ML20210B418
| ML20210B418 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 09/12/1986 |
| From: | Corbin McNeil Public Service Enterprise Group |
| To: | Bernero R NRC OFFICE OF ADMINISTRATION (ADM), Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0313, RTR-NUREG-313 NLR-N86113, NUDOCS 8609180070 | |
| Download: ML20210B418 (6) | |
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Public Service Electric and Gas Cornpany Ctrbin A. McNeill, Jr.
Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609 339-4800 Vice President -
Nuctear September 12, 1986 NLR-N86113 i
Rules and Procedures Branch Division of Rules and Records
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Office of Administration i
United States Nuclear Regulatory Commission j
Washington, DC 20555 Attention:
Mr. Robert M. Bernero, Director i
Division of BWR Licensing Gentlemen:
COMMENTS ON DRAFT GENERIC LETTER ON IGSCC AND NUREG-0313, REVISION 2 HOPE CREEK GENERATING STATION 1
On July 21, 1986, a notice of issuance appeared in the Federal Register indicating that public comments were being solicited on a draft of NUREG-0313, Revision 2, " Technical Report on Material Selection and Processing Guidelines for BWR Coolant Pressure Boundary Piping," and the a'ssociated draft Generic Letter.
To be assured of due consideration, comments were to be received by i
September 20, 1986.
In accordance with this provision, Public Service Electric and 8
j Gas Company (PSE&G) of fers the following comments.
contains comments pertinent to both draft NUREG-0313 and the implementing Generic Letter. contains comments applicable to draft NUREG-0313, Revision 2 only.
If you should have any questions in this regard, please do not i
hesitate to contact us.
l Sincerely,
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Attachments l
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8609180070 860912 00 PDR ADOCK 05000354
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PDR g
l Mr. Robert E. Bernero 2
9/12/86 C
Mr. D.
H. Wagner USNRC Licensing Project Manager Mr.
R.
W.
Borchardt USNRC Senior Resident Inspector
ATTACHMENT 1 The following comments are applicable to sections of both draft NUREG-0313, Revision 2 and the draft Generic Letter (except for 4
comment #10).
Each comment is preceded by the document and page number of the section it addresses.
A slash (/) separates NUREG-0313 and the Generic Letter sections.
Comment #10 is applicable to the draft Generic Letter only.
i 1.
Generic Letter, pg. 2/NUREG-0313, Revision 2, pg. 2.2 (paragraph 2.1.1)
The " Staff Position on Materials" section states that materials considered resistant to sensitization and IGSCC in l
BWR piping systems are low carbon wrought austenitic stainless steels.
This section and Table 1 of draft i
NUREG-0313 specifically list 304L, 304NG, 316L, 316NG, and j
.347NG as being acceptable.
304 and 316 stainless steels should also be listed with a footnote indicating that "with proper remedies applied these materials are acceptable."
2.
Generic Letter, pg. 2/NUREG-0313, Revision 2, pg. 2.2 (paragraph 2.1.2)
The "Staf f Position on Materials" section of the Generic l
Letter and NUREG state that carbon must be as specified in Table 1 "by both heat and product analyses."
This statement i
should be changed to "by either ladle or product analysis."
Either of these-analyses are sufficient to verify the carbon i
content of steels.
3.
Generic Letter, pg. 2/NUREG-0313, Revision 2, pg. 2.2 4
(paragraph 2.1.1) i i
Part (2) of "Staf f Position on Materials" states that weld j
metal of type 308L grade with a minimum of 8% ferrite as l
deposited is considered resistant to sensitization and
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Other weld metals would also be acceptable with the above s tipula tion (i.e. 8% ferrite content).
Examples are 316L and 309L.
Ferrite content for welds is usually I
specified in terms of ferrite number (FN).
4.
Generic Letter, pg. 2/NUREG-0313, Revision 2, pg. 2.2 l
(paragraph 2.1.1.)
Part (2) of the " Staff Position on Materials" section indicates that while type 308L grade weld metal may be used as a cladding on the inside of-a pipe (as a i
f corrosion-resistant cladding [ CRC} }, "this is not recommended generally, as the cladding may make volumetric inspections more difficult.
It is PSE&G's position that this statement should be deleted.
While the use of CRC does make volumetric i
inspections more difficult, this option should still be left open to licensees.
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5.-
Generic Letter, pg. 2/NUREG-0313, Revision 2, pg. 2.3 (paragraph 2.1.1) part (4) of the " Staff Position on Materials" section states that materials considered resistant to sensitizaticn and i
IGSCC are "high toughness, low strength carbon steel grades, with a specified minimum yield strength of 35,000 psi or lower.
PSE&G is not aware of any cases where carbon steel material has been shown to_be susceptible to sensitization or IGSCC.
