ML20053C419
| ML20053C419 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 02/22/1982 |
| From: | Felton J NRC OFFICE OF ADMINISTRATION (ADM) |
| To: | Hiatt S AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML20049A255 | List: |
| References | |
| FOIA-81-516, TASK-A-49, TASK-OR NUDOCS 8206020094 | |
| Download: ML20053C419 (3) | |
Text
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Ms. Susan L. Hiatt
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g 8275 Munson Road IN RESP 0N Mentor, OH 44060 TO F0IA-81-516
Dear Ms. Hiatt:
This is in response to your letters dated December 22, 1981, and January 13, 1982, in which you requested pursuant to the Freedom of Information Act,13 different categories of documents which you _ listed in your letter.
The documents listed os Appendix A were found to be responsive to your request.
These documents are enclosed.
As you are aware, the decision of the Commission is to waive 75% of the reproduction costs for any documents relevant to a contention admitted by the Atomic Safety and Licensing Board.
Charges for the documents relating to items 6 and 8 of your request reflect this decision and you are being charged accordingly.
Excluding NUREG-0772, (Item 8) you are being charged in full for the remaining NUREG documents.which you requested.
Two NRC Regulatory Guides were found to be responsive to your request.
There is a set fee of $1.50 by the NRC for each of these Regulatory Guides.
Finally, as specified in 10 CFR 9.14(b), the charge for reproducing the remaining 329 pages at five cents ($0.05) per page is $16.45.
As agreed to in your telephone conversation of February 10, 1982, with Nina Toms of ray staff, you will bear the charges for the documents being sent to you.
The total charge for your request is $42.79.
You will be billed by our Division of Accounting for this amount.
Should you have any questions regarding your request, please contact Ms. Toms at (301)492-8133.
This review and aggragation of an additional document subject to your request has not yet been completed.
When this review is completed, you will be notified of our determination.
Sincerely,
/
y;/
,y J. M. Felton, Director Division of Rules and Records Office of Administration
Enclosures:
As stated 8206020094 820222 PDR FOIA HIATT81-516 PDR
1 Re:
l Appendix A Amount 1.
Letter to Joseph H. White from S. H. Hanauer, January 21, 1982 (2 pages) 50.10 2.
Extracted page from " Preliminary Task Action Plan -
Pressurized Thermal Shock (PTS) (TASK-49)"(1 page) 0.05 3.
CLI-81-15,14NRC 1 (1981) June 29,1981 (13 pages) 0.65 4.
SECY-80-107," Proposed Interim Hydrogen Control Requirements for Small Contai.nments" (40 pages) 2.00 5.
SECY-80-170A, " Additional Information Re: Proposed Interim Hydrogen Control Requirements" (41 pages) 2.05 6.
SECY-81-245, " Interim Amendments to 10 CFR Part 50 Related to Hydrogen Control and Certain Degraded Core Considerations" (105 pages) 5.25 7.
NUREG-0772*
' Technical Bases for Estimating Fission i
Project Behavior During LWR Accidents" 2.00 8.
" Transportation Security Personnel.
Training Manual" 9.50 9.
SECY-80-409*
" Proposed Rulemaking to Amend 10 CFR Part 50 Concerning Anticipated Transients Without Scram (ATWS) EventC 0.34 10.
Branch Technical Position CSB 6-2 (15 pages) 0.75 11.
Reg. Guide 1.7, " Control of Combustible _ Gas Concentrations in Containment Following a loss-of-Coolant Accident"**
1.50 12.
NUREG/CR-0913, " Generation of Hydrogen During the First Three Hours of the Three Mile Island Accident" 2.00 13.
NUREG/CR-1561, "The Behavior of Hydrogen During Accidents in Light Water Reactors, August 1980" 7.50 14.
NUREG/CR-1575, " Hydrogen Mixing in a closed Containment Compartment Based on a One-Dimensional _Model with Connective Effects," June 1980 2.00 Relates to an ASLB Contention; charged 25% of cost NRC charge for all Reg. Guides is $1.50
Re: 'F01A-81-516 Appendix A (Continued)
Amount-
- 15. ' Letter from C. L. Wheeler to W. Johnston, April 6, 1981 (11 pages)
$0.55 16.
Reg. Guide 1.97, " Instrumentation for Light-Water Cooled Nuclear Power Plants to Access Plant and Environs Conditions During and Following an Accident," December 1980 1.50 17.
Thermal Analysis of In-Core Thermocouples in Boilin Water Reactors by S. Levy, November 1981 (35 pages)g 1.75~
18.
General Electric Evaluation of the Need for BWR Core Thermocouples, November 16, 1981 (37 pages) 1.85
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January 21, 1982 Fr. Joseph H. Uhite III 11 South !!erion Avenue Dryn Mawr, Pennsylvania 19010
Dear Mr. White:
Your Decmber 29, 1981 letter sent to the' iiRC Conaissioners with freedon of infomation requests concerning pressure vessel cobrittle ent-has been referred to ne for a technical response.
It is the consensus of our working group nenbers who are working on the pressurized themal shock (PTS or "enbrittlenent") issue that the problea is not as significant at BURS as it is at PUP.s.
However, I an unaware of any particular, single individual who is responsible.'or this position.
It is sinply the opinion held by knowledgenle staff members and their nanagement.
