHAR\5055AREY.COM to ree-tve e copy of thee docu=nt, indleste in the boa: aca = c m w/o attache nt; ar= , caly w/sttachsener === = u c'opy 0FC ECGB:DE E ECGB:DE C ECG((h ECGB:DE ECGB:DE d.
- NAME HASHAR h [- PODELLh6' RROTHMAN M GBdGdi TMCLELLAf72w i-DATE 5//67 5/ M/97 5/ g /97 5/Ib/97 5/8 /97 0FFL.CIAL RECORD COPY e
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,. ComENTS ON Pt0 POSE) RlVIS104 TO 10 CFR 50.55a COMS AN)5"ANDAR)S tutE General Content and Femat
- 1. When we are trying to revise and streamline the regulation, it is an '
opportune time to think about endorsements of other ASME Subsections.
which are used in practice, on an ad hoc basis, but have never been endorsed, that is, Subsections NE, NF, IWF and Division 2 of Section III. For example,10 CFR 50.44(c)(iv)(B) and (C) use specific provisions of subsection NE, and 04 vision II of section III. We '
recognize that such endorsements are not in your planning. However, it is extremely important that we officially recognize their use for future applications by endorsing them.
- 2. Attempts to simplify the content of the rule are apparent. However.
some sections still need improvement, for example, Paragraph (g)(4) has 16 lines and two sentences. In three column Federal Register format, each sentence will be 19 and 21 lines long. Have mercy on readers.
Snecific Comments 3.
Section when an(b)(1)(1) and alternative to (b)(2)(x1): Section the requirement (s)(a)(3 of the) endorsed codes isof the rule applies proposed. It is a far fetched application, when it is extended for the staff evaluation of ' engineering judgement.' If necessary, Section
.(a)(3) should be modified to include the requirements and criteria for such evaluations.
- 4. Section (b)(2)(vi): The requirement that the licensees implement the 1995 Edition with the 1996 Addenda of Subsections IWE and IWL after September 9, 2001, with a new inspection interval is contrary to the requirement-in the current rule that the inspection performed in the five year expedited examination period (prior to September 9, 2001) shall be considered as the first period examination of the first interval. Also, as regulators, we are not loosing anything by letting licensees continue to use the 1992 Edition with the 1992 Addenda of the Subsections until tne start of their next interval. Mandating the
-Edition change in the same inspection intervel, without substantial safety benefit, would be an additional burden on the licensees. For application to containment ISI, the use of the 1995 Edition with 1996 Addenda should be made voluntary.
- 5. Section Delete have been(b)(2)(ix): incorporated in the(A), (B), (C), and (D). These exceptions 1996 Addenda of Subsection IWL. However, these exceptions are applicable to the 1992. Edition (with the 1992 Addenda) of the Code.
- 6. Section 3, " Alternatives
- of the Draft Regulatory Analysis: A fourth alternative is to make 50.55a a perfomance based rule, and develop Regulatory Guides to endorse various codes and standards. Pros and cons of such an alternative should he discussed.
Attachment
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Li 7. Section 50.55a(b)(2)(xiv) applies to Section XI; IWC-1220, Components Exempt from Examination". However, the staff should also consider the exclusions contained in Table IWC-2500-1, Examination Categories C-F-1 and C-F-2. Item Nos. C5.10, and C5.50 which excludes ultrasonic examination for piping welds s 3/8" nominal wall thickness for piping >
NPS 4. Based on field experience the staff has determined that
! ultrasonic examination of piping welds < 3/8" can be perfomed effectively up to 0.2" thickness. Furthemore, the Code, Table IWC-2500-1. Examination Categories C-F-1, and C-F-2, Item Nos. C5.20 and C5.60 (which applies to Safety Injection piping in PWRs) requires that a volumetric and surface exam be perfomed on piping welds > 1/5 inch nominal wall thickness for piping 1 NPS 2 and 1 NPS 4 circumferential weld. Therefore, the Code recognizes that meaningful volumetric j
examinations can be performed on piping welds s 3/G" nominal wall thickness for piping 1,NPS 2 and 1 NPS 4" circumferential weld.
4 It has been the staff's experience and cancern that when excluding thin l
walled piping welds, complete systems > 4 NPS (8 NPS to 10 NPS) may not 1
be volumetrically examined, especially the Residual Heat Romoval, Emergency Core Cooling and Containment Heat Removal systems. As a
!. matter of routine in a staff's request for additional information regarding the review of a licensee's 10-year inservice inspection program plan update, the staff requests information from the licensee to i
ensure that whole systems are not excluded from its program plan for examination based on the < 3/8" wall thickness exclusion criteria. The staff also advises licensees, that it is technically prudent-to volumetrically examine a sample of thin wall welds. The staff has found i
that a number of licensees follow our recommendation, while others choose to ignore it and just follow the Code requirements.
The Code, Table IWC-2500-1, Examination Categories C-F-1 and C-F-2, Item Nos. C5.10 and C5.50 exclusions above, should be revoked for the Residual Heat Removal, Emergency Core Cooling and Containment Heat j
i Removal Systems. The staff concludes that complete systems are not being volumetrically examined because of the Code exclusions based on i-i wall thickness. -In addition, the staff concluded that changing the i
regulation will ensure the operational readiness of the subject systems.
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