ML20062H948
| ML20062H948 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 08/12/1982 |
| From: | Bachmann R NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | Bloch P, Kline J, Paxton H Atomic Safety and Licensing Board Panel |
| References | |
| NUDOCS 8208160219 | |
| Download: ML20062H948 (5) | |
Text
. --
I.
August 12, 1982 1
Peter R. Bloch, Chairman Dr. Jerry R. Kline Administrative Judge Administrative Judge Atomic Safety and Licensing Board Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 Washington, DC 20555 f
Dr. Hugh C. Paxton Administrative Judge i
1 1229 41st Street Los Alamos, NM 87544 P
F In the Matter of l
Wisconsin Electric Power Company (Point Beach Nuclear Plant, Units 1 and 2)
Docket No. 50_266 and 50 301 l
(Repair to Steam Generator Tubes) i
Dear A6ninistrative Judges:
L This is to infonn the Licensing Board and the parties, at the request of Judge Bloch, of recent telephone conversations between Judge Bloch and mysel f.
On August 9, 1982, Judge Bloch telephoned to inquire about an article entitled " Utilities Given NRC Laundry List of Steam Cenerator Proposals," published on pages 1-4 of the August 5,1982 issue of Nucleonics Week (copy enclosed). His inquiry was whether the Staff intended to provide information on matters discussed in the meeting described in the article to the Board and parties as part of the record in this proceeding.
I responded by telephone on August 10, 1982.
I informed Judge Bloch that the Staff did not intend to submit such information. The reason for not doing so is essentially contained in the last paragraph of the article. The steps described to bring the requirements into final form are expected to take some years, and at the present time, the proposed requirements are merely-open for comment. Therefore, the Staff believes they have no bearing on the l
current proceeding. Judge Bloch and I did not discuss the substantive merits of any of the proposed requirements.
e Sincerely, i
Richard G. Bachmann Counsel for NRC Staff 4
Enclosure:
as stated cc w/ enclosure:
Service List i
! 0FC. :0
- 0 ELD 2.. __:
hma n n / J h S AT ' g.... _ : _ _ _ _ _ _ _.. _ :..... _ _ _ _ _ _ _ :.... _ _ _ _ _ _ _ : _ _ _ _ _ _
NAME :
by r
DATE :08/11/82
- 08/l\\ 82
/
8208160219 820812 DESIGNATEDORIGINAll}
P Certified By
%m Y
A McGraw Hill Publication incorporating NUCLEONICS 1 NUCLEONICSWEEK wt 23 No. 31 August 5,1982
~__.
m.
t t
(
I i
?
l c--_
UTILITIES GIVEN NRC LAUNDRY LIST OF STEAM GENERATOR PROPOSALS NRC last week handed PWR owners a long list of proposed new requirements intended to prevent or mitigate the effects of steam generator malfunctions, covering steam generator integrity, plant systems re-sponses to steam generator tube breaks, and radiological consequences following steam generator incidents.
(t On top of that, NRC also alerted the utility people to a whole batch of possible additional requirements.
Although the utilities organized only last week to formulate an interim response to the proposed require. '
ments, initialindications were that some of the proposals are being viewed skeptically as to their necessity and value. NRC staff, for its part,is still conducting value impact studies which it will consider in conjunc-t.
i
,i
-i,'
9 irrr,i*c;9 fI.H m iC M.* A tion with the utilities' responses before taking further action.
. a..y e,.
,,.., a n....
.u.;
,w,
, m.
he proposed requirements were explained by NRC licensing division staff for the first time July {9 y m
to members of the steam generator owners group at a meeting in Bethesda, Md. (NW,29 July,2). De piar-pc4 of the meeting, said Gus Lainas, assistant director oflicensing for safety assessment, was "to r
(
4
, dustry feedback relative to value impact." At the direction of,the commissioners, NRC staff drew up the %-,
proposals to consider the ramifications of the Jan. 25,1982 accident at Rochester Gas & Electric's Ginns plant,in conjunction with staff work on unresolved safety issues which had been going on well before the Ginna tube rupture. Many of the proposals stem from the Ginna event; others are based on staff observations of other events and problems at PWRs.
"A tube rupture in any plant is a tube ruptme in all plants," said NRC Director of Licensing Darrell Eisenhut at one point. The July 29 proposals, added Eisenhut at another point in the meeting, will hopefully ;39 resolve the uneesolved safety issues. "(Ilopefully) there won't be another document,".he said.
