ML20058K153

Requests Commission Approval of Staff Plan to Perform Licensability Review of Pius Conceptual Reactor Design

ML20058K153
Person / Time
Issue date:	02/20/1990
From:	Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:
References
TASK-PINC, TASK-SE SECY-90-055, SECY-90-55, NUDOCS 9003060147
Download: ML20058K153 (9)

Text

WMMMMMMMMMMMMMMMM4 l

RELEASED TO THE PDR

.t

.\\

5 j.9jp/qo 5

s

_.....I........Y POLICY ISSUE February 20, 1990 (NEGATIVE CONSENT)

SECY-90-055 For:

The Commissioners From:

James M. Taylor, Executive Director for Operations

Subject:

PIUS DESIGN REVIEW

Purpose:

To request Commission approval of the staff's plan to perform a licensability review of the PIUS conceptual reactor design.

Sumary:

This paper provides background information, a discussion of technical issues and a proposed plan for RES to process ASEA Brown Boveri's (ABB Atom) application for a licensability review of PIUS. The review will be conducted in accordance with the review priorities described in SECY-89-334, "Recomended Priorities for Review of Standard Plant Designs" (e.g. ABWR, CE System 80+, CANDU, etc.). The estimated resources needed for this review are modest and are within the current budget plans for RES. However, the staff is mindful of the recent decisions by the Commission not to undertake the additional expenditure of resources at this time on the CANDU-3 review. Proceeding with the PIUS review may be viewed as inconsistent with this resource decision on CANDU-3.

Background:

ABB Atom, Incorporated, a newly formed division of ABB Atom.

is a new American company formed jointly by ABB Atom and United Engineers & Constructors. ABB Atom Inc. was created toperformdetaileddesignandmarketingofPIUS(Process Inherent Ultimate Safety) in the United States and, following NRC design certification, to construct PIUS on a turnkey basis.

ABB Atom has many years of experience in the design of Boiling WaterReactors(BWRs). The BWRs designed by ABB Atom have had a favorable operating experience as evidenced by their high capacity factor, about 80 percent for the last 10 years.

The ABB Atom BWRs have maintained a low personnel exposure during that same period of time. The design philosophy of the company has been to include the layout of the entire plant in the design. Their latest design, the ABB Atom BWR-75, includes the entire plant. General Electric's ABWR, which the staff is currently reviewing, has a number of design features similar to the BWR-75. These design features include fine motion control rod drives and no recirculation loop piping. Six ABB Atom BWR-75 plants have been placed in operation since 1978.

j CONTACT.

NOTE:

TO BE MADE PUBLICLY AVAILABLE Jerry N. Wilson, RES, WHEN THE FINAL SRM IS MADE

• • '* JO93066f)%f M^*'^"

Vm ggggmmmmmmmmf

i e

The Comissioners 2

t ABB Atom has also acquired experience in the PWR area through fuel and core licensing agreements with Westinghouse. The merger of ASEA and Brown 3overi to form ABB Atom has also brought to the company the experience of the Brown Boveri Reaktor company in the design of the 1300 MWe Mulheim-Kahrlich PWR plant under a Babcock and Wilcox license.

Discussion:

In their letter of October 5, 1989, ABB Atom requested a licensability review of the PIUS conceptual design in accordance with NUREG-1226, " Development and Utilization of the NRC Policy Statement on the Regulation of Advanced Nuclear Power Plants." The Comission's Policy for Regulation of Advanced Nuclear Power Plants (51 FR 24643) encourages early interaction between the NRC and advanced reactor designers.

The PIUS design complies with the definition of an advanced design and qualifies for the review approach described in NUREG-1226.

ABB Atom's long-term goal is to obtain a Design Certification from the NRC under the provisions of 10 CFR Part 52. ABB Atom also enclosed letters from five U.S. utilities which support their recuest for an NRC design review of PIUS. ABB Atom requestec that the NRC perform the licensability review within one year and begin the design certification review innediately thereafter. The RES review plan discussed herein is concerned solely with their request for a licensability review.

Important Features of PIUS The PIUS design began 13 years ago in the ASEA SECURE heating reactor design. Over the years, the design has evolved into the form requested to be reviewed for licensability and design certification. The PIUS design is basically a PWR using thermal-hydraulic phenomena to accomplish several of the functions usually left to mechanical systems. These phenomena primarily maintain separation of fluid regions by thermal density gradients.

The PIUS design is a four-bop pressurized water reactor rated at 640 MWe. The design uses uranium oxide fuel similar in design to PWR fuel rods. Tha entire reactor coolant system is housed in a prestressed conciete containment structure. The four steam generators are lo(sted outside the concrete reactor vessel as shown-in Figure 1.

