ML20029B278
| ML20029B278 | |
| Person / Time | |
|---|---|
| Issue date: | 12/13/1990 |
| From: | Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Carr K, Curtiss J, Rogers K NRC COMMISSION (OCM) |
| References | |
| FRN-57FR47802, REF-10CFR9.7 AD93-1, AD93-1-003, AD93-1-3, NUDOCS 9103060364 | |
| Download: ML20029B278 (10) | |
Text
.......................s RELEASED TO'THE PO
.I'
. p,[
NUCLEAR R UL 0
MN h.....-
Oecember 13, 1990 MEMORANDUM FOR:
Chairman Carr Commissioner Rogers Commissioner Curtiss Commissioner Remick FROM:
James M. Taylor
[
Executive Director l
for operations 1
SUBJECT:
COMMISSION BRIEFING ON SOURCE TERM UPDATE AND DECOUPLING SITING FROM DESIGN (SECY-90-341) on october 15, 1990 the staff briefed the Commission on the subject SECY paper.
The staff has received the Staff Require-ments Memorandum (SRM) dated November 16, 1990 (M901015B), in which questions were asked regarding examining possible alternatives to the plan and schedule proposed in SECY 90-341.
Specifically, the staff was requamted to examine wheths:r revic Mn of Part 100 could be completed prior to the receipt of an early site application.
The staff has examined.a range of options with respect to updating source terms and revising Part 100 and Part 50.
These options as well as the staff's recommendations are discussed 4
below.
Responses to the first two questions in the SRM are also providod in this memorandum.
To summarize, the scaff now recommends a change from that given in SECY-90-341, and proposes'that:
(1)
The issuance of an Advance Notice of Proposed Rulemaking (ANPR) be deleted.
(2)
Part 100 be revised only once and as soon as possible so as to facilitate an early site permit review.
This would be accompanied by an interim revision of Part 50 which would be carried out and completed in parallel with the revision of Part 100.
Site criteria (e.g.,
population density and distribution) would be added to Part 100.
Reference to the TID source term and to dose calculction: and criterin would he rEzcycd from Part 100 and placed into Part 50.
An updated TID source term would not he incorporated into Part 50 at this time.
Any dose calculations performed uti]izing the interim revision of Part 50 would be for establishing plant performance criteria such as control room habitability or containment leak rate, and not for 9103060364 90121,3 q
PDR ORG NE EPDR
@r4 pduuo4
2 assessing site suitability.
Appendix A' to Part 100 would also be revised to provide updated seismic site critoria.
Any criteria not associated with selection of the site or establishment of the safe shutdown earthquake magnitude would be put into Part 50.
(3)
A final revision of Part 50 would be undertaken to add performance requirements to plant design features based on updated source term and severe accident insights, and to replace the dose calculations and criteria.
Updated TID source term insights would be incorporated at this time.
Although it is not possible to complete this final revicion of Part 50 prior to initiation of the passive LWR design reviews, the staff would proceed as fast as practicable on this rulemaking.
(4)
In parallel with development of the revision to Part 100 and the interim revision to Part 50, the staff intends to continue work on an updated TID.
Existing and future plants vill not have to wait until the finnl Part 50 revision is complete to take advantage of the updated source term information.
As noted in SECY 341, the staff intends to apply appropriate revisions to current practice based on updated nource term and covere accident insights for future plants as a part of the design certification rulemaking.
Results of updated source term insights would also be made available for voluntary use by existing licensees.
This is consistent with the SRM dated February 13,
' Appendix A,10CFR Part 100, " Seismic and Geologic Siting Criteria for Nuclear Power Plants", was issued in 1973.
It has initially been a very useful siting regulation, but because of advances in the geological sciences and the occurrence of issues during licensing activities for several nuclear power plants that were unforseen by the authors, significant difficulties arose during its application.