Under the category of" steam generator integrity," licensing division staff explained eight.grougis of
,y propos-d requirements-
^ ' ' '
- ^'M*
i
..t.
s Presention and detection of looselarts and foreign objects. Bis would include secondary side inspec-e,
,4. u m c
tion above the tube sheet of the entire periphery of the tube bundle, and the tube lane; improved quality, assurance (QA) and quality control (QC) procedures to preclude introduction of foreign objects into the pri-mary and secondary sides of the steam generators;and installation and operation of steam,generatorloose '
parts monitoring systems on the primary and secondary. sides.,, '
Some plants already incorporate these procedures - most notably, staff said, Rochester G&E's Ginna, whose tube rupture Jan. 25 was attributed to a loo'se part.With regard to the frequency of secondary side 7 inspections, Lainas said that if no monitoring' system was in place by the time of a steam generator's next t.
eddy current irspection, that an access be made for secondary side inspection. Eisenhut said that the secon'd-ary inspection might be a "one time, event"accqmpanied by a followup,QA program. Eisenhut added,that ;g Aq2 he recently saw a report on a newly delivered steam generator which,upon inspection of the secondary side, displayed "a bucket ofloose parts.""Is a good QA/QC program plus a loose parts monitoring system good
. enough?" he asked.
' O ' ',. u' *,
u.:
.n Stabilization and monitoring of degraded tubes. NRC is proposing that licensees prepare and submit.y m
a report which identifies progressive kinds of degradation currently present or likely to occur in their plants; and which contains criteria and procedures for (a) monitoring of plugged non-leaking tubes for which rates.
of progressive degradation are unpredictable, and (b) stabilization of degraded tubes with potential for sev g erences and damage to adjacent tubes. NRC staff bases this proposal upon evidence that plugged tubes can g degrade further after plugging. " Sentinel" plugs which allow limited amounts of water to monitor the rate of degradation in plugged tubes have been used at Sweden's Ringhals 3 and were recently installed at Florida Power & Light's Turkey Point-4, NRC staff noted.1,..,,,,
,t
..j
.x..,,,
in response to questions from the steam gerie'rator owners group as to the necessity of this program.in,
conjunction with a loose parts monitoring system, Lainas emphasized that foreign objects are "not.the only l
~ degradation mode...."
,,,, g, t u., t. H., '.,
.w,,2 p ur t
,a.
Tube in-service inspection (ISI) program.This would include a somewhat lengthy list of requirements, itself: inspection of the cold leg sides of steam generators; maximum intervsis between steam generator in. A i'-
spections of 48 months, compared with currently allowable intervals of 80 to 160 months; def'mition'ofM.
l "special subsets" of tubes, to avoid excessive inspection of tubes not experiencing degradation;a 100%1a:p l
spection or statistically determined inspection if either more than 1% of tubes are defective, or 5% degraded; additional denting inspections; tube inspections to be conducted in response to repair of any leaks;inclusio'n' l
of denting acceptance limits in a reactor's technical specifications; and reports to NRC ofinspection results -
prior to operation of the plant if data exceeds plugginglimits. _. T M e t
.o6.'
.~,
Improved eddy current techniques. One of NRC's reasons for this proposalis the Jah. 25 Ginna event,-
in which the ruptured tube had exhibited no differential signal during an eddy current inspection in April i
1981.
l
,.7, 7 g.,,,, g, gg,; g,1G 2 3! ilJIT U Primary to-secondary leakage limits. IIere NRC would revise technical specifica' ions for the primary-t secondary leak ' rates so that they are consistent with applicable standard technical specifications'. "
Secondary water ch'emistry programs. Under this category NRC would require programs to mimnuze l
steam generator tube degradation, with the definition of the program included in the reactor's license condi->
h j
tions, although not specifically included in the license. Although NRC would not establish any criteria forg l
standards such as water pli, each utility would do so, and would be obligated to explain to NRC the ration,n l
ale. Utilities with operating plants which are shut down for steam generator repairs as a consequence of cotw '
rosion would be required to commit themselves to revised water chemistry guidelines prior to restart. Conrad 3
NUCtIONICS WEEK - August 5,1982
/
(
[
McCracken of NRC's mechanical engineering branch said that plants in the licensing stage now would be so-quired to have a program of secondary water chemistry control; operating plants would be required only to
[
~> m : < v i. <
rnake a commitment to a program if degradation occurs.
Condenser in-service inspection program. If a reactor exceeds secondary water chemistry limits so as to result in power reductions twice per quarter due to condenser leakap, NRC would require a license con-j dition which commits the utility to perform condenser ISIS. His program would be included in the plant's operating procedures. Utilities with operating plants which are shut down for steam generator repairs as a]
consequence of corrosion when the requirement takes effect would be required to commit themselves to a.
program.