Therefore, specifying strength requirements for I
carbon steel materials is unwarrauted and should be deleted.
4 6.
Generic Letter, pg.2/NUREG-0313, Revision 2, pg. 2.4 (paragraph 2.2,1)
The'" Staff Position on Processes" section states that "The
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processes considered to be fully qualified for providing resistance to IGSCC in new or replacement piping welds are the following."
The phrase "new or replacement" infers that i
the staff requires that piping be replaced.
This is not the case as stated in the Note for Recipients of Draft NUREG-0313 Revision No. 2 that was attached to these documents.
The phrase "new and replacement" should be deleted, as it is misleading.
7.
Generic Letter, pg. 3/NUREG-0313, Revision 2, pg. 2.6
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(paragraph 2.3.1)
Under the "Staf f Position on Water Chemistry," the claim is made that "the successful development and application of Hydrogren' Water Chemistry (HWC) is highly important and desirable to reduce the probability of IGSCC in components i
other than piping, particularly in structures and components inside the reactor vessel.
"At this time there is i
insuf ficient evidence indicating that HWC inhibits IGSCC in reactor vessel internals to the same degree it inhibits IGSCC i
in piping during plant operation.
It is PSE&G's contention l
that the second paragraph under the " Staff Position on Water.
6 Chemistry" should be deleted.
8.
Generic Letter, pg. 4/NUREG-0313, Revision 2, pg. 6.1 l
(paragraph 6.0) t Under "Staf f Position on Leak Detection" in the draft l
Generic Letter and under the section entitled
" Leak l-De tect io n" in draft NUREG-0313 the requirement is made that l
plant shutdown should be initiated when any leakage detection system indicates that 1) there is an increase in the rate of unidentified leakage in excess of 2 gpm or its l
equivalent within a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, or, 2) the total l
unidentified leakage attains a rate of 5 gpm or its l
equivalent.
These leak rate limits should be applicable as specified in plant Technical Specifications.
A statement j
i should be added indicating this, t
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9.
Generic Letter, pg. 7/NUREG-0313, Revision 2, pgs.
5.5, 5.7 (paragraphs 5.3.2.3, 5.3.2.4, 5.3.2.5, and Table III)
Both the draft NUREG and Generic Letter require an augmented inspection for a range of weldment conditions (See Table 1 of the draft Generic Letter and Table II of the draft NUREG).
These weld conditions are specified by Catagories A through G.
For weld cotagories C, D,
and E an inspection period of 3 1/3 years is proposed.
This inspection time increment make outage scheduling more difficult in that an outage will have to be planned in 3 1/3 years increments solely for veld inspections (for a plant with these weld conditions).
A more acceptable inspection requirement from a planning standpoint would be a schedule tied specifically to refueling outages.
Therefore PSE&G proposes that the "3 1/3 years" increment should be replaced wi.th "every second ref ueling outage or 4 years."
10.
Generic Letter, pg. 5 The section entitled ' Limits on Number of Cracked Weldmonts in Piping" proposes a limit on the number of weldment.s in a piping system that can contain cracks larger than those acceptable under ASME Boiler and Pressure Vessel Code Section XI, IWB-3500, with or without repairs.
The proposed limit is 25% of the walds in a piping system.
It is PSE&G's position that no limit should be specified.
Any limits should be made on an individual plant basis with appropriate remedies applied.
The limit should not be generic in rature.
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e ATTACHMENT 2 The following comments are applicable to sections of draf t NUREG-0313, Revision 2.
Each comment is preceded by the page number of the section it addresses.
1.
NUREG-0313, Revision 2, pg. 1.3 (paragraph 1.5)
The section entitled " Piping Replacement" states that
" serious consideration should also be given to weld joint design, welding processes, and SI processes to provide residual stress improvement to the new piping."
From the report it is unclear as to what is meant by
" weld joint design" considerations.
The meaning of this phrase should be clarified or the phrase deleted.
2.
NUREG-0313, Revision 2, pg. 3.1 (paragraph 3.1.1)
Under " Weld Overlay Reinforcement," the statement is made that " Weld overlay is performed with cooling water flowing through the pipe during welding...." Weld overlay is not necessarily performed with cooling water flowing through the subject pipe.
Therefore a more accurate statement would be " Weld overlay may be performed with cooling water flowing through the pipe during welding...."
3.
NUREG-0313, Revision 2, pg. 4.3 (paragraph 4.4.2)
Under " Design Overlays" the statement is made that the thickness of the design overlay should be "at least two layers of weld metal after the surface has passed surf ace examination by penetrant inspection."
A clarification should be made to show that the base material surface be examined by penetrant inspection, not the weld retal surface.
The following modification to the above sentence would accomplish this.
"The thickness of the designed overlay should be at least two layers of weld metal after the base material l
surface has passed examination by penetrant inspection."
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