Several NRC documents since that time, such as SECY-79-300 " Identification of Issues Pertaining to Seismic and Geological Siting Regulation, Policy and Practice for Nuclear Power Plants," NUF-0625
" Report of the Siting Policy Task Force" and NUREG-1061 " Report of
- Nuclear Regulatory Comission Piping Review Committee," have enumerated the deficiencies and difficulties with Appendix A, for example, the definitions of tectonic province and capable fault and the role of Operating Basis Earthquake in plant design, and have strongly recommended that it be revised.
[
On September 6, 1990, the EDO approved the plan to begin work to revise Appendix A and assigned a high priority status to this activity.
The staff intent is for the revised regulation to be general in nature with more detailed information contained in supporting regulatory guids,
i t
l J
3 1990, which stated that changes to regulatory positions would be proposed "as ccon as possible for both current and advanced reactor designs in those areas where the NRC has a sufficient technical basis from availabic research results (e.g.,
tission product timing)."
The ma]or benefit of this revised recommendation is that proposed rules revising Part 100 and containing interim revisions to Part 50 are expected to be available for public comment by about December 1991 and completed by September 1992, shortly before the time that an early site review applicr " ion is expected.
Another, albeit less tangible advantrge of the interim Part 50 revisions is that, for the existing plants, the current licensing basis and prior design features that have been driven by the Part 100 dose assessments would remtin intact.
While the principal rulemaking actions contemplated here are aimed at future plant and siting activition under Part 52 procedures, the interim changes in Part 50 would preserve a status quo for existing plants.
This preservation is seen as beino important to existing plants and to subsequent license renewal activities.
The staff intends, however, that the final Part 50 revision to incorporate updated source terms and severe accident insights would clearly represent the preferred licensing bares, ac applicable, for future plants.
The use of such u optional for existing licensees. pdated cource terms would remain In arriving at this change in recommendations, the staff considered the following options:
Ontion 1: Revise Part 100 twice; revise Part 50 onco.
(Staff proposal in SEcY-90-341)
This option involves the issuance of an Advance Notice of Proposed Rulemaking (ANPR), and an interim revision of Part 100 to add site criteria and to include an updated TID source term as a reference in the regulation.
This would be followed by a seconc. rulemaking involving a final revision of part 100 (removing any reference to a source term or dose calculation) in parallel with a revision of Part 50 to address design / performance requirements which replace the dose calculation of Part 100.
The advantages of this option are tho; (1) an interim revision of Part 100 could be accomplished quickly, and (2) placing an updated TID into Part 100 provides a " logical" follow-on to existing staff practice which could help support review or the evolutionary LWR designs as well as allow existing planto to take advantage of an up-to-dato understanding of cource terms.
The major disadvantage of thic option is that a siting rulemaking is not expected to be completed by the time an early site application is submitted.
t l
4 QP11Qn_2: Revise Part 100 once; revise Port 50 twice.
(Recommended Option)
This option would revise Part 100 only once.
Site critoria would be added, dose calculations and criteria and reference to any source term would be deleted, and Appendix A to Part 100 would be revised.
In addition, an ANPR would not be issued.
In parallel with the revision of Part 100, an interim revision of Part 50 would be undertaken. In this interim revision, the present TID source term, dose calculations and criteria (for assessment of plant features) would be located in Part 50 so that appropriate criteria remain in the regulations for application to any plant reviews underway or initiated prior to the final Part 50 revision.
A final revision of Part 50 would be undertaken later.
The major advantage of this option is that deleting the ANPR and revising Part 100 only once shortens the schedule for any siting rulemaking and allows a rulemaking on siting to be completed by the time an early site application is expected.
This option provides a clear step that would facilitate a decoupled review of design and/or siting proposals.
The disadvantage of this option is that on interim revision of PLrt 50 must be accomplished in parallel with the revision of Part 100 in order to retain a reference to a cource term in the regulations.
Ontion 3:
Part 100 update associated with site criteria This option would retain reference to the TID source term and to dose calculations and criteria in Part 100, but would add site criteria to Part 100.
Appendix A would also be revised.
This phase could be carried out quickly.
A second phase would then require a parallel rulemaking to (1) revise Part 100 again to remove any reference to a source term, dose calculation and criteria, and (2) a revision of Part 50 to address plant safety features and reference an updated TID source term in this Part.