5" Upper inspection ports installation. In what proved to be th' most controversial proposal a[the JuQ e
29 meeting, NRC said it was moving toward requiring the installation of upper inspection ports in U tube i
steam generators licensed after Jan.1,1983; installation of ports in currently operating plants would be eval-usted on a case by case basis. NRC's rationale is that U tube steam generators generally have only lowerin-i spection ports. Plants which have installed upper ports experience easier evaluation of dentingin the upper i
part of the steam generators, and easier tube removal for examination, as well as easier monitoring of the up-l per portion of the unit. Jack Strosnider of NRC's materials engineering branch said that eight plants in the t
U.S. already have such ports. Eisenhut added that some new operating licenses in process contain a commit-ment by the utility to install them.
l Members of the steam generator owners group,however, appeared unswayed. A Florida Power & Light executive said the utility has "had them for years" at Turkey Point and not needed them. Another utility representative said installation of the upper inspection ports would cost $300,000 per steam generator "and we may get nothing out of them." In response, Eisenhut said it would be less expensive to do the work now,
[
.n rather than later, when degradation in the U-bend itself occurs. Emphasizing the insurance.like nature of the ports, Eisenhut drew an analogy to problems recently discovered in Westinghouse D-2 and D-3 steam gener-ators at Duke Power's McGuire 1 and other plants. "Who would have expected the vibration problems at.
I McGuire?" he asked.
Strosnider said that in-house discuuions among the NRC staff produced some of the same arguments l
raised by the utilities. The upper port installation proposal, he added, will be subjected to a valoe impact,
analysis conducted by Science Applications Inc. (SAI).
, ;. g l
j Under a separate category of" plant systems response," NRC has three groups of proposals: reactor.
y coolant system (RCS) control during a steam generator tube rupture; safety injection signal reset; and con-tainment isolation and reset. The RCS pressure control during a rupture provoked the most comment from the utilities.
l NRC is proposing that utilities " determine optimal means of controlling and reducing pressure" em-l t
phasizing use of existing equipment; optimize procedures, techniques and systems; consider usage of the pi-lot operated relief valve (porv) and auxiliary spray systems;and aim for minimizingleakage,maximizmg 3
(
pressure control and minimizing voids (bubbles)in the reactor coolant system. The staff based its proposals j j
on four events in which there was difficulty in managing reactor coolant system pressure following a steam j i
generator tube rupture.
g f.
i t. ;' ~ l [
The use of the porv-which during the Ginna event remained open after one cycling and resulted in l
m.
N-a steam bubble in the reactor head - was questioned by staff members. "Why use the porv?" asked one staff l
I member, responding to a question by a utility person as to the advantages of using the porv over the auxil.
j l
lary spray system. The staffer added,"It's not clear that if you use the auxiliary spray once or twice in the j
'l life of a plant it will be damaged. It's clear that using the porv is preferential." A member of the owners group responded that NRC needs to spe!! out its objectives better.
Related to the use of the porv is NRC's concern over the 30 minutes called for in reactor design for j
the emergency core cooling system to take over after a tube rupture. "Our concern is not (the existence) of a (steam) bubble per se," said one staffer,"but the fact that the half-hout has never been met in the instances -
of bubbles."
Beyond the proposed requirements, NRC licensing division staffinformed the owners group last week,
of a whole parcel of possible additional regulations for "which no details are available yet." These include,.
among many others, requirements on tube sleeving design, installation and inspection; s pressurized thermal i shock program; instrumentation for detection ofinadequate core cooling;and a control room design review
~
j
- w '.
4..'
c-w J eW program.
i.
h The owsers group was clearly not equipped to respond to NRC's proposals in the same time frame ad }
t
, NRC staff would like. At the conclusion of the meeting, Lainas asked owners group chairman Alfred Schmidt l
l of Florida Power & Light when the group might give NRC its comments. When Schmidt replied "a couple of t months," Lainas said,"That's a little longer than we anticipated.... But we're interested in a quality re-w
'~
NUCLEONICS WEEK - Aupst 5,1982 0
- 3 I
l. -
-._ _ _ _, __ f l..-
~ '
spense.... Ilow about a meeting half 2ay in between to give us an ides as to the status and whether your'
- comments are worth waiting for?" Schmidt agreed, after which Lainas said that value impact studies on the various proposals would continue.
~. ~
o.
5.45 Following the meeting with NRC, the owners group met by itself for organizational purposes. In a con.
versation this week with Nucleonics Week, one knowledgeable source said "certain people would respond to (f <
various issues" before the group gave NRC a collective review. The owners group is drawing on some Electric Power Research Institute (Epri) staff for some issues, he added, and is seeking information, but not staff ex-pertise, from the Institute of Nuclear Power Operations (Inpo). The owners group shculd be able to give the licensing division a status report in a few weeks, the source said.
.n. c:
NRC, for its part,is undecided as to what form the steam generator requirements eventually will take.
After the steam generator owners group submits its final comments, and SAI finishes its value impact,,,,,,
studies,liceissing division staff will come up with recommendations to be forwarded to NRC's Committeej to Review Generic Requirements and the Advisory Committee on Reactor Safeguards. Only then will the,
final form be clear, the source added,"whether it's a rule, an order, or what." Final action will be takers by the commissioners themselves, he said. - Jeff Yacker, Bethesdr, Nd no,
.