The containment done and the reactor vessel head are removed for refueling. The PIUS reactor design predominantly utilizes existing Light Water i

Reactor (LWR) technology. The major design parameters have been conservatively chosen to provide:

1 1.

lowered core power density l

The Comissioners 3

2.

lowered linear heat rating 3.

negative power coefficient through the fuel cycle 4

Iowered reactor pressure and temperature as compared to conventional PWR plants The PlVS design incorporates departures from current LWR technology that the designer states add passive safety. Thest departures are limited to the following areas:

1.

thermal-hydraulic principle of the reactor 2.

density locks (themal barriers) 3.

siphon breaker 4.

wet thermal insulation 5.

prestressed concrete reactor vessel 6.

longterm residual heat removal system 7.

reactivity control without control rods Because there is no applicable reactor experience with some of these features, they will require intensive staff review efforts. Additional time may be necessary if there are other i

technical matters not previously reviewed and approved for use in the U.S.

This effort will include time for the NRC staff to become familiar with the PIUS design through extensive interactions with the ABB Atom technical representatives. A data base from test facilities has been developed to support all of the claims of the ABB designers with the exception of the absence of active control rods. These tests have been based on scale model facilities using an electrically heated simulated fuel assembly.

ABB Atom claims that physical principles support the use of l

all of the departures including the absence of control rods.

l ABB Atom suggests that the lack of control rods eliminates the risk of reactivity insertion due to control rod withdrawal.

For conventional LWRs Appendix A to 10 CFR Part 50 requires tworeactivitycontrolsystems. One must be capable of taking the reactor core to cold shutdown and the second must be capable of taking the core subcritical. This issue will require extensive staff consideration.

l Because the PlVS design incorporates a typical restressed concrete containment structure, containment wil not be a major issue in the licensability review as it was for the DOE supportedadvancedreactordesigns(MHTGR, PRISM,andSAFR).

Our review will check the containment design bases. We will also review ABB Atom's plans to seek relie" from the current requirements for preplanned offsite emergency planning.

While the PIUS design differs significantly from light water reactor designs currently licensed and operating in the United States, it is based on physical principles and scale model

The Connissioners 4

1 l

tests performed in Sweden. A PlVS type heating reactor (SECURE) has received various levels of review for licensability by the authorities in Finland, the Federal Republic of Germany, and Italy. We plan to obtain copies of these reviews.

Staff Review of PIUS The major milestones and activities needed to complete the licensability review of PIUS will include:

1.

Preliminary planning meetings with ABB Atom (already in progress).

2.

ABB Atom's submittal of technical descriptions of P!US (targeted for March 1990) and conducting NRC information exchange sessions to develop NRC staff

)

knowledge of the PlVS design.

j 3.

Introductory briefings for ACRS and the Concission.

4 RES review of the materials, including analyses of the thermal-hydraulic aspects of the design and selected accident sequences.

5.

Perform preliminary assessment of need for a prototype test or demonstration facility in accordance with SRM dated December 15, 1989.

6.

Preparation of the results of the staff review by RES in theformofaSafetyEvaluationReport(SER).

7.

Review and comment on the SER by NRR and ACRS.

The review will be conducted within the existing organizational structure of RES consistent with the review approach set forth in NUREG-1226 and the review priorities described in SECY-89-334 " Recommended Priorities for Review of Standard Plant Designs." The Advanced Reactors and Generic Issues Branch (ARGIB) will serve as the focal point for the review and will provide project management and technical review resources. Due to the limited resources available in-RES, ARGIB will use a part-time effort by an existing project manager and will seek additional part-time review work by other RES reviewers. SER input on the technical review of the thermal-hydraulic and reactivity control aspects of the PIUS design will be provided by the Reactor and Plant Systems Branch in RES. Resources programmed for design review of advanced, passive LWRs will be used. Using this approach will permit the project manager to obtain technical input from others in their specific functional discipline more readily

s The Commissioners 5

and will allow the reviewers to work on non-PIUS issu9s dt. ring periods when the PIUS information required to perform the 1

review is not available.

l This review approach is similar to the one employed on issues related to the MHTGR, PRISM, and SAFR designs. Limited contractor assistance is estimated for the PIUS review since analytical capability now exists within RES due to the recent acquisition of a parallel processor corputer through an SBIR contract.

This computer can run the RELAPS/M002 systems analysis code needed for the analysis of the thermal-hydraulic design. The staff estimates that the review will require a aproximately one FTE per year in FY 90 and FY 91 to perform tie PIUS licensability review. These estimates are preliminary and are based on experience with the reviews of the Modular High Tem)erature Gas Reactor, the PRISM liquid metal reactor, and tie SAFR liquid metal reactor conce)tual designs. We anticipate a lower resource need for the

)IUS review because the number of issues requiring extensive evaluation to determine licensability is smaller. These estimates may be revised after the preliminary safety information documuts are submitted and schedules for submitting additional materials are defined. We do not plan to charge a fee for the licensability review in accordance with the past practice for conceptual design reviews.