Although the first revision of Part 100 could be completed expeditjously, this option suffers from the same disadvantages of Option i discussed earlier; namely, two revisions of Part 100 would be required, which make completion of rulemaking on siting unlikely prior to receipt of an early site review application.
Optlan_it Revise Part 100 once; revise Part 50 once.
This option would revise Part 100 only once, incorporating the changes as given in Option 2.
Part 50 would also be revised only once by incorporating updated source term and severe accident insights into the requirements for plant engineered safety features.
l 5
The advantage of this option is that it would involve one revision each for Parts 50 and 100.
On the other hand, this rulemaking would have to be conducted in parallel, since a source term would no longer appear in Part 100.
The pacing item in this option is the revision of Part 50, which could be difficult to finalize until further experience in the review of the advanced LWRs is gained.
Hence, this option is not compatible with the proposed schedule for an early site review application.
Based upon an assessment of the options discussed above, the staff concludes that Option 2, a single revision of Part 100 in parallel with an interim revision of Part 50; followed by a final revision of Part 50, can provide for a compatible schedule for an early site review application.
This option also has cons..ierable merit in that it allows staff experience gained in the reslew of advanced LWRs to be factored into a final rule for Part 50.
None of the options considered can accomplish a completed revision of Part 50 prior to the expected submittal dates for *he passive LWRs.
Estimated schedules for each of the four opsions discussed are enclosed (Enclosures 1-4).
Finally, the staff is also responding to Questions 1 and 2 in the ADM deted November 16, 1990, as follows:
Ennstion 1:
How long would it take to incorporate Regulatory Guide 4.7 into the regulations?
Why should the portions of Part 100 which influence design remain in place until the final step, as proposed in the staff's plan?
Resnonset Some additional effort is needed to provide a more explicit technical basis, presently lacking, for the guidelines pra ently in the Regulatory Guide.
This may result
. some modification of the criteria currently in Regulatory Guide 4.7 The staff estimates the most expeditious way that applicable site criteria based upon Regulatory Guide 4.7 could be incorporated into the proposed revision of Part 100 is that shown in Option 2.
As noted above, Option 2 would revise Part 100 only once and would be strictly related to siting; hence, any portions of Part 100 which presently could influence design would be placed into Part 50.
Cucction 2:
The staff's proposal states that the second revision to Part 100 and the revision to Part 50 would be accomplished prior to the completion of review of passive designs.
How will this schedule allow designers to provide for the new require-ments of these two rulemakings in their designs?
i l
1
i 6
Ersnonse:
Tha staff is presently in the process of reviewing proposed new designs, including those for the passive plants.
As staff recommendations on proposed new requirements arise, those will be transmitted to the Commission (e.g.,
SECY-90-016 approach) and, upon approval, will be forwarded to applicants.
Approved staff recommendations would become the basis for subsequent revisions to part 50.
This process is expected to allow designers to become aware of and to factor any now Commission approved NRC requirements into the designs of these plants well before they become formally codified in a revision to Part 50.
In connection with the second phase of rulemaking the Commission will need to address the back-fitting decision as to whether the new dose calculation requirements will be backfit into previously approved certified designs.
/'J.
en M.
aylor
{ -Executive Director for Operations
Enclosures:
as stated cc:
SECY OGC 1
1 a
--s 4_
J4 6-4 h+b4 8 414,54 4 4 ed den-h e
- G O N 31-
" M A 4 'A M hMOEMA4
'"'""O"AE'* eh M"A 4'="*WdIAf**E^
^8Ae*
'^-
'" M M M A M"OA
^ - - ~-+ '
8 4
t 9
I 3
E CE, Er
=
V 2
Y Y
e o-E 3
a 3
ew 2
S
- a e
s a
w e-w 5
5 5
5-E 5
gE
=
a W
"C.l E
Ed w5 E
tf I w.
2 W
8.
35 E
.I: s W
=
"ut.
N w[
a w
~.