Reasons for their opinions are well founded in the basic differences between a RIR and a BUR.
BURS are ouite di'ferent. fron PMP.s both in basic design and in cperating condition.
Both types of differences contribute tc the staff's consensus, as discussed below.
First, as !!r. Basdekas wrote, the fast neutrcn flux at the EUR yessel wall is substantially 'ower than for a P.!R.
This causes the vessel to be nuch less enbrittled for a given period of operation than a PWR.
This luaer flux is due to the basic design of a BUP, which recuires nore space between the nuclear core and the pressure vessel for the recirculation flou path. That extra space is largely full of Water, and the water reduces the neutron flux which causes the enbrittlenent.
There are additional reasons for the staff's consensus that !!r. Rasdekas did not nention.
First, BUR pressure vessels are about 6" thick at the nest irradiated (erbrittled) location, whereas F.!R vessels are about 8" thick due to ' he higher Pi!R cperating pressure.(about 2250 psia for a t
P:!R cmpared to 1050 psig for a BMP., i.e., another basic desien difference).
With respect to pressurized themal shock (the event which could cause an c"brittled vessel to fail), this difference in thickness is inportant because it results in lower then al. stress intensity.at the tip of a crack.
l The basic conditions under which a BUR operate.s oakes it ruch inss likely that the sinultaneous reoid cooling and high pressure ;onditions necessary to create a significant PTS event will occur.
That is, BURS l
operate by design with saturated water, i.e., the water exists as an ecuilibrina nixture of stean and liouid water at the boiling teoperature for the existing pressure (about 5507 at abcut 1050 psig, just as 2127 is 'the ' -iling temperature at atonspher,ic pressure, O psig).
The result
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P Mr. Joseph H. L'hite III.
is that any rapid cooling of the water in the vessel will inherently result in a corresponding pressure decrease, thereby precluding the necessary conditions for FTS of sinultaneous rapid cooling and high pressure.
.91Rs ocerate by design with subcooled water inside the pressure vessel considerably below the saturation temperature, and under those conditions it is easier to cool the water and maintain or re-establish high pressure to create FTS conditions.
The above argunent that PTS events are nuch less probable for BWP.s is borne out by operating experience. There have been no severe PTS events at domestic or foreign BURS.
In summary, BNRs have.less enbrittleaent due to the lower neutron flux at the vessel wall (so the naterial is better able to stand stresses);
there would be less thernal stress intensity at the crack tip during PTS events due to the thinner wall, and less pressure stress due to the lower pressure; and finally it is very nuch less probable that a PTS.
event will occur since it is very difficult to sinultaneously produce the necessary low temperature with high pressure conditions.
I hope the above addresses your basic concern, vhich I interpret to be that HRC nay not be properlj considering the PTS issue for Bl.'Rs.
I am aware that this letter does not answer your specific reque'sts for data. The ' reason is that we do not have extensive, fornal data of the type you requested for BURS '(nor do we need it for the above reascns).
He do have a considerable amount of informal knowledge of flux and fluence r.easurements at BURS which reinforce the staff's above stated consensus, but it does not exist in a formal report format that we could meaningfully send to you. Ue are not respohsible for and do not have the non-URC, non-government, and industry studies you requested.
1 We do consider the FTS concern to be important for PURs and we have a full tiae task nanager, Dr. Roy Woods, whose essignrent is resolution of PTS concerns.
If you would like nore detail than has been. included in this brief letter, he,will be pleased to talk to you if you call hin at (301) 492-4714.
Sincerely, l
l l
S. H. Hanauer, Director l
Division of Safety Technology Office of Muclear Reactor Regulation l
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-Qlote: Page extracted from "Prefiminary Task Action Plpn - Pressurized Thermal Shock (PTS) (TASK-49). The' remainder of the report.is not germane to your request.
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1.
INTRODUCTION AND BACKGROUND
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Pressure vessel themal shock has been considered for many years in the context of assuring integrity of the vessel when subjected to cold emergency core cooling water during a large loss of coolant acc.ident (LOCA).
Based on a series of themal shock experiments (unpressurized) conducted at Oak Ridge National Laboratory (0RNL) beginning in 1976 and based on fracture mechanics analyses verified by the experiments, it was concluded that a postulated flaw would not propagate through the vessel wall during a large LOCA.
Therefore, the vessel integrity would be maintained during subsequent reflooding which would occur at relatively lw pressure due to presence of the large break.
It was subsequently recognized that there could be transients in pressurized water reactors (PWRs) in which the vessel could be subjected to severe overcooling (themal shock) followed by repressurization.*
In these l
- The NRC staff does not believe boiling water reactors (BWRs) have a 3
significant PTS concern because:. fluence at the vessel inner wall is lower for most BWRs due to presence of the jet pumps (i.e., more water h
is between the fuel region and the vessel); BWR vessels are thinner, by the approximate ratio (6/8)g PWRs, resulting in lower themal stresses approximately 6" vs. the 8" fo i
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= 0.56; BWRs are more difficult to l-g repressurize, due to valve setpoints (approximately 1200 psig vs.
9 approximately 2200 psig for PWRs), due to the ' larger void volume nomally C -
present, and due to their nomal operation at saturation conditions; and j
operating experience does not show a history of significant PTS events.
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l A-49/1 11 /
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