The NRC has in place an advanced reactor cooperative agreement with the licensing authorities in Italy (ENEA). Through that agreement, we will request a cosy of their analytical plant models for the PIUS design whici were developed in Italy for the RELAP5 code.

In return, ENEA wants the NRC to provide them with an analytical plant model for AP600. 'We also plan to exchange analytical review results with ENEA. Obtaining the PIUS computer model by information exchange will reduce model development costs. However, we will need to compare the ENEA model to the PIUS design submitted to the NRC and perform I

updates to the latest version of the design. The staff also feels that it is appropriate to perform a verification of the model as we would with any plant model.

If we cannot get an 69reement with ENEA; then we will have a contractor develop a model of PIUS. Thus, we estimate the total contractor support for the PIUS review to be $200-300K in FY 90 depending on the availability of the model.

RES will have the lead in the review of the PIUS design and, as such, will determine technical areas where research is necessary and will oversee this research.

If the staff determines that the unique features of the PIUS design indicate a need for regulatory guidance, or that existing regulatory guidance needs to be modified, this will be done in consultation with NRR. Guidance may be needed in the areas of i

e l

The Comissioners 6

arestressed concrete reactor vessel design, thermal tydraulics, and reactivity control systems.

)

==

Conclusion:==

The proposed review will be conducted within the existing organizational structure of RES, with a project manager assigned part-time to the project. Staff resources are considered adequate to complete this review in accordance with the review priorities

. forth in SECY-89-334 We will use RES resources programid for advanced, passive LWRs. The staff does not anticipate that existing regulatory guidance will have to be modified for the conceptual design review stage. New regulatory guidance may need to be developed when final design approval and design certification are sought by ABB Atom, Inc.

Coordination:

NRR has concurred and OGC has no legal objection.

Recommendations: That the Comission:

1.

Note that the staff is proposing to initiate its review oTTIUS in accord with the above plans and resource expenditures.

2.

Note that the decision to proceed with the PlVS review couTd be viewed as inconsistent with the decision not to fund review of CANDU design.

3.

Note that the staff plans to inform ABB Atom of its plan to initiate the requested licensability review after 10 working days from the.date of this paper unless otherwise instructed by the Comission.

/

WW J

ms M. Tay ecutive D ctor for Operations

Enclosures:

As stated

i

4.

[

~

-C ;

9.,

1 y

6 t

i.-

7 SECY' NOTE:

In-the absence of instructions to the contrary, SECY-I will notify the staff on~ Tuesday, March 6, 1990, that

-i the Commission, by negative consent, assents to the l

s action proposed in this paper.

?

. DISTRIBUTION:

Commissioners

- i OGC4 9:

OIG-

- I LSS.

GPA 1

4 REGIONAL OFFICES j

EDO D

- ACRS i

ACNW-

' ASLBP.

j ASLAP

' SECY-7

-' k i

a J

1 p

I lt t

1 I '

i' l.'

]

1 1

.l

~

c u,g

.g 1

64 -

~

7 l

i g

1 5 -

x

/

N 5

N r

4 5

j'

{

l, e

l l

~N i

/; l-p

1. \\

L

\\

\\,

lf

'l O !h l

3\\

i I

e'

. n l

.y+, _

Figure i ABB Atom WW ASEA BROWN BOVERI

TRANSMITTAL TO:

Y Document Control Desk, Pl.24 ADVANCE COPY TO:

Public Document Room *

/ 0 / / 9,/ 90 DATE:

SECY,OperationsBranc[l.[

FROM:

Attached are copies of SECY par i related documents.

They are being forwarded for entry o Daily Accession List and placement in the Public Document.suom.

No other distribution is requested or required.

M sA.i M I L 9 0 - s c r D~ ~11.

n 90-os7

% fn 9s -i.rr-t-

2. 90 - et 7 dki /obbo 12. %

fo

,2 P f Ada.1

• Qs'M MW~

g k

9o-o rJ 13, q's. ; p p g n e se / g g o O*"..f W

Wn 9 e - a ir

&.h.f. k 90-ar7~~ la. dkA- !!/Y/9o AA4 4

&.W'M

b. M 'A sm &n So-orr 1s. A%.a n 9o -s EF t

5

.WSW l

6

% 90- O fd ~

16.

N 4

%.KLan M &

7. A2dl tA.W VC- !/~J~~

l7.

8.

- 80 O Io 7 18.

%.WJW 9,Ak.e dt. 4 l Lt A W h ' 0 G 7 19.

W

10. & k VO'067 20.

• PDR is advanced two copies of each SECY paper and one copy of each related document.

3C2C2 D Fo1 t\\i

-.