G 2
ww tw Eel*
I W
tu Ia e
J D
8 o
52 w
$W Zy t
to E
gr
- c g
- t- "
O M
e m
y l
Q C
1 g
.$a" I.
ta, 1;
~
W W
8 1
I B
5 2-e a
o 5,
h I
W f
N IS 8
E E
g r
C gI ag a
B
_i
,s 5,
a e
e r-r s u
x
.s r,
y 53 0
W w
a t
N g,
g, d
Wg I
8 I
d t
.a 2
E t.
E R
8E y
~
-a
-=
R t
t l
. _ _...,.,....,, -.._--.-.. _ _,-~ - - -.. - - - - - -.. _ _. -... -.. _
Enclo w e 2 OPTI0ff 2 SCHEDULE 1
SOURCE TERM ACTIviT!ES FT 1990 FT 1991 FT 1992 FT 1993 PMASE 0=E RULE"ar t%
CRGR IS5UE FOR final CaGR 10 START ACR5 TO CW6 PJBLIC CDM"ENT PEG ACRS C rr.
- CEVIStost TO PART 100 END issJ Cop *'E4T FIMA
- INTERIM REVIS104-PART 50 SUPPORT!uG ACTIVITIES L
- TECW. ASSESSMENT OF POP.
DERSITT CRITERIA
- BwL tFDATE OF RE! EASES
- ORkt CALCUL AT10NS OF IODINE CHEMICAL FORM
- t#EL CALCULAftowS 04 TIM:h0 TST D8 AFT
- YtD-14544 UPDATE 1
1 PM45E TW PJtEMACWG START ACRS/CRGR 70 CDT4.
ISSUE FOR EuD issue
- FINAL REVISION-> ART 50 V
PUBLIC C&aeEmi CtmMEwT F!aAt Pit 4T Aw3 SITE REYttv5 EVOLUTIONARY PASSIVE SER SER
- EPRI Atut DOCUMr =YS XE h
EITE ASPLICArtts
- EARLY SITE REVIEWS
a a
l 4
j O
M 9
g e
u "m
- 6 n=
e 5
elm c
8
~
8 g
3 w.
9 H
'~
a B
i I
D G
E goN e
g
- s..
y De b
een I
,d W
g s
4 U
E h
w I
g m
8 u
e n
v>
r i
ac
=
O e-.
0 I
M CL.
g C
t n
s
-?
NN
... w 4
t td>
2_
=g
-g n
)
8 a
=
w O
M h
5, v,
g a
g s'
h 3
L a-W 8
8 g
A w
W
.D l
g l
A 5
I=5 a Cg Q
e g
r 1
r ge e g-g g
e e
g e
a s=
=
e
-s
_8 g
g
, ::._g-55 5
g
=
e-5 E --
4-a W-3 WW I B
E O
E
- g 5'
E 3
w a
4
[
t g
+
,2.;___.-..._,
.. _.. _ _., _. -.. -. _ - _. _.... _. _ _. _. _. _,.... _ _... _.. _,.... _.... _... ~, _ -. - _. _ _...
OPTIOf{ 4 SCl!EDill E SOURCE TERM ACTIirITIES FY ??90 FY 1991 FY 1972 FY ???3 i
l SUPPORTiwG ACTIVITIES
- BNL UPDATE OF FELEASES i
i
- CR4L CALCULATIONS OF IODINE CNEMICAL FORM
- INEL CALCULAT!O45 04 TIP!wG
+
4 1ST CRAFT TID-14%41FDATE O TECM. ASSESSMENT OF pgggt POP. DENSITY CRITE*lA RUL EMSKING 0 REVISIDs TO PAR
- 1M SidRT ERGR/ACRS TO CDPM.
FOR CD99ENT Eso Ctyg8ENT i
mr 1r y
r O REVIS!Ost TO PART 50 y
b FtANT AND SITE ret!Chrs E M ui!ONARY PASSilfE l
MR ER
- EPRI Attat DOCUMtuTS
>JE i
- EARLY SITE REVlfitS
!TE APPttCATion i
J
- - - - - -